tag:theconversation.com,2011:/us/topics/coral-1830/articlesCoral – The Conversation2024-03-08T16:21:36Ztag:theconversation.com,2011:article/2242842024-03-08T16:21:36Z2024-03-08T16:21:36ZRestored coral reefs can grow as fast as healthy reefs after just four years – new study<p>The coral reefs of south Sulawesi are some of the most diverse, colourful and vibrant in the world. At least, they used to be, until they were <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/rec.12866">decimated by dynamite fishing</a> in the 1990s. </p>
<p>As part of a team of coral reef ecologists based in Indonesia and the UK, we study the reefs around Pulau Bontosua, a small Indonesian island in south Sulawesi. Thirty years on, what were once large areas of thriving coral are now degraded sites are still devoid of colour, fish and other marine life. Broken skeletons of dead corals roll around on the seabed, crushing and killing any new coral larvae that try to settle and preventing the reefs from recovering naturally. </p>
<p>In many places around the world, damage like this might be described as irreparable. But at Pulau Bontosua, the story is different. Here, efforts by the <a href="https://www.buildingcoral.com/">Mars coral restoration programme</a> have brought back the coral and important ecosystem functions, as outlined by our new study, <a href="https://doi.org/10.1016/j.cub.2024.02.009">published in Current Biology</a>. We found that within just four years, restored reefs grow at the same rate as nearby healthy reefs. </p>
<p>The Mars coral restoration programme is one of the world’s largest restoration projects and has collaborated with local communities for more than a decade. Healthy coral fragments are attached to hexagonal, sand-covered steel frames called “reef stars”. These reef stars are installed on damaged reefs, where they stabilise the loose rubble, support growth of new coral and provide habitat for reef animals to move in.</p>
<h2>Speedy recovery</h2>
<p>The transplanted corals grow remarkably quickly. Within a year, fragments have developed into proper colonies. After two years, they interlock branches with their neighbours. After just four years, they completely overgrow the reef star structures and restoration sites are barely distinguishable from nearby healthy reefs.</p>
<p>The combined growth of many corals generates a complex limestone (calcium carbonate) framework. This provides habitat for marine life and protects nearby shorelines from storm damage by <a href="https://theconversation.com/coral-reefs-work-as-natures-sea-walls-it-pays-to-look-after-them-26655">absorbing up to 97% of coastal wave energy</a>. </p>
<p>We measured the overall growth of the reef framework by calculating its <a href="https://www.exeter.ac.uk/research/projects/geography/reefbudget/">carbonate budget</a>. That’s the balance between limestone production (by calcifying corals and coralline algae) and erosion (by grazing sea urchins and fishes, for example). A healthy reef produces up to 20kg reef structure per square metre per year, while a degraded reef is shrinking rather than growing, as erosion exceeds limestone production. Therefore, overall reef growth gives an indication of reef health.</p>
<p>At Pulau Bontosua, our survey data shows that in the years following restoration, coral cover, coral colony sizes and carbonate production rates tripled. Within four years, restored reefs were growing at the same speed as healthy reefs, and thereby provided the same important ecosystem functions.</p>
<p>This success is encouraging, but challenges still remain. The corals used to construct these restored reefs are predominantly branching coral types, chosen by the restoration team because they are easier to attach to the reef stars. This means that restored reefs have a lower diversity of coral types than healthy reefs, which host an abundance of boulder-like and encrusting corals as well as branching types. </p>
<p>These structural differences may affect the species of marine life that inhabit the reef. Branching corals are also notoriously sensitive to <a href="https://www.worldwildlife.org/pages/everything-you-need-to-know-about-coral-bleaching-and-how-we-can-stop-it">bleaching</a>, which happens when warmer water temperatures cause stress to corals and turn them white. Differences in the types of coral making up the reef ecosystem may therefore affect the reef’s ability to survive future heat waves. </p>
<h2>A warming world</h2>
<p>Marine heat waves are becoming <a href="https://theconversation.com/the-great-barrier-reef-has-been-bleaching-for-at-least-400-years-but-its-getting-worse-101691">more frequent and severe</a> and pose a huge threat to coral reefs and restoration efforts worldwide. Recently, thousands of <a href="https://theconversation.com/the-heroic-effort-to-save-floridas-coral-reef-from-extreme-ocean-heat-as-corals-bleach-across-the-caribbean-210974">nursery corals had to be rescued</a> when water temperatures spiked in the Florida Keys.</p>
<p>It’s imperative that coral reef restoration strategies include plans for warming waters. In some cases, efforts can be prioritised in areas where transplanted corals are less likely to encounter lethal conditions in the near future. In other cases, projects can enhance coral heat tolerance through <a href="https://theconversation.com/the-great-barrier-reef-can-repair-itself-with-a-little-help-from-science-85182">assisted evolution</a>. </p>
<p>There is some evidence that coral heat tolerance can also <a href="https://theconversation.com/remote-pacific-coral-reef-shows-at-least-some-ability-to-cope-with-ocean-warming-new-study-211852">increase naturally</a>. Whether this coral adaptation can keep pace with ocean warming will depend on global action to cut carbon emissions.</p>
<p>Outcomes of any reef restoration project will depend on environmental conditions, natural coral larvae supply, restoration techniques and the effort invested in maintaining the project. This Indonesian project shows that when conditions are right and efforts are well placed, success is possible. Hopefully, this inspires further global efforts to restore functioning coral reefs and to recreate a climate in which they can thrive.</p>
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<img alt="Imagine weekly climate newsletter" src="https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<p class="fine-print"><em><span>Ines Lange receives funding from the Bertarelli Program in Marine Science. Logistical research support for this study was provided by Mars Sustainable Solutions.</span></em></p><p class="fine-print"><em><span>Tim Lamont receives funding from the Royal Commission for the Exhibition of 1851, and the Fisheries Society of the British Isles. </span></em></p><p class="fine-print"><em><span>Tries Blandine Razak does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Artificial reef stars have been added to damaged coral reefs in Sulawesi, Indonesia. A new study shows that within just four years, restored reefs are thriving as much as healthy reefs.Ines Lange, Senior Research Fellow in Coral Reef Ecology, University of ExeterTim Lamont, Research Fellow, Lancaster UniversityTries Blandine Razak, Researcher, IPB UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2232072024-02-22T03:21:11Z2024-02-22T03:21:11ZSentinels of the sea: ancient boulder corals are key to reef survival in a warmer world<figure><img src="https://images.theconversation.com/files/574821/original/file-20240212-20-avdzaz.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C5568%2C3700&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Giacomo d Orlando </span></span></figcaption></figure><p>Seas surrounding Australia this month hit an <a href="https://coralreefwatch.noaa.gov/data_current/5km/v3.1_op/daily/png/ct5km_baa5-max-7d_v3.1_seel_current.png">alarming level</a> of warming. It comes on the back of serious <a href="https://research.noaa.gov/2023/06/28/global-ocean-roiled-by-marine-heatwaves-with-more-on-the-way/">marine heatwaves</a> in the Northern Hemisphere summer.</p>
<p>Such warming is <a href="https://floridakeys.noaa.gov/corals/climatethreat.html#:%7E:text=Rising%20(or%20even%20falling)%20water,the%20coral%20turns%20completely%20white.">highly dangerous</a> for corals. Every <a href="https://www.annualreviews.org/doi/pdf/10.1146/annurev-animal-021122-093315">half a degree</a> of ocean warming increases their risk of bleaching and potential death.</p>
<p>The best long-term strategy to protecting Earth’s coral reefs is to dramatically cut greenhouse gas emissions and so limit global warming. But in the meantime, we must urgently make corals more resilient and protect those that are vulnerable.</p>
<p>That is particularly true for the huge, ancient features of reefs known as boulder corals. Research suggests they will be a vital part of reef survival in a warmer world.</p>
<figure class="align-center ">
<img alt="A map of Australia surrounded by patches of yellow, red and purple" src="https://images.theconversation.com/files/576928/original/file-20240221-26-asgzx0.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/576928/original/file-20240221-26-asgzx0.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=447&fit=crop&dpr=1 600w, https://images.theconversation.com/files/576928/original/file-20240221-26-asgzx0.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=447&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/576928/original/file-20240221-26-asgzx0.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=447&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/576928/original/file-20240221-26-asgzx0.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=562&fit=crop&dpr=1 754w, https://images.theconversation.com/files/576928/original/file-20240221-26-asgzx0.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=562&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/576928/original/file-20240221-26-asgzx0.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=562&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">An image showing various levels of bleaching alert around Australia as of February 19, 2024.</span>
<span class="attribution"><span class="source">NOAA Coral Reef Watch</span></span>
</figcaption>
</figure>
<h2>The old-growth trees of the sea</h2>
<p>Boulder corals (<em>Porites</em>) can grow to more than <a href="https://link.springer.com/referenceworkentry/10.1007/978-90-481-2639-2_273#:%7E:text=Porites%20has%20attracted%20the%20attention,10%20m%20(indeterminate%20growth).">10m high</a> and live for <a href="https://onlinelibrary.wiley.com/doi/10.1111/brv.12391">more than 600 years</a>. In Australia they are often referred to as “bommies”. Each bommie can comprise multiple species, but they’re often a single massive individual.</p>
<p>The corals <a href="https://www.sciencedirect.com/science/article/pii/S0169534716000574?via%3Dihub">play a crucial role</a> in reefs, including providing habitat for marine life. Importantly, they can <a href="https://www.pnas.org/doi/full/10.1073/pnas.1716643115">maintain these functions</a> even when other coral species are absent.</p>
<p><a href="https://www.nature.com/articles/s41598-019-40150-3">Some species</a> are thought to be <a href="https://www.int-res.com/articles/meps2011/434/m434p067.pdf">resistant to stress</a>. Old corals have <a href="https://www.nature.com/articles/s41558-018-0351-2">likely experienced</a>
– and survived – past warming episodes, proving <a href="https://www.science.org/doi/10.1126/sciadv.abq8349">their resilience</a>.</p>
<p>For example, a paper in 2021 described a giant boulder coral discovered on the Great Barrier Reef which <a href="https://www.nature.com/articles/s41598-021-94818-w">was thought to be</a> more than 400 years old. It has survived 80 major cyclones, numerous coral bleaching events and centuries of exposure to other threats.</p>
<p>This resilience can benefit the whole reef ecosystem. We can think of boulder corals as akin to old-growth trees in a forest. Just like forests containing big, old trees are <a href="https://theconversation.com/contrary-to-common-belief-some-forests-get-more-fire-resistant-with-age-95059">more resistent</a> <a href="https://www.jstor.org/stable/26267895#:%7E:text=The%20adaptations%20of%20large%20trees,to%20withstand%20and%20survive%20fire.">to fire</a>, studies show a mix of different growth forms, including old and large boulder corals, <a href="https://www.nature.com/articles/s41558-021-01037-2">fare better</a> in the long-term under marine warming. </p>
<p>Older and bigger corals may also produce <a href="https://esajournals.onlinelibrary.wiley.com/doi/abs/10.1002/ecy.1588?casa_token=tFnyWSTHmk0AAAAA:RkR06I_gTJk6p3vOCCdJdwku2CXO5tpUsChBn5_Nmhxfojl11fVg4uibQsWM4JFigd3dXzUYl_H8">more offspring</a>, so can more rapidly replenish the reef after disturbances.</p>
<p>Clearly, as our oceans face unprecedented pressures under climate change, we must protect – and learn from – these sentinels of the sea.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/snorkellers-discover-rare-giant-400-year-old-coral-one-of-the-oldest-on-the-great-barrier-reef-166278">Snorkellers discover rare, giant 400-year-old coral – one of the oldest on the Great Barrier Reef</a>
</strong>
</em>
</p>
<hr>
<h2>Preparing for the challenges ahead</h2>
<p>Understanding boulder corals is crucial to predicting how they might cope under climate change, and planning for their protection.</p>
<p>But scientists still have much to learn about boulder corals. In particular, we <a href="https://www.nature.com/articles/s41559-023-02319-y">don’t know</a> exactly how many species exist, their life histories and how they evolved. </p>
<p>My colleagues and I are aiming to overcome this knowledge gap. We are studying reefs across Australia, with a particular focus on boulder corals at Ningaloo Reef off Western Australia.</p>
<p>We are creating maps of what species of boulder corals exist and where they are located. And using cutting-edge <a href="https://threatenedspeciesinitiative.com/">genomics technology</a>, such as DNA sequencing, we are measuring the tolerance of each species to warming and trying to predict when they will reproduce. </p>
<p>Importantly, we are also examining the mutually beneficial relationship between the corals and algae. This relationship provides algae with shelter, gives corals their colour and provides nutrients to both partners. It may also be a <a href="https://link.springer.com/chapter/10.1007/978-3-319-75393-5_6">main factor</a> in coral resistance to warmer temperatures.</p>
<p>So far, we have found more diversity than initially expected. This is exciting because it may signal an increased capacity to resist different types of stress. But the work to fully map Ningaloo’s coral diversity has only just begun.</p>
<p>We hope our findings, once finalised, can inform local community management actions such as:</p>
<ul>
<li>public education campaigns and signs</li>
<li>managing visitor numbers to reefs</li>
<li>installing public moorings to reduce harm from boat anchoring, especially during coral spawning.</li>
</ul>
<p>The information can also be used in broader management actions such as:</p>
<ul>
<li>establishing “baseline” conditions from which to measure change</li>
<li>zoning decisions, including the establishment or ramping up of of marine park protections, especially for resilient coral species and individuals</li>
<li>impact assessments following events such as heatwaves</li>
<li>direct conservation actions for iconic, at-risk bommies, such as providing shade to diminish stress from heat</li>
<li>the development of national reef management plans.</li>
</ul>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/photos-from-the-field-why-losing-these-tiny-loyal-fish-to-climate-change-spells-disaster-for-coral-167119">Photos from the field: why losing these tiny, loyal fish to climate change spells disaster for coral</a>
</strong>
</em>
</p>
<hr>
<h2>Something worth fighting for</h2>
<p>The stress to coral wrought by recent marine heatwaves compounds damage incurred over decades. The Great Barrier Reef, for example, has <a href="https://theconversation.com/5-major-heatwaves-in-30-years-have-turned-the-great-barrier-reef-into-a-bleached-checkerboard-170719">experienced five</a> major heatwaves in 30 years. </p>
<p>Broadly, making reefs more resilient to these pressures involves:</p>
<ul>
<li>resisting, recovering, managing and adapting to shocks across ecosystems</li>
<li>improving governance structures</li>
<li>preparing human communities for change. </li>
</ul>
<p>Awareness of the need to increase reef resilience is growing. For example, it formed the basis of a 2017 <a href="https://elibrary.gbrmpa.gov.au/jspui/bitstream/11017/3287/1/GBRMPA%20Blueprint%20for%20Resilience%20-%20Low%20Res.pdf">blueprint</a> for the Great Barrier Reef and a <a href="https://www.barrierreef.org/uploads/Ningaloo-Strategy-v230216.pdf">strategy</a> for the Ningaloo Coast released last year.
But more work is required. </p>
<p>There’s also a need for coordination across Australia’s reef areas. This might include the exchange of knowledge and data between researchers and combined lobbying efforts to better protect reef ecosystems.</p>
<p>What’s more, Traditional Owners must be offered the opportunity to be consulted about, and meaningfully engaged in, protection of reef areas, including <a href="https://theconversation.com/climate-change-will-strike-australias-precious-world-heritage-sites-and-indigenous-knowledge-is-a-key-defence-222393?utm_medium=Social&utm_source=Twitter#Echobox=1707258796-1">co-management of Sea Country</a>.</p>
<p>The <a href="https://australiancoralreefsociety.org">Australian Coral Reef Society</a>, of which I am a councillor, last week released <a href="https://australiancoralreefsociety.org/acrs-letter-calling-parliament-reduce-atmospheric-carbon/">an open letter</a> to the federal government, calling for action on climate change to protect reefs. The task has never been more urgent. </p>
<p>There is still a lot of reef worth fighting for – but only if we act now.</p>
<p><em>The author would like to acknowledge the contribution of Ningaloo marine park managers – in particular, Dr Peter Barnes – to the research she and her colleagues are undertaking.</em></p><img src="https://counter.theconversation.com/content/223207/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Kate Quigley receives funding from the Australian Research Council in the form of the Discovery Early Career Researcher Award (DECRA) and holds a joint position as Principal Research Scientist at Minderoo Foundation, a philanthropic organisation.</span></em></p>The best strategy to protecting Earth’s coral reefs is to dramatically cut greenhouse gas emissions. But in the meantime, we must urgently make corals more resilient.Kate Marie Quigley, DECRA Research Fellow (James Cook University), Principal Research Scientist (Minderoo Foundation), James Cook UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2233222024-02-14T03:56:08Z2024-02-14T03:56:08ZThe world’s coral reefs are bigger than we thought – but it took satellites, snorkels and machine learning to see them<figure><img src="https://images.theconversation.com/files/575519/original/file-20240214-20-mjiqz2.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C4607%2C2592&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/aerial-view-great-barrier-reef-whitsundays-1496224889">Shutterstock</a></span></figcaption></figure><p>The world’s coral reefs are close to 25% larger than we thought. By using satellite images, machine learning and on-ground knowledge from a global network of people living and working on coral reefs, <a href="https://www.sciencedirect.com/science/article/pii/S2949790624000016?via%3Dihub">we found</a> an extra 64,000 square kilometres of coral reefs – an area the size of Ireland. </p>
<p>That brings the total size of the planet’s shallow reefs (meaning 0-20 metres deep) to 348,000 square kilometres – the size of Germany. This figure represents whole coral reef ecosystems, ranging from sandy-bottomed lagoons with a little coral, to coral rubble flats, to living walls of coral. </p>
<p>Within this 348,000 km² of coral is 80,000 km² where there’s a hard bottom – rocks rather than sand. These areas are likely to be home to significant amounts of coral – the places snorkellers and scuba divers most like to visit. </p>
<p>You might wonder why we’re finding this out now. Didn’t we already know where the world’s reefs are? </p>
<p>Previously, we’ve had to pull data from many different sources, which made it harder to pin down the extent of coral reefs with certainty. But now we have high resolution satellite data covering the entire world – and are able to see reefs as deep as 30 metres down. </p>
<p>We coupled this with direct observations and records of coral reefs from over <a href="https://allencoralatlas.org/attribution">400 individuals and organisations</a> in countries with coral reefs from all regions, such as the Maldives, Cuba and Australia. </p>
<p>To produce the maps, we used machine learning techniques to chew through 100 trillion pixels from the Sentinel-2 and Planet Dove CubeSat satellites to make accurate predictions about where coral is – and is not. The team worked with almost 500 researchers and collaborators to make the maps. </p>
<p>The result: the world’s first comprehensive map of coral reefs extent, and their composition, produced through the <a href="https://allencoralatlas.org/">Allen Coral Atlas</a>. </p>
<p>The maps are already proving their worth. Reef management agencies around the world are using them to plan and assess conservation work and threats to reefs. </p>
<figure class="align-center ">
<img alt="Researcher towing a GPS on Great Barrier Reef during an expedition." src="https://images.theconversation.com/files/575477/original/file-20240213-26-wxc8ic.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/575477/original/file-20240213-26-wxc8ic.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=337&fit=crop&dpr=1 600w, https://images.theconversation.com/files/575477/original/file-20240213-26-wxc8ic.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=337&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/575477/original/file-20240213-26-wxc8ic.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=337&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/575477/original/file-20240213-26-wxc8ic.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/575477/original/file-20240213-26-wxc8ic.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/575477/original/file-20240213-26-wxc8ic.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">We combined satellite data with real world observations. Here, Dr Eva Kovacs tows a GPS on the Great Barrier Reef.</span>
<span class="attribution"><a class="source" href="https://allencoralatlas.org/blog/meet-the-team-university-of-queensland/">Allan Coral Atlas</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<h2>Where is this hidden coral?</h2>
<p>You can see the difference for yourself. In the interactive slider below, red indicates the newly detected coral in reefs off far north Queensland. </p>
<p><iframe id="tc-infographic-1015" class="tc-infographic" height="400px" src="https://cdn.theconversation.com/infographics/1015/df887cb0211a347030b52f7e8261bcacbc7e9463/site/index.html" width="100%" style="border: none" frameborder="0"></iframe></p>
<p>This infographic shows the new detail we now have for the Tongue Reef, in the seas off Port Douglas in Far North Queensland. </p>
<p><iframe id="tc-infographic-1017" class="tc-infographic" height="400px" src="https://cdn.theconversation.com/infographics/1017/21ab9e743c8e2a3a716df327b0946c4bf8e47468/site/index.html" width="100%" style="border: none" frameborder="0"></iframe></p>
<p>Our maps have three levels of detail. The first is the most expansive – the entire coral reef ecosystem. Seen from space, it has light areas of coral fringed by darker deeper water. </p>
<p>Then we have geomorphic detail, meaning what the areas within the reef look like. This includes sandy lagoons, reef crests exposed to the air at low tide, sloping areas going into deeper water and so on.</p>
<p><iframe id="tc-infographic-1016" class="tc-infographic" height="400px" src="https://cdn.theconversation.com/infographics/1016/ba3212ee64a358a16ca6b5ccfb454b415a72afe1/site/index.html" width="100%" style="border: none" frameborder="0"></iframe></p>
<p>And finally we have fine detail of the benthic substrates, showing where you have areas dominated by coral cover. </p>
<p>Coral can’t grow on sand. Polyps have to attach to a hard surface such as rock before they can begin expanding the reef out of their limestone-secreting bodies. </p>
<p>Some of our maps include fine detail of benthic substrates, meaning where coral is most likely to be and the substrates (seafloor) available to the polyps, such as existing coral, sand, rubble, or seagrass. </p>
<iframe src="https://flo.uri.sh/visualisation/16796582/embed" title="Interactive or visual content" class="flourish-embed-iframe" frameborder="0" scrolling="no" style="width:100%;height:600px;" sandbox="allow-same-origin allow-forms allow-scripts allow-downloads allow-popups allow-popups-to-escape-sandbox allow-top-navigation-by-user-activation" width="100%" height="400"></iframe>
<div style="width:100%!;margin-top:4px!important;text-align:right!important;"><a class="flourish-credit" href="https://public.flourish.studio/visualisation/16796582/?utm_source=embed&utm_campaign=visualisation/16796582" target="_top"><img alt="Made with Flourish" src="https://public.flourish.studio/resources/made_with_flourish.svg"></a></div>
<iframe src="https://flo.uri.sh/visualisation/16784641/embed" title="Interactive or visual content" class="flourish-embed-iframe" frameborder="0" scrolling="no" style="width:100%;height:600px;" sandbox="allow-same-origin allow-forms allow-scripts allow-downloads allow-popups allow-popups-to-escape-sandbox allow-top-navigation-by-user-activation" width="100%" height="400"></iframe>
<div style="width:100%!;margin-top:4px!important;text-align:right!important;"><a class="flourish-credit" href="https://public.flourish.studio/visualisation/16784641/?utm_source=embed&utm_campaign=visualisation/16784641" target="_top"><img alt="Made with Flourish" src="https://public.flourish.studio/resources/made_with_flourish.svg"></a></div>
<p>It’s a crucial time for the world’s coral reefs. We’re discovering the full extent of shallow water reefs – while other researchers are finding large new <a href="https://www.theguardian.com/environment/2024/jan/19/deep-sea-coral-reef-atlantic-coast">black coral reefs</a> in deeper water. </p>
<p>But even as we make these discoveries, coral reefs are reeling. Climate change is steadily heating up the sea and making it more acidic. Coral polyps can’t <a href="https://theconversation.com/the-heroic-effort-to-save-floridas-coral-reef-from-extreme-ocean-heat-as-corals-bleach-across-the-caribbean-210974">handle too much heat</a>. These wonders of biodiversity are home to a quarter of the ocean’s species.</p>
<figure class="align-center ">
<img alt="Scientist doing coral reef research." src="https://images.theconversation.com/files/575481/original/file-20240213-20-h7bnsp.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/575481/original/file-20240213-20-h7bnsp.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=337&fit=crop&dpr=1 600w, https://images.theconversation.com/files/575481/original/file-20240213-20-h7bnsp.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=337&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/575481/original/file-20240213-20-h7bnsp.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=337&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/575481/original/file-20240213-20-h7bnsp.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=423&fit=crop&dpr=1 754w, https://images.theconversation.com/files/575481/original/file-20240213-20-h7bnsp.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=423&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/575481/original/file-20240213-20-h7bnsp.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=423&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Making these maps took plenty of underwater research as well as satellite data. This photo shows Dr Chris Roelfsema conducting a photo transect in a remote area of the Great Barrier Reef.</span>
<span class="attribution"><a class="source" href="https://allencoralatlas.org/blog/new-funds-for-coral-reef-field-engagement/">Allen Coral Atlas</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>In good news, these maps are already leading to real world change. We’ve already seen new efforts to conserve coral reefs in Indonesia, several Pacific island nations, Panama, Belize, Kenya and Australia, among others. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/how-do-coral-reefs-thrive-in-parts-of-the-ocean-that-are-low-in-nutrients-by-eating-their-algal-companions-212049">How do coral reefs thrive in parts of the ocean that are low in nutrients? By eating their algal companions</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/223322/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Mitchell Lyons receives funding from Australian Research Council and Australian Commonwealth Government. Mitchell Lyons works for the University of Queensland and the University of New South Wales. </span></em></p><p class="fine-print"><em><span>Stuart Phinn receives funding from the Australian Research Council, Queensland and New South Wales state governments, Geoscience Australia and other Commonwealth agencies, and SmartSAT CRC. He works for the University of Queensland and was the founding director of Earth Observation Australia and Australia's Terrestrial Ecosystem Research Network (TERN). </span></em></p>Our new maps show coral reefs are more extensive than we thought.Mitchell Lyons, Postdoctoral research fellow, The University of QueenslandStuart Phinn, Professor of Geography, Director - Remote Sensing Research Centre, Chair - Earth Observation Australia, The University of QueenslandLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2091962024-01-08T13:36:16Z2024-01-08T13:36:16ZWhat happens to the ocean if we take out all the fish? A marine ecologist explains the complex roles fish play in their ecosystem<figure><img src="https://images.theconversation.com/files/543088/original/file-20230816-19-h6b36a.jpg?ixlib=rb-1.1.0&rect=6%2C12%2C2038%2C1348&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Fish swim in a reef at Pearl and Hermes Atoll in the Northwestern Hawaiian Islands.</span> <span class="attribution"><a class="source" href="https://newsroom.ap.org/detail/UNBiodiversity/3ead5d56c624402893c0df11ab789657/photo?Query=ocean%20fish&mediaType=photo&sortBy=&dateRange=Anytime&totalCount=262&currentItemNo=31&vs=true">AP Photo/Jacob Asher </a></span></figcaption></figure><figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=293&fit=crop&dpr=1 600w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=293&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=293&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=368&fit=crop&dpr=1 754w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=368&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=368&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption"></span>
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</figure>
<p><em><a href="https://theconversation.com/us/topics/curious-kids-us-74795">Curious Kids</a> is a series for children of all ages. If you have a question you’d like an expert to answer, send it to <a href="mailto:curiouskidsus@theconversation.com">curiouskidsus@theconversation.com</a>.</em></p>
<hr>
<blockquote>
<p><strong>What would happen to the ocean if we took out all the fish? – Reny, age 12</strong></p>
</blockquote>
<hr>
<p>The ocean is massive and covers most of the surface of our planet. In addition to its size, it’s packed with life, ranging from an astounding diversity of plants, microbes, worms, corals and crabs to squids, whales and, yes, even fish. The ocean is full of fish, so much so that they make up the <a href="https://doi.org/10.1073/pnas.1711842115">second-largest amount of all carbon</a> – the material that makes up living things – in the entire animal kingdom. They’re just behind the group containing insects and crustaceans.</p>
<p>Most people only interact with the ocean from a beach or in a boat, so it can be hard to wrap your head around how many fish there really are. But the ocean is swarming with them, from its surface <a href="https://www.nbcnews.com/news/world/deepest-ever-fish-filmed-japan-scientists-rcna77858">to its depths</a>. </p>
<p>These fish also come in all kinds of shapes and sizes, ranging from the tiny sardines, guppies and blennies that you might <a href="https://www.palmbeachpost.com/story/opinion/columns/guest/2020/01/25/point-of-view-call-for-more-diversity-not-only-more-fish-in-marine-protected-areas/112150854/">see on a coral reef</a> to massive tunas and whale sharks that you might find <a href="https://www.fisheries.noaa.gov/feature-story/surface-slicks-are-pelagic-nurseries-diverse-ocean-fauna">out in the open ocean</a>. </p>
<p>These fish perform all kinds of <a href="https://doi.org/10.1002/ecs2.4288">roles in their ecosystems</a> that support the lives of other organisms around them. If they disappeared one day, the ocean would look very different.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/542471/original/file-20230813-127481-q0e3vz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/542471/original/file-20230813-127481-q0e3vz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=337&fit=crop&dpr=1 600w, https://images.theconversation.com/files/542471/original/file-20230813-127481-q0e3vz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=337&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/542471/original/file-20230813-127481-q0e3vz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=337&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/542471/original/file-20230813-127481-q0e3vz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/542471/original/file-20230813-127481-q0e3vz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/542471/original/file-20230813-127481-q0e3vz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">School of slopehead parrotfish.</span>
<span class="attribution"><span class="source">NOAA, Kevin Lino</span></span>
</figcaption>
</figure>
<p>I’m a <a href="https://koryevans.weebly.com/">scientist who studies fish</a>, their diversity and all the ways they contribute to ocean environments.</p>
<h2>Fish as food</h2>
<p>Fish play important roles as both <a href="https://www.noaa.gov/education/resource-collections/marine-life/aquatic-food-webs">predators and prey</a> in ocean ecosystems. Thousands of species throughout the ocean and terrestrial ecosystems rely on fish for food – <a href="https://www.fisheries.noaa.gov/feature-story/economic-importance-seafood">including people</a>. </p>
<p>In coral reef ecosystems, small fish are eaten by larger fish and other marine animals. This means the little fish form the base of the food web – they provide energy to the bigger fish and other creatures. </p>
<figure class="align-center ">
<img alt="Conceptual food web of a coral reef ecosystem identifying key functional groups." src="https://images.theconversation.com/files/542472/original/file-20230813-197557-ebgabl.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/542472/original/file-20230813-197557-ebgabl.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=569&fit=crop&dpr=1 600w, https://images.theconversation.com/files/542472/original/file-20230813-197557-ebgabl.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=569&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/542472/original/file-20230813-197557-ebgabl.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=569&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/542472/original/file-20230813-197557-ebgabl.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=715&fit=crop&dpr=1 754w, https://images.theconversation.com/files/542472/original/file-20230813-197557-ebgabl.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=715&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/542472/original/file-20230813-197557-ebgabl.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=715&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Links between different species of coral reef animals.</span>
<span class="attribution"><span class="source">Global Change Biology, Rogers et al., 2015</span></span>
</figcaption>
</figure>
<p>Outside of the water, many birds, mammals and reptiles eat fish and rely on them as an <a href="https://doi.org/10.1016/S0921-8009(99)00015-4">essential source of protein</a>. </p>
<p>Even land plants can benefit from the presence of fish. On the western coast of the United States, salmon returning to small streams after spending several years at sea function as a conveyor belt of nutrients. The salmon feed not only animals that catch them, like bears, but also the plants that border the streams. Studies have shown that some plants get <a href="https://www.adfg.alaska.gov/index.cfm?adfg=wildlifenews.view_article&articles_id=407">70% of their nitrogen</a> from salmon that die on or near the river banks. </p>
<p>Humans also depend on fish as a food source. Fish and other seafood products are an important protein source for <a href="https://www.nature.org/en-us/what-we-do/our-priorities/provide-food-and-water-sustainably/food-and-water-stories/global-fisheries/">nearly 3 billion people</a>. Human populations have been eating and following fish around the world for <a href="https://doi.org/10.1073/pnas.1710186114">thousands of years</a>. </p>
<h2>Fish maintain habitats</h2>
<p>Fish are also more than just food. As fish themselves forage for food, they can create and maintain important <a href="https://doi.org/10.1007/s00338-006-0112-y">habitats for other organisms</a>. In coral reef ecosystems, plant-eating fish control the growth of algae by constantly grazing it down. Without the help of these herbivores, or plant-eating fish, the algae would rapidly grow and smother the coral, effectively killing it. </p>
<p>One type of herbivorous fish, the parrotfish, <a href="https://ocean.si.edu/ocean-life/fish/tough-teeth-and-parrotfish-poop">feeds directly on the corals</a>. At first, this may seem bad for the corals, but the grazing done by parrotfish can actually increase a coral colony’s rate of growth. And <a href="https://ocean.si.edu/ocean-life/fish/tough-teeth-and-parrotfish-poop">the poop</a> – yes, the poop – from parrotfish has been shown to be <a href="https://doi.org/10.1016/j.tim.2022.03.006">particularly nutritious</a> for corals. Parrotfish poop also forms part of the <a href="https://ocean.si.edu/ocean-life/fish/tough-teeth-and-parrotfish-poop">beautiful white sand beaches</a> that you may have enjoyed on a family vacation.</p>
<p>Other fish create habitats for other animals and influence their environment by <a href="https://www.ingentaconnect.com/content/umrsmas/bullmar/1986/00000038/00000001/art00006">disturbing sand</a> while they feed. By moving the sand around, they’re exposing tiny organisms hiding in the sand, which other animals can eat. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/_pN5-96nduge?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Some fish sift through sand to find their food. That creates more opportunities for other creatures to find food in the sand.</span></figcaption>
</figure>
<p>Despite the fact that many types of fish are confined to the ocean, their presence can be felt across many habitats. They can directly and indirectly affect the lives of the organisms that depend on them for food and shelter. Without fish, Earth would gradually lose its beautiful white sand beaches, the coral reef ecosystems would be overgrown with algae, lots of people would run out of food to eat, and we would lose some of the planet’s most fascinating creatures.</p>
<hr>
<p><em>Hello, curious kids! Do you have a question you’d like an expert to answer? Ask an adult to send your question to <a href="mailto:curiouskidsus@theconversation.com">CuriousKidsUS@theconversation.com</a>. Please tell us your name, age and the city where you live.</em></p>
<p><em>And since curiosity has no age limit – adults, let us know what you’re wondering, too. We won’t be able to answer every question, but we will do our best.</em></p><img src="https://counter.theconversation.com/content/209196/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Kory Evans receives funding from National Science Foundation. </span></em></p>There are so many fish in the ocean that if you took them out, important habitats and food sources for many creatures would be lost.Kory Evans, Assistant Professor of BioSciences, Rice UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1943352023-12-10T19:07:20Z2023-12-10T19:07:20ZHow an underwater sculpture trail plays a role in the health – and beauty – of the Great Barrier Reef<p>The widespread demise of coral reefs due to climate change is <a href="https://www.ipcc.ch/report/ar6/syr/downloads/report/IPCC_AR6_SYR_SPM.pdf">now a certainty</a>. But what role does art have in our future for coral reefs? </p>
<p>Art is about feelings. One of the great challenges today is that we often feel untouched by the problems of others and by global issues like climate change. This is where art can make a difference.</p>
<p>Engaging with a thoughtful work of art can connect you to your senses, body and mind. Art can be used as a tool to raise awareness, promote conversation and rally behind a cause. </p>
<p>One way this is happening on the Great Barrier Reef is through an underwater sculpture trail. Here reef sculptures are drawing attention to inspirational scientists, the science of climate change, reef restoration, citizen science and traditional culture.</p>
<h2>What are reef sculptures?</h2>
<p>Reef sculptures are a form of artificial reef: man-made structures placed into an aquatic environment to mimic certain characteristics of a natural reef.</p>
<p>Artificial reefs were historically deployed for fishers and divers to concentrate marine life and to shift pressure from other popular locations.</p>
<p>Artificial reefs take many forms, such as reef balls, pods, concrete pipes, wrecks and sculptures. They can be sites of ecological research, conservation and arts and culture.</p>
<p>The first modern reef sculpture was created by Jason deCaires Taylor at Grenada in the West Indies in 2006. This sculpture aimed to provide a restorative response to a damaged marine ecosystem and enhance marine tourism. </p>
<p>The largest underwater sculpture in the world is the <a href="https://www.moua.com.au/">Museum of Underwater Art</a> created with deCaires Taylor at John Brewer Reef, offshore from Townsville. The Coral Greenhouse is a skeletal building made from pH-neutral cement and corrosion-resistant stainless steel. It covers an area of 72 square metres and weights 165 tonnes, with eight human figures depicting scientists, conservationists and coral gardeners.</p>
<p>A <a href="https://www.mdpi.com/2077-1312/10/11/1617">recent report</a> on this sculpture found statistically significant increases in fish abundance and diversity. There were no changes over time in invertebrate abundance, invertebrate diversity and tourist perceptions of aesthetic values.</p>
<p>Structural designs of underwater sculptures need to be able to adapt into the surrounding natural landscape, creating a transition point from the manufactured to natural. </p>
<p>Small intricate matrices provide protection for small fish. Textured planters encourage coral restoration efforts by scientists.</p>
<p>But there are still <a href="https://www.mdpi.com/2076-3298/10/7/121">gaps in our knowledge</a> in how effective artificial reefs are for potential local, regional or global impact by increasing awareness of coral reef decline and positive actions.</p>
<h2>Government policy bans underwater sculptures</h2>
<p>A <a href="https://elibrary.gbrmpa.gov.au/jspui/bitstream/11017/4011/1/FINAL-Policy-on-Fish-Aggregating-Devices-and-Artificial-Reefs.pdf">new Reef Authority policy</a> on fish-aggregating devices and artificial reefs has banned the creation of new underwater sculptures on the Great Barrier Reef.</p>
<p>Its report found artificial reefs are “not compatible” with the main objective of the Marine Park Act, which is “to provide for the long-term protection and conservation of the environment, biodiversity and heritage values of the Great Barrier Reef Region”.</p>
<p>Instead of artificial reefs, the <a href="https://elibrary.gbrmpa.gov.au/jspui/bitstream/11017/3287/1/GBRMPA%20Blueprint%20for%20Resilience%20-%20Low%20Res.pdf">authority recommends initiatives</a> that include ramping up crown-of-thorns starfish control, strengthening compliance, enhanced protection of key species for reef recovery, and testing and deploying methods for reef restoration.</p>
<p>But since 2017, the community, artists, traditional owners, citizen scientists, the tourism industry and local, state and federal governments have supported <a href="https://www.dtis.qld.gov.au/tourism/funds/growing-infrastructure/museum-of-underwater-art">the Museum of Underwater Art</a>.</p>
<p>This museum has provided jobs and revenue, raised awareness and amplified <a href="https://www.dtis.qld.gov.au/tourism/funds/growing-infrastructure/museum-of-underwater-art">important messages about reef conservation</a>. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/young-crown-of-thorns-starfish-can-survive-heatwaves-thats-yet-more-bad-news-for-the-great-barrier-reef-215543">Young crown-of-thorns starfish can survive heatwaves. That's yet more bad news for the Great Barrier Reef</a>
</strong>
</em>
</p>
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<h2>The positive impact of the reef sculpture</h2>
<p>We have been surveying the life at the Museum of Underwater Art since 2018.</p>
<p>In 2018 (pre-installation), 2020 (post-installation), 2021 and 2022, divers recorded species and abundance of individuals sighted.</p>
<p>In 2018, 12 species and 65 individual creatures were recorded at the location of the museum. The <a href="https://www.mdpi.com/2077-1312/10/11/1617">2022 survey</a> found 46 species and 365 individuals. </p>
<p>The site has also become a <a href="https://reefecologic.org/project/moua/#:%7E:text=Bringing%20life%20to%20the%20Coral%20Greenhouse&text=On%2014%20March%202021%2C%20Reef,131%20corals%20on%20treatment%20locations">reef restoration demonstration site</a>. Planting corals on underwater sculptures is an innovative method of linking art, science, tourism, education and conservation. </p>
<p>Coral gardening is a reef-restoration technique modelled on terrestrial gardening. Small cuttings of coral colonies, called fragments, are transplanted from the surrounding reef to populate the new artificial reef. The corals help to rapidly transform the art installation into a biotic location.</p>
<p>In March 2020, 131 corals were transplanted onto Taylor’s sculptures. After one year, 91.6% of the coral survived. </p>
<p>Our research on planting corals in relatively deep water of 18 metres has been challenging and innovative. Interestingly, the results are better than for shallow-water coral projects, which average an 80% survival rate after one year.</p>
<p>We also assessed tourist attitudes to the artificial reef. We found high satisfaction with the art, coral and fish observed at the site.</p>
<p>Interestingly, tourists in the Whitsundays rated <a href="https://www.researchgate.net/publication/357916065_Innovative_local_response_to_cyclone_damaged_reef_leads_to_rapid_tourism_recovery">the beauty of underwater art</a> higher than the beauty of natural reefs.</p>
<h2>Reaching new hearts</h2>
<p>Katharina Fabricious, a senior research scientist at the Australian Institute of Marine Science, <a href="https://www.abc.net.au/news/2023-05-18/museum-of-underwater-art-great-barrier-reef-ocean-sentinels/102337556">says</a>:</p>
<blockquote>
<p>Conservation needs to be communicated in a whole range of different ways, and art is reaching people that scientists sometimes cannot reach.</p>
</blockquote>
<p>The future of the Museum of Underwater Art is uncertain due to its classification as an artificial reef. The renewal or refusal of the many permits required for the artworks will be considered in the context of the new policy. It means this is the largest and possible the last underwater sculpture in the Great Barrier Reef.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/concern-for-the-great-barrier-reef-can-inspire-climate-action-but-the-way-we-talk-about-it-matters-216992">Concern for the Great Barrier Reef can inspire climate action - but the way we talk about it matters</a>
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</em>
</p>
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<img src="https://counter.theconversation.com/content/194335/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Adam Smith through Reef Ecologic Pty Ltd receives funding for research from the Australian and Queensland Government. He is a voluntary Board member of the not for profit Museum of Underwater Art Pty Ltd</span></em></p><p class="fine-print"><em><span>Nathan Cook through Reef Ecologic Pty Ltd receives funding for research from the Australian and Queensland Government. </span></em></p>Reef sculptures are a form of artifical reef: man-made structures placed into an aquatic environment to mimic certain characteristics of a natural reef.Adam Smith, Adjunct Associate Professor, James Cook UniversityNathan Cook, Marine Scientist, James Cook UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2110882023-10-12T21:13:09Z2023-10-12T21:13:09ZHow clouds protect coral reefs, but will not be enough to save them from us<iframe style="width: 100%; height: 100px; border: none; position: relative; z-index: 1;" allowtransparency="" allow="clipboard-read; clipboard-write" src="https://narrations.ad-auris.com/widget/the-conversation-canada/how-clouds-protect-coral-reefs-but-will-not-be-enough-to-save-them-from-us" width="100%" height="400"></iframe>
<p>Coral reefs are vital <a href="https://www.noaa.gov/education/resource-collections/marine-life/coral-reef-ecosystems">ecosystems</a> for people and coastal communities. They provide <a href="https://www.coast.noaa.gov/states/fast-facts/coral-reefs.html">food and livelihoods</a> and protect coastlines from storms, contribute to local economies and preserve cultural heritage.</p>
<p>However, warming ocean temperatures as a result of human-made climate change present considerable risks to the reefs. The recent rise in <a href="https://doi.org/10.1038/nature21707">coral bleaching</a> all over the world is the most visible impact.</p>
<p>But what is <a href="https://oceanservice.noaa.gov/facts/coral_bleach.html">coral bleaching</a>? Coral bleaching is a phenomenon that occurs when the white skeleton of the corals becomes visible after the microalgae that live inside their translucent tissues are expelled. </p>
<p>Even though coral reefs can <a href="https://reefresilience.org/stressors/bleaching/bleaching-biology/">recover</a> from bleaching events, the process, much like the regrowth of a forest following a windstorm or wildfire, requires a considerable amount of time. And, as our research has shown, an appreciation of the role of cloud cover.</p>
<h2>Relief in the clouds</h2>
<p>Although coral bleaching is generally linked only to ocean temperatures, the process itself is a product of the interaction between high <a href="https://reefresilience.org/stressors/bleaching/bleaching-biology/">temperatures and sunlight levels in a given area</a>. </p>
<p>If the temperatures are high enough, the coral and microalgae become more light-sensitive. When combined with <a href="https://doi.org/10.3389/fmicb.2014.00422">excessive sunlight</a>, this sensitivity harms the microalgae which, in turn, results in the production of chemical compounds called <a href="https://doi.org/10.1242/jeb.009597">reactive oxygen species</a>. These compounds are harmful to many species and in the case of reefs cause the coral to expel its microalgae.</p>
<p>In the same way that clouds protect us from harmful exposure to UV rays, clouds also provide a protective barrier for the world’s coral reefs. Field studies of coral bleaching events in <a href="https://www.int-res.com/abstracts/meps/v222/p209-216/">French Polynesia</a> and in the <a href="https://doi.org/10.1038/s41598-019-40150-3">Republic of Kiribati</a> found that periods of cloudiness may have reduced the bleaching severity and extent. </p>
<p>Climate change is projected to kill off most of the world’s coral reefs, even in scenarios with only <a href="http://dx.doi.org/10.1038/nclimate1674">1.5 C</a> of global warming. Yet, to date, most analysis has only considered the effect of temperature. Could incorporating clouds change the forecast?</p>
<h2>Considering cloudiness</h2>
<p>In order to understand how cloudiness might influence the response of coral reefs to climate change, <a href="https://doi.org/10.1371/journal.pclm.0000090">our recent study</a> used a <a href="https://doi.org/10.1371/journal.pone.0281719">global historical database</a> containing almost 38,000 coral bleaching reports to train an algorithm that estimates bleaching severity based on incoming light and temperature stress. </p>
<p>Our algorithm was then <a href="https://www.climateneutralgroup.com/en/news/five-future-scenarios-ar6-ipcc/">applied to four different future climate scenarios</a> on the world’s coral reefs to assess if and when bleaching conditions would become too frequent for reefs to recover. The results indicate that under a low emissions scenario, increased cloudiness would indeed have an effect on the coral bleaching conditions. This means that corals would have more time to recover from the impacts of rising temperatures and improve their resilience. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/coral-reefs-how-climate-change-threatens-the-hidden-diversity-of-marine-ecosystems-211007">Coral reefs: How climate change threatens the hidden diversity of marine ecosystems</a>
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</em>
</p>
<hr>
<p>However, even under a low carbon emission scenario, this extra time will not be enough to prevent more than 70 per cent of global reefs experiencing frequent bleaching conditions with not enough time in between to fully recover.</p>
<p>This highlights the severity of the coral bleaching crisis caused by thermal stress and the limitations of relying solely on cloudiness as a protective mechanism. Simply put, while clouds can offer some relief to corals, they cannot mitigate the long-term consequences of climate change when the sea surface temperature becomes too high.</p>
<h2>Clear implications</h2>
<p>Cloud cover may offer temporary relief to coral reefs by delaying the adverse environmental conditions responsible for coral bleaching. However, that seems to be partially true only in the lowest emission scenario which would be possible only if we dramatically cut greenhouse gas emissions.</p>
<p>Without doing that, dangerously frequent bleaching conditions are unavoidable and reefs will continue to be threatened even if we cut down emissions now. Moreover, we also need to get serious about habitat and biodiversity protection <a href="https://www.epa.gov/coral-reefs/threats-coral-reefs">to increase resilience</a>. </p>
<p>Only by doing this could coral reefs stand a chance at surviving the increasing pressures of climate change. Any other approach has its head in the clouds.</p><img src="https://counter.theconversation.com/content/211088/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Pedro C. González Espinosa receives funding from the Nippon Foundation Ocean Nexus, School of Resource and Environmental Management (REM), Simon Fraser University (SFU). </span></em></p><p class="fine-print"><em><span>Simon Donner receives funding from Natural Sciences and Engineering Research Council and the Social Sciences and Humanities Research Council.</span></em></p>Understanding how both cloud cover and temperature work to promote coral bleaching provides valuable insight into how reefs will change over various climate scenarios.Pedro C. González Espinosa, Postdoctoral Reserach Fellow, The School of Resource and Environmental Management, Simon Fraser UniversitySimon Donner, Professor, Department of Geography, University of British ColumbiaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2128492023-09-20T21:09:33Z2023-09-20T21:09:33ZSex life discovery raises IVF hope for endangered purple cauliflower soft coral<figure><img src="https://images.theconversation.com/files/549271/original/file-20230920-25-omlgkz.jpg?ixlib=rb-1.1.0&rect=7%2C27%2C1650%2C2293&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">David Harasti</span></span></figcaption></figure><p>Vital coastal habitat was destroyed in the devastating floods that hit New South Wales in 2021 and 2022. </p>
<p>The purple cauliflower soft coral <em>Dendronephthya australis</em>, now listed as an endangered species, was almost completely wiped out in the Port Stephens estuary and along the coast. That’s a tragedy because this coral shelters young snapper and the endangered White’s seahorse. </p>
<p>Unfortunately, a lack of knowledge hampered recovery efforts – until now. </p>
<p>In <a href="https://doi.org/10.1007/s00227-023-04298-x">our new research</a> we discovered how the coral reproduces. We used IVF (in-vitro fertilisation) to create baby coral in the lab. And we successfully transplanted the coral into the wild. This offers new hope for the survival of the species. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/tOIFmMCRU3I?wmode=transparent&start=58" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Understanding the sex life of purple cauliflower soft coral offers hope for the species.</span></figcaption>
</figure>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/beautiful-rare-purple-cauliflower-coral-off-nsw-coast-may-be-extinct-within-10-years-160184">Beautiful, rare 'purple cauliflower' coral off NSW coast may be extinct within 10 years</a>
</strong>
</em>
</p>
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<h2>Variety is the spice of life</h2>
<p>Corals have a complicated sex life. There’s more than one way to “do it”. And gender varies too. </p>
<p>Corals can reproduce asexually, meaning they create genetic copies of themselves. This process often entails shedding polyps that can attach to reefs to form new colonies. </p>
<p>Using this process is a common approach for coral restoration. It’s a bit like propagating plants. Cuttings or fragments are removed from adult colonies, briefly maintained in the lab, and then new corals are transplanted into the wild. This isn’t a simple process for soft corals, though we have been exploring <a href="https://doi.org/10.1002/aqc.3895">ways to make this work</a> for <em>Dendronephthya australis</em>.</p>
<p>Many corals are hermaphrodites, which means they have both male and female reproductive organs. Others form colonies that are entirely male or female. And some mix or swap sexes. </p>
<p>Spawning is the release of eggs and sperm. Again, corals can use various techniques. Broadcast spawning is where eggs and sperm are released into the water column. Brooding is where eggs are fertilised within colonies and later released as larvae. </p>
<p>But until sexual reproduction of an individual species is observed, their sex life remains a private matter.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/548615/original/file-20230916-27-tj4s7a.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Graphic illustrating the life cycle of the purple cauliflower coral, which begins with an egg being fertilised by sperm, to embryo cell division within 2-4 hours, to fully grown larvae by day 5, to metamorphosis to polyp from 8 days of age." src="https://images.theconversation.com/files/548615/original/file-20230916-27-tj4s7a.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/548615/original/file-20230916-27-tj4s7a.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=337&fit=crop&dpr=1 600w, https://images.theconversation.com/files/548615/original/file-20230916-27-tj4s7a.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=337&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/548615/original/file-20230916-27-tj4s7a.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=337&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/548615/original/file-20230916-27-tj4s7a.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/548615/original/file-20230916-27-tj4s7a.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/548615/original/file-20230916-27-tj4s7a.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The life cycle of the purple cauliflower coral <em>Dendronephthya australis</em> begins with an egg being fertilised by sperm, proceeds to embryo cell division within 2-4 hours, to fully grown larvae by day 5, to metamorphosis to polyp from 8 days of age.</span>
<span class="attribution"><span class="source">Meryl Larkin</span></span>
</figcaption>
</figure>
<h2>A chance discovery in the lab</h2>
<p>We were growing coral in the lab, raising asexual clones from fragments, when we noticed something unusual. </p>
<p>There were small orange dots inside some of the corals. These were much larger than the grains of dry orange “coral food” we fed them. So they had to be something else. </p>
<p>We soon realised the orange dots were unfertilised eggs. Half of the fragments in our care contained eggs. As sperm is much smaller, we had to sacrifice small portions of the remaining coral fragments for closer inspection of their contents (under a microscope). In doing this, we discovered the other half were sperm-bearing. </p>
<p>As fate would have it, we had collected fragments from two donor colonies – one female and one male. By chance, we discovered <em>Dendronephthya australis</em> is “gonochoric” (meaning colonies are either male or female). </p>
<p>We watched the corals carefully over the following weeks and made more discoveries. Females spawned (released their eggs) around the “neap tide” (when the moon appears half full) during the summer months. </p>
<p>Maybe the coral evolved to spawn when tidal currents are slowest, to maximise the chance of fertilisation. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/548616/original/file-20230916-27-8l7r3c.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A closeup photo of a soft coral fragment containing unfertilised eggs (orange dots)" src="https://images.theconversation.com/files/548616/original/file-20230916-27-8l7r3c.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/548616/original/file-20230916-27-8l7r3c.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=470&fit=crop&dpr=1 600w, https://images.theconversation.com/files/548616/original/file-20230916-27-8l7r3c.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=470&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/548616/original/file-20230916-27-8l7r3c.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=470&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/548616/original/file-20230916-27-8l7r3c.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=591&fit=crop&dpr=1 754w, https://images.theconversation.com/files/548616/original/file-20230916-27-8l7r3c.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=591&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/548616/original/file-20230916-27-8l7r3c.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=591&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Unfertilised eggs (orange dots) were observed in <em>Dendronephthya australis</em> fragments for the first time.</span>
<span class="attribution"><span class="source">Meryl Larkin</span></span>
</figcaption>
</figure>
<h2>Coral IVF for making babies</h2>
<p>We used IVF techniques to fertilise harvested eggs. Cell division occurred within hours. Mobile larvae grew over the following week. </p>
<p>From eight days of age, the larvae started to transform into polyps; we were the first people to witness these tiny cauliflower coral babies (as single polyps).</p>
<p>Within just a few weeks, we had produced 280 babies from just a few coral fragments. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/548617/original/file-20230916-29-f94gns.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A closeup photo showing baby single coral polyps after metamorphosis from the larval stage" src="https://images.theconversation.com/files/548617/original/file-20230916-29-f94gns.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/548617/original/file-20230916-29-f94gns.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=429&fit=crop&dpr=1 600w, https://images.theconversation.com/files/548617/original/file-20230916-29-f94gns.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=429&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/548617/original/file-20230916-29-f94gns.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=429&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/548617/original/file-20230916-29-f94gns.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=539&fit=crop&dpr=1 754w, https://images.theconversation.com/files/548617/original/file-20230916-29-f94gns.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=539&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/548617/original/file-20230916-29-f94gns.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=539&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Researchers achieved larval settlement, witnessing the change to the single polyp stage of the soft coral.</span>
<span class="attribution"><span class="source">David Harasti</span></span>
</figcaption>
</figure>
<p>Understanding how the purple cauliflower coral reproduces is important for several reasons:</p>
<ul>
<li><p>maintaining genetic diversity: if the sex ratio becomes unbalanced, the effective population size will be lower than the total number of remaining individuals</p></li>
<li><p>achieving fertilisation: broadcast spawning in corals is density-dependent. That means if more colonies are lost, the chance of natural sexual reproduction decreases </p></li>
<li><p>restoring gender balance: any attempt to grow more coral from fragments will need to ensure both male and female colonies are represented </p></li>
<li><p>scaling up production: sexual reproduction provides an opportunity to raise more baby corals while maintaining genetic diversity in the population. </p></li>
</ul>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/548618/original/file-20230916-29-ebwo29.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A photo of a Four-month-old juvenile coral transplanted in Port Stephens" src="https://images.theconversation.com/files/548618/original/file-20230916-29-ebwo29.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/548618/original/file-20230916-29-ebwo29.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=475&fit=crop&dpr=1 600w, https://images.theconversation.com/files/548618/original/file-20230916-29-ebwo29.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=475&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/548618/original/file-20230916-29-ebwo29.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=475&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/548618/original/file-20230916-29-ebwo29.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=597&fit=crop&dpr=1 754w, https://images.theconversation.com/files/548618/original/file-20230916-29-ebwo29.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=597&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/548618/original/file-20230916-29-ebwo29.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=597&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Four-month-old juvenile coral transplanted in Port Stephens.</span>
<span class="attribution"><span class="source">Meryl Larkin</span></span>
</figcaption>
</figure>
<h2>Ongoing restoration work</h2>
<p>Since this discovery, we have successfully repeated these IVF techniques. We transplanted hundreds of coral babies and released thousands of larvae back into Port Stephens. </p>
<p>Early results suggest some IVF babies survived at least the first 18 months and performed better than the asexual fragments.</p>
<p>We plan to implement the IVF program annually. We’re optimistic that we can boost the population of this endangered coral in ways never thought possible.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/coral-meet-coral-how-selective-breeding-may-help-the-worlds-reefs-survive-ocean-heating-166412">Coral, meet coral: how selective breeding may help the world's reefs survive ocean heating</a>
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</em>
</p>
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<img src="https://counter.theconversation.com/content/212849/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Meryl Larkin receives funding from the NSW Department of Primary Industries, Southern Cross University’s National Marine Science Centre and Marine Ecology Research Centre, and the Australian Government Research Training Program. Ongoing work (subsequent to Meryl Larkin's PhD project) has been supported with funding from the NSW Environmental Trust. </span></em></p><p class="fine-print"><em><span>David Harasti received funding from the NSW Environmental Trust to implement recovery actions for the endangered soft coral.</span></em></p><p class="fine-print"><em><span>Kirsten Benkendorff, Stephen D. A. Smith, and Tom R Davis do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>After a chance discovery in the lab, this team used IVF to make hundreds of coral babies for restoration projects in New South Wales. So far the IVF babies are doing well in the wild.Meryl Larkin, PhD Candidate, Southern Cross UniversityDavid Harasti, Adjunct assistant professor, Southern Cross UniversityKirsten Benkendorff, Professor, Southern Cross UniversityStephen D. A. Smith, Professor of Marine Science, National Marine Science Centre, Southern Cross UniversityTom R Davis, Research Scientist - Marine Climate Change, Hunter New England Local Health DistrictLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2113992023-09-05T12:29:58Z2023-09-05T12:29:58ZClimate change is destroying reefs, but the effects are more than ecological – coral’s been woven into culture and spirituality for centuries<p>Hurricane Idalia made landfall on Florida’s Gulf Coast on Aug. 30, 2023, bringing <a href="https://theconversation.com/what-is-hurricane-storm-surge-and-why-can-it-be-so-catastrophic-145369">surging seas</a> and <a href="https://apnews.com/article/florida-hurricane-idalia-2136985ceea53f5deb600c43aeea1138">winds over 100 mph</a>. Meanwhile, another climate emergency has been unfolding along Florida’s coast this summer: a <a href="https://doi.org/10.1126/science.adk0565">marine heat wave</a> bleaching corals throughout the world’s <a href="https://www.floridamuseum.ufl.edu/southflorida/habitats/corals/geographical-distribution/">third-largest barrier reef</a>.</p>
<p>Similarly, ocean temperatures in many parts of the Atlantic and Pacific are at <a href="https://www.climatecentral.org/climate-matters/record-ocean-heat-impacts-from-hurricanes-to-corals">record highs</a>, with reefs <a href="https://www.theguardian.com/environment/2023/aug/11/coral-bleaching-central-america">from Colombia</a> <a href="https://www.sbs.com.au/news/podcast-episode/concern-grows-over-unexpected-coral-bleaching-on-the-great-barrier-reef/pbi69ju9t">to Australia</a> showing signs of stress in recent years. Scientists warn that the world may be witnessing the start of a <a href="https://earth.google.com/web/@24.4430141,123.8161774,1.99338294a,0d,60y,358.27417338h,113t,0r/data=CkoSSBIgY2EwYzk0ZGNhN2I4MTFlN2I1ZDBiNzRhMWFlNGU2MDMiJGVmZWVkX29jZWFuX2FnZW5jeV9jb3JhbF9ibGVhY2hpbmdfMSIwCixBRjFRaXBPQXhSWk82WHppY1Z0QkJWOVlPOThCMmt2NkRZNTViR2p5azNFcBAF">global coral-bleaching event</a>, which would be <a href="https://www.cnbc.com/2023/08/18/noaa-florida-coral-bleaching-event-could-go-global.html">the fourth on record</a> – and while corals <a href="https://oceanservice.noaa.gov/facts/coral_bleach.html">can survive bleaching</a>, they won’t if the waters stay warm for too long.</p>
<p>Large-scale reef destruction tends to be measured in <a href="https://coast.noaa.gov/states/fast-facts/coral-reefs.html">biological and economic terms</a>. Reefs support about 25% <a href="https://doi.org/10.1371/journal.pone.0025026">of all marine species</a>, protect human lives and property by buffering shorelines and bolster the worldwide economy through fishing and tourism. </p>
<p>But coral’s loss also takes an enormous spiritual, psychological and cultural toll – one of the main topics of <a href="https://miamioh.edu/profiles/cas/michele-navakas.html">my research</a> and recent book, “<a href="https://press.princeton.edu/books/paperback/9780691240091/coral-lives">Coral Lives</a>.” Centuries of writing, painting, storytelling and rituals show that coral has given meaning to human lives for nearly as long as we’ve been around to marvel at it.</p>
<h2>Protective powers</h2>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/545609/original/file-20230830-19-ug6tbg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A Renaissance painting of a woman in a white cap holding a baby who is draped in white fabric and wearing a red necklace." src="https://images.theconversation.com/files/545609/original/file-20230830-19-ug6tbg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/545609/original/file-20230830-19-ug6tbg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=602&fit=crop&dpr=1 600w, https://images.theconversation.com/files/545609/original/file-20230830-19-ug6tbg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=602&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/545609/original/file-20230830-19-ug6tbg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=602&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/545609/original/file-20230830-19-ug6tbg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=756&fit=crop&dpr=1 754w, https://images.theconversation.com/files/545609/original/file-20230830-19-ug6tbg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=756&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/545609/original/file-20230830-19-ug6tbg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=756&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A detail from the 15th-century painting ‘The Senigallia Madonna,’ by Piero della Francesca, depicts Jesus with coral.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/italy-marche-pesaro-urbino-urbino-marche-national-gallery-news-photo/132702015?adppopup=true">Mondadori Portfolio/Hulton Fine Art Collection via Getty Images</a></span>
</figcaption>
</figure>
<p>From the Middle Ages until the 19th century, anxious new parents across Europe and North America clasped red coral necklaces and bracelets to their children’s bodies and gave them red coral to hold – and even teethe on – because coral symbolized physical and spiritual protection. Early Christian art from the medieval and Renaissance periods often features the infant Jesus in red coral, which scholars suggest may also be because its color <a href="https://surface.syr.edu/beads/vol16/iss1/4/">symbolized the blood of Christ</a>.</p>
<p>Coral encircles the necks and wrists of babies and children in more secular portraits, too, particularly during the 18th and 19th centuries. Often a child holds the “coral and bells,” a combination toy and teething aid: Children would alternately shake it as a rattle and chew on the red coral shaft to soothe sore gums. <a href="https://press.princeton.edu/books/paperback/9780691240091/coral-lives">The item was cherished</a> by the families of presidents and poets alike, from George Washington to Henry Wadsworth Longfellow, <a href="https://www.nps.gov/long/blogs/coral-and-silver-baby-rattle.htm">who even wrote about it</a>. “Coral and bells” were such a popular christening present that shops could barely keep it in stock.</p>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/545614/original/file-20230830-25-feg4b1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A close-up photo of a tiny red dagger-shaped item with an ornate silver handle." src="https://images.theconversation.com/files/545614/original/file-20230830-25-feg4b1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/545614/original/file-20230830-25-feg4b1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=800&fit=crop&dpr=1 600w, https://images.theconversation.com/files/545614/original/file-20230830-25-feg4b1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=800&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/545614/original/file-20230830-25-feg4b1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=800&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/545614/original/file-20230830-25-feg4b1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1005&fit=crop&dpr=1 754w, https://images.theconversation.com/files/545614/original/file-20230830-25-feg4b1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1005&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/545614/original/file-20230830-25-feg4b1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1005&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A ‘coral and bells’ toy made in New York in the 18th century.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/rattle-whistle-and-bells-1735-45-made-in-new-york-new-york-news-photo/1216161314?adppopup=true">Sepia Times/Universal Images Group via Getty Images</a></span>
</figcaption>
</figure>
<p>For these families and countless others across centuries, coral was far more than ornamental. By giving a child coral, parents were protecting what was most precious to them: their child’s life. </p>
<h2>The birth of coral</h2>
<p>Belief in the protective powers of coral dates to at least the classical period. According to <a href="https://www.bl.uk/collection-items/ovids-metamorphoses">the first-century Roman poet Ovid</a>, coral carried petrifying powers because it <a href="https://www.jstor.org/stable/3050690">originally emerged from the touch of Medusa</a>, the snake-haired Gorgon whose stare could turn others to stone. In <a href="https://ovid.lib.virginia.edu/trans/Metamorph4.htm">his epic poem “Metamorphoses</a>,” Ovid describes the hero Perseus severing Medusa’s head and laying it on a bed of seaweed that then hardened into coral. By the medieval period, this story gave rise to popular beliefs that wearing coral could ward off the “evil eye.” </p>
<p>Coral was also believed to have curative properties. In the “<a href="https://dpul.princeton.edu/gutenberg/catalog/q237hx283">Historia naturalis</a>,” an encyclopedia of the natural world, Roman author Pliny the Elder wrote of the <a href="https://www.perseus.tufts.edu/hopper/text?doc=Perseus%3Atext%3A1999.02.0137%3Abook%3D32%3Achapter%3D11">sacred and medicinal qualities of coral</a>. The material could remedy a variety of ailments when ingested, he claimed – which also explains why people once thought it was healthy for children to chew on coral.</p>
<p>Modern medicine, of course, argues against these ideas. But during historical periods when <a href="https://ourworldindata.org/child-mortality-in-the-past">child mortality rates may have been almost 50%</a>, coral calmed anxious parents’ fears.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/545640/original/file-20230830-16-camv9y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A formal portrait of three young girls in brightly colored dresses." src="https://images.theconversation.com/files/545640/original/file-20230830-16-camv9y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/545640/original/file-20230830-16-camv9y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=443&fit=crop&dpr=1 600w, https://images.theconversation.com/files/545640/original/file-20230830-16-camv9y.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=443&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/545640/original/file-20230830-16-camv9y.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=443&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/545640/original/file-20230830-16-camv9y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=557&fit=crop&dpr=1 754w, https://images.theconversation.com/files/545640/original/file-20230830-16-camv9y.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=557&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/545640/original/file-20230830-16-camv9y.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=557&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The child at left wears a coral necklace in William Matthew Prior’s portrait of three daughters of African American real estate investor Samuel Copeland.</span>
<span class="attribution"><a class="source" href="https://upload.wikimedia.org/wikipedia/commons/thumb/c/c2/William_Matthew_Prior_-_Three_Sisters_of_the_Copeland_Family_-_48.467_-_Museum_of_Fine_Arts.jpg/512px-William_Matthew_Prior_-_Three_Sisters_of_the_Copeland_Family_-_48.467_-_Museum_of_Fine_Arts.jpg">BotMultichillT/Wikimedia Commons/Museum of Fine Arts Boston</a></span>
</figcaption>
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<p>To this day, in some parts of the world, coral continues to provide a sense of control over situations that are largely out of our hands. In southern Italy, people give one another the “cornicello” for good luck: a small, horn-shaped charm frequently made of red coral. Some rosaries, too, are still <a href="https://americanhistory.si.edu/collections/search/object/nmah_1143060">made of red coral beads</a>, just as they were in the Middle Ages.</p>
<h2>Community bonds</h2>
<p>Beyond protection, coral can also symbolize belonging. Throughout the African diaspora during the 18th and 19th centuries, free and enslaved women in many communities wore red coral jewelry, particularly on special occasions, to commemorate a shared past and create new bonds.</p>
<p>Groups of women in Jamaica and other parts of the Caribbean, for example, <a href="https://press.princeton.edu/books/paperback/9780691240091/coral-lives">wore coral necklaces, earrings and bracelets during Jonkonnu</a>, a Christmas holiday masquerade of West African origins that incorporates traditional music and dance. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/545140/original/file-20230828-17-la7rj9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A colored drawing of women in elaborate costumes with white and red skirts." src="https://images.theconversation.com/files/545140/original/file-20230828-17-la7rj9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/545140/original/file-20230828-17-la7rj9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=504&fit=crop&dpr=1 600w, https://images.theconversation.com/files/545140/original/file-20230828-17-la7rj9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=504&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/545140/original/file-20230828-17-la7rj9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=504&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/545140/original/file-20230828-17-la7rj9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=633&fit=crop&dpr=1 754w, https://images.theconversation.com/files/545140/original/file-20230828-17-la7rj9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=633&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/545140/original/file-20230828-17-la7rj9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=633&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A sketch of Jonkonnu celebrations by 19th century Jamaican artist Isaac Mendes Belisario.</span>
<span class="attribution"><a class="source" href="http://www.slaveryimages.org/s/slaveryimages/item/2308">Slavery Images: A Visual Record of the African Slave Trade and Slave Life in the Early African Diaspora</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc/4.0/">CC BY-NC</a></span>
</figcaption>
</figure>
<p>As historian <a href="https://www.gvsu.edu/history/steeve-buckridge-62.htm">Steeve O. Buckridge</a> explains, these women <a href="https://www.uwipress.com/9789766401436/the-language-of-dress/">used clothing and jewelry</a> to communicate their identities nonverbally. Wearing coral was a way to preserve links to the African cultures from which slavery had severed these women. In many cultures, red coral beads were – and in some cases still are – objects of spiritual, economic and cultural significance. </p>
<p>In fact, coral was so valuable that it came to play a violent role in history. In coastal areas of Western Africa, coral became <a href="https://hal.science/hal-01991948/">currency in the transatlantic slave trade</a>: Slave traders exchanged coral for people.</p>
<p>But when diasporic women wore coral, it became part of their choice to create a different present and future. As scholar <a href="https://cssh.northeastern.edu/faculty/elizabeth-dillon/">Elizabeth Maddock Dillon</a> has also observed, each piece of their elaborate Jonkonnu costumes announced “not only splendor and beauty but <a href="https://www.dukeupress.edu/new-world-drama">a form of social belonging</a>” within different “kinship groups” of their own devising. Coral simultaneously signified slavery and hope for new possibilities.</p>
<h2>Forging the future</h2>
<p>After the Civil War, Black communities in the United States embraced coral for another reason. During Reconstruction, as these communities struggled to create a more just country, writers, religious leaders and activists <a href="https://press.princeton.edu/books/paperback/9780691240091/coral-lives">turned to reefs as an inspiring model</a>.</p>
<p>Even massive coral reefs are made up of millions of microscopic animals called polyps, which many people in the 19th century understood as “laborers” working together to build the reef. According to African American poet and civil rights advocate <a href="https://www.womenshistory.org/education-resources/biographies/frances-ellen-watkins-harper">Frances Ellen Watkins Harper</a>, reefs expand by sustaining others, rather than devaluing or displacing them. In her 1871 poem “<a href="https://catalog.hathitrust.org/Record/009567459">The Little Builders</a>,” Harper chose reefs as an analogy for how listeners and readers, Black and white, should work to build the social and financial bonds equality would depend on.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/545641/original/file-20230830-27-x1m060.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A black and white photograph of a woman in dark clothing standing formally while holding on to a chair." src="https://images.theconversation.com/files/545641/original/file-20230830-27-x1m060.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/545641/original/file-20230830-27-x1m060.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=769&fit=crop&dpr=1 600w, https://images.theconversation.com/files/545641/original/file-20230830-27-x1m060.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=769&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/545641/original/file-20230830-27-x1m060.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=769&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/545641/original/file-20230830-27-x1m060.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=967&fit=crop&dpr=1 754w, https://images.theconversation.com/files/545641/original/file-20230830-27-x1m060.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=967&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/545641/original/file-20230830-27-x1m060.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=967&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Frances Ellen Watkins Harper, pictured in the 19th century book ‘Women of distinction: remarkable in works and invincible in character.’</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/internetarchivebookimages/14598047448/">Internet Archive Book Images/Flickr</a></span>
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<p>But Harper knew that outcome was by no means certain. That’s why the coral analogy worked so well. As Charles Darwin explained in 1842 in a famous <a href="http://darwin-online.org.uk/content/frameset?pageseq=1&itemID=F271&viewtype=text">treatise on coral</a>, reefs are formed by so many relationships among different individual organisms across vast periods of time that their future form and shape can only be unpredictable.</p>
<p>As <a href="https://press.princeton.edu/books/paperback/9780691240091/coral-lives">my book</a> shows, in that unpredictability Black writers like Harper found hope. To them it meant that the actions of one single and seemingly insignificant individual might help transform an entire system.</p>
<h2>Grief and preservation</h2>
<p>Coral’s biological uniqueness and central role in sustaining other forms of life, including humans, are reasons enough to preserve it. And scientists <a href="https://theconversation.com/the-heroic-effort-to-save-floridas-coral-reef-from-extreme-ocean-heat-as-corals-bleach-across-the-caribbean-210974">are making extraordinary efforts</a>, such as <a href="https://www.nytimes.com/2023/07/31/climate/coral-reefs-heat-florida-ocean-temperatures.html">relocating threatened species</a> to dry tanks on land and developing <a href="https://doi.org/10.1126/science.adk4685">tools to predict marine heat waves</a> months in advance. </p>
<p>But for centuries, coral has also shaped thoughts about difficult human problems, from love and loss to social injustice. Reefs have provided knowledge, stories, hopes and histories in many cultures, far beyond the handful mentioned here. As we lose coral, then, we are also losing a material that has given us vital ways to understand and act within an increasingly chaotic world.</p><img src="https://counter.theconversation.com/content/211399/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Michele Navakas has received funding from the National Endowment for the Humanities for research on which this article is based.</span></em></p>Coral has been incorporated into traditions, art and even religion in communities around the world.Michele Currie Navakas, Professor of English, Miami UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2093882023-08-10T19:59:25Z2023-08-10T19:59:25ZAccelerated evolution and automated aquaculture could help coral weather the heat<p>Coral on the Great Barrier Reef has regrown strongly after the big losses of 2016 and 2017, when <a href="https://www2.gbrmpa.gov.au/learn/threats/sea-temperature">water temperatures</a> were significantly above the long-term average. While this is good news, it’s largely luck. The reef experienced mass bleaching in 2020 and 2022, but temperatures cooled just in time to prevent extensive coral deaths. </p>
<p>But the reef’s luck may be about to run out. Hotter El Niño conditions are returning to the Pacific, driving <a href="https://coralreefwatch.noaa.gov/data_current/5km/v3.1_op/daily/png/ct5km_baa-max-7d_v3.1_nwcl_current.png">warmer ocean temperatures</a>. The past few months have seen global temperature records smashed. Already, reefs in Florida, the Caribbean and parts of the Pacific are bleaching. The looming southern summer is a significant concern. </p>
<p>Can anything be done? Keeping emissions under control is obviously vital. But we can also support the Great Barrier Reef’s resilience by speeding up natural adaptation processes. </p>
<p>In our paper <a href="https://doi.org/10.1126/science.adi3023">published today</a> in Science, we describe methods of accelerating the natural evolution of heat-tolerant corals, next-generation aquaculture to rear large numbers of baby corals, and collaborative decision-making with First Nations groups to place these corals onto the Great Barrier Reef at meaningful scale.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/542086/original/file-20230810-23-ax7kkt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="national sea simulator corals" src="https://images.theconversation.com/files/542086/original/file-20230810-23-ax7kkt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/542086/original/file-20230810-23-ax7kkt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/542086/original/file-20230810-23-ax7kkt.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/542086/original/file-20230810-23-ax7kkt.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/542086/original/file-20230810-23-ax7kkt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/542086/original/file-20230810-23-ax7kkt.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/542086/original/file-20230810-23-ax7kkt.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A scientist examines baby coral at our National Sea Simulator, where we research heat tolerant corals and large scale coral aquaculture.</span>
<span class="attribution"><span class="source">AIMS</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<h2>How to breed heat-tolerant coral</h2>
<p>Corals are very different in how they tolerate heat. Some can put up with hot water for longer, whereas others bleach at lower temperatures. </p>
<p>Globally, bleaching thresholds have increased by 0.5°C in a decade. That is, reefs are actually becoming more tolerant of heat. This is likely because more sensitive species and colonies have died off or become less abundant. </p>
<p>Within species, we know individual corals in warmer waters are typically more tolerant than those in cooler waters. </p>
<p>Understanding why some corals have better heat tolerance, and how these attributes can be passed on, means we can figure out which corals are best placed to adapt. Then we can start selectively breeding them.</p>
<p>Coral reefs support a huge diversity of lifeforms, from fish to shrimp to rays and sharks. But on a tiny scale, coral polyps have their own microbial ecosystems, ranging from symbiotic algae which give coral its colour – and much of its food, from photosynthesis – through to the rest of the <a href="https://www.barrierreef.org/news/explainers/coral-microbiome">coral microbiome</a>. </p>
<p>To breed coral better able to adapt to the heat, we have to understand how their microbiome works. One group of symbiotic algae (<em>Durusdinium</em>) living inside coral can actually give their host the gift of increased heat tolerance, though often at the cost of reduced growth. </p>
<p>But if we assist the evolution of other coral-associated algae (<em>Cladocopium</em>), we find heat tolerance of both coral and algae improves, usually without compromising other survival traits. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/542088/original/file-20230810-29-ellk87.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="coral scientist" src="https://images.theconversation.com/files/542088/original/file-20230810-29-ellk87.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/542088/original/file-20230810-29-ellk87.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/542088/original/file-20230810-29-ellk87.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/542088/original/file-20230810-29-ellk87.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/542088/original/file-20230810-29-ellk87.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/542088/original/file-20230810-29-ellk87.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/542088/original/file-20230810-29-ellk87.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">An AIMS coral scientist examining young coral on a seeding device.</span>
<span class="attribution"><span class="source">T.Whitman/AIMS</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>This means we can inoculate the offspring of selectively bred corals with these algae to achieve greater heat tolerance. These methods have now been tested in the laboratory and should scale for mass production.</p>
<p>By interbreeding wild colonies of the same species of coral, we’ve found heat tolerance can be passed to the next generation. </p>
<p>Our researchers are developing tools to pick out these naturally more resilient individuals, during bleaching events or with rapid heat stress experiments. We are also analysing corals’ DNA to identify genetic markers.</p>
<p>Then we measure how heat tolerance and genetic diversity is maintained in the aquaculture facility and back in field conditions. </p>
<p>So while assisted evolution is still very new, our results are encouraging. There is real potential to increase coral heat tolerance to improve survival in hotter seas.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/542077/original/file-20230810-28-7n4kt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="coral spawning" src="https://images.theconversation.com/files/542077/original/file-20230810-28-7n4kt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/542077/original/file-20230810-28-7n4kt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=402&fit=crop&dpr=1 600w, https://images.theconversation.com/files/542077/original/file-20230810-28-7n4kt.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=402&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/542077/original/file-20230810-28-7n4kt.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=402&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/542077/original/file-20230810-28-7n4kt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=505&fit=crop&dpr=1 754w, https://images.theconversation.com/files/542077/original/file-20230810-28-7n4kt.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=505&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/542077/original/file-20230810-28-7n4kt.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=505&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Coral spawning is an event on the reef. Can selective breeding of coral keep them healthy?</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>Accelerate aquaculture to achieve scale</h2>
<p>This year’s marine heatwaves are breaking records. To boost our chances of preserving the Great Barrier Reef, we’ll need to be able to scale up these techniques. </p>
<p>To date, coral restoration and adaptation has been done at relatively small scale and high cost. Coral breeding has largely been done by hand, in small laboratory aquarium facilities, which is slow and expensive. </p>
<p>But this is changing. At our site in Townsville, we’ve made advances in coral aquaculture with the potential to significantly boost production rates while cutting costs. </p>
<p>How do you produce heat-tolerant corals at scale? Settle selected baby corals on small tabs in modular sheets. Separate the individual tabs, each now home to a thriving baby coral, and attach them to special fist-sized structures designed to protect the babies in the ocean. This greatly increases their survival rate once on the reef. </p>
<p>We’re trialling these technologies by depositing these structures in carefully chosen places along the reef where they can grow and, eventually, reproduce. As we scale up production, we will be able to deliver large numbers of structures without requiring divers, by using boats or robots. </p>
<p>These technologies mean we can increasingly automate coral rearing. At present, these techniques are available for around 50 coral species on the Great Barrier Reef. </p>
<p>Making sure human systems work well is also vital. To ensure heat-resistant baby coral thrive, we have to have good ecological models and decision-making processes which take economic, social, and environmental factors into account. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/542087/original/file-20230810-19-i6hwim.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Woppaburra Traditional Custodians" src="https://images.theconversation.com/files/542087/original/file-20230810-19-i6hwim.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/542087/original/file-20230810-19-i6hwim.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/542087/original/file-20230810-19-i6hwim.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/542087/original/file-20230810-19-i6hwim.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/542087/original/file-20230810-19-i6hwim.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/542087/original/file-20230810-19-i6hwim.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/542087/original/file-20230810-19-i6hwim.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Science and traditional knowledge can complement each other.</span>
<span class="attribution"><span class="source">AIMS</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>Success will also depend on meaningful partnerships with Traditional Owners. Combining conventional science and traditional knowledge can bring fresh insights. Marine management of Groote Eylandt in Australia’s north now uses <a href="https://www.frontiersin.org/articles/10.3389/fmars.2020.00716/full">maps produced</a> by scientists working with Anindilyakwa people to combine local knowledge, in-water surveys and satellite data. </p>
<p>As we move towards large-scale restoration and adaptation, Australia’s First Nations rangers could provide a vital community-based workforce to deliver a new suite of management and conservation activities, especially in remote regions. Traditional Owners could also play important roles in <a href="https://www.science.org/doi/10.1126/science.1232310#:%7E:text=Coral%20reef%20recovery%20from%20major,highly%20vulnerable%20to%20catastrophic%20disturbance.">monitoring progress</a>. </p>
<p>Until recently, conservation efforts were aimed at protecting ecosystems from damage and limiting access, allowing natural systems to bounce back. But in the era of global heating, this is no longer enough. Disruptions are coming faster, challenging nature’s resilience. </p>
<p>We have to help. Time is short and there is much to do.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/is-the-great-barrier-reef-reviving-or-dying-heres-whats-happening-beyond-the-headlines-210558">Is the Great Barrier Reef reviving – or dying? Here's what's happening beyond the headlines</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/209388/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Line K Bay receives research funding from the Reef Restoration and Adaptation Program, the Paul G Allen Family Foundation, BHP and Revive & Restore</span></em></p><p class="fine-print"><em><span>Paul Hardisty does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>We used to focus just on protection of vital ecosystems like the reef. But as climate change and other threats accelerate, we need to actively help nature get ready for the heat.Paul Hardisty, CEO, Australian Institute of Marine ScienceLine K Bay, Research Program Director, Australian Institute of Marine ScienceLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2103722023-07-27T01:28:14Z2023-07-27T01:28:14ZThrough the magnifying glass: how cutting-edge technology is helping scientists understand baby corals<p>New photographic technology has allowed scientists to dive beneath the ocean’s surface and peer into the hidden world of baby corals, to learn how these tiny organisms survive and grow in their crucial first year of life.</p>
<p>In a study <a href="https://besjournals.onlinelibrary.wiley.com/doi/abs/10.1111/2041-210X.14175">just published</a>, researchers from Southern Cross University and CSIRO describe how advanced imaging techniques offer new ways to monitor baby corals. </p>
<p>Corals provide vital habitat for a large variety of marine life. So it’s useful to better understand how baby corals select and attach to reefs, establish themselves and grow into adult corals.</p>
<p>This knowledge is particularly important if we want to help reefs recover from devastating events such as mass bleaching and cyclones.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/539177/original/file-20230725-23-wrtgjj.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/539177/original/file-20230725-23-wrtgjj.gif?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=439&fit=crop&dpr=1 600w, https://images.theconversation.com/files/539177/original/file-20230725-23-wrtgjj.gif?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=439&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/539177/original/file-20230725-23-wrtgjj.gif?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=439&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/539177/original/file-20230725-23-wrtgjj.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=552&fit=crop&dpr=1 754w, https://images.theconversation.com/files/539177/original/file-20230725-23-wrtgjj.gif?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=552&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/539177/original/file-20230725-23-wrtgjj.gif?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=552&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">3D animation of a 6-month old coral recruit approximately 2.1 mm in size.</span>
</figcaption>
</figure>
<h2>The secret life of corals</h2>
<p>The life of a coral begins in an annual, synchronised spawning event. Coral colonies release millions of tiny eggs and sperm into the water at the same time. They all rise to the surface where the eggs are fertilised, developing into embryos and then later, into larvae.</p>
<p>Over days or weeks, the millions of larvae disperse with ocean currents. If things go according to nature’s plan, the larvae eventually fall through the water, attach to a reef and grow into adult corals. This process is known as coral “recruitment”.</p>
<p>In healthy coral reefs, this recruitment occurs naturally. But as coral reefs become more degraded – such as through coral bleaching brought on by climate change – <a href="https://www.nature.com/articles/s41586-019-1081-y">fewer coral larvae are produced</a>. This often means recruitment slows down or stops, and natural recovery weakens.</p>
<p>Scientists are working on ways to ensure coral larvae attach to and grow on reefs. This includes collecting coral spawn from the ocean, rearing embryos in floating nurseries and <a href="https://www.nature.com/articles/s41598-017-14546-y">releasing larvae onto damaged reefs</a>.</p>
<p>Coral larvae are less than one millimetre in size, so recruitment occurs on a tiny scale, invisible to the human eye. To better understand the process, researchers traditionally <a href="https://doi.org/10.1007/s003380000081">attach artificial plates</a> to the reef. Once corals have established themselves, the plates are taken back to the lab to be inspected under a microscope.</p>
<p>This method can provide valuable insights, but it does not replicate the natural reef environment. That’s where our research comes in. Essentially, we brought the lab to the reef.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/safe-havens-for-coral-reefs-will-be-almost-non-existent-at-1-5-c-of-global-warming-new-study-176084">Safe havens for coral reefs will be almost non-existent at 1.5°C of global warming – new study</a>
</strong>
</em>
</p>
<hr>
<figure class="align-center ">
<img alt="bleached coral reef" src="https://images.theconversation.com/files/539452/original/file-20230726-23-png2p0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/539452/original/file-20230726-23-png2p0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/539452/original/file-20230726-23-png2p0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/539452/original/file-20230726-23-png2p0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/539452/original/file-20230726-23-png2p0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/539452/original/file-20230726-23-png2p0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/539452/original/file-20230726-23-png2p0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Mass bleaching and other damaging events is limiting the establishment of baby corals.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>Capturing the reef in incredible 3D detail</h2>
<p>Our new study explores the development and application of an innovative imaging approach known as underwater “macrophotogrammetry”.</p>
<p>The technology combines <a href="https://www.uwphotographyguide.com/macro-underwater-photography">macrophotography</a> – photographing small objects close-up, at very high resolution – and <a href="https://www.sciencedirect.com/science/article/pii/S0169534721001944?via%3Dihub">photogrammetry</a> – taking measurements from photos. In this case, we used photogrammetry to “stitch” photos together to recreate three-dimensional models, such as the one below.</p>
<p>The three round objects in the model are “targets” we placed to help the software stitch the photos together. Look closely, and you’ll see a nail head to the left of each target. To give you an idea of the scale of the model, the nail head is 2.8mm in diameter.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/539176/original/file-20230725-25-r3sdrj.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/539176/original/file-20230725-25-r3sdrj.gif?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=337&fit=crop&dpr=1 600w, https://images.theconversation.com/files/539176/original/file-20230725-25-r3sdrj.gif?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=337&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/539176/original/file-20230725-25-r3sdrj.gif?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=337&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/539176/original/file-20230725-25-r3sdrj.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/539176/original/file-20230725-25-r3sdrj.gif?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/539176/original/file-20230725-25-r3sdrj.gif?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A 3D animation of approximately 400 cm² of the reef at micrometre resolution.</span>
</figcaption>
</figure>
<p>Reef-scale photogrammetry can be a <a href="https://doi.org/10.1016/j.tree.2021.07.004">valuable tool</a> to track changes in coral cover and growth over time. However, it does not provide the detailed resolution needed to identify and observe tiny new corals. </p>
<p>Macrophotography provides this incredibly detailed scale. The coupling of the technologies also enables a comprehensive understanding of the entire ecosystem, from the smallest processes to the largest.</p>
<p>We conducted macrophotogrammetry surveys near Lizard Island on the Great Barrier Reef. We marked several 25cm x 25cm locations on the reef. We then captured hundreds of photographs taken at different angles using high-resolution cameras. </p>
<p>Photogrammetry software was used to process the photos, creating precise 3D models that represent the small sections of reef at very high resolution.</p>
<p>The models were examined to find where baby corals settle, to mark their location and measure their size. They reveal the complexity in the reef micro-structure, including tiny crevices, where coral larvae <a href="https://esajournals.onlinelibrary.wiley.com/doi/10.1890/15-0668.1">often settle</a>. </p>
<p>The models also reveal diverse micro-organisms such as small turf algae or invertebrates, <a href="https://www.nature.com/articles/s41598-020-59111-2">which interact with corals</a> during the recruitment process.</p>
<p>Macrophotogrammetry surveys can be conducted at the same reef locations over time. This allows us to monitor the survival and growth of baby corals, and observe changes in the organisms living near them. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/record-coral-cover-doesnt-necessarily-mean-the-great-barrier-reef-is-in-good-health-despite-what-you-may-have-heard-188233">Record coral cover doesn't necessarily mean the Great Barrier Reef is in good health (despite what you may have heard)</a>
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</em>
</p>
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<figure class="align-center ">
<img alt="two divers in shallow water" src="https://images.theconversation.com/files/539170/original/file-20230725-27-j2f1td.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/539170/original/file-20230725-27-j2f1td.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/539170/original/file-20230725-27-j2f1td.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/539170/original/file-20230725-27-j2f1td.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/539170/original/file-20230725-27-j2f1td.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/539170/original/file-20230725-27-j2f1td.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/539170/original/file-20230725-27-j2f1td.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The researchers monitor coral recruitment on a reef slope at Lizard Island.</span>
<span class="attribution"><span class="source">Lauren Hardiman CSIRO</span></span>
</figcaption>
</figure>
<h2>Looking ahead</h2>
<p>Complementary techniques may increase the potential of macrophotogrammetry even further. For example, coral larvae can be <a href="https://doi.org/10.1371/journal.pbio.3001907">dyed various colours</a> before release, making them more visible when they swim to and settle on the reef. This could be captured in 3D models to allow even better tracking of larval restoration efforts.</p>
<p>The use of macrophotogrammetry will deepen our understandings of why some larvae settle and survive on reefs, and others do not. This knowledge can help support our efforts to improve the overall conservation and recovery of coral reefs. </p>
<p>Its application need not be limited to coral reef ecosystems. We are excited about the potential of the technology to drive marine research more broadly.</p>
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<em>
<strong>
Read more:
<a href="https://theconversation.com/thousands-of-photos-captured-by-everyday-australians-reveal-the-secrets-of-our-marine-life-as-oceans-warm-189231">Thousands of photos captured by everyday Australians reveal the secrets of our marine life as oceans warm</a>
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</em>
</p>
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<img src="https://counter.theconversation.com/content/210372/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Marine Gouezo works as a Postdoctoral researcher at Southern Cross University and CSIRO and is involved with the Moving Corals subprogram of the Reef Restoration and Adaptation Program, funded by the partnership between the Australian Government's Reef Trust and the Great Barrier Reef Foundation</span></em></p><p class="fine-print"><em><span>Christopher Doropoulos is a Research Scientist at CSIRO. He co-leads the Moving Corals and EcoRRAP Subprograms as part of the Reef Restoration and Adaptation Program (RRAP). RRAP is funded by the partnership between the Australian Government’s Reef Trust and the Great Barrier Reef Foundation.</span></em></p>This knowledge is particularly important if we want to help reefs recover devastating events such as mass bleaching and cyclones.Marine Gouezo, Postdoctoral research fellow, Southern Cross UniversityChristopher Doropoulos, Senior research scientist, CSIROLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2017782023-03-27T19:01:49Z2023-03-27T19:01:49Z2022 was a good year for nature in Australia – but three nasty problems remain<figure><img src="https://images.theconversation.com/files/517575/original/file-20230327-16-flxve.jpg?ixlib=rb-1.1.0&rect=6%2C0%2C4594%2C3456&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock </span></span></figcaption></figure><p>A new <a href="https://www.ausenv.online">report card</a> on Australia’s environment reveals 2022 was a bumper year for our rivers and vegetation – but it wasn’t enough to reverse the long-term decline in plant and animal species.</p>
<p>The analysis was drawn from many millions of measurements of weather, biodiversity, water availability, river flows and the condition of soil and vegetation. The data is gathered from satellites and field stations and processed by a supercomputer. </p>
<p>From the data, we calculate a score between 0 and 10 to determine the overall condition of Australia’s environment. </p>
<p>In 2022, a third and very wet La Niña year brought a strong improvement in several key indicators, leading to a national score of 8.7 out of 10. This is the best score since 2011. But unfortunately, three wicked problems remain.</p>
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<img alt="scientist kneels in water and takes observation" src="https://images.theconversation.com/files/517574/original/file-20230327-14-t3yn8b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/517574/original/file-20230327-14-t3yn8b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/517574/original/file-20230327-14-t3yn8b.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/517574/original/file-20230327-14-t3yn8b.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/517574/original/file-20230327-14-t3yn8b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/517574/original/file-20230327-14-t3yn8b.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/517574/original/file-20230327-14-t3yn8b.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">A vast number of datasets are combined to generate the environmental scorecard.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
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</figure>
<h2>First, the good news</h2>
<p>By some measures, 2022 was the best year for water availability and plant growth since our national score system began 23 years ago. </p>
<p>New South Wales, Victoria and the ACT enjoyed the highest environmental scores since before 2000. South Australia and Queensland also improved.</p>
<p>Scores for rainfall, river flows and the extent of floodplain inundation were the highest since before 2000 in many parts of eastern Australia. The water supplies of all eastern capital cities all rose and several reached capacity. </p>
<p>Wetland area and waterbird breeding were well above the long-term average. Vegetation density, growth rates and tree cover in NSW and Queensland were the best since before 2000.</p>
<p>It was a bumper year for dryland farmers. Average national growth rates in dryland cropping were a massive 49% better than average conditions. The many full or filling reservoirs are also good news for irrigators.</p>
<h2>What about the losers?</h2>
<p>Some regions missed out on the rainfall bonanza, and many environmental indicators declined. They include the Top End in the Northern Territory, southern inland Western Australia and western Tasmania. </p>
<p>Across the NT, low rainfall and high temperatures meant environmental scores once more declined to the low values seen before 2021. </p>
<p>And in areas where rainfall was high, not everyone benefited. Many homes and businesses flooded, and some farmers lost crops or stock.</p>
<p>At the end of 2022, <a href="https://www.theguardian.com/australia-news/2023/jan/01/river-murray-fish-kill-concerns-grow-as-flood-waters-peak-in-south-australia">reports emerged</a> that floodwaters were causing so-called “blackwater events” and fish kills in the Murray River. Murky floodwaters also ran into the ocean and smothered seagrass meadows, leading <a href="https://theconversation.com/dugongs-and-turtles-are-starving-to-death-in-queensland-seas-and-la-ninas-floods-are-to-blame-190663">dugongs and sea turtles</a> to starve.</p>
<p>The ocean around Australia was the warmest on record in 2022. The Great Barrier Reef suffered the <a href="https://www.aims.gov.au/research-topics/environmental-issues/coral-bleaching/coral-bleaching-events">fourth mass bleaching</a> event in seven years – and alarmingly, the first to occur during a La Niña year, which is usually cooler. </p>
<p>Fortunately, conditions for the remainder of the year favoured coral recovery. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/new-report-shows-alarming-changes-in-the-entire-global-water-cycle-197535">New report shows alarming changes in the entire global water cycle</a>
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<img alt="flood-damaged doll and other items with house in background" src="https://images.theconversation.com/files/517588/original/file-20230327-14-49f0b0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/517588/original/file-20230327-14-49f0b0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/517588/original/file-20230327-14-49f0b0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/517588/original/file-20230327-14-49f0b0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/517588/original/file-20230327-14-49f0b0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/517588/original/file-20230327-14-49f0b0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/517588/original/file-20230327-14-49f0b0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Floodwaters severely damaged homes and businesses last year.</span>
<span class="attribution"><span class="source">Darren England/AAP</span></span>
</figcaption>
</figure>
<h2>Chronic ailments</h2>
<p>Despite many positive indicators, three severe, chronic and untreated problems continue to weaken our environment: habitat destruction, invasive species and climate change.</p>
<p>The rate of habitat destruction shows little sign of improvement. Much vegetation continues to be removed for new housing, mining and agriculture. Fire activity in 2022 was low, but climate change means bushfires will be back soon, and become more frequent and severe over time. </p>
<p>La Niña is already on the way out, although it will probably take more than one hot and dry year before we experience <a href="https://theconversation.com/a-major-scorecard-gives-the-health-of-australias-environment-less-than-1-out-of-10-133444">megafires</a> such as those in the Black Summer of 2019-20.</p>
<p>The scorecard also shows Australia is still struggling to combat pest species. They include fungi, invasive weeds, carp, cane toads, rats, rabbits, goats, pigs, foxes and cats. Every year, about eight million feral cats and foxes <a href="https://theconversation.com/1-7-million-foxes-300-million-native-animals-killed-every-year-now-we-know-the-damage-foxes-wreak-177832">kill</a> 1.5 billion native reptiles, birds and mammals. </p>
<p>Climate change remains a huge problem. La Niña normally brings cool conditions and the average temperature last year in Australia was the coolest since 2012. But it was still relatively warm, at 0.5°C above the long-term average. </p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/fear-and-wonder-podcast-how-scientists-know-the-climate-is-changing-202237">Fear and Wonder podcast: how scientists know the climate is changing</a>
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<p>The combination of habitat destruction, invasive species and climate change has already decimated many Australian species. In 2022, 30 plants and animals were added to the official list of threatened species. </p>
<p>That’s a 43% increase since 2000, bringing the total number to 1,973. Most species added last year were affected by the Black Summer fires.</p>
<p>Our analysis drew on the <a href="https://tsx.org.au">Threatened Species Index</a>, which reports with a three-year time lag. In 2019 the index showed a steady decline of about 3% in the abundance of threatened species each year. This is an overall decline of 62% since 2000. </p>
<p>Threatened plants showed the worst decline (72%), followed by birds (62%) and mammals (33%).</p>
<h2>We can avoid the worst</h2>
<p>Amid the gloom, there are glimmers of hope. Many species feared impacted by the fires proved resilient. Some large new national park areas have been added. Active management is recovering – or at least slowing – the decline of some threatened species, albeit sometimes within the narrow confines of reserves.</p>
<p>Also in 2022, humpback whales were one of the few species in Australian history to be taken off the threatened species list due to a population increase. The species has staged a remarkable recovery since the global moratorium on whaling. </p>
<p>Sadly, there is no fast solution to climate change. Greenhouse gases will linger in the atmosphere for decades to come and further warming is unavoidable. But we can still prevent worse outcomes, by dramatically curbing global emissions.</p>
<p>Australia’s emissions are not falling anywhere near fast enough. They were almost the same in 2022 as in the previous year. And our national emissions remain among the <a href="https://www.sbs.com.au/news/article/interactive-how-australia-compares-to-the-rest-of-the-world-on-co2-emissions/7oooxwnnm">highest</a> in the world per person.</p>
<p>Decisive action is needed. Slowing down habitat destruction, invasive species and climate change is key to preserving our natural resources and species for future generations. </p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/we-found-29-threatened-species-are-back-from-the-brink-in-australia-heres-how-200057">We found 29 threatened species are back from the brink in Australia. Here's how</a>
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</p>
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<img src="https://counter.theconversation.com/content/201778/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Australia’s Environment is produced by the ANU Fenner School for Environment & Society and the Terrestrial Ecosystem Research Network (TERN), an NCRIS-enabled National Research Infrastructure. Albert Van Dijk receives or has previously received funding from several government-funded agencies, grant schemes and programmes.</span></em></p><p class="fine-print"><em><span>Geoff Heard is a current employee of the Terrestrial Ecosystem Research Network (TERN), funded by the National Collaborative Research Infrastructure Strategy. Geoff has previously received funding from several government agencies in Australia for the study and monitoring of threatened species.</span></em></p><p class="fine-print"><em><span>Mark Grant is a current employee of the Terrestrial Ecosystem Research Network (TERN).</span></em></p><p class="fine-print"><em><span>Shoshana Rapley does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Last year was great for plant growth and river flows. But Australia is still on the brink of losing a slew of plant and animal species.Albert Van Dijk, Professor, Water and Landscape Dynamics, Fenner School of Environment & Society, Australian National UniversityGeoffrey Heard, The University of QueenslandMark Grant, Ecosystem Science Programs Lead, Terrestrial Ecosystem Research Network, The University of QueenslandShoshana Rapley, Research assistant, Australian National UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1964702023-02-07T13:34:48Z2023-02-07T13:34:48ZHurricane Harvey more than doubled the acidity of Texas’ Galveston Bay, threatening oyster reefs<figure><img src="https://images.theconversation.com/files/507440/original/file-20230131-4643-5mjeyj.jpg?ixlib=rb-1.1.0&rect=48%2C0%2C5400%2C3564&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Seabirds forage on an oyster shell island on the Texas Gulf Coast.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/an-american-oystercatcher-haematopus-palliatus-foraging-on-news-photo/1449679985">Jon G. Fuller/VW Pics/ Universal Images Group via Getty Images</a></span></figcaption></figure><p>Most people associate hurricanes with high winds, intense rain and rapid flooding on land. But these storms can also change the chemistry of coastal waters. Such shifts are less visible than damage on land, but they can have dire consequences for marine life and coastal ocean ecosystems. </p>
<p>We are oceanographers who study the <a href="https://scholar.google.com/citations?user=u7D6sQgAAAAJ&hl=en">effects of ocean acidification</a>, including on <a href="https://scholar.google.com/citations?user=MOYxO9MAAAAJ&hl=en">organisms like oysters and corals</a>. In a <a href="https://doi.org/10.1038/s43247-022-00608-1">recent study</a>, we examined how stormwater runoff from Hurricane Harvey in 2017 affected the water chemistry of Galveston Bay and the health of the bay’s oyster reefs. We wanted to understand how extreme rainfall and runoff from hurricanes influenced acidification of bay waters, and how long these changes could last. </p>
<p>Our findings were startling. Hurricane Harvey, which generated massive rainfall in the Houston metropolitan area, delivered a huge pulse of fresh water into Galveston Bay. As a result, the bay was two to four times more acidic than normal for at least three weeks after the storm.</p>
<p>This made bay water corrosive enough to damage oyster shells in the estuary. Because oyster growth and recovery rely on many factors, it is hard to tie specific changes to acidification. However, increased acidification certainly would have made it harder for oyster reefs damaged by Hurricane Harvey to recover. And while our study focused on Galveston Bay, we suspect that similar processes may be occurring in other coastal areas.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/507436/original/file-20230131-5037-8ovozq.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Satellite photo of Houston and the gulf coast immediately after Harvey." src="https://images.theconversation.com/files/507436/original/file-20230131-5037-8ovozq.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/507436/original/file-20230131-5037-8ovozq.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/507436/original/file-20230131-5037-8ovozq.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/507436/original/file-20230131-5037-8ovozq.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/507436/original/file-20230131-5037-8ovozq.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/507436/original/file-20230131-5037-8ovozq.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/507436/original/file-20230131-5037-8ovozq.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">This satellite image, taken six days after Harvey made landfall, shows Galveston Bay and other rivers and bays around Houston filled with brown sediment-laden floodwaters.</span>
<span class="attribution"><a class="source" href="https://earthobservatory.nasa.gov/images/90866/texas-waters-run-brown-after-harvey">NASA Earth Observatory</a></span>
</figcaption>
</figure>
<h2>Vast quantities of water</h2>
<p>Scientists predict that climate change will make hurricanes stronger and <a href="https://climate.nasa.gov/news/3184/a-force-of-nature-hurricanes-in-a-changing-climate/">increase the amount of rain they produce</a> over the next several decades. Changes in ocean chemistry, caused by runoff from these storms, are becoming an increasing threat to many marine ecosystems, especially coastal reefs built by oysters and corals. </p>
<p><a href="https://oceanservice.noaa.gov/facts/estuary.html">Coastal estuaries</a> like Galveston Bay, where rivers meet the sea, are some of the most productive ecosystems in the world. Galveston Bay is the largest bay on the Texas coast and one of the largest in the U.S.; it covers about 600 square miles, roughly half the size of Rhode Island. Its extensive oyster reefs provide <a href="https://doi.org/10.1016/j.scitotenv.2021.145132">about 9% of the national oyster harvest</a>. </p>
<p><a href="https://www.climate.gov/news-features/event-tracker/reviewing-hurricane-harveys-catastrophic-rain-and-flooding">Hurricane Harvey</a>, the wettest tropical cyclone in U.S. history, made landfall on the Texas coast as a Category 4 hurricane on Aug. 26, 2017. Harvey stalled at the coast for four days, sitting over both land and ocean. </p>
<p>Maintaining contact with warm Gulf of Mexico waters fueled the storm with both energy and rainfall, allowing it to persist and drop extreme amounts of rain directly onto Houston and surrounding areas – <a href="https://theconversation.com/what-made-the-rain-in-hurricane-harvey-so-extreme-83137">up to 50 inches in four days</a>. All of that rain and floodwater had to go somewhere, and much of it flowed into Galveston Bay. </p>
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<iframe width="440" height="260" src="https://www.youtube.com/embed/YzQGgyrxXiI?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">These videos show the scale of flooding across Houston from Hurricane Harvey.</span></figcaption>
</figure>
<h2>Climate change and ocean acidification</h2>
<p>The ocean acidification issues that we study are a <a href="https://theconversation.com/global-warmings-evil-twin-ocean-acidification-19017">well-known effect related to climate change</a>. Human activities, mainly burning fossil fuel, emit carbon dioxide into the atmosphere. The ocean absorbs about one-third of these emissions, which alters ocean chemistry, making seawater more acidic. </p>
<p>Acidification can <a href="https://www.epa.gov/ocean-acidification/effects-ocean-and-coastal-acidification-marine-life">harm many forms of marine life</a>. It is especially dangerous for animals that build their shells and skeletons out of calcium carbonate, such as oysters and corals. As seawater becomes more acidic, it makes these structures harder to build and easier to erode. </p>
<p>Oysters fuse together as they grow, creating large rocklike underwater reefs that <a href="https://www.youtube.com/watch?v=PbFQ5EndLso">protect shorelines from wave erosion</a>. These reefs <a href="https://www.fisheries.noaa.gov/national/habitat-conservation/oyster-reef-habitat">provide habitat</a> for other creatures, such as barnacles, anemones and mussels, which in turn serve as food sources for many fish species. </p>
<p>Rising atmospheric CO₂ levels are acidifying oceans worldwide. As our study shows, local events like tropical cyclones can add to global acidification. </p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"661924520496922624"}"></div></p>
<h2>Stormwater from Harvey caused extreme coastal acidification</h2>
<p>The main cause of the unprecedented acidification that occurred after Hurricane Harvey was the excessive amount of rainfall and runoff that entered Galveston Bay. To help manage large-scale flooding in the Houston area, the city released large volumes of water from reservoirs for more than two months after Harvey. These releases extended the time during which stormwater entered Galveston Bay and increased its acidity. </p>
<p>Scientists use the pH scale to measure how acidic or basic (alkaline) water is. A pH value of 7 is neutral; higher values are basic, and lower values are acidic. The pH scale is logarithmic, so a decrease of one full unit – say, from 8 to 7 – represents a tenfold increase in acidity. </p>
<p>Rainwater is more acidic than either river water or seawater, which pick up minerals from soil that are slightly basic and can balance out absorbed carbon dioxide from the atmosphere. Rainwater’s pH is around 5.6, compared with <a href="https://datastream.org/en/guide/ph">between 6.5 and 8.2 for rivers</a> and <a href="https://www.noaa.gov/education/resource-collections/ocean-coasts/ocean-acidification">about 8.1 for seawater</a>. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/508452/original/file-20230206-25-fdap84.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Th pH scale with values for common substances." src="https://images.theconversation.com/files/508452/original/file-20230206-25-fdap84.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/508452/original/file-20230206-25-fdap84.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=240&fit=crop&dpr=1 600w, https://images.theconversation.com/files/508452/original/file-20230206-25-fdap84.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=240&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/508452/original/file-20230206-25-fdap84.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=240&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/508452/original/file-20230206-25-fdap84.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=302&fit=crop&dpr=1 754w, https://images.theconversation.com/files/508452/original/file-20230206-25-fdap84.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=302&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/508452/original/file-20230206-25-fdap84.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=302&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The pH scale shows how acidic or basic substances are.</span>
<span class="attribution"><a class="source" href="https://www.epa.gov/acidrain/what-acid-rain">USEPA</a></span>
</figcaption>
</figure>
<p>Galveston Bay contains a mix of fresh water from rivers and salty seawater from the Gulf of Mexico – oysters’ preferred habitat. We collected water samples in the bay two weeks after Harvey and found that the bay was made up almost entirely of river water and rainwater from the storm. </p>
<p>Since rainwater, river water and seawater all have different chemistries, we were able to calculate that rainwater made up almost 50% of the water in the bay. This means that acidic rainwater from Harvey replaced the basic seawater within the bay after the storm. The average bay water pH had dropped from 8 to 7.6, a 2.5-fold increase in acidity. Some zones had pH even as low as 7.4 – four times more acidic than normal. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/507432/original/file-20230131-24-p6tcnw.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Bar charts showing combinations of seawater, river water and rainwater in Galveston Bay before and after Hurricane Harvey." src="https://images.theconversation.com/files/507432/original/file-20230131-24-p6tcnw.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/507432/original/file-20230131-24-p6tcnw.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=466&fit=crop&dpr=1 600w, https://images.theconversation.com/files/507432/original/file-20230131-24-p6tcnw.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=466&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/507432/original/file-20230131-24-p6tcnw.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=466&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/507432/original/file-20230131-24-p6tcnw.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=586&fit=crop&dpr=1 754w, https://images.theconversation.com/files/507432/original/file-20230131-24-p6tcnw.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=586&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/507432/original/file-20230131-24-p6tcnw.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=586&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">These charts show how rainfall and runoff from Hurricane Harvey altered the composition of Galveston Bay after the storm made landfall on August 25, 2017.</span>
<span class="attribution"><a class="source" href="https://doi.org/10.1038/s43247-022-00608-1">Tacey Hicks, modified from Hicks et al., 2022</a>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>This extreme acidification lasted for more than three weeks. Bay waters became corrosive not only to more sensitive larval and juvenile oyster shells, but to adult oyster shells as well. <a href="https://doi.org/10.1002/jgrc.20378">Scientists had predicted</a> that increasing CO₂ could cause this scale of coastal acidification but did not expect to see it until around the year 2100. </p>
<p>The fresh water from Harvey also caused a <a href="https://doi.org/10.1016/j.scitotenv.2021.145132">severe oyster die-off</a> in the bay because oysters need slightly salty water to survive. Harvey struck in the middle of oyster spawning season, and acidification may have slowed reef recovery by making it harder for young oysters to form new shells. Officials at the <a href="https://tpwd.texas.gov/">Texas Parks and Wildlife Department</a> have told us that four years later, in late 2021, some Galveston Bay oyster reefs still showed <a href="https://doi.org/10.1038/s43247-022-00608-1">very low additions of new oysters</a>. </p>
<h2>Other coastal areas at risk</h2>
<p>Only a few studies, including ours, have analyzed how tropical cyclones affect coastal acidification. In our view, however, it is highly possible that other storms have caused the kind of extreme acidification that we detected in the wake of Harvey. </p>
<p>We reviewed the 10 wettest <a href="https://www.wpc.ncep.noaa.gov/tropical/rain/tcmaxima.html">tropical cyclones in the U.S. since 1900</a> and found that nine, including Harvey, caused large amounts of rain and flooding in coastal areas with bay or estuary ecosystems. Other storms didn’t produce as much rainfall as Harvey, but some of the affected bays were much smaller than Galveston Bay, so less rain would have been needed to replace seawater in the bay and cause a similar level of acidification to what Harvey produced.</p>
<p>We think that this likely has already occurred in other places struck by hurricanes but went unrecorded because scientists weren’t able to measure acidification before and after the storms. As climate change continues to make tropical cyclones larger and wetter, we see storm-induced acidification as a significant threat to coastal ecosystems.</p><img src="https://counter.theconversation.com/content/196470/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Tacey Hicks received funding from Texas Sea Grant to support the publication of this study. Tacey Hicks is currently affiliated with the National Oceanic and Atmospheric Administration and Texas Sea Grant as part of the John A Knauss Marine Policy Fellowship. </span></em></p><p class="fine-print"><em><span>Kathryn Shamberger receives funding from the National Science Foundation, US Department of Energy, and US Environmental Protection Agency.</span></em></p>Climate change is making oceans more acidic globally. Now, scientists are finding that large storms can send pulses of acidic water into bays and estuaries, further stressing fish and shellfish.Tacey Hicks, PhD Candidate in Oceanography, Texas A&M UniversityKathryn Shamberger, Associate Professor of Oceanography, Texas A&M UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1978412023-01-18T17:02:06Z2023-01-18T17:02:06ZDesalination could give the Middle East water without damaging marine life – but it must be managed carefully<figure><img src="https://images.theconversation.com/files/504863/original/file-20230117-20-8ur47l.jpg?ixlib=rb-1.1.0&rect=48%2C0%2C5400%2C3581&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A saltier Red Sea could threaten its marine life. </span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/two-free-divers-swimming-over-vivid-222885136">Dudarev Mikhail/Shutterstock</a></span></figcaption></figure><p>More than <a href="https://www.unwater.org/sites/default/files/app/uploads/2021/12/SDG-6-Summary-Progress-Update-2021_Version-July-2021a.pdf">2 billion people</a> live in <a href="https://www.unwater.org/water-facts/water-scarcity#:%7E:text=When%20a%20territory%20withdraws%2025%25%20or%20more%20of%20its%20renewable,UN%2DWater%202021">“water stressed”</a> countries. These are territories where more than 25% of the available freshwater resources are withdrawn for human use each year. </p>
<p>Desalination - the process of removing salt from seawater - is increasingly being used to tackle water scarcity worldwide. Roughly <a href="https://www.sciencedirect.com/science/article/abs/pii/S0048969718349167">16,000 desalination plants</a> now produce 35 trillion litres of freshwater annually. And Jordan, a country located north of the Red Sea, is <a href="https://jordantimes.com/news/local/water-ministry-launches-first-phase-aqaba-amman-water-conveyance-national-project">planning</a> a major desalination plant on the Gulf of Aqaba that will increase its desalination capacity from 4 billion to 350 billion litres each year. </p>
<p>But desalination tends to be energy intensive and produces saline wastewater called brine. On its return to the sea, brine can damage marine ecosystems. <a href="https://www.scientificamerican.com/article/desalination-breakthrough-saving-the-sea-from-salt/">Research</a> suggests that desalination may be making some water bodies, including the Red Sea, the Arabian Gulf and the Mediterranean, saltier.</p>
<p><a href="https://www.sciencedirect.com/science/article/pii/S0011916421005932">We analysed</a> whether current and future desalination plans present a threat to salinity levels in the Red Sea and the Gulf of Aqaba. For both water bodies, the increase in salinity will likely be undetectable and less than natural seasonal variations, in which case it would not harm marine life.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/desalination-may-be-key-to-averting-global-water-shortage-but-it-will-take-time-189169">Desalination may be key to averting global water shortage, but it will take time</a>
</strong>
</em>
</p>
<hr>
<h2>An important marine habitat</h2>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/504665/original/file-20230116-26-tgjeta.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A map of the region surrounding the Red Sea." src="https://images.theconversation.com/files/504665/original/file-20230116-26-tgjeta.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/504665/original/file-20230116-26-tgjeta.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=900&fit=crop&dpr=1 600w, https://images.theconversation.com/files/504665/original/file-20230116-26-tgjeta.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=900&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/504665/original/file-20230116-26-tgjeta.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=900&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/504665/original/file-20230116-26-tgjeta.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1131&fit=crop&dpr=1 754w, https://images.theconversation.com/files/504665/original/file-20230116-26-tgjeta.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1131&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/504665/original/file-20230116-26-tgjeta.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1131&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The Red Sea region.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-vector/red-sea-region-political-map-capitals-663310681">Peter Hermes Furian/Shutterstock</a></span>
</figcaption>
</figure>
<p>The Red Sea is connected to the Indian Ocean at its southern end via a narrow and shallow strait. The Gulf of Aqaba branches off its northern end and is connected to the Indian Ocean only through the Red Sea. </p>
<p>Neither water body has a freshwater inflow, so salinity levels are determined by evaporation and the inward and outward flow of water from the Indian Ocean. Water entering the Red Sea flows north where it evaporates and cools, raising its salinity and density. At the head of the Red Sea, this more saline water sinks and flows southwards as a deeper water layer back to the Indian Ocean. </p>
<p>Between where water enters the Red Sea and where salinity peaks at the northern end of the Gulf of Aqaba, salinity <a href="https://www.io-warnemuende.de/tl_files/forschung/meereswissenschaftliche-berichte/mebe50_2002_manasreh.pdf">rises naturally by 10%</a> from roughly 36.8 to 40.6 practical salinity units (psu). One psu is equivalent to 1g of salt dissolved in 1000g of water. Marine life in the region has adapted to the natural salinity level of their location. </p>
<p>Several <a href="https://whc.unesco.org/en/list/262">Unesco Natural Heritage Sites</a> are located in the northern Red Sea, including Sanganeb and Dungonab Bay and Mukkawar Island Marine National Parks. The national parks are home to coral reefs, seagrass beds, mudflats, mangroves and beaches. These habitats hold significant scientific and conservation value as they support a diverse range of marine species, including the endangered <a href="https://www.worldwildlife.org/species/dugong">dugong</a>. </p>
<p>Most marine species can tolerate minor variations in salinity, but they cannot withstand significant and sustained change. <a href="https://www.int-res.com/abstracts/meps/v181/p309-314/">Research</a> reveals that rates of photosynthesis and respiration in <em>Stylophora pistillata</em>, a species of Red Sea coral, falls by as much as 50% when salinity levels are raised from 38 psu to 40 psu. Most colonies of this coral will die if salinity is kept at this level for a sustained period. </p>
<figure class="align-center ">
<img alt="A male dugong swimming along the sea floor alongside small yellow fish." src="https://images.theconversation.com/files/504865/original/file-20230117-20-5a68sl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/504865/original/file-20230117-20-5a68sl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/504865/original/file-20230117-20-5a68sl.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/504865/original/file-20230117-20-5a68sl.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/504865/original/file-20230117-20-5a68sl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/504865/original/file-20230117-20-5a68sl.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/504865/original/file-20230117-20-5a68sl.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Sanganeb Marine National Park is home to the endangered dugong.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/rare-big-dugong-male-sea-cow-2195272247">Ivanenko Vladimir/Shutterstock</a></span>
</figcaption>
</figure>
<h2>Making the sea even saltier</h2>
<p>Our research used scenario analysis. This is where a number of plausible future scenarios are modelled and their consequences explored. </p>
<p>The most extreme scenario we developed involved high population growth, rapid economic development and falling desalination costs in the Middle East. Nearly 10 trillion litres of water could be desalinated on the Red Sea coast by 2050 and over 2.5 trillion litres along the Gulf of Aqaba in this case. </p>
<p>A less extreme scenario assumed limited population growth and restrained household water consumption. Nearly 2 trillion litres of water could be desalinated by the Red Sea and over 560 billion litres by the Gulf of Aqaba by 2050. </p>
<p>For both scenarios, salinity in the Red Sea increased by less than 0.1%. This increase would be less than the natural seasonal variation in salinity levels and would likely be undetectable. </p>
<p>The Gulf of Aqaba, however, is smaller and more isolated from the Indian Ocean. Salinity in the north of the Gulf therefore <a href="https://www.io-warnemuende.de/tl_files/forschung/meereswissenschaftliche-berichte/mebe50_2002_manasreh.pdf">varies naturally</a> between 40.2 psu and 40.75 psu. We found that the high growth scenario could increase salinity at the head of the Gulf by 0.5%, from approximately 40.6 psu to 40.8 psu. But even this increase is close to the maximum increase in salinity caused by natural variability. </p>
<p>The medium growth scenario would instead produce a change less than natural seasonal variation and would again be undetectable.</p>
<h2>Tackling water scarcity in the Middle East</h2>
<p>Our research suggests that, if carefully managed, rising rates of desalination may not harm the region’s marine ecosystems. This is particularly important as a considerable growth in desalination is likely to occur in the Middle East</p>
<p>Saudi Arabia plan to construct an entire new city in the country’s north west, called <a href="https://en.wikipedia.org/wiki/Neom">Neom</a>, to accommodate <a href="https://www.reuters.com/world/middle-east/saudi-crown-prince-says-zero-carbon-city-neom-will-likely-be-listed-2024-2022-07-25/">9 million people</a> and water intensive sectors like agriculture by 2045. The city will depend on water desalinated from the Red Sea and Gulf of Aqaba. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/0kz5vEqdaSc?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Neom will accomodate 9 million people by 2045.</span></figcaption>
</figure>
<p>Beyond the vicinity of each desalination plant, increased rates of desalination are unlikely to affect broader salinity levels in the region. But <a href="https://www.sciencedirect.com/science/article/pii/S0011916417307750">good plant design</a> and strict environmental regulations will remain critical to avoid environmental harm. </p>
<p>Plant outfalls, through which brine is channelled towards the sea, must ensure rapid dilution by dispersing brine into the Red Sea’s deeper water layer. Ocean currents can then carry the brine out to the Indian Ocean, where it will be further diluted. </p>
<p>Desalination will continue to grow worldwide. If carefully implemented it can be a crucial tool to tackle water scarcity without damaging fragile marine ecosystems.</p><img src="https://counter.theconversation.com/content/197841/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Jordan is planning a major desalination plant on the Gulf of Aqaba – but will it damage nearby marine ecosystems?Jonathan Chenoweth, Senior Lecturer of Environment and Sustainability, University of SurreyRaya A. Al-Masri, Researcher in Resources Governance and Sustainability, University of SurreyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1892312022-08-28T20:04:50Z2022-08-28T20:04:50ZThousands of photos captured by everyday Australians reveal the secrets of our marine life as oceans warm<figure><img src="https://images.theconversation.com/files/481238/original/file-20220826-8211-tauikk.jpg?ixlib=rb-1.1.0&rect=160%2C5%2C1459%2C818&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.redmap.org.au/sightings/3798/">Redmap/Jacob Bradbury</a></span></figcaption></figure><p>As the planet heats up, many marine plants and animals are <a href="https://theconversation.com/climate-driven-species-on-the-move-are-changing-almost-everything-74752">moving</a> locations to keep pace with their preferred temperatures. In the Southern Hemisphere, this means species are setting up home further south.</p>
<p>This shift alters what we see when we go snorkelling, and when and where we catch our seafood. Crucially, it also changes sensitive marine ecosystems. </p>
<p>But it’s not always easy for scientists to know exactly what’s happening below the ocean’s surface. To help tackle this, we examined tens of thousands of photographs taken by Australian fishers and divers submitted to citizen science programs over the last decade. </p>
<p>They revealed climate change is already disrupting the structure and function of our marine ecosystems – sometimes in ways previously unknown to marine scientists.</p>
<figure class="align-center ">
<img alt="man holds large silver fish" src="https://images.theconversation.com/files/481235/original/file-20220826-18-8j5rl4.jpg?ixlib=rb-1.1.0&rect=2%2C2%2C1914%2C1074&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/481235/original/file-20220826-18-8j5rl4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/481235/original/file-20220826-18-8j5rl4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/481235/original/file-20220826-18-8j5rl4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/481235/original/file-20220826-18-8j5rl4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/481235/original/file-20220826-18-8j5rl4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/481235/original/file-20220826-18-8j5rl4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The authors examined tens of thousands of photographs taken by Australian fishers and divers, such as this image of a bonefish found off Western Australia.</span>
<span class="attribution"><span class="source">Redmap</span></span>
</figcaption>
</figure>
<h2>Species on the move</h2>
<p>Warming over the Pacific Ocean has strengthened the East Australian Current over the past several decades, as the below-right animation shows. This has caused waters off Southeast Australia to warm at almost <a href="https://link.springer.com/article/10.1007/s11160-013-9326-6">four times</a> the global average. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/480969/original/file-20220824-14-i52yob.gif?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Animated map of sea surface temperatures in southeast Australia from 2004 to 2022" src="https://images.theconversation.com/files/480969/original/file-20220824-14-i52yob.gif?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/480969/original/file-20220824-14-i52yob.gif?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=337&fit=crop&dpr=1 600w, https://images.theconversation.com/files/480969/original/file-20220824-14-i52yob.gif?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=337&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/480969/original/file-20220824-14-i52yob.gif?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=337&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/480969/original/file-20220824-14-i52yob.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/480969/original/file-20220824-14-i52yob.gif?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/480969/original/file-20220824-14-i52yob.gif?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Animated map of sea surface temperatures in southeast Australia from 2004 to 2022. Data sourced from NASA.</span>
<span class="attribution"><span class="source">Barrett Wolfe</span></span>
</figcaption>
</figure>
<p>There is already irrefutable evidence <a href="https://www.science.org/doi/10.1126/science.aai9214">climate change</a> is causing marine species <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/gcb.15634">to move</a>. Understanding this phenomenon is crucial for conservation, fisheries management and human health. </p>
<p>For example, if fish susceptible to carrying <a href="https://www.redmap.org.au/news/2020/12/10/ciguatera-fish-poisoning/">toxins</a> start turning up where you go fishing, you’d want to know. And if an endangered species moves somewhere new, we need to know so we can protect it.</p>
<p>But the <a href="https://www.ga.gov.au/scientific-topics/marine/coasts-estuaries#:%7E:text=The%20Australian%20coastline%20extends%20approximately,includes%20more%20than%201000%20estuaries.">sheer scale</a> of the Australian coastline means scientists can’t monitor changes in all areas. That’s where the public can help. </p>
<p>Fishers, snorkelers and divers often routinely visit the same place over time. Many develop strong knowledge of species found in a given area. </p>
<p>When a new or unusual species appears in their patch, these members of the public can excel at detecting it. So our project set out to tap into this invaluable community knowledge.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/climate-driven-species-on-the-move-are-changing-almost-everything-74752">Climate-driven species on the move are changing (almost) everything</a>
</strong>
</em>
</p>
<hr>
<figure class="align-center ">
<img alt="large fish and smaller fish on blue marine background" src="https://images.theconversation.com/files/481221/original/file-20220826-8211-tw4ry1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/481221/original/file-20220826-8211-tw4ry1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/481221/original/file-20220826-8211-tw4ry1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/481221/original/file-20220826-8211-tw4ry1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/481221/original/file-20220826-8211-tw4ry1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/481221/original/file-20220826-8211-tw4ry1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/481221/original/file-20220826-8211-tw4ry1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">This sighting of a sea sweep – recorded in May this year off Kangaroo Island by a member of the public – may indicate the species is extending its range.</span>
<span class="attribution"><span class="source">Redmap/Daniel Easton</span></span>
</figcaption>
</figure>
<h2>The value of citizen science</h2>
<p>The <a href="https://www.redmap.org.au/">Redmap</a> citizen science project began in Tasmania in 2009 and went national in 2012. It invites the public to share sightings of marine species uncommon in their area. </p>
<p>Redmap stands for Range Extension Database and Mapping project. Redmap members use their local knowledge to help monitor Australia’s vast coastline. When something unusual for a given location is spotted, fishers and divers can upload a photo with location and size information. </p>
<p>The photos are then verified by a <a href="https://www.redmap.org.au/about/meet-the-scientists/">network</a> of almost 100 marine scientists around Australia. Single observations cannot tell us much. But over time, the data can be used to map which species may be extending their range further south.</p>
<p>The project is supported by the University of Tasmania’s <a href="https://www.imas.utas.edu.au/">Institute for Marine and Antarctic Studies</a>, together with other Australian universities and a range of Commonwealth and state-government bodies.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/warming-oceans-are-changing-australias-fishing-industry-98301">Warming oceans are changing Australia's fishing industry</a>
</strong>
</em>
</p>
<hr>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/481220/original/file-20220826-12-dh55qg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/481220/original/file-20220826-12-dh55qg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=388&fit=crop&dpr=1 600w, https://images.theconversation.com/files/481220/original/file-20220826-12-dh55qg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=388&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/481220/original/file-20220826-12-dh55qg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=388&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/481220/original/file-20220826-12-dh55qg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=488&fit=crop&dpr=1 754w, https://images.theconversation.com/files/481220/original/file-20220826-12-dh55qg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=488&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/481220/original/file-20220826-12-dh55qg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=488&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Screenshot of the Redmap website highlighting a recent coral sighting.</span>
<span class="attribution"><span class="source">Redmap</span></span>
</figcaption>
</figure>
<p>We also examined data from two other national marine citizen science programs: <a href="https://reeflifesurvey.com/">Reef Life Survey</a> and <a href="https://www.inaturalist.org/projects/australasian-fishes">iNaturalist Australasian Fishes Project</a>. The resulting dataset encompassed ten years of photographed species observations made by almost 500 fishers, divers, snorkelers, spearfishers and beachcombers.</p>
<p>The citizen scientists recorded 77 species further south than where they lived a decade ago. Many were observed at their new location over multiple years and even in cooler months. </p>
<p>For example, spearfisher Derrick Cruz got a surprise in 2015 when he saw a coral trout swimming through a temperate kelp forest in his local waters off Sydney, much further south than he’d seen before. He submitted the below photo to Redmap, which was then verified by a scientist.</p>
<figure class="align-center ">
<img alt="Man snorkeling in the ocean, holding up a large orange fish" src="https://images.theconversation.com/files/480719/original/file-20220824-22-qpj3ls.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/480719/original/file-20220824-22-qpj3ls.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/480719/original/file-20220824-22-qpj3ls.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/480719/original/file-20220824-22-qpj3ls.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/480719/original/file-20220824-22-qpj3ls.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=425&fit=crop&dpr=1 754w, https://images.theconversation.com/files/480719/original/file-20220824-22-qpj3ls.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=425&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/480719/original/file-20220824-22-qpj3ls.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=425&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Spearfisher Derrick Cruz, pictured with a coral trout off Sydney.</span>
<span class="attribution"><span class="source">Redmap</span></span>
</figcaption>
</figure>
<p>Citizen scientists using Redmap were also the first to spot the <a href="https://www.redmap.org.au/sightings/566/">gloomy octopus</a> off Tasmania in 2012. Subsequent <a href="https://www.abc.net.au/news/2018-06-28/gloomy-octopus-migrating-to-tasmania-due-to-climate-warming/9919122">genetic studies</a> confirmed the species’ rapid extension into Tasmanian waters. </p>
<p>Similarly, solo eastern rock lobsters have been turning up in Tasmania for some time. But Redmap <a href="https://www.redmap.org.au/sightings/522/">sightings</a> recorded dozens of individuals living together in a “den”, which had not been observed previously.</p>
<p>Other species recorded by citizen scientists moving south include the <a href="https://www.redmap.org.au/sightings/3465/">spine-cheek clownfish</a>, Moorish idol and <a href="https://www.redmap.org.au/sightings/4248/">tiger sharks</a>.</p>
<h2>Supporting healthy oceans</h2>
<p>Using the citizen science data, we produced a <a href="https://www.redmap.org.au/media/uploads/2022/08/08/redmap-report-card-project-nesp-report-draft.pdf">report</a> outlining the assessment methods underpinning our study. We’ve also produced detailed state-based report cards for Western Australia, Tasmania and New South Wales, where coastal waters are warming much faster than the global average.</p>
<p>We also generated a map of the species shifts this revealed, and a downloadable <a href="https://www.redmap.org.au/article/report-card/">poster</a> summarising the findings. This allows the public – including those who contributed data – to see at a glance how climate change is affecting our oceans. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/480858/original/file-20220824-14-p217nk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A map of Australia with southerly lines around the coastline depicting how species distributions have shifted over the last decade" src="https://images.theconversation.com/files/480858/original/file-20220824-14-p217nk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/480858/original/file-20220824-14-p217nk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=459&fit=crop&dpr=1 600w, https://images.theconversation.com/files/480858/original/file-20220824-14-p217nk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=459&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/480858/original/file-20220824-14-p217nk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=459&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/480858/original/file-20220824-14-p217nk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=576&fit=crop&dpr=1 754w, https://images.theconversation.com/files/480858/original/file-20220824-14-p217nk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=576&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/480858/original/file-20220824-14-p217nk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=576&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Left, a downloadable poster summarising the species shifts in distribution. Right, the state-based report cards.</span>
</figcaption>
</figure>
<p>Citizen science has benefits beyond helping us understand changes in natural systems. Projects such as Redmap open up a community conversation about the impacts of climate change in Australia’s marine environment - using the public’s own knowledge and photos.</p>
<p>Our research <a href="https://www.sciencedirect.com/science/article/pii/S0964569117305665">suggests</a> this method engages the community and helps get people involved in documenting and understanding the problems facing our oceans and coasts. </p>
<p>A better understanding – by both scientists and the public – will help ensure healthy ecosystems, strong conservation and thriving fisheries in future. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/how-you-can-help-scientists-track-how-marine-life-reacts-to-climate-change-33370">How you can help scientists track how marine life reacts to climate change</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/189231/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Gretta Pecl receives funding from the Australian Research Council (ARC), the Fisheries Research & Development Corporation (FRDC), the Department of Agriculture Water and the Environment through the National Environmental Science Program (NESP), and the Department of Primary Industries NSW. She is also a Lead Author on the recent IPCC assessment report, and received funding from the Department of Environment and Energy to support travel to IPCC meetings. </span></em></p><p class="fine-print"><em><span>Barrett Wolfe receives funding from the Fisheries Research and Development Corporation, the Department of Agriculture Water and the Environment through the National Environmental Science Program, Department of Primary Industries NSW and NRE Tasmania. He has received past research funding from Seaworld Research and Rescue Foundation and PADI Foundation.</span></em></p><p class="fine-print"><em><span>Curtis Champion receives funding from the Fisheries Research and Development Corporation. He works for the NSW Department of Primary Industries.</span></em></p><p class="fine-print"><em><span>Jan Strugnell receives funding from the Australian Research Council (ARC), the Fisheries Research and Development Corporation (FRDC), the Department of Agriculture Water and the Environment through the National Environmental Science Program (NESP) and the Queensland Government through the Queensland Citizen Science Grants.</span></em></p><p class="fine-print"><em><span>Sue-Ann Watson receives funding from the Australian Research Council (ARC), the Department of Agriculture Water and the Environment through the National Environmental Science Program (NESP) and Queensland Government through the Queensland Citizen Science Grants. </span></em></p>The photographs show how climate change is disrupting our marine ecosystems – sometimes in ways previously unknown to marine scientists.Gretta Pecl, Professor, ARC Future Fellow & Director of the Centre for Marine Socioecology, University of TasmaniaBarrett Wolfe, Postdoctoral Research Fellow, University of TasmaniaCurtis Champion, Research Scientist, Southern Cross UniversityJan Strugnell, Professor Marine Biology and Aquaculture, James Cook UniversitySue-Ann Watson, Senior Research Fellow, James Cook UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1889952022-08-18T16:16:55Z2022-08-18T16:16:55ZThe Mediterranean has experienced record sea temperatures this summer: this could devastate marine life<figure><img src="https://images.theconversation.com/files/479863/original/file-20220818-24-zptalg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Mediterranean coral reefs support diverse ecosystems, their loss would be catastrophic.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/mediterranean-sea-underwater-marine-life-colored-1640978215">Damsea/Shutterstock</a></span></figcaption></figure><p>The ocean <a href="https://oneworldoneocean.com/pages/why-the-ocean/#:%7E:text=The%20ocean%20is%20Earth's%20life%20support&text=That's%20more%20than%20all%20of,of%20life%20on%20our%20planet">sustains all life</a> on our planet. It provides food to eat and oxygen to breathe, while playing a key role in moderating our climate. But marine life is increasingly threatened by climate change. The ocean is becoming considerably warmer, affecting its ability to sustain life.</p>
<p>The <a href="https://www.theguardian.com/environment/2022/jul/30/weather-tracker-mediterranean-sea-hit-by-major-marine-heatwave">searing temperatures</a> seen around the Mediterranean this year are indicative of rising global temperatures. This is set to continue over the next century, contingent on how much CO₂ we continue to emit. </p>
<p>The International Energy Agency <a href="https://www.iea.org/reports/global-energy-review-co2-emissions-in-2021-2">reported</a> that global energy-related CO₂ emissions rose by 6% in 2021 to their highest ever level.</p>
<p>The Mediterranean has been subject to intense thermal conditions in recent years. This has taken a further severe step this year, with sea temperatures reaching a record <a href="https://www.france24.com/en/europe/20220804-heatwaves-threaten-marine-life-as-mediterranean-reaches-record-temperature">30.7°C off Corsica</a>. </p>
<p>A <a href="https://www.annualreviews.org/doi/10.1146/annurev-marine-032720-095144">marine heatwave</a> is defined as an extended period of abnormally high sea temperatures, relative to the seasonal average. They have <a href="https://www.ipcc.ch/report/ar6/wg1/downloads/report/IPCC_AR6_WGI_Chapter09.pdf">doubled in frequency</a> since the 1980s.</p>
<p>Because of the delay between undertaking and publishing ecological work, the most <a href="https://onlinelibrary.wiley.com/doi/epdf/10.1111/gcb.16301">comprehensive study</a> we have on Mediterranean marine heatwaves covers the period 2015-2019.</p>
<p>The study found that the sea temperatures recorded in the Mediterranean over the period were the highest since recording began in 1982. Of almost a thousand field surveys conducted, researchers found that 58% of them contained evidence of the widespread mortality of marine life, tightly linked to periods of extreme heat.</p>
<p>The research provides an insight into the future ecological impacts of marine heatwaves elsewhere. This is significant as substantial temperature increases are forecast for tropical and polar regions in particular.</p>
<p>While the ocean acts as a large carbon sink, we still face increases in the surface temperature of the sea <a href="https://www.ipcc.ch/report/ar6/wg1/downloads/report/IPCC_AR6_WGI_Chapter09.pdf">ranging from 1–3°C</a> before the end of the century. Linked to this overall warming are marine heatwaves of increasing frequency and intensity.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/zhjzQ0pmgnE?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Climate change is causing heatwaves within the ocean.</span></figcaption>
</figure>
<p><a href="https://pubmed.ncbi.nlm.nih.gov/34672757/">Much of the research</a> on marine heatwaves finds that they affect certain habitats particularly strongly, including coral reefs, seagrasses and seaweeds. Marine heatwaves were found to be responsible for the loss of up to 80% of the population of some Mediterranean species between 2015 and 2019.</p>
<p>A mass mortality event is a single, catastrophic incident that rapidly wipes out vast numbers of a species. Around 88% of these events in the Mediterranean were associated with hard sea floor inhabitants, such as corals. However, seagrasses and the more diverse community of the soft sea floor were also severely affected, accounting for 10% and 2% of these events respectively.</p>
<h2>Deaths in shallow water</h2>
<p>More than two-thirds of the deaths of marine organisms occurring on the hard sea floor were in the shallowest waters. Marine environments with a depth of 0–25 metres are subject to particularly intense warming and are home to some of the most biodiverse ecosystems in the Mediterranean, formed by coral-like organisms. <a href="https://royalsocietypublishing.org/doi/10.1098/rspb.2021.2384">Other research</a> estimates that marine heatwaves have been responsible for the loss of 80–90% of Mediterranean coral density since 2003.</p>
<p>Foundation species tend to be habitat-forming organisms and are therefore critical in structuring an ecosystem. They act as nursery grounds, provide protection against predators, and serve as a food source. Foundation species are key to sustaining biodiversity, and their loss will have repercussions for other species. As <a href="https://www.sciencedirect.com/science/article/pii/S2589004219300549">foundation species</a>, the loss of coral, seagrass and seaweed is particularly concerning.</p>
<p>It is not just intense heat stress that is causing mortality events. High water temperatures are associated with the proliferation of <a href="https://www.sciencedirect.com/science/article/pii/S0048969722007938">disease-causing organisms</a>, such as bacteria, fungi and viruses. This may further reduce the ability of the ecosystem to <a href="https://www.nature.com/articles/s41579-019-0223-4">adapt to extreme heat</a>, contributing to additional ecological damage.</p>
<h2>Migration of marine life</h2>
<p>As well as prompting the widespread death of marine life, marine heatwaves often trigger migration. Warm-water invasive species will move towards the warmer areas, replacing species escaping the rising temperatures. Anecdotal evidence suggests that the exceptional temperatures seen across the Mediterranean this summer may be driving extensive mass migration. </p>
<p>In Greece, scientists have observed an increased abundance of <a href="https://greekreporter.com/2022/08/03/marine-heatwave-invasive-fish-mediterranean/">invasive species</a> from warmer waters. This includes the lionfish and silver-cheeked toadfish, both of which are toxic, and carry the potential to inflict considerable ecological damage. </p>
<p><a href="https://www.reabic.net/aquaticinvasions/2022/ACCEPTED/AI_2022_Tsirintanis_etal_correctedproof.pdf">Some research</a> even suggests that invasive species in the eastern Mediterranean, where native populations have collapsed, will soon become the only ones capable of sustaining ecosystems.</p>
<figure class="align-center ">
<img alt="A lionfish with its many fins swimming against a soft coral background within a deep blue ocean." src="https://images.theconversation.com/files/479864/original/file-20220818-2873-jrtzml.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/479864/original/file-20220818-2873-jrtzml.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/479864/original/file-20220818-2873-jrtzml.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/479864/original/file-20220818-2873-jrtzml.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/479864/original/file-20220818-2873-jrtzml.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/479864/original/file-20220818-2873-jrtzml.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/479864/original/file-20220818-2873-jrtzml.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Warmer waters have attracted invasive species such as the lionfish towards the Mediterranean, carrying the potential for considerable ecological damage.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/colorful-lionfish-patrolling-tropical-coral-reef-1160301118">Richard Whitcombe/Shutterstock</a></span>
</figcaption>
</figure>
<p>There have also been <a href="https://www.euronews.com/green/2022/07/26/marine-ecosystems-at-risk-as-temperatures-soar-in-the-mediterranean-sea">sightings</a> of non-native barracuda off France’s south coast. The invasion of predatory species, who find new prey while facing fewer predators, could considerably alter the functioning of the Mediterranean’s ecosystems, most likely to a less-rich form with lower species diversity.</p>
<p>However, while anecdotal evidence is plentiful, research into the ecological effects of marine heatwaves remains in its infancy. There needs to be further <a href="http://www.marineheatwaves.org/">robust scientific studies</a> on which to develop modelling of realistic future scenarios. </p>
<p>Within some branches of the scientific community, the recent intensity and frequency of marine heatwaves suggests we have arrived at a <a href="https://www.pnas.org/doi/10.1073/pnas.2108146119">“climate endgame”</a>. This involves preparation for the full consequences of widespread marine species mortality, should emissions not be curbed. The likely devastating Mediterranean marine heatwave of this year will only add fuel to such discussions.</p>
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<img alt="Imagine weekly climate newsletter" src="https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<p><strong><em>Don’t have time to read about climate change as much as you’d like?</em></strong>
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<hr><img src="https://counter.theconversation.com/content/188995/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>John Spicer has received funding from UKRI. </span></em></p>While official data is yet to be released, this year’s Mediterranean marine heatwave will likely have devastating ecological consequences.John Spicer, Professor of Marine Zoology, University of PlymouthLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1882332022-08-05T03:35:29Z2022-08-05T03:35:29ZRecord coral cover doesn’t necessarily mean the Great Barrier Reef is in good health (despite what you may have heard)<figure><img src="https://images.theconversation.com/files/477785/original/file-20220805-20-jsghmb.jpg?ixlib=rb-1.1.0&rect=0%2C22%2C5000%2C3300&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>In what seems like excellent news, coral cover in parts of the Great Barrier Reef is at a record high, according to <a href="https://www.aims.gov.au/information-centre/news-and-stories/highest-coral-cover-central-northern-reef-36-years">new data</a> from the Australian Institute of Marine Science. But this doesn’t necessarily mean our beloved reef is in good health.</p>
<p>In the north of the reef, coral cover usually fluctuates between 20% and 30%. Currently, it’s at 36%, the highest level recorded since monitoring began more than three decades ago. </p>
<p>This level of coral cover comes hot off the back of a <a href="https://theconversation.com/another-mass-bleaching-event-is-devastating-the-great-barrier-reef-what-will-it-take-for-coral-to-survive-180180">disturbing decade</a> that saw the reef endure six mass coral bleaching events, four severe tropical cyclones, active outbreaks of crown-of-thorns starfish, and water quality impacts following floods. So what’s going on? </p>
<p>High coral cover findings <a href="https://theconversation.com/a-lot-of-coral-doesnt-always-mean-high-biodiversity-10548">can be deceptive</a> because they can result from only a few dominant species that grow rapidly after disturbance (such as mass bleaching). These same corals, however, are extremely susceptible to disturbance and are likely to die out within a few years. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/jWAmmeh-Tek?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">The Great Barrier Reef Long-Term Monitoring annual summary | AIMS.</span></figcaption>
</figure>
<h2>The data are robust</h2>
<p>The <a href="https://peerj.com/articles/4747/">Great Barrier Reef spans</a> 2,300 kilometres, comprising more than 3,000 individual reefs. It is an exceptionally diverse ecosystem that features more than 12,000 animal species, plus many thousand more species of plankton and marine flora.</p>
<p>The reef has been teetering on the edge of receiving an “in-danger” <a href="https://theconversation.com/not-declaring-the-great-barrier-reef-as-in-danger-only-postpones-the-inevitable-164867">listing</a> from the World Heritage Committee. And it was <a href="https://theconversation.com/this-is-australias-most-important-report-on-the-environments-deteriorating-health-we-present-its-grim-findings-186131">recently described</a> in the State of the Environment Report as being in a poor and deteriorating state. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/this-is-australias-most-important-report-on-the-environments-deteriorating-health-we-present-its-grim-findings-186131">This is Australia's most important report on the environment's deteriorating health. We present its grim findings</a>
</strong>
</em>
</p>
<hr>
<p>To protect the Great Barrier Reef, we need to routinely monitor and report on its condition. The Australian Institute of Marine Science’s long-term monitoring program has been collating and delivering this information since 1985.</p>
<p>Its approach involves surveying a selection of reefs that represent different habitat types (inshore, midshelf, offshore) and management zones. The <a href="https://www.aims.gov.au/monitoring-great-barrier-reef/gbr-condition-summary-2021-22">latest report</a> provides a robust and valuable synopsis of how coral cover has changed at 87 reefs across three sectors (north, central and south) over the past 36 years.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/477781/original/file-20220805-19495-n38306.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/477781/original/file-20220805-19495-n38306.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=462&fit=crop&dpr=1 600w, https://images.theconversation.com/files/477781/original/file-20220805-19495-n38306.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=462&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/477781/original/file-20220805-19495-n38306.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=462&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/477781/original/file-20220805-19495-n38306.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=581&fit=crop&dpr=1 754w, https://images.theconversation.com/files/477781/original/file-20220805-19495-n38306.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=581&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/477781/original/file-20220805-19495-n38306.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=581&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">2018: A bare patch of reef at Jiigurru, Lizard Island in 2018 after most of the corals died in the 2016/2017 coral bleaching event.</span>
<span class="attribution"><span class="source">Andy Lewis</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/477783/original/file-20220805-2246-2olazh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/477783/original/file-20220805-2246-2olazh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/477783/original/file-20220805-2246-2olazh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=501&fit=crop&dpr=1 600w, https://images.theconversation.com/files/477783/original/file-20220805-2246-2olazh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=501&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/477783/original/file-20220805-2246-2olazh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=501&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/477783/original/file-20220805-2246-2olazh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=629&fit=crop&dpr=1 754w, https://images.theconversation.com/files/477783/original/file-20220805-2246-2olazh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=629&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/477783/original/file-20220805-2246-2olazh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=629&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">2022: By 2022, the same patch of reef was covered by a vibrant array of plating <em>Acropora</em> corals.</span>
<span class="attribution"><span class="source">Andy Lewis</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>The results</h2>
<p>Overall, the long-term monitoring team found coral cover has increased on most reefs. The level of coral cover on reefs near Cape Grenville and Princess Charlotte Bay in the northern sector has bounced back from bleaching, with two reefs having <a href="https://www.aims.gov.au/sites/default/files/2022-08/AIMS_LTMP_Report_on%20GBR_coral_status_2021_2022_040822F3.pdf">more than 75% cover</a>.</p>
<p>In the central sector, where coral cover has historically been lower than in the north and south, coral cover is now at a region-wide high, at 33%.</p>
<p>The southern sector has a dynamic coral cover record. In the late 1980s coral cover surpassed 40%, before dropping to a region-wide low of 12% in 2011 after Cyclone Hamish. </p>
<p>The region is currently experiencing outbreaks of crown-of-thorns starfish. And yet, coral cover in this area is still relatively high at 34%.</p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1555332997628407808"}"></div></p>
<p>Based on this robust data set, which shows increases in coral cover indicative of region-wide recovery, things must be looking up for the Great Barrier Reef – right?</p>
<h2>Are we being catfished by coral cover?</h2>
<p>In the Australian Institute of Marine Science’s report, reef recovery relates solely to an increase in coral cover, so let’s unpack this term. </p>
<p>Coral cover is a broad proxy metric that indicates habitat condition. It’s relatively easy data to collect and report on, and is the most widely used monitoring metric on coral reefs.</p>
<p>The finding of high coral cover may signify a reef in good condition, and an increase in coral cover after disturbance may signify a recovering reef. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/477779/original/file-20220805-15-eaj1ez.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/477779/original/file-20220805-15-eaj1ez.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/477779/original/file-20220805-15-eaj1ez.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/477779/original/file-20220805-15-eaj1ez.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/477779/original/file-20220805-15-eaj1ez.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/477779/original/file-20220805-15-eaj1ez.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/477779/original/file-20220805-15-eaj1ez.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/477779/original/file-20220805-15-eaj1ez.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption"><em>Acropora hyacinthus</em>, a pioneering species of coral at Lizard Island.</span>
<span class="attribution"><span class="source">Zoe Richards</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>But in this instance, it’s more likely the reef is being dominated by only few species, as the report states that branching and plating <em>Acropora</em> species have driven the recovery of coral cover.</p>
<p><em>Acropora</em> coral are renowned for a “boom and bust” life cycle. After disturbances such as a cyclone, <em>Acropora</em> species function as pioneers. They quickly recruit and colonise bare space, and the laterally growing plate-like species can rapidly cover large areas. </p>
<p>Fast-growing <em>Acropora</em> corals tend to dominate during the early phase of recovery after disturbances such as the recent series of mass bleaching events. However, these same corals are often susceptible to wave damage, disease or coral bleaching and tend to go bust within a few years.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/477780/original/file-20220805-5528-11crg9.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/477780/original/file-20220805-5528-11crg9.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/477780/original/file-20220805-5528-11crg9.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/477780/original/file-20220805-5528-11crg9.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/477780/original/file-20220805-5528-11crg9.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/477780/original/file-20220805-5528-11crg9.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/477780/original/file-20220805-5528-11crg9.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/477780/original/file-20220805-5528-11crg9.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Juvenile branching <strong>Acropora</strong> colonising bare space after a bleaching event.</span>
<span class="attribution"><span class="source">Zoe Richards</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Inferring that a reef has recovered by a person being towed behind a boat to obtain a rapid visual estimate of coral cover is like flying in a helicopter and saying a bushfire-hit forest has recovered because the canopy has grown back. </p>
<p>It provides no information about diversity, or the abundance and health of other animals and plants that live in and among the trees, or coral. </p>
<h2>Cautious optimism</h2>
<p>My <a href="https://theconversation.com/almost-60-coral-species-around-lizard-island-are-missing-and-a-great-barrier-reef-extinction-crisis-could-be-next-163714">study</a>, published last year, examined 44 years of coral distribution records around Jiigurru, Lizard Island, at the northern end of the Great Barrier Reef. </p>
<p>It suggested that 28 of 368 species of hard coral recorded at that location haven’t been seen for at least a decade, and are at risk of local extinction.</p>
<p>Lizard Island is one location where coral cover has rapidly increased since the devastating 2016-17 bleaching event. Yet, there is still a real risk local extinctions of coral species have occurred. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/almost-60-coral-species-around-lizard-island-are-missing-and-a-great-barrier-reef-extinction-crisis-could-be-next-163714">Almost 60 coral species around Lizard Island are 'missing' – and a Great Barrier Reef extinction crisis could be next</a>
</strong>
</em>
</p>
<hr>
<p>While there’s no data to prove or disprove it, it’s also probable that extinctions or local declines of coral-affiliated marine life, such as coral-eating fishes, crustaceans and molluscs have also occurred.</p>
<p>Without more information at the level of individual species, it is impossible to understand how much of the Great Barrier Reef has been lost, or recovered, since the last mass bleaching event. </p>
<p>Based on the coral cover data, it’s tempting to be optimistic. But given more frequent and severe heatwaves and cyclones are predicted in the future, it’s wise to be cautious about the reef’s perceived recovery or resilience.</p><img src="https://counter.theconversation.com/content/188233/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Zoe Richards receives funding from the Australian Research Council.</span></em></p>New data shows coral cover in the Great Barrier Reef is at a record high, despite a disturbing decade of marine heatwaves, cyclones and floods. While the data is robust, it can be deceptive.Zoe Richards, Senior Research Fellow, Curtin UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1823112022-05-05T18:01:15Z2022-05-05T18:01:15ZCorals and sea anemones turn sunscreen into toxins – understanding how could help save coral reefs<figure><img src="https://images.theconversation.com/files/461387/original/file-20220504-16-dvzlw6.jpg?ixlib=rb-1.1.0&rect=172%2C181%2C4820%2C3423&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Many places have banned sunscreens with certain chemicals in an attempt to help protect coral reefs.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/egypt-red-sea-hurghada-teenage-girl-snorkeling-at-royalty-free-image/932631960?adppopup=true">Westend61 via Getty Images</a></span></figcaption></figure><p>Sunscreen bottles are frequently labeled as “reef-friendly” and “coral-safe.” These claims generally mean that the lotions replaced oxybenzone – a chemical that can harm corals – with something else. But are these other chemicals really safer for reefs than oxybenzone?</p>
<p>This question led <a href="https://mitchlab.sites.stanford.edu/djordje-vuckovic">us</a>, two <a href="https://scholar.google.com/citations?hl=en&user=RQcNZ6QAAAAJ">environmental chemists</a>, to team up with <a href="https://med.stanford.edu/pringlelab/people/john-pringle.html">biologists</a> who study <a href="https://med.stanford.edu/pringlelab.html">sea anemones as a model for corals</a>. Our goal was to uncover how sunscreen harms reefs so that we could better understand which components in sunscreens are really “coral-safe.” </p>
<p>In <a href="https://www.science.org/doi/10.1126/science.abo4627">our new study</a>, published in Science, we found that when corals and sea anemones absorb oxybenzone, <a href="https://doi.org/10.1126/science.abn2600">their cells turn it into phototoxins</a>, molecules that are harmless in the dark but become toxic under sunlight.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/461392/original/file-20220504-19-dpmjpk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A dead coral reef." src="https://images.theconversation.com/files/461392/original/file-20220504-19-dpmjpk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/461392/original/file-20220504-19-dpmjpk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/461392/original/file-20220504-19-dpmjpk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/461392/original/file-20220504-19-dpmjpk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/461392/original/file-20220504-19-dpmjpk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/461392/original/file-20220504-19-dpmjpk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/461392/original/file-20220504-19-dpmjpk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Reefs around the world – like the Great Barrier Reef seen here – are bleaching and dying because of stressors like increased water temperatures, and sunscreens may be exacerbating the issues.</span>
<span class="attribution"><span class="source">Amanda Tinoco</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<h2>Protecting people, harming reefs</h2>
<p>Sunlight is made of many different wavelengths of light. Longer wavelengths – like visible light – are typically harmless. But light at shorter wavelengths – like ultraviolet light – can pass through the surface of skin and damage DNA and cells. Sunscreens, including oxybenzone, work by absorbing most of the UV light and converting it into heat.</p>
<p>Coral reefs around the world have suffered in recent decades from <a href="https://oceanservice.noaa.gov/facts/coralreef-climate.html">warming oceans and other stressors</a>. Some scientists thought that sunscreens coming off of swimmers or from wastewater discharges could also be harming corals. They conducted lab experiments that showed that oxybenzone concentrations as low as 0.14 mg per liter of seawater can <a href="https://doi.org/10.1007/s00244-015-0227-7">kill 50% of coral larvae in less than 24 hours</a>. While most field samples typically have lower sunscreen concentrations, one popular snorkeling reef in the U.S. Virgin Islands <a href="https://doi.org/10.1007/s00244-015-0227-7">had up to 1.4 mg oxybenzone per liter of seawater</a> – more than 10 times the lethal dose for coral larvae. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/461389/original/file-20220504-21-dognyj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A chemical diagram of oxybenzone." src="https://images.theconversation.com/files/461389/original/file-20220504-21-dognyj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/461389/original/file-20220504-21-dognyj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=320&fit=crop&dpr=1 600w, https://images.theconversation.com/files/461389/original/file-20220504-21-dognyj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=320&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/461389/original/file-20220504-21-dognyj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=320&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/461389/original/file-20220504-21-dognyj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=403&fit=crop&dpr=1 754w, https://images.theconversation.com/files/461389/original/file-20220504-21-dognyj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=403&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/461389/original/file-20220504-21-dognyj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=403&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Oxybenzone is a common ingredient in many sunscreens.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Oxybenzone.svg#/media/File:Oxybenzone.svg">Fvasconcellos via WikimediaCommons</a></span>
</figcaption>
</figure>
<p>Likely inspired by this research and a number of <a href="https://dx.doi.org/10.1289%2Fehp.10966">other studies</a> <a href="https://doi.org/10.1080/10934529.2011.602936">showing damage</a> to <a href="https://doi.org/10.1016/j.aquatox.2008.08.018">marine life</a>, Hawaii’s legislators <a href="https://www.washingtonpost.com/news/energy-environment/wp/2018/05/02/hawaii-might-be-about-to-ban-your-favorite-sunscreen-to-protect-its-coral-reefs/">voted</a> in 2018 to ban oxybenzone and another ingredient in sunscreens. Soon after, lawmakers in other places with coral reefs, like the <a href="https://psmag.com/news/the-us-virgin-islands-bans-potentially-dangerous-sunscreen-chemicals">Virgin Islands</a>, <a href="https://www.nytimes.com/2018/11/02/world/asia/palau-sunscreen-ban-coral.html">Palau</a> and <a href="https://www.visitaruba.com/news/general/aruba-officially-bans-plastics-and-oxybenzone/">Aruba</a>, implemented their own bans.</p>
<p>There is still an <a href="https://theconversation.com/theres-insufficient-evidence-your-sunscreen-harms-coral-reefs-109567">open debate</a> whether the concentrations of oxybenzone in the environment are high enough to damage reefs. But everyone agrees that these chemicals can cause harm under certain conditions, so understanding their mechanism is important. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/461396/original/file-20220504-15-7bssds.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A number of small test tubes with little sea anemones growing inside of them." src="https://images.theconversation.com/files/461396/original/file-20220504-15-7bssds.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/461396/original/file-20220504-15-7bssds.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/461396/original/file-20220504-15-7bssds.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/461396/original/file-20220504-15-7bssds.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/461396/original/file-20220504-15-7bssds.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/461396/original/file-20220504-15-7bssds.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/461396/original/file-20220504-15-7bssds.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">By putting sea anemones into test tubes with oxybenzone and controlling what kinds of light they were exposed to, we could see whether the sunscreen was reacting to light.</span>
<span class="attribution"><span class="source">Djordje Vuckovic</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<h2>Sunscreen or toxin</h2>
<p>While laboratory evidence had shown that sunscreen can harm corals, very little research had been done to understand how. Some studies suggested that oxybenzone <a href="https://doi.org/10.1016/j.envint.2014.05.015">mimics hormones</a>, disrupting reproduction and development. But another theory that our team found particularly intriguing was the possibility that the sunscreen behaved as a <a href="https://doi.org/10.1007/s00244-015-0227-7">light-activated toxin in corals</a>. </p>
<p>To test this, we used the sea anemones our colleagues breed as a model for corals. Sea anemones and corals are closely related and share a lot of biological processes, including a symbiotic relationship with algae that live within them. It is <a href="https://doi.org/10.1016/j.tree.2008.03.004">extremely difficult to perform experiments with corals under lab conditions</a>, so anemones are typically much better for lab-based studies like ours.</p>
<p>We put 21 anemones in test tubes full of seawater under a lightbulb that emits the full spectrum of sunlight. We covered five of the anemones with a box made of acrylic that blocks the exact wavelengths of UV light that oxybenzone normally absorbs and interacts with. Then we exposed all the anemones to 2 mg of oxybenzone per liter of seawater.</p>
<p>The anemones under the acrylic box were our “dark” samples and the ones outside of it our control “light” samples. Anemones, like corals, have a translucent surface, so if oxybenzone were acting as a phototoxin, the UV rays hitting the light group would trigger a chemical reaction and kill the animals – while the dark group would survive.</p>
<p>We ran the experiment for 21 days. On Day Six, the first anemone in the light group died. By Day 17, <a href="https://doi.org/10.1126/science.abn2600">all of them had died</a>. By comparison, none of the five anemones in the dark group died during the entire three weeks. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/461391/original/file-20220504-18-8tlovg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A close-up of a blue coral." src="https://images.theconversation.com/files/461391/original/file-20220504-18-8tlovg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/461391/original/file-20220504-18-8tlovg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/461391/original/file-20220504-18-8tlovg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/461391/original/file-20220504-18-8tlovg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/461391/original/file-20220504-18-8tlovg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/461391/original/file-20220504-18-8tlovg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/461391/original/file-20220504-18-8tlovg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Corals – like the mushroom coral seen here – and sea anemones absorb oxybenzone and metabolize it, but in doing so, they turn it into a toxin.</span>
<span class="attribution"><span class="source">Christian Renicke</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<h2>Metabolism converts oxybenzone to phototoxins</h2>
<p>We were surprised that a sunscreen was behaving as a phototoxin inside the anemones. We ran a chemical experiment on oxybenzone and confirmed that, on its own, it behaves as a sunscreen and not as a phototoxin. It’s only when the chemical was absorbed by anemones that it became dangerous under light. </p>
<p>Any time an organism absorbs a foreign substance, its cells try to get rid of the substance using various metabolic processes. Our experiments suggested that one of these processes was turning oxybenzone into a phototoxin.</p>
<p>To test this, we analyzed the chemicals that formed inside anemones after we exposed them to oxybenzone. We learned that our anemones had replaced part of oxybenzone’s chemical structure – a specific hydrogen atom on an alcohol group – with a sugar. Replacing hydrogen atoms on alcohol groups with sugars is something that <a href="https://passel2.unl.edu/view/lesson/2aee31ac6c74/7#:%7E:text=Phase%20II%20-%20Introduction,-Phase%20II%20reactions&text=reactions%20are%20anabolic%20processes%20which,solubility%20and%20usually%20reduced%20mobility.">plants</a> and <a href="https://doi.org/10.1007/1-4020-4142-X_3">animals</a> commonly do to make chemicals less toxic and more water soluble so they are easier to excrete.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/461602/original/file-20220505-21-skvp4z.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A chemical chart showing two different molecular structures." src="https://images.theconversation.com/files/461602/original/file-20220505-21-skvp4z.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/461602/original/file-20220505-21-skvp4z.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=155&fit=crop&dpr=1 600w, https://images.theconversation.com/files/461602/original/file-20220505-21-skvp4z.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=155&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/461602/original/file-20220505-21-skvp4z.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=155&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/461602/original/file-20220505-21-skvp4z.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=195&fit=crop&dpr=1 754w, https://images.theconversation.com/files/461602/original/file-20220505-21-skvp4z.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=195&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/461602/original/file-20220505-21-skvp4z.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=195&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">When cells try to process oxybenzone, they replace part of an alcohol group (highlighted in red on the left) with a sugar (in red on the right) and in doing so turn the sunscreen into a phototoxin.</span>
<span class="attribution"><span class="source">Djordje Vuckovic</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>But when you remove this alcohol group from oxybenzone, oxybenzone ceases to function as a sunscreen. Instead, it holds on to the energy it absorbs from UV light and kicks off a series of <a href="https://doi.org/10.1111/php.12716">rapid chemical reactions</a> that <a href="https://doi.org/10.1021/acsomega.9b03244">damage cells</a>. Rather than turning the sunscreen into a harmless, easy-to-excrete molecule, the anemones <a href="https://doi.org/10.1126/science.abn2600">convert oxybenzone into a potent, sunlight-activated toxin</a>.</p>
<p>When we ran similar experiments with mushroom corals, we found something surprising. Even though <a href="https://doi.org/10.1016/j.tree.2008.03.004">corals are much more vulnerable to stressors than sea anemones</a>, they did not die from oxybenzone and light exposure during our entire eight-day experiment. The coral made the same phototoxins from oxybenzone, but all of the toxins were stored in the symbiotic algae living in the coral. The algae seemed to absorb the phototoxic byproducts and, in doing so, likely protected their coral hosts. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/461603/original/file-20220505-22-e336i2.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Two rows of photos of sea anemones, with the top row showing a slower death." src="https://images.theconversation.com/files/461603/original/file-20220505-22-e336i2.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/461603/original/file-20220505-22-e336i2.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=128&fit=crop&dpr=1 600w, https://images.theconversation.com/files/461603/original/file-20220505-22-e336i2.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=128&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/461603/original/file-20220505-22-e336i2.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=128&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/461603/original/file-20220505-22-e336i2.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=161&fit=crop&dpr=1 754w, https://images.theconversation.com/files/461603/original/file-20220505-22-e336i2.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=161&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/461603/original/file-20220505-22-e336i2.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=161&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">This photo series shows how darker-colored anemones on top with algae in them lived longer than the lighter-colored anemones on the bottom that did not have algae living in them.</span>
<span class="attribution"><span class="source">Djordje Vuckovic and Christian Renicke</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>We suspect that the corals would have died from the phototoxins if they did not have their algae. It is not possible to keep corals without algae alive in the lab, so we did some experiments on anemones without algae instead. These anemones died about two times faster and had almost three times as many phototoxins in their cells compared than the same anemones with algae.</p>
<h2>Coral bleaching, ‘reef-safe’ sunscreens and human safety</h2>
<p>We believe there are a few important takeaways from our effort to better understand how oxybenzone harms corals. </p>
<p>First, <a href="https://doi.org/10.1126/science.aan8048">coral bleaching events</a> – in which the corals expel their algal symbionts because of high seawater temperatures or other stressors – likely leave corals particularly vulnerable to the toxic effects of sunscreens. </p>
<p>Second, it’s possible that oxybenzone could also be dangerous to other species. In our study, we found that human cells can also turn oxybenzone into a potential phototoxin. If this happens inside the body, where no light can reach, it’s not an issue. But if this occurs in the skin, where light can create toxins, it could be a problem. Previous studies have suggested that oxybenzone <a href="https://doi.org/10.1097/PSN.0000000000000244">could pose health risks to people</a>, and some researchers have recently <a href="https://doi.org/10.1016/j.jaad.2021.12.011">called for more research into its safety</a>.</p>
<p>Finally, the chemicals used in many alternative “reef-safe” sunscreens contain the same alcohol group as oxybenzone – so could potentially also be converted to phototoxins.</p>
<p>We hope that, taken together, our results will lead to safer sunscreens and help inform efforts to protect reefs. </p>
<p>[<em>Understand new developments in science, health and technology, each week.</em> <a href="https://memberservices.theconversation.com/newsletters/?nl=science&source=inline-science-understand">Subscribe to The Conversation’s science newsletter</a>.]</p><img src="https://counter.theconversation.com/content/182311/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Djordje Vuckovic has spoken with Soliome, a company involved in the production of novel sunscreen components. He received funding from the National Science Foundation. </span></em></p><p class="fine-print"><em><span>Bill Mitch has spoken with Soliome, a company involved in the production of novel sunscreen components. He receives funding from the U.S. National Science Foundation and the Stanford Woods Institute of the Environment.</span></em></p>Researchers have long suspected that an ingredient in sunscreen called oxybenzone was harming corals, but no one knew how. A new study shows how corals turn oxybenzone into a sunlight-activated toxin.Djordje Vuckovic, PhD candidate in Civil and Environmental Engineering, Stanford UniversityBill Mitch, Professor of Civil and Environmental Engineering, Stanford UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1801942022-03-30T18:11:55Z2022-03-30T18:11:55ZInside the Mediterranean sea’s ‘animal forests’: an encounter with the gorgonian corals<figure><img src="https://images.theconversation.com/files/454761/original/file-20220328-13-1efag0j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">An underwater forest formed by the purple gorgonian (Paramuricea clavata) off Marseille at a depth of 60 metres. </span> <span class="attribution"><span class="source">Romain Bricoult / CC BY-NC-ND</span></span></figcaption></figure><p>Gorgonians are an order of soft corals that belong to the large group of Cnidaria, which also includes hard corals, sea anemones, jellyfish and many other species. Gorgonians colonise the seabed all over the world, from shallow coastal areas to deep sea canyons, temperate and tropical areas to polar zones.</p>
<p>Gorgonians’ skeleton can be soft or rigid, horny or calcareous. These organisms can form dense communities that structure the seabed, constituting “animal forests” offering a refuge to a myriad of marine species.</p>
<h2>One of the most beautiful underwater landscapes in the Mediterranean</h2>
<p>In the Mediterranean, a total of five main species of gorgonians can be found living up to 100 metres below the surface. One of them, <em>Paramuricea clavata</em>, forms remarkable populations both by its red colours and the size of its colonies, which can exceed 1 metre in height.</p>
<p>It is one of the most beautiful underwater landscapes in the western Mediterranean, popular among both amateur divers and underwater photographers. The colonies are either male or female and all originate from the planula, a free-swimming or crawling larva type common among Cnidaria. Egg-shaped, the planula uses hairlike projections called cilia to propel itself through the water. It grows slowly (2 to 3 cm/year at most) and can live several decades.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/454778/original/file-20220328-19-2271qa.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/454778/original/file-20220328-19-2271qa.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/454778/original/file-20220328-19-2271qa.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/454778/original/file-20220328-19-2271qa.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/454778/original/file-20220328-19-2271qa.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/454778/original/file-20220328-19-2271qa.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/454778/original/file-20220328-19-2271qa.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=501&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The large purple gorgonian (<em>Paramuricea clavata</em>) is a typical species from the circalittoral rocky bottoms and coralligenous bottoms in the Mediterranean.</span>
<span class="attribution"><span class="source">Dorian Guillemain, CC BY-NC-ND</span></span>
</figcaption>
</figure>
<h2>“Animal forests” weakened by human activities…</h2>
<p>Purple gorgonian beds, like those of other gorgonians, are fragile and vulnerable to human activities in coastal areas. In the Mediterranean, these populations are also regularly affected by the impact of climate change.</p>
<p>Fishing nets and anchors can tear off the fragile colonies or cause injury (necrosis) to the living tissue covering their horny skeletons. Creatures that live on top of other organisms – known as epibion organisms – then proceed to colonise the beds’ exposed areas, threatening the colony’s survival.</p>
<p>Excessive input of sediment in marine environment – referred to as hypersedimentation and linked to coastal constructions and the changes of the courses of rivers – is also a threat to the populations of gorgonians.</p>
<p>Although they have been spared from warming Mediterranean waters, the <em>Paramuricea clavata</em> are locally impacted by fishing and above all by recreational fishing. The vast rock shelf colonised by these giant gorgonians is home to scores of sea breams in the autumn, which themselves are prized by amateur fishermen.</p>
<p>Up to 180 boats were counted on <a href="https://parcmarincotebleue.fr/">29 October 2016</a> during the sea bream reproduction period. Anchors and fishing lines uprooted many giant colonies. It therefore appears essential to control visitor numbers in this conservation area if we are to enable this unique natural heritage to coexist with human activity.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/454779/original/file-20220328-13-rkkxo8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/454779/original/file-20220328-13-rkkxo8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/454779/original/file-20220328-13-rkkxo8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/454779/original/file-20220328-13-rkkxo8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/454779/original/file-20220328-13-rkkxo8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/454779/original/file-20220328-13-rkkxo8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/454779/original/file-20220328-13-rkkxo8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=501&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A fishing net caught in a settlement of purple gorgonians. When the net is lifted, it will cause colonies to be torn off and the living tissue covering their corneal skeleton to die off.</span>
<span class="attribution"><span class="source">Benoist de Vogüé/CC BY-NC-ND</span></span>
</figcaption>
</figure>
<h2>… and by climate change</h2>
<p>Human activities in the coastal area are not the only danger faced by gorgonians. In recent decades, climate change has caused the strong wind on the Provencal coast known as the Mistral to weaken during increasingly long periods. This, in turn, has provoked thermal anomalies in the water column.</p>
<p>The result of this is the submergence of the surface warm water layers (temperature >22 °C) for stretches of several weeks. The latter can be fatal to the gorgonian populations, which are usually exposed to cooler temperatures (around 13 to 15 °C).</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/454780/original/file-20220328-19-uz09rx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/454780/original/file-20220328-19-uz09rx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=458&fit=crop&dpr=1 600w, https://images.theconversation.com/files/454780/original/file-20220328-19-uz09rx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=458&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/454780/original/file-20220328-19-uz09rx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=458&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/454780/original/file-20220328-19-uz09rx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=576&fit=crop&dpr=1 754w, https://images.theconversation.com/files/454780/original/file-20220328-19-uz09rx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=576&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/454780/original/file-20220328-19-uz09rx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=576&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A living tissue slowly dies off, exposing the corneal skeleton of a gorgonian which was subsequently covered by epibiont organisms. This necrosis was caused by a thermal anomaly observed in 2014 at a depth of up to 30 metres.</span>
<span class="attribution"><span class="source">Benoist de Vogüé</span></span>
</figcaption>
</figure>
<p>In 1999, a <a href="https://www.academia.edu/10389935/Mortalit%C3%A9_massive_d_invert%C3%A9br%C3%A9s_marins_un_%C3%A9v%C3%A9nement_sans_pr%C3%A9c%C3%A9dent_en_M%C3%A9diterran%C3%A9e_nord_occidentale">vast thermal anomaly</a> affected gorgonian populations in the western Mediterranean stretching from Spain to Italy. Apart from gorgonians, about 20 other species (sponges, bivalve molluscs, bryozoans, ascidians) were also affected.
The anomaly was characterised by the presence of a column of warm water (23 to 24°C) at a depth ranging from 40 to 60 metres for a month. Other events of this type were then observed in 2003, 2006 and 2009, affecting the gorgonians to a greater or lesser extent.</p>
<p>Factors such as the gorgonians’ genetic makeup or microbiota will dictate how they fare in the face of heat stresses. In the coming decades, <a href="https://theconversation.com/suffering-in-the-heat-the-rise-in-marine-heatwaves-is-harming-ocean-species-112839">significant climatic changes</a> are expected to impact upon these species’ location and distribution. </p>
<h2>Discovering a unique deep-sea community</h2>
<p>Although gorgonian populations in the Mediterranean are well researched down to 50 metres, little is known about those farther below. A unique settlement was discovered a few decades ago off the <em>Côte bleue</em> (northern bay of Marseille) at a depth of 50 to 60 metres. This settlement occupies a vast rock shelf extending over nearly 2,500 hectares.</p>
<p>It is characterised by a high density of gorgonians, but above all by the presence of giant colonies. Hovering between 1.50 and 1.80 metres, these corals are probably around a century old.</p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/454781/original/file-20220328-23-1ps85am.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/454781/original/file-20220328-23-1ps85am.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=900&fit=crop&dpr=1 600w, https://images.theconversation.com/files/454781/original/file-20220328-23-1ps85am.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=900&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/454781/original/file-20220328-23-1ps85am.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=900&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/454781/original/file-20220328-23-1ps85am.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1131&fit=crop&dpr=1 754w, https://images.theconversation.com/files/454781/original/file-20220328-23-1ps85am.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1131&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/454781/original/file-20220328-23-1ps85am.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1131&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A diver inspects a human-sized purple gorgonian (<em>Paramuricea clavata</em>) in the 60-metre-deep, rocky bottom off the <em>Côte bleue</em>, north of Marseille.</span>
<span class="attribution"><span class="source">Romain Bricoult</span></span>
</figcaption>
</figure>
<p>Recent studies have sought to explain the reasons behind the species’ gigantism and tightly knit networks (REFUCLIM programme) and distribution (GIGOR programme). The results seem to show that, apart from their morphology, these gorgonians are genetically unique and clearly distinct from those found at shallower depths.</p>
<p>The environment surrounding them is unique. Not only are the gorgonians regularly subjected to strong inputs of organic matter linked to the proximity of the Rhône’s mouth, but the bottom currents are generally weak. The combination of these two parameters allows the gorgonians to reach exceptional sizes.</p>
<p>One of the issues at stake is that these deep settlements can constitute <a href="https://www.nature.com/articles/s41598-019-41929-0">refuge populations</a>, which are relatively spared from global warming, making them all the more important for the species’ survival.</p>
<p>The study of deep-sea gorgonian populations is a major area of research in the years to come, not only to initiate appropriate protection measures, but also to better understand their connections with the populations inhabiting the sea’s shallower depths.</p><img src="https://counter.theconversation.com/content/180194/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Stéphane Sartoretto received funding from the EC2CO program (coordination: CNRS/INSU) et from AFB (French Agency for the Biodiversité). </span></em></p>Forming tightly woven populations, these bush-like corals offer a refuge to a myriad of marine species.Stéphane Sartoretto, Chercheur en écologie marine (écosystèmes benthiques méditerranéens de substrat dur), IfremerLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1801802022-03-29T03:49:22Z2022-03-29T03:49:22ZAnother mass bleaching event is devastating the Great Barrier Reef. What will it take for coral to survive?<figure><img src="https://images.theconversation.com/files/454879/original/file-20220329-4070-1pkrs9j.jpg?ixlib=rb-1.1.0&rect=0%2C31%2C5176%2C3414&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Bleached coral beside the darker, healthier coral. Photo taken in February</span> <span class="attribution"><span class="source">Nathan Cook</span>, <span class="license">Author provided</span></span></figcaption></figure><p>It’s official: the Great Barrier Reef is suffering its <a href="https://www.bbc.com/news/world-australia-60870239">fourth mass bleaching event</a> since 2016. We dived into the reef yesterday and saw the unfolding crisis firsthand. </p>
<p>Descending beneath the surface at John Brewer Reef near Townsville, our eyes were immediately drawn to the iridescent whites, blues and pinks of stressed corals among the deeper browns, reds and greens of healthier colonies. </p>
<p>It’s a depressing, but all-too-familiar feeling. A sense of: “here we go again”</p>
<p>This is the first time the reef has bleached under the cooling conditions of the natural <a href="https://theconversation.com/back-so-soon-la-nina-heres-why-were-copping-two-soggy-summers-in-a-row-173684">La Niña weather pattern</a>, which shows just how strong the long-term warming trend of climate change is. Despite the cooling conditions, 2021 was one of <a href="https://theconversation.com/2021-was-one-of-the-hottest-years-on-record-and-it-could-also-be-the-coldest-well-ever-see-again-175238">the hottest years on record</a>.</p>
<p>When coral bleaches, it is not dead – yet. Coral reefs that suffer widespread bleaching can still recover if conditions improve, but it’s estimated to take <a href="https://royalsocietypublishing.org/doi/10.1098/rspb.2018.2908">up to 12 years</a>. That is, if there’s no new disturbance in the meantime, such as a cyclone or another bleaching event. </p>
<p>So what conditions are needed for coral recovery? And under what conditions will coral die?</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/454882/original/file-20220329-4070-6lk17u.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A diver inspects bleached coral" src="https://images.theconversation.com/files/454882/original/file-20220329-4070-6lk17u.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/454882/original/file-20220329-4070-6lk17u.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/454882/original/file-20220329-4070-6lk17u.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/454882/original/file-20220329-4070-6lk17u.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/454882/original/file-20220329-4070-6lk17u.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/454882/original/file-20220329-4070-6lk17u.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/454882/original/file-20220329-4070-6lk17u.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Bleaching at John Brewer Reef, near Townsville.</span>
<span class="attribution"><span class="source">Harriet Spark/Grumpy Turtle</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>What it takes for coral to die</h2>
<p>Whether a coral can survive bleaching depends on how long conditions remain stressful, and to what level. What’s more, some <a href="https://doi.org/10.3389/fevo.2020.00178">species are more sensitive</a> than others, such as branching acropora corals, especially if they’ve bleached previously.</p>
<p>If water remains too warm for too long, corals will eventually die. But if the water temperature drops and the ultraviolet light becomes less intense, then the coral may recover and survive.</p>
<p>While the average sea temperatures in the reef currently remain above average, they’ve shown signs of cooling to a more amenable average for coral survival. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/454880/original/file-20220329-25-1bs1wol.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/454880/original/file-20220329-25-1bs1wol.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/454880/original/file-20220329-25-1bs1wol.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=900&fit=crop&dpr=1 600w, https://images.theconversation.com/files/454880/original/file-20220329-25-1bs1wol.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=900&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/454880/original/file-20220329-25-1bs1wol.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=900&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/454880/original/file-20220329-25-1bs1wol.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1131&fit=crop&dpr=1 754w, https://images.theconversation.com/files/454880/original/file-20220329-25-1bs1wol.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1131&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/454880/original/file-20220329-25-1bs1wol.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1131&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Bleaching at John Brewer Reef.</span>
<span class="attribution"><span class="source">Nathan Cook</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p><a href="https://coralreefwatch.noaa.gov/">Sea temperatures</a> in Cleveland Bay, near Townsville, were above 31°C in early March, but thankfully have now reduced to below 29°C. <a href="https://coralreefwatch.noaa.gov/data_current/5km/v3.1_op/daily/png/coraltemp_v3.1_pacific_current.png">Similarly in</a> the Whitsundays, Hardy Reef experienced temperatures as high as 30°C but has receded to nearer 26°C in the past few weeks. </p>
<p>If coral does survives a bleaching event, it is still impacted physiologically, as bleaching can slow <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0088720">growth rates</a> and reduce <a href="https://www.cell.com/current-biology/fulltext/S0960-9822(21)01346-4?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS0960982221013464%3Fshowall%3Dtrue">reproductive capacity</a>. Surviving colonies also become more susceptible to other challenges, such as disease. </p>
<h2>Signs of stress</h2>
<p>Survival also depends on each individual coral’s own resilience: its ability to cope with higher temperatures and increased ultraviolet stress. </p>
<p>For example, fast growing branching corals are the most susceptible to bleaching and are generally the first to die. Long-lived massive corals, such as porites, may be less susceptible to bleaching, show minimal effects of bleaching and recover quicker.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/454883/original/file-20220329-13-6efs8z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Orange fish swim over bleached coral" src="https://images.theconversation.com/files/454883/original/file-20220329-13-6efs8z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/454883/original/file-20220329-13-6efs8z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/454883/original/file-20220329-13-6efs8z.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/454883/original/file-20220329-13-6efs8z.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/454883/original/file-20220329-13-6efs8z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/454883/original/file-20220329-13-6efs8z.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/454883/original/file-20220329-13-6efs8z.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">White and fluorescent corals are currently a common sight on many reefs.</span>
<span class="attribution"><span class="source">Harriet Spark/Grumpy Turtle</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Corals can use fluorescent pigments to shield themselves from excessive ultraviolet radiation – a bit like sunscreen that lets coral manage, filter and attempt to regulate the incoming light. </p>
<p>To the casual observer, fluorescent corals look bright purple, pink, blue and yellow. For reef scientists, fluorescence is an obvious signal that corals are stressed and struggling to regulate their internal balance. As we’ve seen, white and fluorescent corals are currently a common sight on many reefs. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/adapt-move-or-die-repeated-coral-bleaching-leaves-wildlife-on-the-great-barrier-reef-with-few-options-179570">Adapt, move, or die: repeated coral bleaching leaves wildlife on the Great Barrier Reef with few options</a>
</strong>
</em>
</p>
<hr>
<p>Most coral species have fluorescent pigments in their tissue. Some are always visible to humans, especially branching corals with bright blue or pink hues on the their branch tips. </p>
<p>Others are never visible, and some are visible only during times of heat stress when coral colonies boost these fluorescent pigments to fight the increasing ultraviolet intensity in warmer seas. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/454884/original/file-20220329-19-qhgkr3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/454884/original/file-20220329-19-qhgkr3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/454884/original/file-20220329-19-qhgkr3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/454884/original/file-20220329-19-qhgkr3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/454884/original/file-20220329-19-qhgkr3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/454884/original/file-20220329-19-qhgkr3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/454884/original/file-20220329-19-qhgkr3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/454884/original/file-20220329-19-qhgkr3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Bleaching can slow coral growth rates and reduce reproduction.</span>
<span class="attribution"><span class="source">Harriet Spark/Grumpy Turtle</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>Coral can’t adapt fast enough</h2>
<p>Scientists measure heat stress on corals using a metric called “<a href="https://ereefs.aims.gov.au/ereefs-aims/gbr1/dhw_heatstress">degree heating weeks</a>”. </p>
<p>One degree heating week is when the temperature at a given location is more than 1°C over the historical maximum temperature. If the water is 2°C above the historical maximum for one week, this would be considered two degree heating weeks. </p>
<p>Generally speaking, at four degree heating weeks, scientists expect to see signs of stress and coral bleaching. It usually takes eight degree heating weeks for coral to die. </p>
<p>According to Bureau of Meteorology <a href="http://www.bom.gov.au/environment/activities/reeftemp/reeftemp.shtml">data</a>, many parts of the Great Barrier Reef, such as off Cairns and Port Douglas, currently remain in the window of between four and eight degree heating weeks. But some areas, near Townsville and the Whitsundays, are experiencing severe bleaching stress beyond eight degree heating weeks. </p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1506414812904845316"}"></div></p>
<p>While we hope many coral reefs will recover from this round of bleaching, the long term implications cannot be understated.</p>
<p>When corals bleach, they eject their zooxanthellae – single-celled algae that gives coral colour and energy. Some corals may regain their zooxanthellae after the bleaching event is over, but this usually takes between three and six months. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/no-sunscreen-chemicals-are-not-bleaching-the-great-barrier-reef-179938">No, sunscreen chemicals are not bleaching the Great Barrier Reef</a>
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</em>
</p>
<hr>
<p>To make matters worse, full reef recovery requires no new bleaching events or other disturbances in the years that follow. Given the reef has bleached six times since the late 1990s, alongside global climate trajectories, this would appear an <a href="https://www.nature.com/articles/s41586-019-1081-y">unlikely scenario</a>. </p>
<p>While some corals may learn to cope with these new conditions by potentially acquiring more heat-tolerant zooxanthellae, the reality is that change is happening too fast for coral to adapt via evolution. </p>
<p>The severe bleaching in previous years also means future events may appear less severe. But this is simply because most of the heat sensitive corals have <a href="https://doi.org/10.1016/j.cub.2021.09.078">already died</a>, potentially resulting in a lower probability of widespread severe bleaching.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/454885/original/file-20220329-20-d73q6x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Diver inspects bleached coral" src="https://images.theconversation.com/files/454885/original/file-20220329-20-d73q6x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/454885/original/file-20220329-20-d73q6x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/454885/original/file-20220329-20-d73q6x.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/454885/original/file-20220329-20-d73q6x.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/454885/original/file-20220329-20-d73q6x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/454885/original/file-20220329-20-d73q6x.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/454885/original/file-20220329-20-d73q6x.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Any policy without action on climate change is ineffective.</span>
<span class="attribution"><span class="source">Harriet Spark/Grumpy Turtle</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>We need stronger climate policies and action</h2>
<p>Australia has the world’s best marine scientists and marine park managers. And yet, our policies are rated “<a href="https://climateactiontracker.org/countries/australia/">highly insufficient</a>”, according to the latest Climate Action Tracker. </p>
<p>If global emissions continue unabated, Australia may warm <a href="https://theconversation.com/climate-change-has-already-hit-australia-unless-we-act-now-a-hotter-drier-and-more-dangerous-future-awaits-ipcc-warns-165396">by 4°C or more</a> this century. Under this scenario, widespread coral bleaching is likely on the Great Barrier Reef every year <a href="https://www.climatecouncil.org.au/resources/dire-warning-great-barrier-reef-un-inspection-begins-climate-council-briefing/">from 2044 onward</a>.</p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1507209794368970758"}"></div></p>
<p>There has been some glimmers of hope in federal policy in recent years, such as <a href="https://elibrary.gbrmpa.gov.au/jspui/handle/11017/3460">statements recognising</a> the existential threat climate change poses to coral reefs. Despite this recognition, substantial action is lacking, as any policy without action on climate change is ineffective. </p>
<p>If the federal government, reef businesses and individuals are to show leadership and maintain healthy reefs, we need to work together and take rapid, drastic action to reduce carbon emissions. </p>
<p>Committing to a stronger emissions target for 2030 and a carbon neutral footprint for all Great Barrier Reef businesses would go a long way to exhibiting the kind of change required if coral reefs, in their current form, are to survive into the future. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/climate-change-has-already-hit-australia-unless-we-act-now-a-hotter-drier-and-more-dangerous-future-awaits-ipcc-warns-165396">Climate change has already hit Australia. Unless we act now, a hotter, drier and more dangerous future awaits, IPCC warns</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/180180/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Adam Smith receives funding from Australian and Queensland Government and the Great Barrier Reef Foundation.</span></em></p><p class="fine-print"><em><span>Nathan Cook is co-chair of the Australian Coral Restoration Consortium, a regional group of the Coral Restoration Consortium. </span></em></p>Coral reefs that suffer widespread bleaching can still recover if conditions improve, but it’s estimated to take up to 12 years. And that’s if no more bleaching events occur.Adam Smith, Adjunct Associate Professor, James Cook UniversityNathan Cook, Marine Scientist, James Cook UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1760842022-02-01T19:01:55Z2022-02-01T19:01:55ZSafe havens for coral reefs will be almost non-existent at 1.5°C of global warming – new study<figure><img src="https://images.theconversation.com/files/443717/original/file-20220201-27-7t8bbg.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C3409%2C2270&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/sun-rays-filtering-through-water-1655309398">Ajit S N/Shutterstock</a></span></figcaption></figure><p>Coral reefs have <a href="https://www.nature.com/articles/nclimate1674">long been regarded</a> as one of the earliest and most significant ecological casualties of global warming. In <a href="https://doi.org/10.1371/journal.pclm.0000004">new research</a> published in the journal PLOS Climate, we found that the future of these tropical ecosystems – thought to harbour <a href="https://www.iucn.org/resources/issues-briefs/coral-reefs-and-climate-change">more species than any other</a> – is probably worse than anticipated.</p>
<p>Climate change is causing more frequent <a href="https://theconversation.com/uk/topics/marine-heatwaves-39175">marine heatwaves</a> worldwide. Corals have adapted to live in a specific temperature range, so when ocean temperatures are too hot for a prolonged period, corals can bleach – losing the colourful algae that live within their tissue and nourish them via photosynthesis – and may eventually die. </p>
<p>Across the tropics, <a href="https://www.nature.com/articles/nature22901">mass bleaching and die-offs</a> have gone from being rare to a somewhat regular occurrence as the climate has warmed. More frequent heatwaves mean that the time corals have to recover is getting shorter.</p>
<figure class="align-center ">
<img alt="A boulder coral on a reef that has bleached white." src="https://images.theconversation.com/files/443703/original/file-20220201-15-1sq3ipg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/443703/original/file-20220201-15-1sq3ipg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/443703/original/file-20220201-15-1sq3ipg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/443703/original/file-20220201-15-1sq3ipg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/443703/original/file-20220201-15-1sq3ipg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/443703/original/file-20220201-15-1sq3ipg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/443703/original/file-20220201-15-1sq3ipg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Bleached corals are more vulnerable to disease and starvation.</span>
<span class="attribution"><span class="source">Maria Beger</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>In a 2018 report, the Intergovernmental Panel on Climate Change predicted that 1.5°C of global warming would cause <a href="https://www.ipcc.ch/site/assets/uploads/sites/2/2019/02/SR15_Chapter3_Low_Res.pdf">between 70 and 90%</a> of the world’s coral reefs to disappear. Now, with models capable of examining temperature differences between coral reefs one kilometre apart, our team found that at 1.5°C of warming, which the world is predicted to reach in the <a href="https://www.ipcc.ch/report/sixth-assessment-report-working-group-i/">early 2030s</a> without drastic action to limit greenhouse gas emissions, 99% of the world’s reefs will experience heatwaves that are too frequent for them to recover.</p>
<p>That would spell catastrophe for the thousands of species that depend on coral reefs, as well as the roughly <a href="https://wedocs.unep.org/bitstream/handle/20.500.11822/9461/-Marine%20and%20Coastal%20Ecosystems%20and%20Human%20Well-Being_%20A%20synthesis%20report%20based%20on%20the%20findings%20of%20the%20Millennium%20Ecosystems%20Assessment-2006652.pdf?sequence=3&%3BisAllowed=">one billion people</a> whose livelihoods and food supply benefits from coral reef biodiversity. </p>
<h2>Thermal refugia</h2>
<p>The thermal stress of a heatwave can affect corals over a <a href="https://www.science.org/doi/10.1126/science.aan8048">huge geographic area</a>, like the entire northern Great Barrier Reef or archipelagos like the Maldives. A marine heatwave in 2015-16 <a href="https://www.science.org/doi/10.1126/science.aan8048">caused widespread bleaching</a> in each of the Pacific, Atlantic and Indian Oceans. </p>
<p>Corals are small polyp-like animals that form colonies of thousands by secreting a calcium carbonate skeleton that builds a reef. Corals grow slowly, so their recovery following bleaching and die-offs can take a long time and can be hampered by pollution and overfishing. Some species grow faster and are more capable of recovering quicker.</p>
<p>Scientists hope that <a href="https://www.sciencedirect.com/science/article/pii/S000632071300284X">local conditions</a> on some reef tracts will ensure <a href="https://academic.oup.com/icesjms/article/75/1/43/4080230?login=true">suitable temperatures</a> for corals in the future, even when surrounding areas warm. These conditions may be possible due to upwelling, where cooler water is brought to the surface, or strong ocean currents. Reef managers can <a href="https://conbio.onlinelibrary.wiley.com/doi/full/10.1111/conl.12587">prioritise</a> these so-called refugia, which offer corals a greater chance of survival. </p>
<figure class="align-center ">
<img alt="A sunlit coral reef populated by lots of tropical fish." src="https://images.theconversation.com/files/443702/original/file-20220201-14-1ol29sx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/443702/original/file-20220201-14-1ol29sx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/443702/original/file-20220201-14-1ol29sx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/443702/original/file-20220201-14-1ol29sx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/443702/original/file-20220201-14-1ol29sx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/443702/original/file-20220201-14-1ol29sx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/443702/original/file-20220201-14-1ol29sx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Healthy reefs can support a vast array of life.</span>
<span class="attribution"><span class="source">Maarten De Brauwer</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Finding these refugia is difficult, though, as they are likely to be small and the resolution of climate projections that model changes in ocean temperatures over time tend to be too coarse. Our team increased the resolution of climate model projections by downscaling them with historical data from satellite observations to find out where refugia are likely to persist in the future. </p>
<p>We found that, from 1986 to 2019, 84% of the world’s reefs offered sufficient thermal refuge. This meant corals had enough time to recover in between bleaching events. With 1.5°C of global warming above pre-industrial levels, only 0.2% of these refugia remain. At 2°C of warming, safe havens from heat for coral reefs will no longer exist.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/443790/original/file-20220201-15324-1ilqrsk.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Two world maps comparing coral reef refugia 1986-2019 versus at 1.5°C." src="https://images.theconversation.com/files/443790/original/file-20220201-15324-1ilqrsk.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/443790/original/file-20220201-15324-1ilqrsk.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=439&fit=crop&dpr=1 600w, https://images.theconversation.com/files/443790/original/file-20220201-15324-1ilqrsk.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=439&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/443790/original/file-20220201-15324-1ilqrsk.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=439&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/443790/original/file-20220201-15324-1ilqrsk.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=552&fit=crop&dpr=1 754w, https://images.theconversation.com/files/443790/original/file-20220201-15324-1ilqrsk.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=552&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/443790/original/file-20220201-15324-1ilqrsk.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=552&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Most of the world’s reef refugia disappear at 1.5°C.</span>
<span class="attribution"><a class="source" href="https://doi.org/10.1371/journal.pclm.0000004">Dixon et al. (2022)/PLOS Climate</a>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p><a href="https://doi.org/10.1002/essoar.10510201.1">Preliminary findings</a> from another study (yet to complete the peer-review process) would seem to confirm the catastrophic effects of 1.5°C of global warming on coral reefs. This research was carried out independently by scientists in the US using a different method but the same climate models and spatial resolutions.</p>
<h2>The future of coral reefs</h2>
<p>Global warming of 1.5°C is the lower limit that world leaders aspired to maintain when they signed the Paris agreement in 2015. This target is moving <a href="https://unfccc.int/sites/default/files/resource/cma2021_08r01_E.pdf">further out of reach</a>. For coral reefs, there is no safe limit to global warming. Given the rate at which the global average temperature is increasing, marine heatwaves are likely to become so frequent that most of the world’s coral reefs will experience intolerable heat stress regularly. Most reefs have already experienced at least one such event this decade.</p>
<p>Not all regions are stressed at the same time as heatwaves are not global, nor do all corals bleach. Some <a href="https://onlinelibrary.wiley.com/doi/abs/10.1046/j.1461-0248.2001.00203.x%22">coral species</a> are more capable of coping with extreme temperatures than others due to their <a href="https://link.springer.com/article/10.1007/s00338-018-1702-1">growth form</a> or the <a href="https://link.springer.com/content/pdf/10.1007/s00338-010-0696-0.pdf">type of algae</a> within their tissue. Still, the magnitude and frequency of heatwaves predicted in this study will probably affect even resistant coral species, suggesting the world will lose most of its reef biodiversity. Coral reefs of the future are likely to look very different to the colourful and diverse ecosystems we know today. </p>
<figure class="align-center ">
<img alt="An underwater field of coral rubble smothered in algae." src="https://images.theconversation.com/files/443778/original/file-20220201-25-a80n1z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/443778/original/file-20220201-25-a80n1z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/443778/original/file-20220201-25-a80n1z.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/443778/original/file-20220201-25-a80n1z.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/443778/original/file-20220201-25-a80n1z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/443778/original/file-20220201-25-a80n1z.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/443778/original/file-20220201-25-a80n1z.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A dead coral reef.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/dead-coral-reef-killed-by-global-461420095">Rich Carey/Shutterstock</a></span>
</figcaption>
</figure>
<p>Climate change is already <a href="https://www.nature.com/articles/nature22901">degrading coral reefs globally</a>. Now we know that protecting the last remaining temperature refuges will not work on its own. Slashing greenhouse gas emissions this decade is the best hope for saving what remains.</p>
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<img alt="Imagine weekly climate newsletter" src="https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<p class="fine-print"><em><span>Adele Dixon receives funding from NERC (UKRI). </span></em></p><p class="fine-print"><em><span>Maria Beger receives funding from NERC (UKRI). </span></em></p><p class="fine-print"><em><span>Peter Kalmus receives funding from NASA.</span></em></p><p class="fine-print"><em><span>Scott F. Heron receives funding from the Australian Research Council and NASA ROSES Ecological Forecasting.</span></em></p>Marine heatwaves will happen so often that reefs will struggle to weather successive bleaching events.Adele Dixon, PhD Candidate in Coral Biology, University of LeedsMaria Beger, Associate Professor in Conservation Science, University of LeedsPeter Kalmus, Data Scientist, NASAScott F. Heron, Associate Professor in Physics, James Cook UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1752262022-01-25T19:03:20Z2022-01-25T19:03:20ZSome endangered species can no longer survive in the wild. So should we alter their genes?<figure><img src="https://images.theconversation.com/files/442159/original/file-20220124-17-fdh2zz.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C1650%2C930&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Melbourne Zoo</span></span></figcaption></figure><p>Around the world, populations of many beloved species are declining at increasing rates. According to one <a href="https://www.theguardian.com/environment/2020/sep/30/world-plant-species-risk-extinction-fungi-earth">grim projection</a>, as many as 40% of the world’s species may be extinct by 2050. Alarmingly, many of these declines are caused by threats for which few solutions exist.</p>
<p>Numerous species now depend on conservation breeding programs for their survival. But these programs typically do not encourage species to adapt and survive in the wild alongside intractable threats such as climate change and disease.</p>
<p>This means some species can no longer exist in the wild, which causes major downstream effects on the ecosystem. Consider, for example, how a coral reef would struggle to function without corals.</p>
<p>What if there was another way? My colleagues and I have developed an intervention method that aims to give endangered species the genetic features they need to survive in the wild.</p>
<figure class="align-center ">
<img alt="bleached coral with fish" src="https://images.theconversation.com/files/411140/original/file-20210714-13-1bf7ccv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/411140/original/file-20210714-13-1bf7ccv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=320&fit=crop&dpr=1 600w, https://images.theconversation.com/files/411140/original/file-20210714-13-1bf7ccv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=320&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/411140/original/file-20210714-13-1bf7ccv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=320&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/411140/original/file-20210714-13-1bf7ccv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=402&fit=crop&dpr=1 754w, https://images.theconversation.com/files/411140/original/file-20210714-13-1bf7ccv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=402&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/411140/original/file-20210714-13-1bf7ccv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=402&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Genetically altering coral may help them survive in a warmer world.</span>
<span class="attribution"><span class="source">Rick Stuart-Smith</span></span>
</figcaption>
</figure>
<h2>Bringing theory into practice</h2>
<p>Over generations, natural selection enables species to adapt to threats. But in many instances today, the speed at which threats are developing is outpacing species’ ability to adapt. </p>
<p>This problem is especially apparent in wildlife threatened by newly emerging infectious diseases such as chytridiomycosis in amphibians, and in climate-affected species such as corals. </p>
<p>The toolkit my colleagues and I developed is called “targeted genetic intervention” or TGI. It works by increasing the occurrence or frequency of genetic features that impact an organism’s fitness in the presence of the threat. We outline the method in a recent <a href="https://www.sciencedirect.com/science/article/abs/pii/S0169534721003384">research paper</a>.</p>
<p>The toolkit involves <a href="https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/artificial-selection">artificial selection</a> and <a href="https://www.frontiersin.org/articles/10.3389/fbioe.2019.00175/full">synthetic biology</a>. These tools are well established in agriculture and medicine but relatively untested as conservation tools. We explain them in more detail below.</p>
<p>Many tools in our TGI toolkit have been discussed in theory in conservation literature in recent decades. But rapid developments in genome sequencing and synthetic biology mean some are now possible in practice.</p>
<p>The developments have made it easier to understand the genetic basis of features which enable a species to adapt, and to manipulate them.</p>
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<em>
<strong>
Read more:
<a href="https://theconversation.com/we-name-the-26-australian-frogs-at-greatest-risk-of-extinction-by-2040-and-how-to-save-them-166339">We name the 26 Australian frogs at greatest risk of extinction by 2040 — and how to save them</a>
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</em>
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<figure class="align-center ">
<img alt="frog on wet rock" src="https://images.theconversation.com/files/442166/original/file-20220124-19-xc82dx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/442166/original/file-20220124-19-xc82dx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/442166/original/file-20220124-19-xc82dx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/442166/original/file-20220124-19-xc82dx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/442166/original/file-20220124-19-xc82dx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/442166/original/file-20220124-19-xc82dx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/442166/original/file-20220124-19-xc82dx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Some animal species cannot adapt in time to survive threats such as disease.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
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</figure>
<h2>What is artificial selection?</h2>
<p>Humans have long used artificial (or phenotypic) selection to promote desirable characteristics in animals and plants raised for companionship or food. This genetic alteration has led to organisms, such as domestic dogs and maize, that are dramatically different from their wild progenitors.</p>
<p>Traditional artificial selection can lead to outcomes, such as high inbreeding rates, that affect the health and resilience of the organism and are undesirable for conservation. If you’ve ever owned a purebred dog, you might be aware of some of these genetic disorders.</p>
<p>And when it comes to conservation, determining which individuals from a species are resistant to, say, a deadly pathogen would involve exposing the animal to the threat – clearly not in the interests of species preservation.</p>
<p>Scientists in the livestock industry have developed a new approach to circumvent these problems. Called genomic selection, it combines data from laboratory work (such as a disease trial) with the genetic information of the animals to predict which individuals bear genetic features conducive to adaptation. </p>
<p>These individuals are then chosen for breeding. Over subsequent generations, a population’s ability to survive alongside pervasive threats increases.</p>
<p>Genomic selection has led to disease-resistant salmon and livestock that produce more milk and better tolerate heat. But it is yet to be tested in conservation.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/how-this-little-marsupials-poo-nurtures-urban-gardens-and-bushland-and-how-you-can-help-protect-them-175064">How this little marsupial's poo nurtures urban gardens and bushland (and how you can help protect them)</a>
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</em>
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<figure class="align-center ">
<img alt="cows in green field" src="https://images.theconversation.com/files/442161/original/file-20220124-27-11vyq0z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/442161/original/file-20220124-27-11vyq0z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/442161/original/file-20220124-27-11vyq0z.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/442161/original/file-20220124-27-11vyq0z.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/442161/original/file-20220124-27-11vyq0z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/442161/original/file-20220124-27-11vyq0z.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/442161/original/file-20220124-27-11vyq0z.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Artificial selection has been used to develop traits that humans desire in livestock.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>What is synthetic biology?</h2>
<p><a href="https://www.genome.gov/about-genomics/policy-issues/Synthetic-Biology">Synthetic biology</a> is a toolkit for promoting change in organisms. It includes methods such as transgenesis and gene editing, which can be used to introduce lost or novel genes or tweak specific genetic features. </p>
<p>Recent synthetic biology tools such as <a href="https://medlineplus.gov/genetics/understanding/genomicresearch/genomeediting/">CRISPR-Cas9</a> have created a buzz in the medical world, and are also starting to gain the <a href="https://portals.iucn.org/library/node/48408">attention</a> of conservation biologists.</p>
<p>Such tools can accurately tweak targeted genetic features in an individual organism – making it more able to adapt – while leaving the rest of the genome untouched. The genetic modifications are then passed on to subsequent generations.</p>
<p>The method reduces the likelihood of unintended genetic changes that can occur with artificial selection.</p>
<p>Synthetic biology methods are currently being trialled for conservation in multiple species around the world. These include the <a href="https://www.esf.edu/chestnut/resistance.htm">chestnut tree</a> and black-footed <a href="https://neo.life/2021/05/cloning-wildlife-and-editing-their-genes-to-protect-them-and-us/">ferrets</a> in the United States, and <a href="https://theconversation.com/gene-editing-is-revealing-how-corals-respond-to-warming-waters-it-could-transform-how-we-manage-our-reefs-143444">corals</a> in Australia.</p>
<p>I am working with researchers at the University of Melbourne to develop TGI approaches in Australian frogs. We are trialling these approaches in the iconic southern corroboree frog, and plan to extend them to other species if they prove effective.</p>
<p>Worldwide, the disease chytridiomycosis is devastating frog populations. Caused by the fungal pathogen <em>Batrachochytrium dendrobatidis</em>, it has led to the extinction of about <a href="https://www.nationalgeographic.com/animals/article/amphibian-apocalypse-frogs-salamanders-worst-chytrid-fungus">90 frog species</a> and declines in as many as 500 others.</p>
<p>Many frog species now rely on conservation breeding for their continued survival. No effective solution for restoring chytrid-susceptible frogs to the wild exists, because the fungus cannot be eradicated.</p>
<figure class="align-center ">
<img alt="gloved hand removed portion of DNA strand" src="https://images.theconversation.com/files/442155/original/file-20220124-23-cebr8a.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/442155/original/file-20220124-23-cebr8a.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/442155/original/file-20220124-23-cebr8a.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/442155/original/file-20220124-23-cebr8a.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/442155/original/file-20220124-23-cebr8a.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/442155/original/file-20220124-23-cebr8a.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/442155/original/file-20220124-23-cebr8a.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">CRISPR technology could potentially be used to edit the genes of endangered species.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>Looking ahead</h2>
<p>As with many conservation approaches, targeted genetic intervention is likely to involve trade-offs. For example, genetic features that make a species resistant to one disease may make it more susceptible to another.</p>
<p>But the rapid rate of species declines means we should trial such potential solutions before it’s too late. The longer species are absent from an ecosystem, the greater the chance of irreversible environmental changes. </p>
<p>Any genetic intervention of this type should involve all stakeholders, including Indigenous peoples and local communities. And caution should be taken to ensure species are fit for release and pose no risk to the environment.</p>
<p>By bringing the concept of TGI to the attention of the public, government, and other scientists, we hope we will spur discussion and encourage research on its risks and benefits.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/5-major-heatwaves-in-30-years-have-turned-the-great-barrier-reef-into-a-bleached-checkerboard-170719">5 major heatwaves in 30 years have turned the Great Barrier Reef into a bleached checkerboard</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/175226/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Tiffany Kosch is a member of One Health Research Group at the University of Melbourne. Her research is currently funded by the Australian Research Council (grants FT190100462 and LP200301370). Additionally, the genome of their target species, the Southern Corroboree frog is currently being sequenced at no cost to the group by the Vertebrate Genomes Project. </span></em></p>The rapid rate of species declines means we should trial potential solutions before it’s too late.Tiffany Kosch, Research Fellow, The University of MelbourneLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1726022021-12-15T19:08:22Z2021-12-15T19:08:22ZHibbert’s flowers and Hitler’s beetle – what do we do when species are named after history’s monsters?<figure><img src="https://images.theconversation.com/files/437438/original/file-20211214-13-y3duma.jpeg?ixlib=rb-1.1.0&rect=118%2C0%2C3843%2C2232&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Hibbertia_procumbens_(6691568261).jpg">John Tann/Wikimedia Commons</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>“What’s in a name?”, <a href="https://www.bartleby.com/70/3822.html">asked Juliet of Romeo</a>. “That which we call a rose by any other name would smell as sweet.”</p>
<p>But, as with the Montagues and Capulets, names mean a lot, and can cause a great deal of heartache.</p>
<p>My colleagues and I are <a href="https://theconversation.com/its-not-the-science-of-tax-and-five-other-things-you-should-know-about-taxonomy-78926">taxonomists</a>, which means we name living things. While we’ve never named a rose, we do discover and name new Australian species of plants and animals – and there are a lot of them!</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/about-500-000-australian-species-are-undiscovered-and-scientists-are-on-a-25-year-mission-to-finish-the-job-161793">About 500,000 Australian species are undiscovered – and scientists are on a 25-year mission to finish the job</a>
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</p>
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<p>For each new species we discover, we create and publish a Latin scientific name, following a set of international rules and conventions. The name has two parts: the first part is the genus name (such as <em>Eucalyptus</em>), which describes the group of species to which the new species belongs, and the second part is a species name (such as <em>globulus</em>, thereby making the name <em>Eucalyptus globulus</em>) particular to the new species itself. New species are either added to an existing genus, or occasionally, if they’re sufficiently novel, are given their own new genus.</p>
<p>Some scientific names are widely known – arguably none more so than our own, <em>Homo sapiens</em>. And gardeners or nature enthusiasts will be familiar with genus names such as <em>Acacia</em>, <em>Callistemon</em> or <em>Banksia</em>.</p>
<p>This all sounds pretty uncontroversial. But as with Shakespeare’s star-crossed lovers, history and tradition sometimes present problems.</p>
<h2>What’s in a name?</h2>
<p>Take the genus <em><a href="http://www.flora.sa.gov.au/cgi-bin/speciesfacts_display.cgi?form=speciesfacts&name=Hibbertia">Hibbertia</a></em>, the Australian guineaflowers. This is one of the largest genera of plants in Australia, and the one we study. </p>
<p>There are many new and yet-unnamed species of <em>Hibbertia</em>, which means new species names are regularly added to this genus.</p>
<p>Many scientific names are derived from a feature of the species or genus being named, such as <em>Eucalyptus</em>, from the Greek for “well-covered” (a reference to the operculum or bud-cap that covers unopened eucalypt flowers). </p>
<p>Others <a href="https://theconversation.com/its-funny-to-name-species-after-celebrities-but-theres-a-serious-side-too-95513">honour significant people</a>, either living or dead. <em>Hibbertia</em> is named after a wealthy 19th-century English patron of botany, <a href="https://en.wikipedia.org/wiki/George_Hibbert">George Hibbert</a>.</p>
<figure class="align-right ">
<img alt="George Hibbert by Thomas Lawrence" src="https://images.theconversation.com/files/437440/original/file-20211214-15-1u4xyy3.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/437440/original/file-20211214-15-1u4xyy3.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=901&fit=crop&dpr=1 600w, https://images.theconversation.com/files/437440/original/file-20211214-15-1u4xyy3.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=901&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/437440/original/file-20211214-15-1u4xyy3.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=901&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/437440/original/file-20211214-15-1u4xyy3.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1132&fit=crop&dpr=1 754w, https://images.theconversation.com/files/437440/original/file-20211214-15-1u4xyy3.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1132&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/437440/original/file-20211214-15-1u4xyy3.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1132&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">George Hibbert: big fan of flowers and slavery.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:George_Hibbert_by_Thomas_Lawrence,_1811.JPG">Thomas Lawrence/Stephen C. Dickson/Wikimedia Commons</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>And here’s where things stop being straightforward, because Hibbert’s wealth came almost entirely from the transatlantic slave trade. He profited from taking slaves from Africa to the New World, selling some and using others on his family’s extensive plantations, then transporting slave-produced sugar and cotton back to England.</p>
<p>Hibbert was also a prominent member of the British parliament and a <a href="https://www.ucl.ac.uk/lbs/person/view/16791">staunch opponent of abolition</a>. He and his ilk argued that slavery was economically necessary for England, and even that slaves were better off on the plantations than in their homelands. </p>
<p>Even at the time, his views were considered abhorrent by many critics. But despite this, he was handsomely recompensed for his “losses” when Britain finally abolished slavery in 1807.</p>
<p>So, should Hibbert be honoured with the name of a genus of plants, to which new species are still being added today – effectively meaning he is honoured afresh with each new publication?</p>
<p>We don’t believe so. Just like statues, buildings, and <a href="https://theconversation.com/was-first-governor-james-stirling-had-links-to-slavery-as-well-as-directing-a-massacre-should-he-be-honoured-162078">street or suburb names</a>, we think a reckoning is due for scientific species names that honour people who held views or acted in ways that are deeply dishonourable, highly problematic or truly egregious by modern standards.</p>
<figure class="align-left ">
<img alt="Anophthalmus hitleri" src="https://images.theconversation.com/files/437442/original/file-20211214-13-1yaho8u.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/437442/original/file-20211214-13-1yaho8u.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=980&fit=crop&dpr=1 600w, https://images.theconversation.com/files/437442/original/file-20211214-13-1yaho8u.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=980&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/437442/original/file-20211214-13-1yaho8u.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=980&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/437442/original/file-20211214-13-1yaho8u.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1231&fit=crop&dpr=1 754w, https://images.theconversation.com/files/437442/original/file-20211214-13-1yaho8u.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1231&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/437442/original/file-20211214-13-1yaho8u.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1231&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">This beetle doesn’t deserve to be named after the most reviled figure of the 20th century.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Anophthalmus_hitleri_HabitusDors.jpg">Michael Munich/Wikimedia Commons</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>Just as Western Australia’s King Leopold Range <a href="https://www.abc.net.au/news/2020-07-03/wa-king-leopold-ranges-renamed-wunaamin-miliwundi-ranges/12416254">was recently renamed</a> to remove the link to the atrocious <a href="https://en.wikipedia.org/wiki/Leopold_II_of_Belgium">Leopold II of Belgium</a>, we would like <em>Hibbertia</em> to bear a more appropriate and less troubling name.</p>
<p>The same goes for the Great Barrier Reef coral <em><a href="http://www.edgeofexistence.org/species/elegance-coral/">Catalaphyllia jardinei</a></em>, named after Frank Jardine, a brutal dispossessor of Aboriginal people in North Queensland. And, perhaps most astoundingly, the rare Slovenian cave beetle <em><a href="https://www.inaturalist.org/taxa/773804">Anophthalmus hitleri</a></em>, which was named in 1933 in honour of Adolf Hitler. </p>
<p>This name is unfortunate for several reasons: despite being a small, somewhat nondescript, blind beetle, in recent years it has been reportedly <a href="https://www.independent.co.uk/news/world/europe/fans-exterminate-hitler-beetle-6232054.html">pushed to the brink of extinction</a> by Nazi memorabilia enthusiasts. Specimens are even being stolen from museum collections for sale into this lucrative market.</p>
<h2>Aye, there’s the rub</h2>
<p>Unfortunately, the official rules don’t allow us to rename <em>Hibbertia</em> or any other species that has a troubling or inappropriate name.</p>
<p>To solve this, we propose a change to the international rules for naming species. Our <a href="https://onlinelibrary.wiley.com/doi/epdf/10.1002/tax.12620">proposal</a>, if adopted, would establish an international expert committee to decide what do about scientific names that honour inappropriate people or are based on culturally offensive words. </p>
<p>An example of the latter is the <a href="https://onlinelibrary.wiley.com/doi/epdf/10.1002/tax.12622">many names of plants</a> based on the Latin <em>caffra</em>, the origin of which is a word so offensive to Black Africans that its use is <a href="https://www.cfr.org/blog/k-word-south-africa-and-proposed-new-penalties-against-hate-speech">banned in South Africa</a>.</p>
<p>Some may argue the scholarly naming of species should remain aloof from social change, and that Hibbert’s views on slavery are irrelevant to the classification of Australian flowers. We counter that, just like <a href="https://en.wikipedia.org/wiki/Statue_of_Edward_Colston">toppling statues in Bristol Harbour</a> or <a href="https://www.theguardian.com/uk-news/2021/mar/18/goodbye-cecil-rhodes-house-renamed-to-lose-link-to-british-empire-builder-in-africa">removing Cecil Rhodes’ name from public buildings</a>, renaming things is important and necessary if we are to right history’s wrongs.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/was-first-governor-james-stirling-had-links-to-slavery-as-well-as-directing-a-massacre-should-he-be-honoured-162078">WA's first governor James Stirling had links to slavery, as well as directing a massacre. Should he be honoured?</a>
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</p>
<hr>
<p>We believe that science, including taxonomy, must be socially responsible and responsive. Science is embedded in culture rather than housed in ivory towers, and scientists should work for the common good rather than blindly follow tradition. Deeply problematic names pervade science just as they pervade our streets, cities and landscapes.</p>
<p><em>Hibbertia</em> may be just a name, but we believe a different name for this lovely genus of Australian flowers would smell much sweeter.</p>
<hr>
<p><em>This article was co-authored by Tim Hammer, a postdoctoral research fellow at the State Herbarium of South Australia.</em></p><img src="https://counter.theconversation.com/content/172602/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Kevin Thiele does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>One of Australia’s largest groups of flower species is named after a wealthy British slave-trader. And Nazi memorabilia collectors have almost sent “Hitler’s beetle” extinct. It’s time for a change.Kevin Thiele, Adjunct Assoc. Professor, The University of Western AustraliaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1707192021-11-05T00:16:24Z2021-11-05T00:16:24Z5 major heatwaves in 30 years have turned the Great Barrier Reef into a bleached checkerboard<p>Just 2% of the Great Barrier Reef remains untouched by bleaching since 1998 and 80% of individual reefs have bleached severely once, twice or three times since 2016, <a href="https://www.sciencedirect.com/science/article/abs/pii/S0960982221014901">our new study</a> reveals today. </p>
<p>We measured the impacts of five marine heatwaves on the Great Barrier Reef over the past three decades: in 1998, 2002, 2016, 2017 and 2020. We found these bouts of extreme temperatures have transformed it into a checkerboard of bleached reefs with very different recent histories. </p>
<p>Whether we still have a functioning Great Barrier Reef in the decades to come depends on how much higher we allow global temperatures to rise. The bleaching events we’ve already seen in recent years are a result of the world warming by 1.2°C since pre-industrial times. </p>
<p>World leaders meeting at the climate summit in Glasgow must commit to more ambitious promises to drastically cut greenhouse gas emissions. It’s vital for the future of corals reefs, and for the hundreds of millions of people who depend on them for their livelihoods and food security.</p>
<h2>Coral in a hotter climate</h2>
<p>The Great Barrier Reef is comprised of more than 3,000 individual reefs stretching for <a href="https://www.gbrmpa.gov.au/the-reef/reef-facts">2,300 kilometres</a>, and supports more than 60,000 jobs in reef <a href="https://www.gbrmpa.gov.au/our-work/Managing-multiple-uses/tourism-on-the-great-barrier-reef">tourism</a>. </p>
<p>Under climate change, the frequency, intensity and scale of climate extremes is changing rapidly, including the record-breaking marine heatwaves that cause corals to bleach. Bleaching is a stress response by overheated corals, where they lose their colour and many struggle to survive. </p>
<p>If all new COP26 pledges by individual countries are actually met, then the projected increase in average global warming could be brought down <a href="https://www.climate-resource.com/tools/ndcs">to 1.9°C</a>. In theory, this would put us in line with the goal of the Paris Agreement, which is to keep global warming below 2°C, but preferably 1.5°C, this century. </p>
<p>However, it is still not enough to prevent the <a href="https://www.ipcc.ch/sr15/chapter/spm/">ongoing degradation</a> of the world’s coral reefs. The damage to coral reefs from anthropogenic heating so far is very clear, and further warming will continue to <a href="https://www.science.org/doi/10.1126/science.aan8048">ratchet down</a> reefs throughout the tropics. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/not-declaring-the-great-barrier-reef-as-in-danger-only-postpones-the-inevitable-164867">Not declaring the Great Barrier Reef as 'in danger' only postpones the inevitable</a>
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</em>
</p>
<hr>
<h2>Ecological memories of heatwaves</h2>
<p>Most reefs today are in early <a href="https://www.aims.gov.au/reef-monitoring/gbr-condition-summary-2020-2021">recovery mode</a>, as coral populations begin to re-build since they last experienced bleaching in 2016, 2017 and 2020. It takes about a decade for a decent recovery of the fastest growing corals, and much longer for slow-growing species. Many coastal reefs that were severely bleached in 1998 have never fully recovered. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/430169/original/file-20211104-19-1po1sc2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/430169/original/file-20211104-19-1po1sc2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/430169/original/file-20211104-19-1po1sc2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=416&fit=crop&dpr=1 600w, https://images.theconversation.com/files/430169/original/file-20211104-19-1po1sc2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=416&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/430169/original/file-20211104-19-1po1sc2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=416&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/430169/original/file-20211104-19-1po1sc2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=523&fit=crop&dpr=1 754w, https://images.theconversation.com/files/430169/original/file-20211104-19-1po1sc2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=523&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/430169/original/file-20211104-19-1po1sc2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=523&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The fringing reef flat at Orpheus Island on the central Great Barrier Reef, prior to mass coral bleaching in 1998.</span>
<span class="attribution"><span class="source">Bette Willis and Andrew Baird</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/430168/original/file-20211104-27-16wyz5j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/430168/original/file-20211104-27-16wyz5j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/430168/original/file-20211104-27-16wyz5j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=478&fit=crop&dpr=1 600w, https://images.theconversation.com/files/430168/original/file-20211104-27-16wyz5j.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=478&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/430168/original/file-20211104-27-16wyz5j.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=478&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/430168/original/file-20211104-27-16wyz5j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=601&fit=crop&dpr=1 754w, https://images.theconversation.com/files/430168/original/file-20211104-27-16wyz5j.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=601&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/430168/original/file-20211104-27-16wyz5j.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=601&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The same reef flat at Orpheus Island after further bleaching in 2002 and 2016.</span>
<span class="attribution"><span class="source">Bette Willis and Andrew Baird</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Each bleaching event so far has a different geographic footprint. Drawing upon <a href="https://www.mdpi.com/2072-4292/6/11/11579">satellite data</a>, we measured the duration and intensity of heat stress that the Great Barrier Reef experienced each summer, to explain why different parts were affected during all five events. </p>
<p>The bleaching responses of corals differed greatly in each event, and was strongly influenced by the recent history of previous bleaching. For this reason, it’s important to measure the extent and severity of bleaching directly, where it actually occurs, and not rely exclusively on water temperature data from satellites as an indirect proxy.</p>
<p>We found the most vulnerable reefs each year were the ones that had not bleached for a decade or longer. On the other hand, when successive episodes were close together in time (one to four years apart), the heat threshold for severe bleaching increased. In other words, the earlier event had hardened regions of the Great Barrier Reef to subsequent impacts.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/430176/original/file-20211104-15-noksid.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Bleached coral" src="https://images.theconversation.com/files/430176/original/file-20211104-15-noksid.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/430176/original/file-20211104-15-noksid.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/430176/original/file-20211104-15-noksid.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/430176/original/file-20211104-15-noksid.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/430176/original/file-20211104-15-noksid.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/430176/original/file-20211104-15-noksid.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/430176/original/file-20211104-15-noksid.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Bleaching is a stress response by overheated corals.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>For example, in 2002 and 2017, it took much more heat to trigger similar levels of bleaching that were measured in 1998 and 2016. The threshold for bleaching was much higher on reefs that had experienced an earlier episode of heat stress.</p>
<p>Similarly, southern corals, which escaped bleaching in 2016 and 2017, were the most vulnerable in 2020, compared to central and northern reefs that had bleached severely in previous events.</p>
<p>Many different mechanisms could generate these historical effects, or ecological memories. One is <a href="https://www.nature.com/articles/s41586-018-0041-2">heavy losses</a> of the more heat-susceptible coral species during an earlier event – dead corals don’t re-bleach.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/we-just-spent-two-weeks-surveying-the-great-barrier-reef-what-we-saw-was-an-utter-tragedy-135197">We just spent two weeks surveying the Great Barrier Reef. What we saw was an utter tragedy</a>
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<h2>Nowhere left to hide</h2>
<p>Only a single cluster of reefs remains unbleached in the far south, downstream from the rest of the Great Barrier Reef, in a small region that has remained consistently cool through the summer months during all five mass bleaching events. These reefs lie at the outer edge of the Great Barrier Reef, where upwelling of cool water may offer some protection from heatwaves, at least so far.</p>
<hr>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/430397/original/file-20211104-23-29h946.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/430397/original/file-20211104-23-29h946.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/430397/original/file-20211104-23-29h946.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=657&fit=crop&dpr=1 600w, https://images.theconversation.com/files/430397/original/file-20211104-23-29h946.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=657&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/430397/original/file-20211104-23-29h946.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=657&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/430397/original/file-20211104-23-29h946.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=826&fit=crop&dpr=1 754w, https://images.theconversation.com/files/430397/original/file-20211104-23-29h946.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=826&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/430397/original/file-20211104-23-29h946.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=826&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Map of the Great Barrier Reef showing the cumulative level of bleaching observed in 2016, 2017 and 2020. The colours represent the intensity of bleaching, ranging from zero (category 1, dark blue) to severe bleaching that affected more than 60% of corals (category 4, red)</span>
<span class="attribution"><span class="source">Author provided</span></span>
</figcaption>
</figure>
<hr>
<p>In theory, a judiciously placed network of well-protected, climate-resistant reefs might help to repopulate the <a href="https://conbio.onlinelibrary.wiley.com/doi/full/10.1111/conl.12587">broader seascape</a>, if greenhouse gas emissions are curtailed to stabilise temperatures later this century. </p>
<p>But the unbleached southern reefs are too few in number, and too far away from the rest of the Great Barrier Reef to produce and deliver sufficient coral larvae, to promote a long-distance recovery. </p>
<p>Instead, future replenishment of depleted coral populations is more likely to be local. It would come from the billions of larvae produced by recovering adults on nearby reefs that have not bleached for a while, or by corals inhabiting reef in deeper waters which tend to experience less heat stress than those living in shallow water. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/this-situation-brings-me-to-despair-two-reef-scientists-share-their-climate-grief-123520">'This situation brings me to despair': two reef scientists share their climate grief</a>
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<hr>
<p>Future recovery of corals will increasingly be temporary and incomplete, before being interrupted again by the inevitable next bleaching event. Consequently, the patchiness of living coral on the Great Barrier Reef will increase further, and corals will continue to decline under climate change.</p>
<p>Our findings make it clear we no longer have the luxury of studying individual climate-related events that were once unprecedented, or very rare. Instead, as the world gets hotter, it’s increasingly important to understand the effects and combined outcomes of sequences of rapid-fire catastrophes.</p><img src="https://counter.theconversation.com/content/170719/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Terry Hughes receives funding from The Australian Research Foundation. </span></em></p><p class="fine-print"><em><span>Sean Connolly has received funding from the Australian Research Councilfor research including effects of climate change on coral reefs, and he currently receives funding from the Mark and Rachel Rohr foundation for work on climate resilience in the Tropical East Pacific.
</span></em></p>New research shows just 2% of the Great Barrier Reef remains untouched by bleaching since 1998. Its future survival depends on how much higher we allow global temperatures to rise.Terry Hughes, Distinguished Professor, James Cook UniversitySean Connolly, Research Biologist, Smithsonian InstitutionLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1671192021-09-06T20:10:38Z2021-09-06T20:10:38ZPhotos from the field: why losing these tiny, loyal fish to climate change spells disaster for coral<figure><img src="https://images.theconversation.com/files/419517/original/file-20210906-17-9i5p6j.JPG?ixlib=rb-1.1.0&rect=0%2C5%2C3680%2C2748&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Catheline Froehlich</span>, <span class="license">Author provided</span></span></figcaption></figure><p><em>Environmental scientists see flora, fauna and phenomena the rest of us rarely do. In this series, we’ve invited them to share their unique <a href="https://theconversation.com/au/topics/photos-from-the-field-92499">photos from the field</a>.</em></p>
<hr>
<p>If you’ve ever dived on a coral reef, you may have peeked into a staghorn coral and seen small fish whizzing through its branches. But few realise that these small fish, such as tiny goby fish, play a crucial role in helping corals weather the storm of climate change. </p>
<p>But alarmingly, <a href="https://www.nature.com/articles/s41598-021-95778-x#article-info">our new research</a> found gobies decline far more than corals do after multiple cyclones and heatwaves. This is concerning because <a href="https://theconversation.com/snack-sized-candy-fish-explain-a-coral-mystery-117566">such small fish</a> — less than 5 centimetres in length — are critical to coral and reef health.</p>
<p>Unfortunately, the number of cyclones and heatwaves is on the rise. These disasters have begun to occur <a href="https://theconversation.com/this-is-the-most-sobering-report-card-yet-on-climate-change-and-earths-future-heres-what-you-need-to-know-165395">back-to-back</a>, leaving no time for marine life to recover. </p>
<p>With the recent push by UNESCO to list the Great Barrier Reef as “<a href="https://theconversation.com/not-declaring-the-great-barrier-reef-as-in-danger-only-postpones-the-inevitable-164867">in danger</a>”, the world is currently on edge about the status of coral reefs. We’re at a critical stage to take all the necessary measures to save coral reefs worldwide, and we must broaden our focus to understand how the important relationships between corals and fish are affected. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/419516/original/file-20210906-15-7fmuw6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/419516/original/file-20210906-15-7fmuw6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/419516/original/file-20210906-15-7fmuw6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/419516/original/file-20210906-15-7fmuw6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/419516/original/file-20210906-15-7fmuw6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/419516/original/file-20210906-15-7fmuw6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/419516/original/file-20210906-15-7fmuw6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/419516/original/file-20210906-15-7fmuw6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">This five-lined coral goby (<em>Gobiodon quinquestrigatus</em>) is taking a break on a coral branch.</span>
<span class="attribution"><span class="source">Catheline Froehlich</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>Goby fish: the snack-sized friends of coral</h2>
<p>In all environments, organisms can form relationships where they work together to improve each other’s health. This is called a mutual symbiosis, like a <a href="https://theconversation.com/you-scratch-my-back-the-beneficial-and-not-so-beneficial-relationships-between-organisms-57120">you-scratch-my-back</a> principle. </p>
<p>In coral reefs, other examples of mutual symbioses include invisible <a href="https://theconversation.com/what-we-have-in-common-with-corals-and-their-unexplored-microbial-world-64798">zooxanthellae algae</a> living within coral tissue, small <a href="https://theconversation.com/even-fish-have-to-protect-their-reputations-2348">cleaner fish removing parasites</a> from big fish, and eels and groupers <a href="https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.0040431">hunting together</a>. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/419523/original/file-20210906-21-1bnnikh.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/419523/original/file-20210906-21-1bnnikh.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/419523/original/file-20210906-21-1bnnikh.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/419523/original/file-20210906-21-1bnnikh.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/419523/original/file-20210906-21-1bnnikh.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/419523/original/file-20210906-21-1bnnikh.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/419523/original/file-20210906-21-1bnnikh.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/419523/original/file-20210906-21-1bnnikh.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">While this shark is taking a nap, small yellow fish are hiding under its fin, and it is also getting cleaned by a cleaner wrasse (slender black fish with neon blue outline).</span>
<span class="attribution"><span class="source">Catheline Froehlich</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/419529/original/file-20210906-14-mhp6bh.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/419529/original/file-20210906-14-mhp6bh.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/419529/original/file-20210906-14-mhp6bh.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/419529/original/file-20210906-14-mhp6bh.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/419529/original/file-20210906-14-mhp6bh.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/419529/original/file-20210906-14-mhp6bh.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/419529/original/file-20210906-14-mhp6bh.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/419529/original/file-20210906-14-mhp6bh.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Living on the edge: some fish live inside branched corals, while others live around the perimeter of coral bommies like this.</span>
<span class="attribution"><span class="source">Catheline Froehlich</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p><a href="https://lirrf.org/posts/why-do-gobies-and-corals-live-together/">Gobies that live in corals</a> are small, snack-sized fish that rarely venture beyond the prickly borders of their protective coral homes. The Great Barrier Reef is home to more than 20 species of coral gobies, which live in more than 30 species of staghorn corals. </p>
<p>In return for the coral’s protection, the gobies pluck off <a href="https://science.sciencemag.org/content/338/6108/804">harmful algae</a> growing on coral branches, produce a toxin to <a href="https://link.springer.com/article/10.1007/s00338-012-0947-3">deter potential coral-eating fish</a>, and <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0208545">reduce heat stress</a> by swimming around the coral and stopping stagnant water build up. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/419513/original/file-20210906-19-1qum3zv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/419513/original/file-20210906-19-1qum3zv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/419513/original/file-20210906-19-1qum3zv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=379&fit=crop&dpr=1 600w, https://images.theconversation.com/files/419513/original/file-20210906-19-1qum3zv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=379&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/419513/original/file-20210906-19-1qum3zv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=379&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/419513/original/file-20210906-19-1qum3zv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=477&fit=crop&dpr=1 754w, https://images.theconversation.com/files/419513/original/file-20210906-19-1qum3zv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=477&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/419513/original/file-20210906-19-1qum3zv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=477&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The blue-spotted coral goby (<em>Gobiodon erythrospilus</em>) is holding its position by pushing its front pectoral fins against coral branches.</span>
<span class="attribution"><span class="source">Catheline Froehlich</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/419514/original/file-20210906-27-1nn0odg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/419514/original/file-20210906-27-1nn0odg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/419514/original/file-20210906-27-1nn0odg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=382&fit=crop&dpr=1 600w, https://images.theconversation.com/files/419514/original/file-20210906-27-1nn0odg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=382&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/419514/original/file-20210906-27-1nn0odg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=382&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/419514/original/file-20210906-27-1nn0odg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=480&fit=crop&dpr=1 754w, https://images.theconversation.com/files/419514/original/file-20210906-27-1nn0odg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=480&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/419514/original/file-20210906-27-1nn0odg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=480&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Paired romance: these lemon coral gobies (<em>Gobiodon citrinus</em>) live in monogamous pairs while also sharing their coral with a humbug damselfish (<em>Dascyllus aruanus</em>).</span>
<span class="attribution"><span class="source">Catheline Froehlich</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Even if their corals become stressed and bleached, they <a href="http://www.int-res.com/articles/meps2009/394/m394p215.pdf">remain steadfast</a> within the coral, helping it to survive. Without their full-time cleaning staff, corals would be more susceptible when threatened with climate change. </p>
<p>Unfortunately, just like Nemos (clownfish) <a href="https://theconversation.com/saving-nemo-how-climate-change-threatens-anemonefish-and-their-homes-59966">living inside anemones</a>, climate change threatens the mutual symbioses between gobies and corals.</p>
<h2>Coral gobies in decline</h2>
<p>While SCUBA diving, <a href="https://www.nature.com/articles/s41598-021-95778-x#article-info">we surveyed</a> corals and their goby friends over a four-year period (2014-17) of near-continuous devastation at Lizard Island, on the Great Barrier Reef. Over this time, two category 4 <a href="https://theconversation.com/explainer-are-natural-disasters-on-the-rise-39232">cyclones</a> and two <a href="https://theconversation.com/coral-bleaching-comes-to-the-great-barrier-reef-as-record-breaking-global-temperatures-continue-56570">prolonged </a><a href="https://theconversation.com/we-just-spent-two-weeks-surveying-the-great-barrier-reef-what-we-saw-was-an-utter-tragedy-135197">heatwaves</a> wreaked havoc on this world-renowned reef. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/419530/original/file-20210906-24-14unen7.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/419530/original/file-20210906-24-14unen7.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/419530/original/file-20210906-24-14unen7.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/419530/original/file-20210906-24-14unen7.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/419530/original/file-20210906-24-14unen7.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/419530/original/file-20210906-24-14unen7.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/419530/original/file-20210906-24-14unen7.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/419530/original/file-20210906-24-14unen7.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Coral gobies are often hard to spot, so we use underwater flashlights to identify them correctly.</span>
<span class="attribution"><span class="source">Catheline Froehlich</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>What we saw was alarming. After the two cyclones, the 13 goby species (genus <em>Gobiodon</em>) and 28 coral species (genus <em>Acropora</em>) we surveyed declined substantially.</p>
<p>But after the two heatwaves, gobies suddenly fared even worse than corals. While some coral species persisted better than others, 78% no longer housed gobies. </p>
<p>Importantly, every single goby species either declined, or worse, completely disappeared. The few gobies we found were living alone, which is especially concerning because <a href="https://link.springer.com/article/10.1007%2FBF00005004">gobies breed in monogamous pairs</a>, much like most humans do. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/419512/original/file-20210906-21-mo8vqq.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/419512/original/file-20210906-21-mo8vqq.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/419512/original/file-20210906-21-mo8vqq.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/419512/original/file-20210906-21-mo8vqq.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/419512/original/file-20210906-21-mo8vqq.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/419512/original/file-20210906-21-mo8vqq.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/419512/original/file-20210906-21-mo8vqq.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/419512/original/file-20210906-21-mo8vqq.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">After cyclones and heatwaves, we found a lot of dead corals surrounding pockets of living corals and reef life at Lizard Island.</span>
<span class="attribution"><span class="source">Catheline Froehlich</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/419510/original/file-20210906-27-1vyep32.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/419510/original/file-20210906-27-1vyep32.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/419510/original/file-20210906-27-1vyep32.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/419510/original/file-20210906-27-1vyep32.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/419510/original/file-20210906-27-1vyep32.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/419510/original/file-20210906-27-1vyep32.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/419510/original/file-20210906-27-1vyep32.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/419510/original/file-20210906-27-1vyep32.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">We surveyed coral and goby survival and often found a lot of coral debris after heatwaves.</span>
<span class="attribution"><span class="source">Catheline Froehlich</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>Without urgent action, the outlook is bleak</h2>
<p>More and more studies are showing reef <a href="https://theconversation.com/fish-behaving-weirdly-climate-change-makes-reef-fish-do-odd-things-1620">fish behave differently</a> in <a href="https://theconversation.com/ocean-acidification-leaving-fish-in-the-dark-study-22538">warmer and more acidic water</a>. </p>
<p>Warmer water is even changing reef fish on a <a href="https://theconversation.com/i-studied-what-happens-to-reef-fish-after-coral-bleaching-what-i-saw-still-makes-me-nauseous-134247">genetic level</a>. Fish are <a href="https://onlinelibrary.wiley.com/doi/10.1111/eva.12386">struggling to reproduce</a>, to recognise what is <a href="https://www.pnas.org/content/106/6/1848">essential habitat</a>, and to detect predators. Research has shown <a href="https://onlinelibrary.wiley.com/doi/epdf/10.1111/j.1461-0248.2009.01400.x">clownfish</a>, for example, could not tell predatory fish (rockcods and dottybacks) from non-predators (surgeonfishes and rabbitfishes) when exposed to more acidic seawater. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/419521/original/file-20210906-25-1799vne.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/419521/original/file-20210906-25-1799vne.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/419521/original/file-20210906-25-1799vne.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/419521/original/file-20210906-25-1799vne.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/419521/original/file-20210906-25-1799vne.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/419521/original/file-20210906-25-1799vne.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/419521/original/file-20210906-25-1799vne.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/419521/original/file-20210906-25-1799vne.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Finding Nemo swimming in anemone in Lizard Island. The bright pink surrounding it is the column of the anemone. Picture the column as your neck and the tentacles as your hair.</span>
<span class="attribution"><span class="source">Abigail Shaughnessy</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>The bigger picture looks bleak. Corals are likely to become increasingly vulnerable if their symbiotic gobies and other inhabitants continue to decline. This could lead to further disruptions in the reef ecosystem because <a href="https://link.springer.com/article/10.1007%2Fs13199-011-0119-1">mutual symbioses are important for ecosystem stability</a>. </p>
<p>We need to broaden our focus to understand how animal interactions like these are being affected in these trying times. This is an emerging field of study that needs more research in the face of climate change.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/419520/original/file-20210906-13-1priugp.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/419520/original/file-20210906-13-1priugp.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/419520/original/file-20210906-13-1priugp.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/419520/original/file-20210906-13-1priugp.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/419520/original/file-20210906-13-1priugp.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/419520/original/file-20210906-13-1priugp.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/419520/original/file-20210906-13-1priugp.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/419520/original/file-20210906-13-1priugp.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Here, one of my assistants, Al Alder, is measuring the coral so that we can tell what happens to the size of corals after each climatic disaster.</span>
<span class="attribution"><span class="source">Catheline Froehlich</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/419531/original/file-20210906-25-d7xxxg.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/419531/original/file-20210906-25-d7xxxg.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/419531/original/file-20210906-25-d7xxxg.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/419531/original/file-20210906-25-d7xxxg.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/419531/original/file-20210906-25-d7xxxg.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/419531/original/file-20210906-25-d7xxxg.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/419531/original/file-20210906-25-d7xxxg.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/419531/original/file-20210906-25-d7xxxg.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Several fish that are not coral gobies are still found swimming about even after four years of climatic disasters at Lizard Island.</span>
<span class="attribution"><span class="source">Catheline Froehlich</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>On a global scale, multiple disturbances from cyclones and heatwaves are becoming the norm. We need to tackle the problem from multiple angles. For example, we must meet <a href="https://theconversation.com/net-zero-carbon-neutral-carbon-negative-confused-by-all-the-carbon-jargon-then-read-this-151382">net zero carbon emissions by 2050</a> and <a href="https://theconversation.com/manage-the-land-to-protect-the-reefs-15076">stop soil erosion and agricultural runoff</a> from flowing into the sea. </p>
<p>If we do not act now, gobies and their coral hosts may become a distant memory in this warming climate.</p><img src="https://counter.theconversation.com/content/167119/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Catheline Y.M. Froehlich received the Zoltan Florian Marine Biology Fellowship, which is funding from the Lizard Island Doctoral Fellowship program as part of the Australian Museum.</span></em></p><p class="fine-print"><em><span>Marian Wong and O. Selma Klanten do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Goby fish and coral rely on each other to survive. But new research found gobies are declining under climate change, dealing a double blow to Australia’s reefs.Catheline Y.M. Froehlich, PhD Fellow, University of WollongongMarian Wong, Senior Lecturer, University of WollongongO. Selma Klanten, Research Scientist, University of Technology SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1662782021-08-19T19:49:58Z2021-08-19T19:49:58ZSnorkellers discover rare, giant 400-year-old coral – one of the oldest on the Great Barrier Reef<figure><img src="https://images.theconversation.com/files/416646/original/file-20210818-27-qje78r.jpg?ixlib=rb-1.1.0&rect=0%2C70%2C1278%2C887&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Richard Woodgett</span></span></figcaption></figure><p>Snorkellers on the Great Barrier Reef have discovered a huge coral more than 400 years old which is thought to have survived 80 major cyclones, numerous coral bleaching events and centuries of exposure to other threats. We describe the discovery in <a href="http://nature.com/articles/s41598-021-94818-w">research</a> published today.</p>
<p>Our team surveyed the hemispherical structure, which comprises small marine animals and calcium carbonate, and found it’s the Great Barrier Reef’s widest coral, and one of the oldest. </p>
<p>It was discovered off the coast of Goolboodi (Orpheus Island), part of Queensland’s Palm Island Group. Traditional custodians of the region, the Manbarra people, have called the structure Muga dhambi, meaning “big coral”.</p>
<p>For now, Muga dhambi is in relatively good health. But climate change, declining water quality and other threats are taking a toll on the Great Barrier Reef. Scientists, Traditional Owners and others must keep a close eye on this remarkable, resilient structure to ensure it is preserved for future generations.</p>
<figure class="align-center ">
<img alt="coral and snorkellers" src="https://images.theconversation.com/files/416672/original/file-20210818-19-anzpts.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/416672/original/file-20210818-19-anzpts.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/416672/original/file-20210818-19-anzpts.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/416672/original/file-20210818-19-anzpts.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/416672/original/file-20210818-19-anzpts.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/416672/original/file-20210818-19-anzpts.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/416672/original/file-20210818-19-anzpts.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Muga dhambi is the widest coral structure recorded on the Great Barrier Reef.</span>
<span class="attribution"><span class="source">Richard Woodgett</span></span>
</figcaption>
</figure>
<h2>Far older than European settlement</h2>
<p>Muga dhambi is located in a relatively remote, rarely visited and highly protected marine area. It was found during citizen science research in March this year, on a reef slope not far from shore. </p>
<p>We conducted a literature review and consulted other scientists to compare the size, age and health of the structure with others in the Great Barrier Reef and internationally. </p>
<p>We measured the structure at 5.3 metres tall and 10.4 metres wide. This makes it 2.4 metres wider than the widest Great Barrier Reef coral <a href="https://doi.org/10.1007/BF00345677">previously</a> measured by scientists.</p>
<p>Muga dhambi is of the coral genus <em>Porites</em> and is one of a large group of corals known as “massive Porites”. It’s brown to cream in colour and made of small, stony polyps. </p>
<p>These polyps secrete layers of calcium carbonate beneath their bodies as they grow, forming the foundations upon which reefs are built.</p>
<p>Muga dhambi’s height suggests it is aged between 421 and 438 years old – far pre-dating European exploration and settlement of Australia. We made this calculation based on rock coral growth rates and annual sea surface temperatures.</p>
<p>The Australian Institute of Marine Science has investigated more than 328 colonies of massive Porites corals along the Great Barrier Reef and has aged the oldest at 436 years. The institute has not investigated the age of Muga dhambi, however the structure is probably one of the oldest on the Great Barrier Reef.</p>
<p>Other comparatively large massive Porites have previously been found throughout the Pacific. One exceptionally large colony in American Samoa measured 17m × 12m. Large Porites have also been found near Taiwan and Japan.</p>
<figure class="align-center ">
<img alt="Mountainous island and blue sea" src="https://images.theconversation.com/files/416650/original/file-20210818-23-wt3kj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/416650/original/file-20210818-23-wt3kj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=386&fit=crop&dpr=1 600w, https://images.theconversation.com/files/416650/original/file-20210818-23-wt3kj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=386&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/416650/original/file-20210818-23-wt3kj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=386&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/416650/original/file-20210818-23-wt3kj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=485&fit=crop&dpr=1 754w, https://images.theconversation.com/files/416650/original/file-20210818-23-wt3kj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=485&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/416650/original/file-20210818-23-wt3kj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=485&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Muga dhambi was discovered in waters off Goolboodi (Orpheus Island).</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>Resilient, but under threat</h2>
<p>We reviewed environmental events over the past 450 years and found Muga dhambi is unusually resilient. It has survived up to 80 major cyclones, numerous coral bleaching events and centuries of exposure to invasive species, low tides and human activity.</p>
<p>About 70% of Muga dhambi consisted of live coral, but the remaining 30% was dead. This section, at the top of the structure, was covered with green boring sponge, turf algae and green algae.</p>
<p>Coral tissue can die from exposure to sun at low tides or warm water. Dead coral can be quickly colonised by opportunistic, fast growing organisms, as is the case with Muga dhambi.</p>
<p>Green boring sponge invades and excavates corals. The sponge’s advances will likely continue to compromise the structure’s size and health.</p>
<p>We found marine debris at the base of Muga dhambi, comprising rope and three concrete blocks. Such debris is a threat to the marine environment and species such as corals.</p>
<p>We found no evidence of disease or coral bleaching.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/the-great-barrier-reef-is-in-trouble-there-are-a-whopping-45-reasons-why-122930">The Great Barrier Reef is in trouble. There are a whopping 45 reasons why</a>
</strong>
</em>
</p>
<hr>
<figure class="align-center ">
<img alt="to come" src="https://images.theconversation.com/files/416678/original/file-20210818-21-13b0f9w.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/416678/original/file-20210818-21-13b0f9w.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/416678/original/file-20210818-21-13b0f9w.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/416678/original/file-20210818-21-13b0f9w.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/416678/original/file-20210818-21-13b0f9w.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/416678/original/file-20210818-21-13b0f9w.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/416678/original/file-20210818-21-13b0f9w.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The structure may be compromised by the advance of a sponge species across Muga dhambi (sponge is the darker half in this image).</span>
<span class="attribution"><span class="source">Richard Woodgett</span></span>
</figcaption>
</figure>
<h2>‘Old man’ of the sea</h2>
<p>A Traditional Owner from outside the region took part in our citizen science training which included surveys of corals, invertebrates and fish. We also consulted the Manbarra Traditional Owners about and an appropriate cultural name for the structure. </p>
<p>Before recommending Muga dhambi, the names the Traditional Owners considered included:</p>
<ul>
<li>Muga (big)</li>
<li>Wanga (home)</li>
<li>Muugar (coral reef)</li>
<li>Dhambi (coral)</li>
<li>Anki/Gurgu (old)</li>
<li>Gulula (old man)</li>
<li>Gurgurbu (old person).</li>
</ul>
<p>Indigenous languages are an integral part of Indigenous culture, spirituality, and connection to country. Traditional Owners suggested calling the structure Muga dhambi would communicate traditional knowledge, language and culture to other Indigenous people, tourists, scientists and students.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/how-traditional-owners-and-officials-came-together-to-protect-a-stunning-stretch-of-wa-coast-163078">How Traditional Owners and officials came together to protect a stunning stretch of WA coast</a>
</strong>
</em>
</p>
<hr>
<figure class="align-center ">
<img alt="coral rock under water with sky" src="https://images.theconversation.com/files/416682/original/file-20210818-23-nmb1be.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/416682/original/file-20210818-23-nmb1be.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/416682/original/file-20210818-23-nmb1be.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/416682/original/file-20210818-23-nmb1be.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/416682/original/file-20210818-23-nmb1be.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/416682/original/file-20210818-23-nmb1be.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/416682/original/file-20210818-23-nmb1be.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">It’s hoped the name Muga dhambi will encourage recognition of the connection Indigenous people have to the coral structure.</span>
<span class="attribution"><span class="source">Richard Woodgett</span></span>
</figcaption>
</figure>
<h2>A wonder for all generations</h2>
<p>No database exists for significant corals in Australia or globally. Cataloguing the location of massive and long-lived corals can be benefits. </p>
<p>For example from a scientific perspective, it can allow analyses which can help understand century-scale changes in ocean events and can be used to verify climate models. Social and economic benefits can include diving tourism and citizen science, as well as engaging with Indigenous culture and stewardship.</p>
<p>However, cataloguing the location of massive corals could lead to them being damaged by anchoring, research and pollution from visiting boats.</p>
<p>Looking to the future, there is real concern for all corals in the Great Barrier Reef due to threats such as climate change, declining water quality, overfishing and coastal development. We recommend monitoring of Muga dhambi in case restoration is needed in future.</p>
<p>We hope our research will mean current and future generations care for this wonder of nature, and respect the connections of Manbarra Traditional Owners to their Sea Country.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/not-declaring-the-great-barrier-reef-as-in-danger-only-postpones-the-inevitable-164867">Not declaring the Great Barrier Reef as 'in danger' only postpones the inevitable</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/166278/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Adam Smith received funding from the Australian Government’s Reef Trust and the Great Barrier Reef Foundation to conduct this research. Adam is Deputy Chair of the Museum of Underwater Art.</span></em></p><p class="fine-print"><em><span>Nathan Cook received funding the partnership between the Australian Government’s Reef Trust and the Great Barrier Reef Foundation to conduct this research. Research was conducted in partnership with Reef Check Australia as part of their reef monitoring program.
</span></em></p><p class="fine-print"><em><span>Vicki Saylor does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The remarkably resilient structure is in good health, for now. But work is needed to ensure it is preserved for future generations.Adam Smith, Adjunct Associate Professor, James Cook UniversityNathan Cook, Marine Scientist , James Cook UniversityVicki Saylor, Manbarra Traditional Owner, Indigenous KnowledgeLicensed as Creative Commons – attribution, no derivatives.