tag:theconversation.com,2011:/au/topics/2016-coral-bleaching-event-26991/articles
2016 coral bleaching event – The Conversation
2023-06-07T03:14:54Z
tag:theconversation.com,2011:article/206750
2023-06-07T03:14:54Z
2023-06-07T03:14:54Z
Warm is the new norm for the Great Barrier Reef – and a likely El Niño raises red flags
<p>The Bureau of Meteorology this week <a href="https://media.bom.gov.au/releases/1170/the-bureau-of-meteorology-issues-an-el-nino-alert/">declared</a> a 70% chance of an El Niño developing this year. This raises concern for the health of the Great Barrier Reef, which is under continuing threat from climate change.</p>
<p>Recent summers have shown the <a href="https://theconversation.com/5-major-heatwaves-in-30-years-have-turned-the-great-barrier-reef-into-a-bleached-checkerboard-170719">devastating damage</a> heat stress can wreak on the reef. We must act urgently to protect this underwater marvel – through this likely El Niño, and beyond.</p>
<p>We are coral reef and climate scientists, and policy experts. We’ve seen how the Great Barrier Reef is nearing its tipping point. After this point, it will become <a href="https://theconversation.com/adapt-move-or-die-repeated-coral-bleaching-leaves-wildlife-on-the-great-barrier-reef-with-few-options-179570">unrecognisable as a functioning ecosystem</a>.</p>
<p>But the scale of climate threat is beyond the tools currently used to manage the Great Barrier Reef. New measures and sustained effort are needed – at local, national, and international scales – if we’re serious about saving this natural wonder.</p>
<h2>International treasure under threat</h2>
<p>The Great Barrier Reef is internationally renowned for its <a href="https://elibrary.gbrmpa.gov.au/jspui/handle/11017/2787">biodiversity</a>, including more than 450 species of coral, 1,600 species of fish and 6,000 species of molluscs. </p>
<p>It is also an <a href="https://www2.gbrmpa.gov.au/learn/reef-facts">economic workhorse</a>, contributing about A$6 billion to the Australian economy and providing some 64,000 full-time jobs. Many industries and coastal communities in Queensland rely on a healthy Great Barrier Reef. </p>
<p>But Australia’s reefs are <a href="https://theconversation.com/the-great-barrier-reef-is-in-trouble-there-are-a-whopping-45-reasons-why-122930">in trouble</a> and climate change is the biggest threat – bringing heatwaves, severe cyclones and more acidic oceans.</p>
<p>The background temperature of the Great Barrier Reef has <a href="https://www2.gbrmpa.gov.au/learn/threats/sea-temperature">warmed by 0.8°C</a> since 1910. This warming can couple with ocean temperature variability, such as from El Niño and its counterpart, La Niña. But because the Great Barrier Reef is already struggling under climate change, an El Niño could mean even more pressure.</p>
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Read more:
<a href="https://theconversation.com/what-the-next-australian-government-must-do-to-save-the-great-barrier-reef-182861">What the next Australian government must do to save the Great Barrier Reef</a>
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<figure class="align-center ">
<img alt="Graph showing changes in sea temperature, ocean pH, sea level and tropical cyclones" src="https://images.theconversation.com/files/530022/original/file-20230605-29-jm1why.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/530022/original/file-20230605-29-jm1why.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=327&fit=crop&dpr=1 600w, https://images.theconversation.com/files/530022/original/file-20230605-29-jm1why.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=327&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/530022/original/file-20230605-29-jm1why.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=327&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/530022/original/file-20230605-29-jm1why.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=410&fit=crop&dpr=1 754w, https://images.theconversation.com/files/530022/original/file-20230605-29-jm1why.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=410&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/530022/original/file-20230605-29-jm1why.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=410&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">Indicative changes in sea temperature, ocean pH, sea level and tropical cyclones based on climate projections (from Great Barrier Reef 2019 Outlook Report).</span>
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<h2>The bathtub is filling</h2>
<p>We hope this analogy helps explain the situation.</p>
<p>Imagine a bathtub. The water inside it represents global sea-surface temperature. When the bathtub was only half-full, temporary heat variability (from El Niño) caused splashes, but they were contained in the tub.</p>
<p>Now fast-forward to the present day. For more than a century, humans have been heating the planet by burning fossil fuels. The background temperature has risen and the bathtub is now almost filled to the brim. Add a splash of heat from El Niño and the bath spills over.</p>
<p>These splashes bring consequences: more mass bleaching of coral and, in severe cases, widespread coral death.</p>
<p>El Niño and La Niña have become <a href="https://theconversation.com/new-study-helps-solve-a-30-year-old-puzzle-how-is-climate-change-affecting-el-nino-and-la-nina-205128">more variable</a> in recent decades. This has meant more frequent and stronger events – bigger splashes in the bathtub – that pose a grave threat to the Great Barrier Reef’s health and biodiversity. </p>
<p>All the while, the bathtub keeps filling. </p>
<p>The World Meteorological Organisation <a href="https://hadleyserver.metoffice.gov.uk/wmolc/WMO_GADCU_2023-2027.pdf">reported</a> that the next five years will be the warmest since records began. And 2023 will almost certainly be among the <a href="https://www.ncei.noaa.gov/access/monitoring/monthly-report/global/202304/supplemental/page-2">ten warmest years</a> on record. </p>
<p>Earth’s average temperature is <a href="https://theconversation.com/global-warming-to-bring-record-hot-year-by-2028-probably-our-first-above-1-5-c-limit-205758">predicted</a> to exceed 1.5°C of warming in at least one of the next five years. This would produce a big splash – but it doesn’t represent the bathtub level reaching the brim.</p>
<p>Under the global climate accord known as the Paris Agreement, nations <a href="https://unfccc.int/process-and-meetings/the-paris-agreement">are pursuing efforts to limit</a> the average global temperature increase to 1.5°C above pre-industrial levels. Background warming beyond 1.5°C is widely considered by climate scientists as dangerous. We’re entering an era in which hot and more frequent splashes are imminent – and the survival of coral reefs is becoming increasingly threatened.</p>
<p>Clearly, the global warming we’re seeing now is unprecedented. We must turn off the tap.</p>
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<img alt="graph showing increase in atmospheric CO₂ concentration" src="https://images.theconversation.com/files/530226/original/file-20230606-23-9qrejq.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/530226/original/file-20230606-23-9qrejq.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=349&fit=crop&dpr=1 600w, https://images.theconversation.com/files/530226/original/file-20230606-23-9qrejq.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=349&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/530226/original/file-20230606-23-9qrejq.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=349&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/530226/original/file-20230606-23-9qrejq.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=438&fit=crop&dpr=1 754w, https://images.theconversation.com/files/530226/original/file-20230606-23-9qrejq.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=438&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/530226/original/file-20230606-23-9qrejq.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=438&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">Atmospheric carbon dioxide concentration from the Mauna Loa Observatory has increased from below 320 parts per million (ppm) to over 420 ppm since 1958 (Data: Scripps CO₂ Program).</span>
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<h2>An inadequate tool kit</h2>
<p>Unless global emissions are drastically reduced, frequent severe bleaching is <a href="https://unesdoc.unesco.org/ark:/48223/pf0000265625">projected</a> this century for all 29 World Heritage-listed coral reefs.</p>
<p>This would cause untold ecological damage. It would also reduce the reefs’ ability to support human communities that depend on them.</p>
<p>Coral bleaching is not the only threat to the Great Barrier Reef. <a href="https://theconversation.com/we-all-know-the-great-barrier-reef-is-in-danger-the-un-has-just-confirmed-it-again-195551#:%7E:text=The%20most%20significant%20threats%20are,unsustainable%20fishing%20and%20coastal%20development.">Other</a> pressing problems include poor water quality from land-based runoff, crown-of-thorns starfish and unsustainable fishing and coastal development.</p>
<p>So how do we deal with all of this? A range of management actions exists. </p>
<p>Banning fishing in some areas and limiting exploitation elsewhere has benefited conservation, while also <a href="https://www.sciencedirect.com/science/article/pii/S0960982212003958">enhancing fisheries</a>.</p>
<p>But other actions have had mixed success. And not all available tools are being applied effectively.</p>
<p>For example, “<a href="https://www2.gbrmpa.gov.au/access/zoning/special-management-areas">special management areas</a>” were intended to restrict human use of the Great Barrier Reef for conservation or management purposes. But their use has been limited. And emergency implementations of these areas, allowed under the law, have never been used.</p>
<p>Crucially, none of the available actions were designed to respond to climate threats. The reality is, the scale of climate disturbance is beyond the available management tools.</p>
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Read more:
<a href="https://theconversation.com/we-all-know-the-great-barrier-reef-is-in-danger-the-un-has-just-confirmed-it-again-195551">We all know the Great Barrier Reef is in danger – the UN has just confirmed it. Again</a>
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<iframe src="https://player.vimeo.com/video/404223289" width="500" height="281" frameborder="0" webkitallowfullscreen="" mozallowfullscreen="" allowfullscreen=""></iframe>
<figcaption><span class="caption">Source: Australian Academy of Science.</span></figcaption>
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<h2>What are we waiting for?</h2>
<p>The scientific evidence is unequivocal. We must work at local, national, and international scales to help the Great Barrier Reef better cope with climate change. The likely arrival of an El Niño makes this task ever more urgent. </p>
<p>Australian and international governments must take immediate and decisive action on emissions reduction. This includes banning new coal and gas projects and rapidly shifting to renewable energy. Communities reliant on fossil-fuel industries should be helped to transition to new livelihoods.</p>
<p>Reef management agencies need to tackle climate threats more effectively – at a scale commensurate with the problem. This requires a new way of managing key areas. That could mean, for example, temporarily closing off parts of the Great Barrier Reef affected by coral bleaching to give them a reprieve from other stressors such as fishing and tourism.</p>
<p>And individuals must also ensure our everyday choices – in transport, consumption and elsewhere – help tackle the climate threat.</p>
<p>It’s time for us all to double-down and ensure the survival of the Great Barrier Reef, and the planet. There is no room for complacency. So what are we waiting for?</p>
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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>
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<img src="https://counter.theconversation.com/content/206750/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Scott F. Heron is receiving and has received funding from Australian Research Council, as well as from international government sources. Together with Jon Day, Scott developed the Climate Vulnerability Index (CVI) for World Heritage that has also been applied to assess climate impacts upon other areas of significance.</span></em></p><p class="fine-print"><em><span>Jodie L. Rummer has received funding from the Australian Research Council. She is the current Vice President of the Australian Coral Reef Society.</span></em></p><p class="fine-print"><em><span>Jon Day previously worked for the Great Barrier Reef Marine Park Authority between 1986 and 2014, and was one of the Directors at GBRMPA between 1998 and 2014. He represented Australia as one of the formal delegates to the World Heritage Committee between 2007-2011.</span></em></p>
The scale of climate threat is beyond the tools we have to manage the Great Barrier Reef. New measures and sustained effort are needed.
Scott F. Heron, Associate Professor in Physics, James Cook University
Jodie L. Rummer, Professor of Marine Biology, James Cook University
Jon C. Day, PSM, Adjunct Senior Research Fellow, College of Science and Engineering, James Cook University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/137383
2020-05-21T20:17:05Z
2020-05-21T20:17:05Z
Marine heat waves spell trouble for tropical reef fish — even before corals die
<figure><img src="https://images.theconversation.com/files/336587/original/file-20200520-152327-r9k34j.jpg?ixlib=rb-1.1.0&rect=81%2C126%2C5898%2C3872&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A school of convict tang (_Acanthurus triostegus_) swim on Kiritimati's dead reefs after the 2015–16 marine heatwave.</span> <span class="attribution"><span class="source">(Kevin Bruce)</span>, <span class="license">Author provided</span></span></figcaption></figure><p>Despite the <a href="https://wwf.panda.org/our_work/oceans/problems/">many challenges facing the world’s oceans</a> today, coral reefs remain strongholds of marine biodiversity. <a href="https://www.sciencedirect.com/science/article/pii/S0960982214016236">Thousands of species of fish</a> of all shapes and sizes call these colourful, complex and economically important ecosystems home. <a href="https://doi.org/10.1038/nclimate3382">Impending ocean warming, however, spells trouble for these fishes</a>.</p>
<p>Ever since the <a href="https://www.icriforum.org/documents/status-of-coral-reefs-of-the-world-2000/">first global coral bleaching event</a> devastated reefs in the late 1990s, scientists have worked to document the effects of these catastrophic phenomena on coral reef fishes. In the wake of severe bleaching, <a href="https://www.mdpi.com/1424-2818/3/3/424">coral mortality often leads to changes in the community of fish that live on the reef</a>: fish that feed on corals decline, while those that feed on algae increase as the latter proliferates. </p>
<p>But what happens to fish during a severe heat stress event — that is, when water temperatures rise, but the corals have not yet bleached and died? It seems that very few scientists have tried to find out. </p>
<p><a href="https://doi.org/10.1002/eap.2124">Our new study</a>, published in <em>Ecological Applications</em>, surveyed reef fish communities before, during and after the 2015–16 El Niño on Kiritimati, a coral atoll in the Pacific Ocean, that is part of the country of Kiribati. Our research suggests that short-term increases in water temperature may have devastating impacts on reef fish populations and the local communities that rely on them.</p>
<h2>Heating up the world’s largest atoll</h2>
<p>Kiritimati, or Christmas Island, is the world’s largest coral atoll — ring-shaped reef — by land mass. The nearest major airport is more than 2,000 kilometres away, in Hawaii. The people who live on Kiritimati are <a href="https://doi.org/10.1016/j.ocecoaman.2016.01.012">highly dependent on reef fish</a> as a source of both food and income.</p>
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<img alt="" src="https://images.theconversation.com/files/336588/original/file-20200520-152349-1wz6wbe.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/336588/original/file-20200520-152349-1wz6wbe.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/336588/original/file-20200520-152349-1wz6wbe.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/336588/original/file-20200520-152349-1wz6wbe.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/336588/original/file-20200520-152349-1wz6wbe.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/336588/original/file-20200520-152349-1wz6wbe.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/336588/original/file-20200520-152349-1wz6wbe.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 healthy coral reef on Kiritimati, prior to the El Niño in 2015–16.</span>
<span class="attribution"><span class="source">(Kristina Tietjen)</span>, <span class="license">Author provided</span></span>
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<p>While the 2015–16 El Niño <a href="https://www.doi.org/10.1126/science.aan8048">wreaked havoc on reefs worldwide</a>, its effects were especially catastrophic around Kiritimati. <a href="https://doi.org/10.1371/journal.pone.0190957">Unprecedented levels of heat stress</a> persisting for 10 straight months led to <a href="https://www.washingtonpost.com/news/energy-environment/wp/2016/04/12/why-dead-coral-reefs-stir-fears-of-dangerous-climate-change/">over 80 per cent coral mortality</a> around the island, but not before triggering a change in the local fish community.</p>
<h2>Stressed-out reef fish</h2>
<p>After just two months of heat stress, reef fish populations around the atoll had plummeted by half. The number of fish species also declined, with some species disappearing entirely. Five species, including the Chevron butterflyfish (<em>Chaetodon trifascialis</em>), which feeds exclusively on live coral, have not been seen since. </p>
<p>One year after the heat wave, however, we found — somewhat surprisingly — that total reef fish biomass and abundance had recovered, rebounding to levels similar to those we’d observed in years prior to the heat wave. This begs the question: What exactly happened during those long, heat-stricken months?</p>
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<a href="https://images.theconversation.com/files/336589/original/file-20200520-152338-17yd9op.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/336589/original/file-20200520-152338-17yd9op.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/336589/original/file-20200520-152338-17yd9op.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/336589/original/file-20200520-152338-17yd9op.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/336589/original/file-20200520-152338-17yd9op.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/336589/original/file-20200520-152338-17yd9op.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/336589/original/file-20200520-152338-17yd9op.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/336589/original/file-20200520-152338-17yd9op.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>
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<span class="caption">The pufferfish, <em>Arothron meleagris</em>, one of the many reef fish species on Kiritimati that declined during the heat wave.</span>
<span class="attribution"><span class="source">(Sean Dimoff)</span>, <span class="license">Author provided</span></span>
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<p>While severe heat stress can lead to <a href="http://www.int-res.com/abstracts/meps/v401/p233-243/">decreased fitness</a> and even <a href="https://doi.org/10.1111/gcb.12455">mortality</a> in reef fishes, we believe that most of the missing fish sought shelter on the deeper, cooler reefs around the island during the heat wave. Once the heat had subsided, they could have easily returned to the shallows.</p>
<p>Yet the recovery of the reef fish community was not the same across the board. Sites on the atoll nearest to the villages, where the reefs have been heavily affected by dredging, fishing and pollution, had impaired recovery relative to areas of the atoll far from villages where the reefs were nearly pristine prior to the heat wave. </p>
<p>This suggests that local environmental protection could help make reefs more resilient to the ravages of severe ocean warming. While it may not be enough to entice fish to stay put during a severe warming event, high-quality reefs may be more attractive to these fish upon their return.</p>
<h2>A window into the future</h2>
<p>If the reef fish return once the heat stress is over, is their disappearance in the short-term really a big deal? Considering that the survival of <a href="https://www.wri.org/publication/reefs-risk-revisited">millions of people worldwide</a> depends on tropical reef fishes, we believe the answer to this question is a resounding yes.</p>
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<img alt="" src="https://images.theconversation.com/files/336583/original/file-20200520-152344-jc7044.jpg?ixlib=rb-1.1.0&rect=65%2C113%2C3844%2C2880&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/336583/original/file-20200520-152344-jc7044.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/336583/original/file-20200520-152344-jc7044.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/336583/original/file-20200520-152344-jc7044.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/336583/original/file-20200520-152344-jc7044.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/336583/original/file-20200520-152344-jc7044.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/336583/original/file-20200520-152344-jc7044.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">A healthy coral reef on Kiritimati, prior to the heat wave.</span>
<span class="attribution"><span class="source">(Kieran Cox)</span>, <span class="license">Author provided</span></span>
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</figure>
<p>The impacts of climate change on coral reefs are only <a href="https://www.doi.org/10.1126/science.aaw6974">predicted to worsen</a> in the coming decades. Studying the effects of severe heat stress in the present can serve as a window into the future, foreshadowing the consequences of gradual ocean warming and <a href="https://doi.org/10.1038/s41586-018-0383-9">more frequent and severe marine heat waves</a> that are predicted to occur. </p>
<p>By understanding how fish populations react to elevated water temperatures, we can also attempt to predict and mitigate the effects of ocean warming on highly reef-dependent communities such as those on Kiritimati.</p>
<p>Within the realm of coral reef research, most studies on heat stress to date have focused on the <a href="https://link.springer.com/chapter/10.1007%2F978-94-017-7499-4_8">link between heat stress and coral bleaching</a>, and the <a href="https://doi.org/10.3390/d3030424">knock-on effects of catastrophic bleaching on reef fishes</a>. However, corals are not the only animals affected by the heat stress itself. Unless we intervene to limit climate change globally, we may risk losing not only corals but critically important reef fishes as well.</p><img src="https://counter.theconversation.com/content/137383/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jennifer M.T. Magel receives funding from the Natural Sciences and Engineering Research Council of Canada. </span></em></p><p class="fine-print"><em><span>Julia K. Baum receives funding from the Natural Science and Engineering Research Council of Canada, the Pew Charitable Trusts, National Geographic, and the Rufford Foundation. </span></em></p>
Reef fish vanish during marine heat waves, but may bounce back quickly on reefs that have few other environmental stressors.
Jennifer M.T. Magel, Research Assistant, Biology, University of Victoria
Julia K. Baum, Professor of Biology, University of Victoria
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/135197
2020-04-06T20:06:07Z
2020-04-06T20:06:07Z
We just spent two weeks surveying the Great Barrier Reef. What we saw was an utter tragedy
<figure><img src="https://images.theconversation.com/files/325543/original/file-20200406-74261-hftf3v.jpeg?ixlib=rb-1.1.0&rect=736%2C592%2C5254%2C3386&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Author supplied </span></span></figcaption></figure><p>The Australian summer just gone will be remembered as the moment when human-caused climate change struck hard. First came drought, then deadly bushfires, and now a bout of coral bleaching on the Great Barrier Reef – the third in just five years. Tragically, the 2020 bleaching is severe and the most widespread we have ever recorded.</p>
<p>Coral bleaching at regional scales is caused by spikes in sea temperatures during unusually hot summers. The first recorded mass bleaching event along Great Barrier Reef occurred in 1998, then the <a href="http://www.bom.gov.au/climate/change/archive/media99.shtml">hottest year on record</a>.</p>
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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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<p>Since then we’ve seen four more mass bleaching events – and more temperature records broken – in 2002, 2016, 2017, and again in 2020. </p>
<p>This year, February had the<a href="https://www.abc.net.au/news/2020-03-15/cyclone-great-barrier-reef-bleaching-record-seas-temperatures/12050102"> highest monthly sea surface temperatures</a> ever recorded on the Great Barrier Reef since the Bureau of Meteorology’s records began in 1900.</p>
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<iframe src="https://player.vimeo.com/video/404223289" width="500" height="281" frameborder="0" webkitallowfullscreen="" mozallowfullscreen="" allowfullscreen=""></iframe>
<figcaption><span class="caption">Source: Australian Academy of Science.</span></figcaption>
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<h2>Not a pretty picture</h2>
<p>We surveyed 1,036 reefs from the air during the last two weeks in March, to measure the extent and severity of coral bleaching throughout the Great Barrier Reef region. Two observers, from the ARC Centre of Excellence for Coral Reef Studies and the Great Barrier Reef Marine Park Authority, scored each reef visually, repeating the same procedures developed during early bleaching events. </p>
<p>The accuracy of the aerial scores <a href="https://www.nature.com/articles/nature21707?dom=icopyright&src=">is verified</a> by underwater surveys on reefs that are lightly and heavily bleached. While underwater, we also measure how bleaching changes between shallow and <a href="https://www.nature.com/articles/s41467-018-05741-0">deeper reefs</a>.</p>
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Read more:
<a href="https://theconversation.com/attention-united-nations-dont-be-fooled-by-australias-latest-report-on-the-great-barrier-reef-128304">Attention United Nations: don't be fooled by Australia's latest report on the Great Barrier Reef</a>
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<p>Of the reefs we surveyed from the air, 39.8% had little or no bleaching (the green reefs in the map). However, 25.1% of reefs were severely affected (red reefs) – that is, on each reef more than 60% of corals were bleached. A further 35% had more modest levels of bleaching.</p>
<p>Bleaching isn’t necessarily fatal for coral, and it affects <a href="https://theconversation.com/how-much-coral-has-died-in-the-great-barrier-reefs-worst-bleaching-event-69494">some species more than others</a>. A pale or lightly bleached coral typically regains its colour within a few weeks or months and survives. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/325544/original/file-20200406-74225-nyhw98.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/325544/original/file-20200406-74225-nyhw98.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/325544/original/file-20200406-74225-nyhw98.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/325544/original/file-20200406-74225-nyhw98.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/325544/original/file-20200406-74225-nyhw98.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/325544/original/file-20200406-74225-nyhw98.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/325544/original/file-20200406-74225-nyhw98.png?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">The 2020 coral bleaching event was the second-worst in more than two decades.</span>
<span class="attribution"><span class="source">ARC Centre of Excellence for Coral Reef Studies</span></span>
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<p>But when bleaching is severe, many corals die. In 2016, half of the shallow water corals died on the northern region of the Great Barrier Reef <a href="https://www.nature.com/articles/s41586-018-0041-2">between March and November</a>. Later this year, we’ll go underwater to assess the losses of corals during this most recent event.</p>
<p>Compared to the four previous bleaching events, there are fewer unbleached or lightly bleached reefs in 2020 than in 1998, 2002 and 2017, but more than in 2016. Similarly, the proportion of severely bleached reefs in 2020 is exceeded only by 2016. By both of these metrics, 2020 is the second-worst mass bleaching event of the five experienced by the Great Barrier Reef since 1998.</p>
<p>The unbleached and lightly bleached (green) reefs in 2020 are predominantly offshore, mostly close to the edge of the continental shelf in the northern and southern Great Barrier Reef. However, offshore reefs in the central region were severely bleached again. Coastal reefs are also badly bleached at almost all locations, stretching from the Torres Strait in the north to the southern boundary of the Great Barrier Reef Marine Park.</p>
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<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/325593/original/file-20200406-74220-1axw6r6.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/325593/original/file-20200406-74220-1axw6r6.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/325593/original/file-20200406-74220-1axw6r6.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=438&fit=crop&dpr=1 600w, https://images.theconversation.com/files/325593/original/file-20200406-74220-1axw6r6.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=438&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/325593/original/file-20200406-74220-1axw6r6.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=438&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/325593/original/file-20200406-74220-1axw6r6.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=551&fit=crop&dpr=1 754w, https://images.theconversation.com/files/325593/original/file-20200406-74220-1axw6r6.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=551&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/325593/original/file-20200406-74220-1axw6r6.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=551&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="attribution"><a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
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<p>For the first time, severe bleaching has struck all three regions of the Great Barrier Reef – the northern, central and now large parts of the southern sectors. The north was the worst affected region in 2016, followed by the centre in 2017. </p>
<p>In 2020, the cumulative footprint of bleaching has expanded further, to include the south. The distinctive footprint of each bleaching event closely matches the location of <a href="https://www.nature.com/articles/nature21707?dom=icopyright&src=">hotter and cooler conditions in different years</a>.</p>
<h2>Poor prognosis</h2>
<p>Of the five mass bleaching events we’ve seen so far, only 1998 and 2016 occurred during <a href="http://www.bom.gov.au/climate/updates/articles/a008-el-nino-and-australia.shtml">an El Niño</a> – a weather pattern that spurs warmer air temperatures in Australia. </p>
<p>But as summers grow hotter under climate change, we no longer need an El Niño to trigger mass bleaching at the scale of the Great Barrier Reef. We’ve already seen the first example of back-to-back bleaching, in the consecutive summers of 2016 and 2017. The gap between recurrent bleaching events is shrinking, hindering a full recovery. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/325547/original/file-20200406-74216-8dr0g6.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/325547/original/file-20200406-74216-8dr0g6.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=325&fit=crop&dpr=1 600w, https://images.theconversation.com/files/325547/original/file-20200406-74216-8dr0g6.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=325&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/325547/original/file-20200406-74216-8dr0g6.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=325&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/325547/original/file-20200406-74216-8dr0g6.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=409&fit=crop&dpr=1 754w, https://images.theconversation.com/files/325547/original/file-20200406-74216-8dr0g6.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=409&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/325547/original/file-20200406-74216-8dr0g6.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=409&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">For the first time, severe bleaching has struck all three regions of the Great Barrier Reef.</span>
<span class="attribution"><span class="source">ARC Centre of Excellence for Coral Reef Studies</span></span>
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<p>After five bleaching events, the number of reefs that have escaped severe bleaching continues to dwindle. Those reefs are located offshore, in the far north and in remote parts of the south. </p>
<p>The Great Barrier Reef will continue to lose corals from heat stress, until global emissions of greenhouse gasses are reduced to net zero, and sea temperatures stabilise. Without urgent action to achieve this outcome, it’s clear our coral reefs will not survive business-as-usual emissions. </p>
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Read more:
<a href="https://theconversation.com/i-studied-what-happens-to-reef-fish-after-coral-bleaching-what-i-saw-still-makes-me-nauseous-134247">I studied what happens to reef fish after coral bleaching. What I saw still makes me nauseous</a>
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<img src="https://counter.theconversation.com/content/135197/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Terry Hughes receives funding from the Australian Research Council. He provides scientific advice to the Queensland and Commonwealth government. He is the Director of the ARC Centre of Excellence for Coral Reef Studies.</span></em></p><p class="fine-print"><em><span>Morgan Pratchett receives funding from the Australian Research Council, Director of National Parks, and Fisheries Research and Development Corporation. His research is directed at improving management of marine systems in Queensland, Australia and throughout the world.</span></em></p>
Coral bleaching last summer was severe and widespread. And for the first time, severe bleaching has struck all three regions of the Great Barrier Reef.
Terry Hughes, Distinguished Professor, James Cook University
Morgan Pratchett, Professor, ARC Centre of Excellence for Coral Reef Studies, James Cook University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/119232
2019-06-24T20:10:00Z
2019-06-24T20:10:00Z
‘Sadness, disgust, anger’: fear for the Great Barrier Reef made climate change feel urgent
<figure><img src="https://images.theconversation.com/files/280864/original/file-20190624-61747-1wkzrx2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Tourists are experiencing 'Reef grief'.</span> <span class="attribution"><span class="source">Matt Curnock</span>, <span class="license">Author provided</span></span></figcaption></figure><p>Media coverage of mass coral bleaching on the Great Barrier Reef may have been a major tipping point for public concerns around climate change, according to research published today.</p>
<p>Severe and extensive bleaching during the summers of 2016 and 2017 has been <a href="https://theconversation.com/back-to-back-bleaching-has-now-hit-two-thirds-of-the-great-barrier-reef-76092">directly attributed to human-caused climate change</a>. Much of the ensuing <a href="https://www.researchgate.net/publication/324259357_Competing_and_conflicting_messages_via_online_news_media_Potential_impacts_of_claims_that_the_Great_Barrier_Reef_is_dying">media coverage used emotional language</a>, with many reports of the Reef <a href="https://www.outsideonline.com/2112086/obituary-great-barrier-reef-25-million-bc-2016">dying</a>.</p>
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Read more:
<a href="https://theconversation.com/back-to-back-bleaching-has-now-hit-two-thirds-of-the-great-barrier-reef-76092">Back-to-back bleaching has now hit two-thirds of the Great Barrier Reef</a>
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<p>While the physical effects of the bleaching have been well documented, we wanted to understand the social and cultural impact. </p>
<p>Our research, including a <a href="http://dx.doi.org/10.1038/s41558-019-0504-y">study published today</a> in Nature Climate Change, has compared survey responses from thousands of Australians and international visitors, before and after the bleaching event.</p>
<h2>Reef grief</h2>
<p>Our research team conducted face-to-face interviews with 4,681 visitors to the Great Barrier Reef region, in 14 coastal towns from Cooktown to Bundaberg, over June to August in both 2013 and 2017. We asked more than 50 questions about their perceptions and values of the Reef, as well as their attitudes towards climate change.</p>
<p>We found a large proportion of respondents, including Australians and overseas visitors, expressed forms of <a href="https://link.springer.com/article/10.1007/s11625-019-00666-z">grief</a> in response to loss and damage to the iconic ecosystem. Negative emotions associated with words given in short statements about “what the Great Barrier Reef means to you”, included sadness, disgust, anger and fear. </p>
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Read more:
<a href="https://theconversation.com/hope-and-mourning-in-the-anthropocene-understanding-ecological-grief-88630">Hope and mourning in the Anthropocene: Understanding ecological grief</a>
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<p>Emotional appeals are widely used in media stories and in social media campaigns, and appealing to fear in particular can heighten a story’s <a href="https://doi.org/10.1080/15213269.2014.941112">impact and spread online</a>.</p>
<p>However, a side-effect of this approach is the erosion of people’s perceived ability to take effective action. This is called a person’s “self-efficacy”.
This effect is now well documented in <a href="https://doi.org/10.1177/1075547008329201">reactions to representations of climate change</a>, and is actually a barrier to positive community engagement and action on the issue.</p>
<p>In short, the more afraid someone is for the Great Barrier Reef, the less they may feel their individual efforts will help to protect it. </p>
<p>While our results show a decline in respondents’ self-efficacy, there was a corresponding increase in how highly they valued the Reef’s biodiversity, its scientific heritage and its status as an international icon. They were also more willing to support action to protect the Reef. This shows widespread empathy for the imperilled icon, and suggests greater support for collective actions to mitigate threats to the Reef.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/280878/original/file-20190624-97777-avb0wc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/280878/original/file-20190624-97777-avb0wc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/280878/original/file-20190624-97777-avb0wc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/280878/original/file-20190624-97777-avb0wc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/280878/original/file-20190624-97777-avb0wc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/280878/original/file-20190624-97777-avb0wc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=504&fit=crop&dpr=1 754w, https://images.theconversation.com/files/280878/original/file-20190624-97777-avb0wc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=504&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/280878/original/file-20190624-97777-avb0wc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=504&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">Researchers surveyed thousands of visitors to the Great Barrier Reef in 2013 and 2017.</span>
<span class="attribution"><span class="source">Matt Curnock</span>, <span class="license">Author provided</span></span>
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<h2>Changing attitudes</h2>
<p>We observed a significant increase in the proportion of people who believe that climate change is “an immediate threat requiring action”. In 2013 some 50% of Australian visitors to the Great Barrier Reef region agreed climate change is an immediate threat; in 2017 that rose to 67%. Among international visitors, this proportion was even higher (64% in 2013, rising to 78% in 2017).</p>
<p>This represents a remarkable change in public attitudes towards climate change over a relatively short period. Previous surveys of <a href="https://www.researchgate.net/profile/Zoe_Leviston/publication/284563911_Australian_attitudes_to_climate_change_and_adaptation_2010_-_2014/links/5706110c08ae44d70ee34ca4/Australian-attitudes-to-climate-change-and-adaptation-2010-2014.pdf">Australian climate change attitudes</a> over 2010 to 2014 showed that aggregate levels of opinion remained stable over that time. </p>
<p>Comparing our findings with other <a href="https://doi.org/10.1016/j.ocecoaman.2018.03.037">recent research</a> describing the extent of coverage and style of reporting associated with the 2016-2017 mass coral bleaching event, we infer that this event, and the associated media representations, contributed significantly to the shift in public attitudes towards climate change. </p>
<h2>Moving beyond fear</h2>
<p>As a source of <a href="https://www.nature.com/articles/palcomms201546">national pride</a> and with World Heritage status, the Great Barrier Reef will continue to be a high profile icon representing the broader climate change threat.</p>
<p>Media reports and advocacy campaigns that emphasise fear, loss and destruction can get attention from large audiences who may take the message of climate change on board.</p>
<p>But this does not necessarily translate into positive action. A more purposeful approach to public communication and engagement is needed to encourage collective activity that will help to mitigate climate change and reduce other serious threats facing the Reef. </p>
<p>Examples of efforts that are underway to reduce pressures on the Reef include improvements to water quality, control of crown-of-thorns starfish outbreaks, and reducing poaching in protected zones. Tourism operators on the Reef are also playing an important role in restoring affected areas, and are educating visitors about threats, to improve Reef stewardship.</p>
<p>Clearly there remains an immediate need to reduce greenhouse gas emissions to ensure the Reef’s World Heritage qualities are maintained for future generations.</p>
<p>However, maintaining hope, and offering accessible actions towards attainable goals is critical to engaging people in collective efforts, to help build a more sustainable future in which coral reefs can survive.</p>
<p><br></p>
<hr>
<p><em>The authors would like to acknowledge Nadine Marshall, who co-wrote this article while employed by CSIRO. We thank our other co-authors of the Nature Climate Change paper, including Lauric Thiault (National Center for Scientific Research, PSL Université Paris), Jessica Hoey and Genevieve Williams (Great Barrier Reef Marine Park Authority), Bruce Taylor and Petina Pert (CSIRO Land and Water) and Jeremy Goldberg (CSIRO & James Cook University). The scientific results and conclusions, as well as any views or opinions expressed herein, are those of the authors and do not necessarily reflect those of the Australian Government or the Minister for the Environment, or the Queensland Government, or indicate commitment to any particular course of action.</em></p><img src="https://counter.theconversation.com/content/119232/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>This research by the authors uses data from the Social and Economic Long-Term Monitoring Program (SELTMP) for the Great Barrier Reef, with funding provided by the Australian and Queensland Governments as part of the Reef 2050 Integrated Monitoring and Reporting Program (2017-2019) and the Australian Government’s National Environmental Research Program (2011-2015), Tropical Ecosystems Hub. </span></em></p><p class="fine-print"><em><span>Scott Heron receives funding from the Australian Research Council.</span></em></p>
Severe coral bleaching may have been the crucial factor in bringing home the reality of climate change for many people.
Matt Curnock, Social Scientist, CSIRO
Scott F. Heron, Senior Lecturer, James Cook University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/95142
2018-04-18T20:23:50Z
2018-04-18T20:23:50Z
How the 2016 bleaching altered the shape of the northern Great Barrier Reef
<figure><img src="https://images.theconversation.com/files/215347/original/file-20180418-163978-1aql97h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Staghorn and tabular corals suffered mass die-offs, robbing many individual reefs of their characteristic shapes.</span> <span class="attribution"><span class="source">ARC Centre of Excellence for Coral Reef Studies/ Mia Hoogenboom</span></span></figcaption></figure><p>In 2016 the Great Barrier Reef suffered <a href="https://theconversation.com/its-official-2016s-great-barrier-reef-bleaching-was-unlike-anything-that-went-before-88078">unprecedented mass coral bleaching</a> – part of a <a href="https://theconversation.com/au/topics/2016-coral-bleaching-event-26991">global bleaching event</a> that dwarfed its predecessors in 1998 and 2002. This was followed by <a href="https://theconversation.com/back-to-back-bleaching-has-now-hit-two-thirds-of-the-great-barrier-reef-76092">another mass bleaching</a> the following year. </p>
<p>This was the first case of back-to-back mass bleaching events on the reef. The result was a 30% loss of corals in 2016, a further 20% loss in 2017, and big changes in community structure. New research <a href="http://nature.com/articles/doi:10.1038/s41586-018-0041-2">published in Nature today</a> now reveals the damage that these losses caused to the wider ecosystem functioning of the Great Barrier Reef.</p>
<p>Fast-growing staghorn and tabular corals suffered a rapid, catastrophic die-off, changing the three-dimensional character of many individual reefs. In areas subject to the most sustained high temperatures, some corals died without even bleaching – the first time that such rapid coral death has been documented on such a wide scale. </p>
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Read more:
<a href="https://theconversation.com/its-official-2016s-great-barrier-reef-bleaching-was-unlike-anything-that-went-before-88078">It's official: 2016's Great Barrier Reef bleaching was unlike anything that went before</a>
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<p>The research team, led by <a href="https://theconversation.com/profiles/terry-hughes-9894">Terry Hughes</a> of James Cook University, carried out extensive surveys during the two bleaching events, at a range of scales.</p>
<p>First, aerial surveys from planes generated thousands of videos of the reef. The data from these videos were then verified by teams of divers in the water using traditional survey methods. </p>
<p>Finally, teams of divers took samples of corals and investigated their physiology in the laboratory. This included counting the density of the microalgae that live within the coral cells and provide most of the energy for the corals. </p>
<p>The <a href="http://nature.com/articles/doi:10.1038/s41586-018-0041-2">latest paper</a> follows on from <a href="https://www.nature.com/articles/nature21707">earlier research</a> which documented the 81% of reefs that bleached in the northern sector of the Great Barrier Reef, 33% in the central section, and 1% in the southern sector, and compared this event with previous bleaching events. <a href="http://science.sciencemag.org/content/359/6371/80">Another previous paper</a> documented the reduction in time between bleaching events since the 1980s, down to the current interval of one every six years. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/215349/original/file-20180418-163982-1mmwasn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/215349/original/file-20180418-163982-1mmwasn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/215349/original/file-20180418-163982-1mmwasn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/215349/original/file-20180418-163982-1mmwasn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/215349/original/file-20180418-163982-1mmwasn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/215349/original/file-20180418-163982-1mmwasn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/215349/original/file-20180418-163982-1mmwasn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/215349/original/file-20180418-163982-1mmwasn.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>
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<span class="caption">Different colour morphs of Acropora millepora, each exhibiting a bleaching response during mass coral bleaching event.</span>
<span class="attribution"><span class="source">ARC Centre of Excellence for Coral Reef StudiesStudies/ Gergely Torda</span></span>
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<p>Although reef scientists have been <a href="http://www.publish.csiro.au/MF/MF99078">predicting the increased frequency</a> and severity of bleaching events for two decades, this paper has some surprising and alarming results. Bleaching events occur when the temperature rises above the average summer maximum for a sufficient period. We measure this accumulated heat stress in “degree heating weeks” (DHW) – the number of degrees above the average summer maximum, multiplied by the number of weeks. Generally, the higher the DHW, the higher the expected coral death. </p>
<p>The US National Oceanic and Atmospheric Administration has suggested that <a href="https://coralreefwatch.noaa.gov/satellite/dhw.php">bleaching generally starts at 4 DHW</a>, and death at around 8 DHW. Modelling of the <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/gcb.12390">expected results of future bleaching events</a> has been based on these estimates, often with the expectation the thresholds will become higher over time as corals adapt to changing conditions. </p>
<p>In the 2016 event, however, bleaching began at 2 DHW and corals began dying at 3 DHW. Then, as the sustained high temperatures continued, coral death accelerated rapidly, reaching more than 50% mortality at only 4-5 DHW. </p>
<p>Many corals also died very rapidly, without appearing to bleach beforehand. This suggests that these corals essentially shut down due to the heat. This is the first record of such rapid death occurring at this scale. </p>
<p>This study shows clearly that the structure of coral communities in the northern sector of the reef has changed dramatically, with a predominant loss of branching corals. The post-bleaching reef has a higher proportion of massive growth forms which, with no gaps between branches, provide fewer places for fish and invertebrates to hide. This loss of hiding places is one of the reasons for the reduction of <a href="https://www.independent.co.uk/environment/fish-populations-collapse-great-barrier-reef-coral-bleaching-australia-a8294751.html">fish populations</a> following severe bleaching events. </p>
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Read more:
<a href="https://theconversation.com/the-worlds-coral-reefs-are-in-trouble-but-dont-give-up-on-them-yet-78588">The world's coral reefs are in trouble, but don't give up on them yet</a>
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<p>The International Union for Conservation of Nature (IUCN), which produces the <a href="http://www.iucnredlist.org">Red List</a> of threatened species, recently extended this concept to <a href="https://www.iucn.org/theme/ecosystem-management/our-work/red-list-ecosystems">ecosystems</a> that are threatened with collapse. This is difficult to implement, but this new research provides the initial and post-event data, leaves us with no doubt about the driver of the change, and suggests threshold levels of DHWs. These cover the requirements for such a listing. </p>
<p>Predictions of recovery times following these bleaching events are difficult as many corals that survived are weakened, so mortality continues. Replacement of lost corals through recruitment relies on healthy coral larvae arriving and finding suitable settlement substrate. Corals that have experienced these warm events are often slow to recover enough to reproduce normally so larvae may need to travel from distant healthy reefs.</p>
<p>Although this paper brings us devastating news of coral death at relatively low levels of heat stress, it is important to recognise that we still have plenty of good coral cover remaining on the Great Barrier Reef, particularly in the <a href="https://theconversation.com/the-worlds-coral-reefs-are-in-trouble-but-dont-give-up-on-them-yet-78588">southern and central sectors</a>. We can save this reef, but the time to act is now. </p>
<p>This is not just for the sake of our precious Great Barrier Reef, but for the people who live close to reefs around the world that are at risk from climate change. Millions rely on reefs for protection of their nations from oceanic swells, for food and for other ecosystem services. </p>
<p>This research leaves no doubt that we must reduce global emissions dramatically and swiftly if we are save these vital ecosystems. We also need to invest in looking after reefs at a local level to increase their chances of surviving the challenges of climate change. This means adequately <a href="https://theconversation.com/the-new-great-barrier-reef-pollution-plan-is-better-but-still-not-good-enough-83233">funding improvements to water quality</a> and <a href="https://theconversation.com/the-story-behind-australias-marine-reserves-and-how-we-should-change-them-65220">protecting as many areas as possible</a>.</p><img src="https://counter.theconversation.com/content/95142/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Selina Ward is a councillor for the Australian Coral Reef Society.</span></em></p>
The 2016 bleaching event resulted in 30% mortality on the Great Barrier Reef, with many corals dying of the heat before they bleached and the loss of branching corals creating less complex reef structure.
Selina Ward, Senior Lecturer, School of Biological Sciences, The University of Queensland
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/88078
2017-12-13T19:08:11Z
2017-12-13T19:08:11Z
It’s official: 2016’s Great Barrier Reef bleaching was unlike anything that went before
<p>It is no longer news that the Great Barrier Reef has suffered <a href="https://theconversation.com/how-much-coral-has-died-in-the-great-barrier-reefs-worst-bleaching-event-69494">extreme bleaching</a>. </p>
<p>In early 2016, we heard that the reef had suffered the worst bleaching ever recorded. <a href="https://www.nature.com/articles/nature21707">Surveys published in June that year</a> estimated that 93% of coral on the vast northern section of the reef was bleached, and 22% had already been killed. </p>
<p><a href="https://theconversation.com/year-on-year-bleaching-threatens-great-barrier-reefs-world-heritage-status-74606">Further reports from this year</a> show that bleaching again occurred. The back-to-back bleaching hit more than two-thirds of the Great Barrier Reef and may <a href="https://theconversation.com/the-great-barrier-reef-isnt-listed-as-in-danger-but-its-still-in-big-trouble-80681">threaten its UNESCO World Heritage listing</a>. </p>
<p>After recent years of damage, what does the future hold for our priceless reef? </p>
<p>Our <a href="http://www.ametsoc.net/eee/2016/ch28.pdf">new research</a>, published in the Bulletin of the American Meteorological Society’s <a href="https://www.ametsoc.org/ams/index.cfm/publications/bulletin-of-the-american-meteorological-society-bams/explaining-extreme-events-from-a-climate-perspective/">special report on climate extremes</a>, shows the news isn’t good for the Great Barrier Reef’s future. </p>
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Read more:
<a href="https://theconversation.com/how-to-work-out-which-coral-reefs-will-bleach-and-which-might-be-spared-84842">How to work out which coral reefs will bleach, and which might be spared</a>
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<p>Coral reefs are complex ecosystems that are affected by many factors. Changes in sea surface temperatures, rainfall, cloudiness, agricultural runoff, or <a href="https://theconversation.com/cloudy-issue-we-need-to-fix-the-barrier-reefs-murky-waters-39380">water quality</a> can affect a reef’s health and <a href="https://theconversation.com/au/topics/great-barrier-reef-threats-series-17189">resilience to stress</a>. </p>
<p><a href="https://theconversation.com/great-barrier-reef-bleaching-would-be-almost-impossible-without-climate-change-58408">Early analysis</a> of the 2016 bleaching suggested that the Great Barrier Reef was suffering from thermal stress brought on by human-caused climate change. </p>
<p>Our study took a new and comprehensive approach to examine these multiple climatic and environmental influences.</p>
<p>We set out to answer the crucial question: could anything else have bleached the Great Barrier Reef, besides human-induced climate change? </p>
<h2>Clear fingerprint</h2>
<p>The results were clear. Using a suite of climate models, we found that the significant warming of the Coral Sea region was likely caused by greenhouse gases from human activities. This warming was the primary cause of the extreme 2016 bleaching episode. </p>
<p>But what about those other complex factors? The 2016 event coincided with an El Niño episode that was <a href="https://theconversation.com/el-nino-is-over-but-has-left-its-mark-across-the-world-59823">among the most severe ever observed</a>. The <a href="https://theconversation.com/explainer-el-nino-and-la-nina-27719">El Niño-Southern Oscillation system</a>, with its positive El Niño and negative La Niña phases, has been linked to bleaching of various coral reefs in the past. </p>
<p>Our study showed that although the 2016 El Niño probably also contributed to the bleaching, this was a secondary contributor to the corals’ thermal stress. The major factor was the increase in temperatures because of climate change. </p>
<p>We next analysed other environmental data. <a href="https://link.springer.com/article/10.1007/s00338-015-1350-7">Previous research</a> has found that corals at sites with better water quality (that is, lower concentrations of pollution particles) are more resilient and less prone to bleaching. </p>
<p>Pollution data used in our study show that water quality in 2016 may have been better than in previous bleaching years. This means that the Great Barrier Reef should have been at lower risk of bleaching compared to long-term average conditions, all else being equal. Instead, record bleaching hit the reef as a result of the warming temperature trend. </p>
<h2>Previous events</h2>
<p>The final part of our investigation involved comparing the conditions behind the record 2016 bleaching with those seen in previous mass bleaching episodes on the Great Barrier Reef, in 1997-98 and 2010-11.</p>
<p>When we analysed these previous events on the Reef, we found very different factors at play. </p>
<p>In 1997-98 the bleaching coincided with a <a href="https://celebrating200years.noaa.gov/magazine/enso/el_nino.html">very strong El Niño event</a>. Although an El Niño event also occurred in 2016, the two were very different in terms of the distribution of unusually warm waters, particularly in the eastern equatorial Pacific. In 1997-98, the primary cause of the bleaching – which was less severe than in 2016 – was El Niño. </p>
<p>In 2010-11, the health of the Great Barrier Reef was impaired by runoff. That summer brought <a href="http://www.bom.gov.au/climate/current/annual/aus/2011/">record high rainfall to eastern Australia</a>, causing widespread flooding across Queensland. As a result of the discharge of freshwater onto the reef reducing the salinity, bleaching occurred. </p>
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Read more:
<a href="https://theconversation.com/feeling-helpless-about-the-great-barrier-reef-heres-one-way-you-can-help-76014">Feeling helpless about the Great Barrier Reef? Here's one way you can help</a>
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<p>There have been many reports in recent years warning of trouble for the Great Barrier Reef. Sadly, our study is yet another warning about the reef’s future – perhaps the most comprehensive warning yet. It tells us that the 2016 bleaching differed from previous mass bleaching events because it was driven primarily by human-induced climate warming.</p>
<p>This puts the Great Barrier Reef in grave danger of future bleaching from further greenhouse warming. The local environmental factors that have previously helped to protect our reefs, such as good water quality, will become less and less able to safeguard corals as the oceans warm. </p>
<p>Now we need to take immediate action to reduce greenhouse gas emissions and limit further warming. Without these steps, there is simply no future for our Great Barrier Reef.</p><img src="https://counter.theconversation.com/content/88078/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Sophie Lewis receives funding from the Australian Research Council. </span></em></p><p class="fine-print"><em><span>Jennie Mallela receives funding from The Australian Research Council and the Australian National University. </span></em></p>
The 2016 bleaching on the Great Barrier Reef was the worst on record. Now a new analysis points the finger squarely at human-induced warming, and warns that the entire reef’s future is at stake.
Sophie Lewis, Research fellow, Australian National University
Jennie Mallela, Research Fellow in Coral Reef Monitoring and Reef Health Appraisal, Australian National University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/84842
2017-10-02T18:40:34Z
2017-10-02T18:40:34Z
How to work out which coral reefs will bleach, and which might be spared
<p>Regional variations in sea surface temperature, related to seasons and El Niño, could be crucial for the survival of coral reefs, according to our <a href="http://nature.com/articles/doi:10.1038/nclimate3399">new research</a>. This suggests that we should be able to identify the reefs most at risk of mass bleaching, and those that are more likely to survive unscathed.</p>
<p>Healthy coral reefs support diverse ecosystems, hosting <a href="http://www.reefresilience.org/coral-reefs/reefs-and-resilience/value-of-reefs/">25% of all marine fish species</a>. They provide food, coastal protection and <a href="http://www.reefresilience.org/coral-reefs/reefs-and-resilience/value-of-reefs/">livelihoods for at least 500 million people</a>.</p>
<p>But global warming, coupled with other pressures such as nutrient and sediment input, changes in sea level, waves, storms, ventilation, hydrodynamics, and ocean acidification, could lead to the <a href="http://e360.yale.edu/features/is_the_end_in_sight_for_the_worlds_coral_reefs">end of the world’s coral reefs in a couple of decades</a>.</p>
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Read more:
<a href="https://theconversation.com/how-much-coral-has-died-in-the-great-barrier-reefs-worst-bleaching-event-69494">How much coral has died in the Great Barrier Reef's worst bleaching event?</a>
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<p>Climate warming is the major cause of stress for corals. The world just witnessed an event described as the “<a href="https://coralreefwatch.noaa.gov/satellite/analyses_guidance/global_coral_bleaching_2014-17_status.php">longest global coral die-off on record</a>”, and scientists have been raising the alarm about coral bleaching for decades. </p>
<p>The first global-scale mass bleaching event happened in 1998, destroying <a href="http://www.reefbase.org/resource_center/publication/statusreport.aspx?refid=27173">16% of the world coral reefs</a>. Unless greenhouse emissions are drastically reduced, the question is no longer if coral bleaching will happen again, but when and how often?</p>
<p>To help protect coral reefs and their ecosystems, effective management and conservation strategies are crucial. Our research shows that understanding the relationship between natural variations of sea temperature and human-driven ocean warming will help us identify the areas that are most at risk, and also those that are best placed to provide safe haven.</p>
<h2>A recurrent threat</h2>
<p>Bleaching happens when sea temperatures are unusually high, causing the corals to expel the coloured algae that live within their tissues. Without these algae, corals are unable to reproduce or to build their skeletons properly, and can ultimately die.</p>
<p>The two most devastating global mass bleaching events on record – in 1998 and <a href="https://theconversation.com/au/topics/2016-coral-bleaching-event-26991">2016</a> – were both triggered by <a href="https://theconversation.com/australias-climate-in-2016-a-year-of-two-halves-as-el-nino-unwound-70758">El Niño</a>. But when water temperatures drop back to normal, corals can often recover.</p>
<p>Certain types of coral can also acclimatise to rising sea temperatures. But as our planet warms, periods of bleaching risk will become more frequent and more severe. As a consequence, corals will have less and less time to recover between bleaching events.</p>
<p>We are already witnessing a decline in coral reefs. Global populations have declined by <a href="http://www.reefbase.org/resource_center/publication/statusreport.aspx?refid=27173">1-2% per year</a> in response to repeated bleaching events. Closer to home, the Great Barrier Reef <a href="http://www.pnas.org/content/109/44/17995.full.pdf">lost 50% of its coral cover between 1985 and 2012</a>.</p>
<h2>A non-uniform response to warming</h2>
<p>While the future of worldwide coral reefs looks dim, not all reefs will be at risk of recurrent bleaching at the same time. In particular, reefs located south of 15ºS (including the Great Barrier Reef, as well as islands in south Polynesia and Melanesia) are likely to be the last regions to be affected by harmful recurrent bleaching.</p>
<p>We used to think that Micronesia’s reefs would be among the first to die off, because the climate is warming faster there than in many other places. But our research, <a href="http://nature.com/articles/doi:10.1038/nclimate3399">published today in Nature Climate Change</a>, shows that the overall increase in temperature is not the only factor that affects coral bleaching response. </p>
<p>In fact, the key determinant of recurrent bleaching is the natural variability of ocean temperature. Under warming, temperature variations associated with seasons and climate processes like El Niño influence the pace of recurrent bleaching, and explain why some reefs will experience bleaching risk sooner than others in the future.</p>
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<a href="https://images.theconversation.com/files/188294/original/file-20171002-28500-6tjhbm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/188294/original/file-20171002-28500-6tjhbm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/188294/original/file-20171002-28500-6tjhbm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/188294/original/file-20171002-28500-6tjhbm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/188294/original/file-20171002-28500-6tjhbm.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/188294/original/file-20171002-28500-6tjhbm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/188294/original/file-20171002-28500-6tjhbm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/188294/original/file-20171002-28500-6tjhbm.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>
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<span class="caption">Different zones of the Pacific are likely to experience differing amounts of climate variability.</span>
<span class="attribution"><span class="license">Author provided</span></span>
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<a href="https://images.theconversation.com/files/188290/original/file-20171002-28494-11s9zjp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/188290/original/file-20171002-28494-11s9zjp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/188290/original/file-20171002-28494-11s9zjp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=205&fit=crop&dpr=1 600w, https://images.theconversation.com/files/188290/original/file-20171002-28494-11s9zjp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=205&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/188290/original/file-20171002-28494-11s9zjp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=205&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/188290/original/file-20171002-28494-11s9zjp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=257&fit=crop&dpr=1 754w, https://images.theconversation.com/files/188290/original/file-20171002-28494-11s9zjp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=257&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/188290/original/file-20171002-28494-11s9zjp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=257&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">Degrees of future bleaching risk for corals in the three main Pacific zones.</span>
<span class="attribution"><span class="license">Author provided</span></span>
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<p>Our results suggest that El Niño events will continue to be the major drivers of mass bleaching events in the central Pacific. As average ocean temperatures rise, even mild El Niño events will have the potential to trigger widespread bleaching, meaning that these regions could face severe bleaching every three to five years within just a few decades. In contrast, only the strongest El Niño events will cause mass bleaching in the South Pacific. </p>
<p>In the future, the risk of recurrent bleaching will be more seasonally driven in the South Pacific. Once the global warming signal pushes summer temperatures to dangerously warm levels, the coral reefs will experience bleaching events every summers. In the western Pacific, the absence of natural variations of temperatures initially protects the coral reefs, but only a small warming increase can rapidly transition the coral reefs from a safe haven to a permanent bleaching situation.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/feeling-helpless-about-the-great-barrier-reef-heres-one-way-you-can-help-76014">Feeling helpless about the Great Barrier Reef? Here's one way you can help</a>
</strong>
</em>
</p>
<hr>
<p>One consequence is that, for future projections of coral bleaching risk, the global warming rate is important but the details of the regional warming are not so much. The absence of consensus about regional patterns of warming across climate models is therefore less of an obstacle than previously thought, because globally averaged warming provided by climate models combined with locally observed sea temperature variations will give us better projections anyway.</p>
<p>Understanding the regional differences can help reef managers identify the reef areas that are at high risk of recurring bleaching events, and which ones are potential temporary safe havens. This can buy us valuable time in the battle to protect the world’s corals.</p><img src="https://counter.theconversation.com/content/84842/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Clothilde Emilie Langlais was funded by the Pacific Australian Climate Science and Adaptation Program funded by AusAid.</span></em></p><p class="fine-print"><em><span>Scott Heron receives funding and support from the U.S. National Oceanic and Atmospheric Administration's Satellites division (NESDIS) and Coral Reef Conservation Program, and is affiliated with James Cook University. The contents in this piece are solely the opinions of the authors and do not constitute a statement of policy, decision or position on behalf of NOAA or the U.S. Government.</span></em></p><p class="fine-print"><em><span>Andrew Lenton 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>
Regional variations in sea temperature can make all the difference between a coral reef suffering major bleaching or surviving as a refuge for corals, new research shows.
Clothilde Emilie Langlais, research scientist at CSIRO Oceans and Atmosphere, CSIRO
Andrew Lenton, Senior Research Scientist, Oceans and Atmosphere, CSIRO
Scott F. Heron, Physical Scientist, National Oceanic and Atmospheric Administration
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/76014
2017-04-11T20:11:47Z
2017-04-11T20:11:47Z
Feeling helpless about the Great Barrier Reef? Here’s one way you can help
<figure><img src="https://images.theconversation.com/files/164780/original/image-20170411-31902-177i0m4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Diana Kleine using a CoralWatch chart to measure coral health. </span> <span class="attribution"><span class="source">Chris Roelfsema/CoralWatch</span>, <span class="license">Author provided</span></span></figcaption></figure><p>It is easy to feel overwhelmed when confronted with reports of the <a href="https://www.theguardian.com/environment/2017/mar/10/great-barrier-reef-coral-bleaching-worsens-as-scientists-fear-heatwaves-impact">second mass bleaching event</a> on the Great Barrier Reef in as many years. But there is a way to help scientists monitor the reef’s condition.</p>
<p><a href="http://www.coralwatch.org">CoralWatch</a> is a citizen science program started at The University of Queensland 15 years ago, with two main aims: to monitor the environment on a vast scale, and to help people get informed about marine science.</p>
<p>These goals come together with coral health monitoring. Divers, snorkellers or people walking around reef areas during low tides can send us crucial information about coral bleaching, helping us to build detailed pictures of the health of different reefs.</p>
<p>Participants can use a colour chart, backed up through the CoralWatch <a href="https://itunes.apple.com/us/app/data-entry/id1014927844?mt=8">app</a> or <a href="http://www.coralwatch.org">website</a>, to measure accurately the colour and type of coral they see. The chart covers 75% of known corals and can be used with no prior training. </p>
<p>We also ask people to enter the type of coral (branching, boulder, plate or soft), the location and the weather. This allows scientists to quickly identify the location and extent of any problems (and is an excellent way to learn more about our reefs). </p>
<p>You don’t even have to go to a reef to participate and discover through CoralWatch; we have classroom and virtual reef systems, and just talking the problem through can help.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/164768/original/image-20170411-31875-14vhs3p.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/164768/original/image-20170411-31875-14vhs3p.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/164768/original/image-20170411-31875-14vhs3p.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=553&fit=crop&dpr=1 600w, https://images.theconversation.com/files/164768/original/image-20170411-31875-14vhs3p.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=553&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/164768/original/image-20170411-31875-14vhs3p.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=553&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/164768/original/image-20170411-31875-14vhs3p.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=694&fit=crop&dpr=1 754w, https://images.theconversation.com/files/164768/original/image-20170411-31875-14vhs3p.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=694&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/164768/original/image-20170411-31875-14vhs3p.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=694&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">CoralWatch chart. Volunteers match the colour and four basic coral types: branching, boulder, plate and soft.</span>
<span class="attribution"><span class="source">CoralWatch</span></span>
</figcaption>
</figure>
<p>The graphs shown below are samples of CoralWatch data from the northern and southern reef during 2016’s catastrophic mass bleaching event. The pair of graphs further down the page show data from just a few days ago at Lady Elliot Island and the very remote North Mariana Islands in the West Pacific. </p>
<p>The Heron Island graph shows a healthy reef, as the southern areas of the reef escaped the worst of the bleaching last year. In contrast, Monsoon Reef (which lies off Port Douglas) and many others in the north bleached badly, or in some cases <a href="https://theconversation.com/how-much-coral-has-died-in-the-great-barrier-reefs-worst-bleaching-event-69494">simply died</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/164773/original/image-20170411-31886-u86skz.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/164773/original/image-20170411-31886-u86skz.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/164773/original/image-20170411-31886-u86skz.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=207&fit=crop&dpr=1 600w, https://images.theconversation.com/files/164773/original/image-20170411-31886-u86skz.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=207&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/164773/original/image-20170411-31886-u86skz.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=207&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/164773/original/image-20170411-31886-u86skz.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=260&fit=crop&dpr=1 754w, https://images.theconversation.com/files/164773/original/image-20170411-31886-u86skz.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=260&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/164773/original/image-20170411-31886-u86skz.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=260&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 graphs show the contrast between a healthy and unhealthy reef. The bars represent observed coral matched to the colours (1-6) on the CoralWatch card and how frequently each were seen. Scores averaging between 4-6 are normal.</span>
<span class="attribution"><span class="source">CoralWatch</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Scores averaging between four and six are normal and represent <a href="https://theconversation.com/in-pictures-a-close-up-look-at-the-great-barrier-reefs-bleaching-57495">good levels of symbiotic algae</a>, which generate nutrients for the coral. Scores below three signify that coral is in distress.</p>
<p>The impact of this year’s mass bleaching is still being quantified. However, reefs in the middle section and far south of the reef – such as Lady Elliot Island – are now showing varying degrees of bleaching, from light to severe. Many of the remaining corals in the north are also <a href="https://tenplay.com.au/channel-ten/the-project/extra/season-8/barrier-reef-%20bleaching">showing signs of bleaching again</a>.</p>
<p>What seems certain is that we will lose many more corals, along with the fish and invertebrate life they support, again this year.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/164774/original/image-20170411-31879-hytuk.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/164774/original/image-20170411-31879-hytuk.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/164774/original/image-20170411-31879-hytuk.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=210&fit=crop&dpr=1 600w, https://images.theconversation.com/files/164774/original/image-20170411-31879-hytuk.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=210&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/164774/original/image-20170411-31879-hytuk.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=210&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/164774/original/image-20170411-31879-hytuk.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=264&fit=crop&dpr=1 754w, https://images.theconversation.com/files/164774/original/image-20170411-31879-hytuk.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=264&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/164774/original/image-20170411-31879-hytuk.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=264&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 health at Lady Elliot Island and the very remote North Mariana Islands, from March 2017.</span>
<span class="attribution"><span class="source">CoralWatch</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>The results for the North Mariana Islands, from a CoralWatch survey conducted last week, shows mid-level coral bleaching and demonstrate that even very remote reefs are not climate-proof.</p>
<p>Australians increasingly believe the government <a href="http://www.abc.net.au/news/2016-09-26/77pc-of-australians-believe-climate-change-occurring-survey-says/7876416">needs to act on climate change</a>. Some of this change in opinion is likely fuelled by <a href="https://tenplay.com.au/channel-ten/the-project/extra/season-8/barrier-reef-bleaching">continued reports of coral bleaching</a>.</p>
<p>CoralWatch doesn’t only help build a detailed picture of reef health. Like other citizen science projects, such as Reef Check, it can help speed up our <a href="https://theconversation.com/year-on-year-bleaching-threatens-great-barrier-reefs-world-heritage-status-74606">fatally slow</a> response to climate change. There are three key benefits.</p>
<p>First, we need to improve mutual understanding between scientists and the public. The CoralWatch mantra is: tell me and I’ll forget; teach me and I may remember; involve me and I’ll learn. Citizen science is a natural fit for everyone, no matter your level of education or knowledge. </p>
<p>Children are the citizens of the future, and helping them to understand their changing world is a moral and social imperative. CoralWatch works closely with schools and groups like the Marine Teachers Association of Queensland, and is used in more than 75 countries worldwide.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/164784/original/image-20170411-31875-t2dj91.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/164784/original/image-20170411-31875-t2dj91.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/164784/original/image-20170411-31875-t2dj91.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/164784/original/image-20170411-31875-t2dj91.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/164784/original/image-20170411-31875-t2dj91.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/164784/original/image-20170411-31875-t2dj91.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/164784/original/image-20170411-31875-t2dj91.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/164784/original/image-20170411-31875-t2dj91.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"></a>
<figcaption>
<span class="caption">A coral health chart being used in the field.</span>
<span class="attribution"><span class="source">CoralWatch</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Second, we need to encourage lifestyle change. Many people, as they become more engaged in citizen science, will naturally adopt more environmentally friendly habits. Getting involved in protecting the Great Barrier Reef – and other <a href="http://www.ala.org.au/get-involved/citizen-science/">citizen science projects</a> – can be a great dose of perspective on our place in the natural world. </p>
<p>However, as personally rewarding as they can be, individual lifestyle choices alone won’t deliver the rapid and widespread change we need to save our reefs. That’s why we need to bridge the disconnect between what most of Australia wants and the politicians who ultimately have the power to fast-track change. Citizen scientists are also informed voters and consumers, who can demand better policies from companies and governments. </p>
<p>The future of the Great Barrier Reef is in the hands of Australians, and it will take all of us to preserve it for our children.</p>
<p><br></p>
<hr>
<p><em>Updated on May 4, 2017. The authors would like to acknowledge the contribution of Monique Grol to this article.</em></p><img src="https://counter.theconversation.com/content/76014/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Justin Marshall is affiliated with Coral Watch which has recently received Queensland State Government funding for this project and previously from the Sustainable Tourism Cooperative Research Centre, the Australia Indonesia Institute and the Information Society Innovation Fund Asia.</span></em></p><p class="fine-print"><em><span>Chris Roelfsema is affiliated with CoralWatch as a volunteer trainer and science adviser.</span></em></p><p class="fine-print"><em><span>Diana Kleine is a project manager for CoralWatch, which has recently received Queensland State Government funding for this project and previously from the Sustainable Tourism Cooperative Research Centre, the Australia Indonesia Institute and the Information Society Innovation Fund Asia.</span></em></p>
As the Great Barrier Reef suffers a second wave of mass bleaching, there is a way to get involved.
Justin Marshall, ARC Laureate Fellow, The University of Queensland
Chris Roelfsema, Research Fellow (Coastal and Marine), The University of Queensland
Diana Kleine, Coral Watch Project Manager, The University of Queensland
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/75053
2017-04-06T04:38:39Z
2017-04-06T04:38:39Z
The Great Barrier Reef’s safety net is becoming more complex but less effective
<figure><img src="https://images.theconversation.com/files/163603/original/image-20170403-16542-1ax509b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The Great Barrier Reef is currently experiencing a second wave of bleaching. </span> <span class="attribution"><span class="source">AAP Image/WWF AUSTRALIA, BIOPIXEL</span></span></figcaption></figure><p>The Great Barrier Reef is under serious threat, as the <a href="https://theconversation.com/great-barrier-reef-bleaching-would-be-almost-impossible-without-climate-change-58408">coral-bleaching crisis</a> continues to unfold. These problems are caused by global climate change, but our ability to react to them – or prevent more harm – is clouded by a tangled web of bureaucracy.</p>
<p>Published this week, my <a href="http://www.pnas.org/content/early/2017/03/22/1620830114">latest research</a> shows the increasingly complex systems for governing the Reef are becoming less effective.</p>
<p>Earlier this month, the Great Barrier Reef Marine Park Authority and the National Coral Reef Taskforce confirmed that a <a href="https://www.coralcoe.org.au/media-releases/scientists-mobilise-as-bleaching-resumes-on-great-barrier-reef">second wave of mass bleaching</a> is now unfolding on the Reef. The same week, the Australian government quietly announced an unexpected <a href="http://www.environment.gov.au/minister/frydenberg/media-releases/mr20170307a.html">review of the governance of the Great Barrier Reef Marine Park Authority</a>.</p>
<p>This most recent coral bleaching crisis brings the governance of the reef into stark relief.</p>
<h2>How did we get here?</h2>
<p>Yet this problem didn’t always exist. In 2011, a state-of-the-art system governed the complete range of marine, terrestrial, and global threats to the reef. The management of the Great Barrier Reef Marine Park was (and still is) the responsibility of the Australian government, primarily through the statutory <a href="http://www.gbrmpa.gov.au">Great Barrier Reef Marine Park Authority</a>.</p>
<p>A highly collaborative working relationship, dating back to 1979, existed with the State of Queensland. Complementary marine, land, water, and coastal arrangements were established over four decades. The <a href="http://whc.unesco.org/en/list/154">United Nations Educational, Scientific and Cultural Organization</a> (UNESCO) provided important international oversight as a consequence of the 1981 World Heritage listing.</p>
<p>By 2011, the management of the reef had received international acclaim, with the 2004 rezoning process (which divides the reef into eight zones for different activities) receiving <a href="http://www.gbrmpa.gov.au/about-us/corporate-information/awards-and-recognitions">19 international, national, and local awards</a>.</p>
<p>Yet despite the attention of federal lawmakers and considerable acclaim, in 2014 <a href="http://whc.unesco.org/en/decisions/6049/">UNESCO was considering the Great Barrier Reef for an “In Danger” listing</a>. Appearing on this list is a strong signal to the international community that a World Heritage area is threatened and corrective action needs to be taken.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/163781/original/image-20170404-21938-6216dq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/163781/original/image-20170404-21938-6216dq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/163781/original/image-20170404-21938-6216dq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/163781/original/image-20170404-21938-6216dq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/163781/original/image-20170404-21938-6216dq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/163781/original/image-20170404-21938-6216dq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/163781/original/image-20170404-21938-6216dq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/163781/original/image-20170404-21938-6216dq.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">Lizard Island in 2016, after the worst climate change-induced coral bleaching event ever recorded.</span>
<span class="attribution"><span class="source">AAP Image/XL Catlin Seaview Survey</span></span>
</figcaption>
</figure>
<h2>What went wrong?</h2>
<p>So what went wrong? <a href="http://www.pnas.org/content/early/2017/03/22/1620830114">My study</a> examined the structure and context of the systems for protecting the reef, which offers insight into how well they’re working.</p>
<p>It’s worth noting that complex systems aren’t inherently bad. A polycentric approach – which literally means “multiple centres”, instead of a single governing body – can be both stable and effective. But I found that in the case of the Great Barrier Reef, it masks serious problems.</p>
<p>A number of stresses, like climate change, economic crises, resource industry pressure and local political backlashes against conservation, have all combined to impact effective management of the reef.</p>
<p>Furthermore, successive governments keep making new announcements (new laws, programs, funds, and plans) while at the same time chipping away at the pre-existing laws, departments and funding.</p>
<p>Low-visibility examples include the introduction of a policy that encourages developers who want to build on or near the reef to <a href="https://www.environment.gov.au/marine/gbr/reef-trust">make an offset payment into the Reef Trust</a>, which funds activity to improve water quality. However, many stakeholders believe that this has also made getting consent for development easier.</p>
<p>This is because, while there is no evidence of actual corruption, there is no mechanism to minimise the potential for undue industry influence under this policy. The Department of Environment grants approval for developments, and also oversees the offset fund into which the developers pay. Many stakeholders regard this as a conflict of interest. Indeed, the 2016 Audit of the Reef Trust by the Australian National Audit Office concluded that the Department should have “considered more fully the risks and costs associated with alternative program delivery models to underpin its advice to government on the design of the Reef Trust”.</p>
<p>More visible examples include the dismantling of complementary policies and institutions, including the repeals of <a href="https://www.dilgp.qld.gov.au/resources/factsheet/planning/sprp-draft-coastal-protection.pdf">Queensland coasts and catchments legislation</a> in 2013, and <a href="http://www.aph.gov.au/About_Parliament/Parliamentary_Departments/Parliamentary_Library/pubs/rp/rp1516/Climate2015">Australian climate law and policy</a> in 2014.</p>
<p>A <a href="http://www.tandfonline.com/doi/abs/10.1080/09644016.2015.1074385">2015 study of OECD countries</a> singled out the Australian Department of Environment for unusually frequent changes of both name and composition. The same study also showed that Australia has one of the sharpest declines in staff at national environment authorities since the 1990s, relative to other OECD countries.</p>
<p>Between 2005 and 2015, the Great Barrier Reef Marine Park Authority itself saw its resources plateau, and an increasing politicisation of decisions. Its independence was also reduced through a series of small, incremental actions. Since 2005, there has been at least ten “regime changes”, ranging from small tweaks to large restructurings.</p>
<p>Core funding across all relevant agencies has failed to keep pace with costs, at the same time as demands on them rose in response to the Queensland resources and population boom, not to mention global climate change. In recognition of the increasing local pressures on the regime, a A$124 million funding boost to the Authority over 10 years was announced in December 2016.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/163587/original/image-20170403-19466-1e37c5q.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/163587/original/image-20170403-19466-1e37c5q.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/163587/original/image-20170403-19466-1e37c5q.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/163587/original/image-20170403-19466-1e37c5q.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/163587/original/image-20170403-19466-1e37c5q.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/163587/original/image-20170403-19466-1e37c5q.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/163587/original/image-20170403-19466-1e37c5q.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/163587/original/image-20170403-19466-1e37c5q.png?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">Schematic of major changes to regime structure, context, and effectiveness over time. Different types of change influence the structure and effectiveness of the regime in different ways.</span>
<span class="attribution"><a class="source" href="http://www.pnas.org/content/early/2017/03/22/1620830114.full">PNAS</a></span>
</figcaption>
</figure>
<p>However, reef stakeholders must increasingly focus their attention on how all of this fits together as a streamlined system or as a network, rather than how to actually make it effective.</p>
<p>If we are to save the Great Barrier Reef from climate change, then we need to fix its governance.</p>
<h2>What needs to come next</h2>
<p>In 2015, after the government released their Reef 2050 Plan, UNESCO decided not to list the Reef as in danger, pending a 2016 assessment of progress. UNESCO is yet to make a recommendation, although the fact that the plan has very little mention of human-induced climate change may prove to be an issue.</p>
<p>Despite scientific outcry, the Australian government successfully lobbied UNESCO to remove the Great Barrier Reef and other Australian sites from its <a href="https://www.theguardian.com/environment/planet-oz/2016/may/30/australias-censorship-of-unesco-climate-report-is-like-a-shakespearean-tragedy">draft report on World Heritage and Tourism in a Changing Climate</a> in 2016.</p>
<p>In response to public concern, the National Climate Change Adaptation Research Facility and the ARC Centre of Excellence for Coral Reef Studies held a <a href="http://www.nccarf.edu.au/sites/default/files/attached_files/GBR_PIB_WEB.pdf">policy consultation workshop</a> with stakeholders and experts from all levels of government, industry representatives, environmental NGOs and peak scientific bodies like the Australian Institute of Marine Science. Participants made various recommendations for reform, including:</p>
<ul>
<li><p>meeting the national climate mitigation challenge that <a href="https://theconversation.com/beyond-paris-what-was-really-achieved-at-the-cop21-climate-summit-and-what-next-52320">Australia supported at COP21 in Paris</a> (first and foremost)</p></li>
<li><p>strengthening independent oversight of environmental decision-making (for example, reinstating the formal joint ministerial council)</p></li>
<li><p>reinstating the independence and diversity of the Great Barrier Reef Management Authority, by improving the role and composition of the board and executive management</p></li>
<li><p>properly costing and funding the protection of the Great Barrier Reef.</p></li>
</ul>
<p>Yes, the Great Barrier Reef is in <a href="http://www.nature.com/nature/journal/v543/n7645/full/nature21707.html">crisis</a>, but the coral-bleaching problem is also <a href="http://www.pnas.org/content/early/2017/03/22/1620830114">a governance disaster</a>. Regressive change, both large and small, has been masked by the complexity of the governance regime. Clear analysis of the minor and major transformations required to update the regime will be critical. If there’s no real reform, a UNESCO “in danger” listing seems inevitable.</p>
<p><em>This article was amended on April 16, 2016, to clarify two points. Environmental offsets for planning applications are voluntary, rather than mandatory as was originally stated. The original article also stated that funding for the Great Barrier Reef Marine Park Authority has plateaued; this was the case from 2005-15 but in December 2016 it was awarded an extra A$124 million in funding over 10 years.</em></p><img src="https://counter.theconversation.com/content/75053/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Tiffany Morrison 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 Great Barrier Reef is in crisis, as a second wave of coral bleaching hits. But the system of bodies and laws that protect it are getting more complicated – and less productive.
Tiffany Morrison, Principal Research Fellow, ARC Centre of Excellence for Coral Reef Studies, James Cook University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/74606
2017-03-15T19:16:20Z
2017-03-15T19:16:20Z
Year-on-year bleaching threatens Great Barrier Reef’s World Heritage status
<p>The Great Barrier Reef has already been badly <a href="https://theconversation.com/great-barrier-reef-bleaching-would-be-almost-impossible-without-climate-change-58408">damaged by global warming</a> during three extreme heatwaves, in 1998, 2002 and 2016. A <a href="http://www.gbrmpa.gov.au/media-room/latest-news/coral-bleaching/2017/second-wave-of-mass-bleaching-unfolding-on-great-barrier-reef">new bleaching event</a> is under way now. </p>
<p>As shown in a <a href="http://dx.doi.org/10.1038/nature21707">study</a> published in Nature today, climate change is not some distant future threat. It has already degraded large tracts of the Great Barrier Reef over the past two decades.</p>
<p>The extreme marine heatwave in 2016 killed <a href="https://theconversation.com/how-much-coral-has-died-in-the-great-barrier-reefs-worst-bleaching-event-69494">two-thirds of the corals</a> along a 700km stretch of the northern Great Barrier Reef, from Port Douglas to Papua New Guinea. It was a game-changer for the reef and for how we manage it. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/160816/original/image-20170314-13485-1xcoigd.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/160816/original/image-20170314-13485-1xcoigd.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/160816/original/image-20170314-13485-1xcoigd.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=863&fit=crop&dpr=1 600w, https://images.theconversation.com/files/160816/original/image-20170314-13485-1xcoigd.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=863&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/160816/original/image-20170314-13485-1xcoigd.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=863&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/160816/original/image-20170314-13485-1xcoigd.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1084&fit=crop&dpr=1 754w, https://images.theconversation.com/files/160816/original/image-20170314-13485-1xcoigd.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1084&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/160816/original/image-20170314-13485-1xcoigd.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1084&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 caused by extreme heat in summer 2016, based on extensive aerial surveys. Category 4 in red: 60-100% of colonies were bleached; Category 3 in orange: 30-60% bleached.</span>
<span class="attribution"><span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Our study shows that we cannot climate-proof coral reefs by improving water quality or reducing fishing pressure. Reefs in clear water were damaged as much as muddy ones, and the hot water didn’t stop at the boundaries of no-fishing zones. There is nowhere to hide from global warming. The process of replacement of dead corals in the northern third of the reef will take at least 10-15 years for the fastest-growing species.</p>
<p>The Great Barrier Reef is internationally recognised as a World Heritage Area. In 2015 UNESCO, the world body with oversight of World Heritage Areas, considered <a href="https://theconversation.com/explainer-what-is-the-list-of-world-heritage-in-danger-15679">listing the reef as a site “in danger”</a> in light of <a href="http://www.gbrmpa.gov.au/managing-the-reef/great-barrier-reef-outlook-report">declines in its health</a>. </p>
<h2>Australia’s response falling short</h2>
<p>In response to concerns from UNESCO, Australia devised a plan, called the <a href="http://www.environment.gov.au/marine/gbr/long-term-sustainability-plan">Reef 2050 Long-term Sustainability Plan</a>. Its ultimate goal is to improve the “Outstanding Universal Value” of the reef: the attributes of the Great Barrier Reef that led to its inscription as a World Heritage Area in 1981. </p>
<p>We have written an <a href="https://independent.academia.edu/DiTarte">independent analysis</a>, delivered to UNESCO, which concludes that to date the implementation of the plan is far too slow and has not been adequately funded to prevent further degradation and loss of the reef’s values. A major shortcoming of the plan is that it virtually ignores the greatest current impact on the Great Barrier Reef: human-caused climate change.</p>
<p>The unprecedented loss of corals in 2016 has substantially diminished the condition of the World Heritage Area, reducing its biodiversity and aesthetic values. Key ecological processes are under threat, such as providing habitat, calcification (the formation of corals’ reef-building stony skeletons) and predation (creatures eating and being eaten by corals). Global warming means that Australia’s aim of ensuring the Great Barrier Reef’s values improve every decade between now and 2050 is no longer attainable for at least the next two decades.</p>
<h2>What needs to change</h2>
<p>Our report makes 27 recommendations for getting the Reef 2050 Plan back on track. The following are critical:</p>
<ul>
<li><p>Address climate change and reduce emissions, both nationally and globally. The current lack of action on climate is a major policy failure for the Great Barrier Reef. Local action on water quality (the focus of the Reef 2050 Plan) does not prevent bleaching, or “buy time” for future action on emissions. Importantly, though, it does contribute to the recovery of coral reefs after major bleaching.</p></li>
<li><p>Reduce run-off of sediment, nutrients and pollutants from our towns and farms. To date the progress towards <a href="https://theconversation.com/great-barrier-reef-report-to-un-shows-the-poor-progress-on-water-quality-69779">achieving the water quality targets</a> and uptake of best management practice by farmers is very poor. Improving water quality can help recovery of corals, even if it doesn’t prevent mortality during extreme heatwaves.</p></li>
<li><p><a href="https://theconversation.com/current-management-is-not-enough-to-halt-pollution-on-the-great-barrier-reef-49055">Provide adequate funding</a> for reaching net zero carbon emissions, for achieving the Reef 2050 Plan targets for improved water quality, and limiting other direct pressures on the reef.</p></li>
</ul>
<p>At this stage, we do not recommend that the reef be listed as “in danger”. But if we see more die-backs of corals in the next few years, little if any action on emissions and inadequate progress on water quality, then an “in danger” listing in 2020, when UNESCO will reconsider the Great Barrier Reef’s status, seems inevitable.</p>
<hr>
<p><em>This article was co-authored by <a href="https://independent.academia.edu/DiTarte">Diane Tarte</a>, co-director of Marine Ecosystem Policy Advisors Pty Ltd. She was a co-author of the independent report to UNESCO on the Great Barrier Reef.</em></p><img src="https://counter.theconversation.com/content/74606/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Terry Hughes receives competitive research funding from the Australian Research Council. He is the lead author on today’s Nature paper on recurrent coral bleaching, and a co-author on the independent report to UNESCO on the Reef 2050 Plan.</span></em></p><p class="fine-print"><em><span>Barry Hart 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 his position as Emeritus Professor, Monash University .</span></em></p><p class="fine-print"><em><span>Karen Hussey 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 her position as Professor and Deputy Director at the Global Change Institute, University of Queensland. </span></em></p>
The Great Barrier Reef is bleaching again. Without greater action on climate change and water quality, its World Heritage status could be listed as “in danger”.
Terry Hughes, Distinguished Professor, James Cook University, James Cook University
Barry Hart, Emeritus Professor Water Science, Monash University
Karen Hussey, Deputy Director, Global Change Institute, The University of Queensland
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/73938
2017-03-09T18:20:03Z
2017-03-09T18:20:03Z
Does a new era of bleaching beckon for Indian Ocean coral reefs?
<figure><img src="https://images.theconversation.com/files/160219/original/image-20170309-21039-3gifot.png?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A typical reef scene within the Chagos Archipelago</span> <span class="attribution"><span class="license">Author provided</span></span></figcaption></figure><p>Despite extensive media coverage, campaigns and scientists’ warnings, still the world is not fully aware of <a href="http://www.nature.org/ourinitiatives/habitats/coralreefs/coral-reefs-coral-bleaching-what-you-need-to-know.xml">what coral bleaching is</a> and why it is happening. Mention bleaching and some think that it is <a href="https://theconversation.com/in-pictures-a-close-up-look-at-the-great-barrier-reefs-bleaching-57495">the death of the Great Barrier Reef’s coral</a>, but the problem is much more widespread.</p>
<p>“<a href="http://oceanservice.noaa.gov/facts/coral_bleach.html">Bleaching</a>” is when corals lose the highly productive algae (termed zooxanthellae) from their tissues due to stress from <a href="https://theconversation.com/the-oceans-are-becoming-too-hot-for-coral-and-sooner-than-we-expected-48832">high sea temperatures</a> and solar irradiation. The algae and coral have a symbiotic relationship: the algae remove the coral’s waste products while the coral gives the algae a safe environment to live in, and provides compounds for photosynthesis. Without the algae, the coral no longer has a sufficient source of food, meaning that it essentially starves to death.</p>
<p>Due to its iconic status and numerous nearby scientific institutes, the Great Barrier Reef often receives <a href="https://theconversation.com/david-attenborough-says-the-great-barrier-reef-is-in-grave-danger-its-time-to-step-up-58204">the most attention</a> when it comes <a href="https://theconversation.com/how-much-coral-has-died-in-the-great-barrier-reefs-worst-bleaching-event-69494">to coral bleaching</a>. But there are many other reefs across the globe that are experiencing the same problem. These reef provinces encompass undeveloped, remote and unpopulated areas, where, unlike near the Great Barrier Reef, monitoring and research is either non-existent, scarce or sporadic. </p>
<h2>Chagos reefs</h2>
<p>The <a href="https://theconversation.com/the-chagos-islands-are-unique-and-worth-protecting-15179">Chagos Archipelago</a> is a British overseas territory located in the middle of the Indian Ocean, consisting of 55 islands distributed across six atolls, and covering an area the size of France. It certainly fulfils the remote criterion: the Maldives are the next island group, 300 miles to the north, and it is more than 900 miles to the more substantial landmass of the Indian subcontinent. In total, the reefs and shallow banks cover some 60,000km² – nearly three times the size of Wales.</p>
<p>For the past decade, we have been carrying out <a href="http://www.cieem.net/data/files/Resource_Library/Conferences/2016_UKOT__Marine_SIG_Conference/07._UKOTMarine_Conf_2016__John_Turner.pdf">research in the Chagos Archipelago</a>. What we have found is that although reefs vary in condition across the large archipelago, most were vibrant during earlier <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4260629/">surveys</a> and managed to rebound from the first major bleaching event in <a href="http://www.bioone.org/doi/abs/10.1579/0044-7447-31.1.40">1997/98</a> – when around 16% of the world’s coral was killed, and only about 10% of living coral was left to some 30m depth. </p>
<p>After the <a href="https://theconversation.com/as-the-earth-enters-its-third-mass-bleaching-event-will-corals-survive-50740">2015 global bleaching event</a> occurred, we knew that the Chagos Archipelago had been affected, but it was only during our 2016 survey that we found the bleaching had been as bad as it was in 1997/98.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/159978/original/image-20170308-24198-qymji3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/159978/original/image-20170308-24198-qymji3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/159978/original/image-20170308-24198-qymji3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/159978/original/image-20170308-24198-qymji3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/159978/original/image-20170308-24198-qymji3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/159978/original/image-20170308-24198-qymji3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/159978/original/image-20170308-24198-qymji3.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">A degraded reef in Chagos, pictured in April 2016.</span>
</figcaption>
</figure>
<p>We were struck by the stark increase in dead coral, mostly the branching <a href="http://www.coralhub.info/cf/a-z/acropora/">Acropora</a> which form wide table-like structures, similar to a canopy, over large portions of the reef. We found that on reefs dominated by this coral type, more than 50% of the live coral which was present in 2015 has died in shallow areas.</p>
<p>What is most alarming is that these surveys took place immediately before the 2016 bleaching event began in earnest, and went on to surpass 2015 in severity. The true condition of the reefs within the Chagos Archipelago at present is unknown, as we haven’t yet been able to revisit the study sites.</p>
<h2>Hat-trick events</h2>
<p>We also don’t know when, or if, a 2017 bleaching event will occur on the Chagos Archipelago. But based on <a href="https://coralreefwatch.noaa.gov/vs/gauges/chagos_archipelago.php">global sea temperature patterns</a> so far, and <a href="https://www.theguardian.com/environment/2017/feb/24/great-barrier-reef-could-face-another-big-coral-bleaching-event-this-year">early indications of bleaching</a> starting on the Great Barrier Reef – which usually precedes events in the Indian Ocean – a 2017 event could begin in a matter of weeks.</p>
<p>This could very well be the start of a new era for the coral reefs of the Indian Ocean and beyond. Of course, bleaching itself is not a new phenomenon, having been <a href="http://bit.ly/2nhBoTm">first recorded in 1911</a> in the Florida Keys, and is likely to have occurred, certainly at local scales, throughout the last several millennia of global reef growth. What is completely new, however, is this frequency of bleaching events: if a 2017 event materialises it will be part of an unprecedented “hat-trick” of yearly back-to-back mass coral bleachings. Corals may recover from mild and infrequent bleaching events, but will die from severe and repeated loss of their algal symbionts.</p>
<p><a href="https://www.google.com/url?hl=en-GB&q=http://www.nature.com/nature/journal/v425/n6955/full/nature01987.html&source=gmail&ust=1489170191344000&usg=AFQjCNHyR4zpZaarMCWvNd3cwOkgS5-UAw">Scientists warned</a> in 1999 that if global warming patterns continued, reefs in the Indian Ocean could start to bleach every five to 10 years by 2010. Unfortunately, it appears these predictions have been met and may even be surpassed in the next decade.</p>
<h2>Reducing the impact</h2>
<p>There is no easy way to stop coral bleaching. A frequent suggestion is to focus on removing localised impacts and stressors such as <a href="https://theconversation.com/how-fish-and-clean-water-can-protect-coral-reefs-from-warming-oceans-60434">over-fishing and excess nutrient inputs</a> from agriculture. However, the Chagos islands are already devoid of these pressures, and yet appear to be equally susceptible to the effects of global warming as more populated reef areas. </p>
<p>Though we don’t know if these reefs can bounce back from bleaching, based on the previous pattern following the 1998 global bleaching event – where up to 90% of corals died in some parts of the Chagos Archipelago – the reefs could take a decade or more to recover. But if these yearly repeat bleachings carry on, it could be like pressing the reset button on each trajectory of recovery just as it gets underway.</p>
<p>Nonetheless, it could be argued that if anywhere has a chance of recovery the Chagos Archipelago does, and by continuing to research this location we may learn more about what factors promote and drive reef recovery in the process.</p><img src="https://counter.theconversation.com/content/73938/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Ronan Roche receives funding from the UK government via the Darwin Initiative and RCUK sources.</span></em></p><p class="fine-print"><em><span>Prof John Turner receives funding from Darwin Initiative. He is affiliated with the Chagos Conservation Trust as a Trustee.</span></em></p>
The British overseas territory faces an environmental crisis.
Ronan Roche, Research Fellow, Bangor University
John Turner, Professor & Dean of Postgraduate Research, Bangor University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/69494
2016-11-28T19:16:13Z
2016-11-28T19:16:13Z
How much coral has died in the Great Barrier Reef’s worst bleaching event?
<figure><img src="https://images.theconversation.com/files/147710/original/image-20161128-22732-1rqpee3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Scientists assess coral deaths in the worst-affected part of the Reef in November 2016.</span> <span class="attribution"><span class="source">Andreas Dietzel, ARC Centre of Excellence for Coral Reef Studies. </span>, <span class="license">Author provided</span></span></figcaption></figure><p>Two-thirds of the corals in the northern part of the Great Barrier Reef have died in the reef’s worst-ever bleaching event, according to our latest underwater surveys. </p>
<p>On some reefs in the north, nearly all the corals have died. However the impact of bleaching eases as we move south, and reefs in the central and southern regions (around Cairns and Townsville and southwards) were much less affected, and are now recovering. </p>
<p>In 2015 and 2016, the hottest years on record, we have witnessed at first hand the threat posed by human-caused climate change to the world’s coral reefs. </p>
<p>Heat stress from record high summer temperatures damages the microscopic algae (zooxanthellae) that live in the tissues of corals, turning them white. </p>
<p>After they bleach, these stressed corals either slowly regain their zooxanthellae and colour as temperatures cool off, or else they die.</p>
<p>The Great Barrier Reef bleached severely for the first time in 1998, then in 2002, and now again in 2016. This year’s event was more extreme than the two previous mass bleachings. </p>
<h2>Surveying the damage</h2>
<p>We undertook extensive underwater surveys at the peak of bleaching in March and April, and again at the same sites in October and November. In the northern third of the Great Barrier Reef, we recorded an average (median) loss of 67% of coral cover on a large sample of 60 reefs.</p>
<p>The dieback of corals due to bleaching in just 8-9 months is the largest loss ever recorded for the Great Barrier Reef. </p>
<p>To put these losses in context, over the 27 years from 1985 to 2012, scientists from the Australian Institute of Marine Science measured the <a href="http://www.pnas.org/content/109/44/17995.full">gradual loss of 51% of corals</a> on the central and southern regions of the Great Barrier Reef. </p>
<p>They reported no change over this extended period in the amount of corals in the remote, northern region. Unfortunately, most of the losses in 2016 have occurred in this northern, most pristine part of the Great Barrier Reef.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/147709/original/image-20161128-22761-j247bj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/147709/original/image-20161128-22761-j247bj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/147709/original/image-20161128-22761-j247bj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=849&fit=crop&dpr=1 600w, https://images.theconversation.com/files/147709/original/image-20161128-22761-j247bj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=849&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/147709/original/image-20161128-22761-j247bj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=849&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/147709/original/image-20161128-22761-j247bj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1066&fit=crop&dpr=1 754w, https://images.theconversation.com/files/147709/original/image-20161128-22761-j247bj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1066&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/147709/original/image-20161128-22761-j247bj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1066&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption"></span>
<span class="attribution"><span class="source">ARC Centre of Excellence for Coral Reef Studies</span></span>
</figcaption>
</figure>
<h2>Bright spots</h2>
<p>The bleaching, and subsequent loss of corals, is very patchy. Our map shows clearly that coral death varies enormously from north to south along the 2,300km length of the Reef. </p>
<p>The southern third of the Reef did not experience severe heat stress in February and March. Consequently, only minor bleaching occurred, and we found no significant mortality in the south since then. </p>
<p>In the central section of the Reef, we measured widespread but moderate bleaching, which was comparably severe to the 1998 and 2002 events. On average, only 6% of coral cover was lost in the central region in 2016. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/147711/original/image-20161128-22751-1aqbtma.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/147711/original/image-20161128-22751-1aqbtma.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/147711/original/image-20161128-22751-1aqbtma.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/147711/original/image-20161128-22751-1aqbtma.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/147711/original/image-20161128-22751-1aqbtma.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/147711/original/image-20161128-22751-1aqbtma.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/147711/original/image-20161128-22751-1aqbtma.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/147711/original/image-20161128-22751-1aqbtma.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">Healthy coral in the southern Great Barrier Reef in November 2016.</span>
<span class="attribution"><span class="source">Tory Chase, ARC Centre of Excellence for Coral Reef Studies.</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>The remaining corals have now regained their vibrant colour. Many central reefs are in good condition, and they continue to recover from Severe Tropical Cyclones Hamish (in 2009) and Yasi (2011).</p>
<p>In the eastern Torres Strait and outermost ribbon reefs in the northernmost part of the Great Barrier Reef Marine Park, we found a large swathe of reefs that escaped the most severe bleaching and mortality, compared to elsewhere in the north. Nonetheless, 26% of the shallow-water corals died. </p>
<p>We suspect that these reefs were partially protected from heat stress by strong currents and upwelling of cooler water across the edge of the continental shelf that slopes steeply into the Coral Sea.</p>
<p>For visitors, these surveys show there are still many reefs throughout the Marine Park that have abundant living coral, particularly in popular tourism locations in the central and southern regions, such as the Whitsundays and Cairns.</p>
<h2>Darkspots</h2>
<p>The northern third of the Great Barrier Reef, extending 700km from Port Douglas to Papua New Guinea, experienced the most severe bleaching and subsequent loss of corals. </p>
<p>On 25% of the worst affected reefs (the top quartile), losses of corals ranged from 83-99%. When mortality is this high, it affects even tougher species that normally survive bleaching.</p>
<p>However, even in this region, there are some silver linings. Bleaching and mortality decline with depth, and some sites and reefs had much better than average survival. A few corals are still bleached or mottled, particularly in the north, but the vast majority of survivors have regained their colour.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/147712/original/image-20161128-22739-1210fa1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/147712/original/image-20161128-22739-1210fa1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/147712/original/image-20161128-22739-1210fa1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/147712/original/image-20161128-22739-1210fa1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/147712/original/image-20161128-22739-1210fa1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/147712/original/image-20161128-22739-1210fa1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/147712/original/image-20161128-22739-1210fa1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/147712/original/image-20161128-22739-1210fa1.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">Dead table corals killed by bleaching in the north, November 2016.</span>
<span class="attribution"><span class="source">Greg Torda, ARC Centre of Excellence for Coral Reef Studies.</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>What will happen next?</h2>
<p>The reef science and management community will continue to gather data on the bleaching event as it slowly unfolds. The initial stage focused on mapping the footprint of the event, and now we are analysing how many bleached corals died or recovered over the past 8-9 months. </p>
<p>Over the coming months and for the next year or two we expect to see longer-term impacts on northern corals, including higher levels of disease, slower growth rates and lower rates of reproduction. The process of recovery in the north – the replacement of dead corals by new ones – will be slow, at <a href="http://theconversation.com/how-will-the-barrier-reef-recover-from-the-death-of-one-third-of-its-northern-corals-60186">least 10-15 years</a>, as long as local conditions such as water quality remain conducive to recovery. </p>
<p>As global temperatures continue to climb, time will tell how much recovery in the north is possible before a fourth mass bleaching event occurs.</p>
<p><em>This article was co-authored by David Wachenfeld, Director for Reef Recovery at the Great Barrier Reef Marine Park Authority.</em></p><img src="https://counter.theconversation.com/content/69494/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Terry Hughes receives competitive research funding from the Australian Research Council</span></em></p><p class="fine-print"><em><span>Britta Schaffelke works for the Australian Institute of Marine Science, a publicly funded research organization that receives funding from the Australian Government, foundations, State Government Departments and private industry.</span></em></p><p class="fine-print"><em><span>James Kerry 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>
Two-thirds of the corals in the northern part of the Great Barrier Reef have died on in the reef’s worst-ever bleaching event, according to the latest underwater surveys.
Terry Hughes, Distinguished Professor, James Cook University, James Cook University
Britta Schaffelke, Research Program Leader - A Healthy and Sustainable Great Barrier Reef, Australian Institute of Marine Science
James Kerry, Senior Research Officer, ARC Centre of Excellence for Coral Reef Studies, James Cook University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/67063
2016-10-27T00:12:28Z
2016-10-27T00:12:28Z
Will the Great Barrier Reef recover from its worst-ever bleaching?
<figure><img src="https://images.theconversation.com/files/143238/original/image-20161026-11236-1niwebj.JPG?ixlib=rb-1.1.0&rect=229%2C256%2C3418%2C2086&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Bleached corals are still alive, but they are starving, and often die in the following weeks.</span> <span class="attribution"><span class="source">Greg Torda</span>, <span class="license">Author provided</span></span></figcaption></figure><p>A <a href="http://www.gbrmpa.gov.au/media-room/coral-bleaching">fifth of the Great Barrier Reef’s corals are dead</a> after the worst bleaching event on record. Most of these deaths occurred in the northern part of the reef above Lizard Island. </p>
<p>Months after the bleaching event, research teams are now taking stock of the damage. Corals can recover from bleaching. But in a changing world they will have less time to do so before the next event. </p>
<h2>Bleaching 101</h2>
<p>Reef-building corals are animals that live symbiotically with one-celled algae (a species of dinoflagellate known as <a href="https://en.wikipedia.org/wiki/Symbiodinium">Symbiodinium</a>, or colloquially as zooxanthellae). </p>
<p>The coral host provides safe habitat within its cells and supplies nutrients, while the algae in return feeds the coral with products from photosynthesis. This partnership is highly efficient. It allows stony corals that require a lot of energy to produce their skeletons to thrive in nutrient-poor tropical waters. But it is also a fragile balance. </p>
<p>Environmental stress, most commonly caused by increased water temperatures and elevated light conditions, can cause the zooxanthellae to produce <a href="https://en.wikipedia.org/wiki/Reactive_oxygen_species">too much reactive oxygen species</a>, which is toxic to the coral. So the coral expels the algae.</p>
<p>This is what is actually happening when a coral “<a href="http://www.gbrmpa.gov.au/managing-the-reef/threats-to-the-reef/climate-change/what-does-this-mean-for-species/corals/what-is-coral-bleaching">bleaches</a>”. Expelling 90% or more of the algae, the coral’s skeleton becomes visible through its tissues. </p>
<p>A bleached coral can stay alive but is deprived of its primary food source and will begin to starve. Its metabolism suffers, the immune system becomes compromised, it becomes more susceptible to disease, and defence against coral predators, such as snails known as <a href="http://www.reefresilience.org/coral-reefs/stressors/predator-outbreaks/drupella/">Drupella</a>, is weakened. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/143185/original/image-20161025-4714-gdjir2.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/143185/original/image-20161025-4714-gdjir2.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/143185/original/image-20161025-4714-gdjir2.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/143185/original/image-20161025-4714-gdjir2.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/143185/original/image-20161025-4714-gdjir2.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/143185/original/image-20161025-4714-gdjir2.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/143185/original/image-20161025-4714-gdjir2.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">Survivors of the bleaching are suffering from increased predation pressure. Drupella snails aggregate on the remaining live corals around Lizard Island following the 2016 bleaching event.</span>
<span class="attribution"><span class="source">Greg Torda</span></span>
</figcaption>
</figure>
<p>Depending on the intensity and duration of environmental stress, corals can die from the immediate impacts of a severe heat stress; starvation; disease or being eaten. </p>
<p>If conditions get better, corals can regain their symbiotic algae – and with it their brownish colour - from the surrounding water or from the multiplication of the remnant algae within their cells. In this way individual coral colonies can recover. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/143182/original/image-20161025-4717-12u5twr.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/143182/original/image-20161025-4717-12u5twr.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/143182/original/image-20161025-4717-12u5twr.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/143182/original/image-20161025-4717-12u5twr.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/143182/original/image-20161025-4717-12u5twr.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/143182/original/image-20161025-4717-12u5twr.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/143182/original/image-20161025-4717-12u5twr.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">Corals weakened by heat stress are more susceptible to coral diseases. Here, skeletal eroding band disease is slowly killing a Pocillopora colony in the aftermath of the 2016 bleaching event.</span>
<span class="attribution"><span class="source">Greg Torda</span></span>
</figcaption>
</figure>
<p>Different coral species bleach at different stress levels, and some species are more likely to die directly from the conditions that cause bleaching. </p>
<p>For example, the fastest-growing corals are highly effective at capturing light to feed their algal fuel cells. Even under normal conditions they are living close to their maximum tolerance of temperature and light. These corals are far more susceptible to more light and temperature than other, slower growing corals.</p>
<p>Incidentally, these fast-growing corals are also the ones that provide the bulk of the intricate three-dimensional structure to the reef that is critical to most reef critters, including fish. Because of their enhanced metabolism, fast-growing corals also die in greatest numbers during bleaching events, therefore they have been considered the losers of coral bleaching. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/143180/original/image-20161025-4735-1c3t7da.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/143180/original/image-20161025-4735-1c3t7da.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/143180/original/image-20161025-4735-1c3t7da.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/143180/original/image-20161025-4735-1c3t7da.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/143180/original/image-20161025-4735-1c3t7da.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/143180/original/image-20161025-4735-1c3t7da.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/143180/original/image-20161025-4735-1c3t7da.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">Field of recently dead staghorn corals. These corals still provide habitat for some reef critters, but will soon erode to rubble.</span>
<span class="attribution"><span class="source">Greg Torda</span></span>
</figcaption>
</figure>
<h2>Reef recovery</h2>
<p>Due to the variability in bleaching and coral deaths, even moderate bleaching events can decrease the amount of live coral on the reef’s structure and can dramatically alter the species composition. </p>
<p>The recovery of the reef after a disturbance, such as a bleaching event, happens when the amount of live coral covering the reef, the structural complexity, and the composition of the coral community all return to the levels prior to disturbance.</p>
<p>This requires the re-colonisation of the reef by coral propagules (larvae or fragments) that grow into large mature colonies over the course of years and decades. </p>
<p>In severe bleaching events, such as the most recent 2016 mass bleaching event on the Great Barrier Reef and in parts of the remote Pacific Ocean, even the more thermally-tolerant, slow-growing corals severely bleached; several locations suffered large numbers of coral deaths. </p>
<p>The loss of slow growing corals is particularly alarming, because replacing these colonies will require decades, and in some cases centuries, to return the reefs to what they were just a short time ago. </p>
<p>It is unlikely that the reefs affected by the 2016 event in the northern Great Barrier Reef will recover for many decades. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/143179/original/image-20161025-4721-1yopfxj.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/143179/original/image-20161025-4721-1yopfxj.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/143179/original/image-20161025-4721-1yopfxj.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/143179/original/image-20161025-4721-1yopfxj.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/143179/original/image-20161025-4721-1yopfxj.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/143179/original/image-20161025-4721-1yopfxj.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/143179/original/image-20161025-4721-1yopfxj.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">Other symbiotic organisms such as this anemone can also bleach when stressed.</span>
<span class="attribution"><span class="source">Greg Torda</span></span>
</figcaption>
</figure>
<h2>Will there be a next time?</h2>
<p>It is highly unlikely that reefs will get the decades they need to recover – in fact, the frequency of bleaching events is increasing. </p>
<p>Current trends in <a href="https://www.ncdc.noaa.gov/cag/time-series/global/shem/ocean/ytd/12/1880-2014">ocean temperature</a> and future predictions suggest bleaching will occur each year within the coming decades. Some reefs around the world have just experienced consecutive years of bleaching, with barely any opportunity for colonies, let alone reefs, to recover.</p>
<p>Can corals adapt or acclimatise to elevated water temperatures over the course of a few years? Corals inhabiting unusually warm waters, such as the <a href="https://en.wikipedia.org/wiki/Persian_Gulf">Persian Gulf</a> and some areas of the <a href="http://www.worldwildlife.org/places/coral-triangle">Coral Triangle</a>, demonstrate that long-term adaptation to a high temperature regime has been possible. </p>
<p>However, evidence to date suggests that these adaptive processes are unlikely to be able to keep up with climate change.</p>
<p>Action to reduce atmospheric CO<sub>2</sub> levels, and halt the associated warming, must be quickly and vigorously pursued to avert the predicted degradation of coral reefs. If this is not undertaken, the consequences for reefs will only be amplified from what we have seen this year.</p><img src="https://counter.theconversation.com/content/67063/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Tracy Ainsworth receives funding from The Australian Research Council Discovery Program and the ARC Center of Excellence for Coral Reef Studies. </span></em></p><p class="fine-print"><em><span>Greg Torda receives funding from the Australian Research Council. He is also affiliated with the Australian Institute of Marine Science. </span></em></p><p class="fine-print"><em><span>Scott Heron receives funding and support from the U.S. National Oceanic and Atmospheric Administration's Satellites division (NESDIS) and Coral Reef Conservation Program, and is affiliated with James Cook University. The contents in this piece are solely the opinions of the authors and do not constitute a statement of policy, decision or position on behalf of NOAA or the U.S. Government.</span></em></p>
Months after record breaking coral bleaching, research teams are taking stock of the damage on the Great Barrier Reef.
Tracy Ainsworth, Research Fellow, ARC Centre of Excellence for Coral Reef Studies, James Cook University
Greg Torda, Postdoctoral research fellow, James Cook University
Scott F. Heron, Physical Scientist, National Oceanic and Atmospheric Administration
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/65876
2016-09-22T05:02:08Z
2016-09-22T05:02:08Z
The Great Barrier Reef’s ‘new normal’ is a forlorn sight
<figure><img src="https://images.theconversation.com/files/138722/original/image-20160922-11668-k8jh6r.png?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Months after the bleaching event on the Great Barrier Reef, signs of the hoped-for recovery are scant.</span> <span class="attribution"><span class="source">Kirsten Tidswell/Climate Council</span>, <span class="license">Author provided</span></span></figcaption></figure><p>Images of this year’s <a href="https://theconversation.com/in-pictures-a-close-up-look-at-the-great-barrier-reefs-bleaching-57495">coral bleaching on the Great Barrier Reef</a> shocked the world. Some tour operators <a href="http://www.couriermail.com.au/news/queensland/great-barrier-reef-signs-of-recovery-despite-major-coral-bleaching/news-story/e826d014a1b593efaf879cbb030804d5">expressed concern</a> that the extensive and <a href="https://theconversation.com/great-barrier-reef-bleaching-stats-are-bad-enough-without-media-misreporting-58283">sometimes simplistic</a> media coverage would hurt their businesses. </p>
<p>The reef was a hot-button issue during the federal election, with both major parties pledging funding for programs to <a href="http://www.smh.com.au/federal-politics/federal-election-2016/election-2016-coalitions-1-billion-funding-promise-for-great-barrier-reef-20160612-gphd86.html">enhance water quality</a>. Some politicians and tour operators <a href="http://www.couriermail.com.au/news/queensland/great-barrier-reef-signs-of-recovery-despite-major-coral-bleaching/news-story/e826d014a1b593efaf879cbb030804d5">expressed optimism</a> about the reef’s ability to recover.</p>
<p>It was the culmination of the longest, most extensive and most severe mass coral bleaching event ever recorded – an event that <a href="http://coralreefwatch.noaa.gov/satellite/analyses_guidance/global_coral_bleaching_2014-17_status.php">began in the North Pacific in mid-2014</a>. The Great Barrier Reef was not spared, this year experiencing its <a href="http://www.bom.gov.au/environment/doc/marine-heatwave-2016.pdf">hottest sea surface temperatures since records began</a> – 29.1°C in February (1.1°C above the 1961-90 average), 29.1°C (1.3°C above average) in March and 27.8°C (1.0°C above average) in April. </p>
<p>Evidence of bleaching was found on <a href="https://theconversation.com/great-barrier-reef-bleaching-stats-are-bad-enough-without-media-misreporting-58283">93% of the more than 900 individual reefs surveyed</a> that month, with the most severe impacts on the most pristine and isolated reefs of the far north. A preliminary estimate is that <a href="http://www.gbrmpa.gov.au/media-room/coral-bleaching">22% of coral has now died</a>, with 85% of these deaths occurring between Cape York and just north of Lizard Island.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/138719/original/image-20160922-11634-hjjc5h.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/138719/original/image-20160922-11634-hjjc5h.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/138719/original/image-20160922-11634-hjjc5h.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=700&fit=crop&dpr=1 600w, https://images.theconversation.com/files/138719/original/image-20160922-11634-hjjc5h.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=700&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/138719/original/image-20160922-11634-hjjc5h.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=700&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/138719/original/image-20160922-11634-hjjc5h.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=880&fit=crop&dpr=1 754w, https://images.theconversation.com/files/138719/original/image-20160922-11634-hjjc5h.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=880&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/138719/original/image-20160922-11634-hjjc5h.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=880&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 extent of coral bleaching observed on the Great Barrier Reef.</span>
<span class="attribution"><a class="source" href="http://www.gbrmpa.gov.au/__data/assets/pdf_file/0008/247931/GBR-Coral-Mortality-13-June-2016.pdf">GBRMPA/AIMS/Commonwealth Government/Queensland Government</a></span>
</figcaption>
</figure>
<p>At the height of the bleaching, the Climate Council’s chief executive, Amanda McKenzie, and councillor Tim Flannery visited a reef off Port Douglas that local tour operators have long regarded as one of the best – the quintessential underwater wonderland.</p>
<p>Amanda and Tim reported their <a href="https://www.climatecouncil.org.au/reef-reality-check">shock and anger</a> at what they saw – extensive areas of corals bleached brilliant white (see the Climate Council’s <a href="https://www.climatecouncil.org.au/reefreport">May 2016 report</a> for a summary of the bleaching).</p>
<p>Several months later, the public’s shock and outrage has largely dissipated, but the question remains: are there signs that the reef’s hoped-for recovery is actually happening?</p>
<h2>Reef revisited</h2>
<p>This week, I joined Tim and Amanda in revisiting the site that had so dismayed them back in April. We were guided by the passionate conservationist <a href="https://www.greatbarrierreeflegacy.org/the-team/">John Rumney</a>, who has been diving here for more than 40 years. Marine scientist <a href="https://www.greatbarrierreeflegacy.org/the-team/">Dean Miller</a> was our videographer, above and below the water.</p>
<p>It was a beautiful day on the reef – calm and sunny. We noted that it was three years to the day since the incoming Abbott government <a href="http://www.abc.net.au/news/2013-09-19/federal-government-scraps-climate-commission/4968816">sacked the Climate Commission</a> – which in turn led to the establishment of the ongoing <a href="http://www.abc.net.au/news/2013-09-24/tim-flannery-to-relaunch-climate-commission/4976608">Climate Council</a>.</p>
<p>Wet-suited, we slipped into the water and paddled towards the coral, our progress monitored by a drone buzzing overhead like some giant, demented mosquito.</p>
<p>So what did we find? Structurally, the reef appears intact, but the whole landscape is, well, subdued. While pockets of brilliant blue staghorn remain, much of the coral that bleached earlier this year is dead, the white skeletons filmed over by greenish-brown filamentous algae. </p>
<p>The fish community has also changed. Algae-eating species such as surgeon fish are doing well, but coral-feeders are hardly to be seen – I spotted only a single parrot fish in an hour of snorkelling. Meanwhile, the corals themselves seem to be showing symptoms of white spot and white band diseases, conditions associated with their diminished immune systems after the stress of bleaching.</p>
<p>The mood on the boat after the snorkelling was also subdued. The locals had not visited this particular reef since the height of the bleaching. Having now seen the extent of the coral death that has resulted, they fear this will eventually weaken the structural integrity of the reef, making it susceptible to future damage from storms.</p>
<p>This November’s spawning will hopefully reseed the reef, but our companions on the trip acknowledged that any repeated bleaching within the next few years will greatly reduce the chances of recovery.</p>
<p>As our boat pulled away from the reef, another took its place, full of tourists donning their snorkelling gear. I found myself hoping that most of them were first-timers – unencumbered by memories of the reef’s former glory.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/138723/original/image-20160922-11668-1qwrrtj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/138723/original/image-20160922-11668-1qwrrtj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/138723/original/image-20160922-11668-1qwrrtj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=315&fit=crop&dpr=1 600w, https://images.theconversation.com/files/138723/original/image-20160922-11668-1qwrrtj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=315&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/138723/original/image-20160922-11668-1qwrrtj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=315&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/138723/original/image-20160922-11668-1qwrrtj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=395&fit=crop&dpr=1 754w, https://images.theconversation.com/files/138723/original/image-20160922-11668-1qwrrtj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=395&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/138723/original/image-20160922-11668-1qwrrtj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=395&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">As Climate Councillor Tim Flannery discovered, there is not yet much sign that the reef is bouncing back.</span>
<span class="attribution"><span class="source">Kirsten Tidswell/Climate Council</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Back in the real world, Australia’s greenhouse emissions continue to rise (by <a href="http://www.environment.gov.au/system/files/resources/7c0b18b4-f230-444a-8ccd-162c8545daa6/files/nggi-quarterly-update-dec-2015.pdf">1.1% in 2014-15</a>) and the government’s current target of reducing emissions 26-28% below 2005 levels by 2030 is manifestly inadequate, <a href="https://theconversation.com/the-climate-change-authority-report-a-dissenting-view-64819">even if achieved</a>. </p>
<p>The continued burning of coal, oil and gas is estimated to have made the bleaching on the Great Barrier Reef this year <a href="https://theconversation.com/great-barrier-reef-bleaching-would-be-almost-impossible-without-climate-change-58408">at least 175 times more likely</a>. At present rates of climate change, this level of bleaching could occur <a href="https://www.climatescience.org.au/content/978-extreme-coral-bleaching-may-be-new-normal-2034">every two years by the 2030s</a>. That would make recovery between events virtually impossible.</p>
<p>The forlorn, diminished state of Australia’s greatest natural treasure must continue to serve as a visible warning of what we stand to lose. The new normal is a very sad place to be.</p><img src="https://counter.theconversation.com/content/65876/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Lesley Hughes is affiliated with WWF-Australia (Board member and member of Eminent Scientist Advisory Group), Wentworth Group of Concerned Scientists, Climate Council of Australia </span></em></p>
Member of the Climate Council this week returned to one of the areas of the Great Barrier Reef that was worst affected by this year’s coral bleaching. What they found was far from encouraging.
Lesley Hughes, Professor, Department of Biological Sciences, Macquarie University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/60927
2016-06-21T05:15:46Z
2016-06-21T05:15:46Z
PolicyCheck: What are the parties really offering to save the Great Barrier Reef?
<p>The Great Barrier Reef has become a major issue in the federal election campaign, with the stakes raised by the <a href="https://theconversation.com/coral-bleaching-taskforce-more-than-1-000-km-of-the-great-barrier-reef-has-bleached-57282">most severe bleaching ever documented</a> and suggestions that the next few years will be our <a href="https://theconversation.com/this-election-is-our-last-chance-to-save-the-great-barrier-reef-59381">last chance</a> to avert major damage to this World Heritage-listed icon. </p>
<p>Last week, Prime Minister Malcolm Turnbull and federal environment minister Greg Hunt announced a further commitment of <a href="https://www.liberal.org.au/latest-news/2016/06/13/coalition-deliver-1-billion-boost-protect-great-barrier-reef">up to A$1 billion over ten years</a>, from an existing A$10 billion “special account” administered by the <a href="http://www.cleanenergyfinancecorp.com.au/">Clean Energy Finance Corporation</a>.</p>
<p>Turnbull said that this new Reef Fund will provide loans to finance more energy- and water-efficient irrigation systems on farms, as well as improved pesticide and fertiliser application systems. He also raised the possibility of the fund being used to finance solar panels on farms, saying:</p>
<blockquote>
<p>The Reef Fund will support clean energy projects in the Reef catchment. It will finance solar panels and other renewable energy substitutes on farms as well as more energy efficient equipment in agriculture, local government and tourism.</p>
</blockquote>
<p>The government says that this financing will be on top of A$461 million already pledged for the Great Barrier Reef, currently planned to be spent on incentive programs to help farmers move to more “water quality friendly” management practices as has been happening over the past seven years.</p>
<p>Labor, for its part, has <a href="http://www.100positivepolicies.org.au/great_barrier_reef_plan_fact_sheet">pledged A$500 million over five years</a> – including A$123 million as a continuation of an existing Coalition pledge – to be split between scientific research, pollution reduction and restoration projects, and reef management.</p>
<h2>Is this enough money?</h2>
<p>We already have relatively robust estimates of the funds needed to bring the reef’s water quality into line with the government’s official water quality guidelines <a href="http://www.gbrmpa.gov.au/__data/assets/pdf_file/0017/4526/GBRMPA_WQualityGuidelinesGBRMP_RevEdition_2010.pdf">set by Great Barrier Reef Marine Park Authority in 2010</a>. Unfortunately, we also know it will cost much more than either major party has pledged so far. </p>
<p><a href="http://www.sciencedirect.com/science/article/pii/S0272771416301469">One estimate</a> (on which I worked) puts the cost at between A$5 billion and A$10 billion over ten years. These amounts are far in excess of the current spending trajectory, based on what has already been spent: just under half a billion dollars on farming and water-quality management, as outlined above.</p>
<p>This funding has achieved <a href="http://www.reefplan.qld.gov.au/measuring-success/report-cards/2014/">some limited success</a> in reducing pollution on the Great Barrier Reef. But it is now clear that much more funding and regulation will be needed to meet the required water quality guidelines.</p>
<h2>How much money have the parties pledged?</h2>
<p>Financial commitments, both in government budgets and election pledges, are difficult to assess accurately. Funding can be committed across several budgets, and it is important to distinguish between no-strings funding and loan financing.</p>
<p>Here is a breakdown of what the three leading parties are promising to deliver.</p>
<p><strong>The Coalition</strong> will spend A$450 million over 6 years (from various programs including Reef Trust and Reef Plan) or about A$350 million over 5 years (from this July) plus the new A$1 billion loan facility, which will be portioned out over 10 years. </p>
<p><strong>Labor</strong> has made a A$500-million, five-year commitment, albeit contingent on maintaining A$123 million of funding previously pledged by the Coalition, with A$377 million representing newly pledged funds.</p>
<p>Labor’s half-billion-dollar total can be broken down into A$377 million of direct, on-ground spending plus other current ongoing budget funding. The other roughly A$130 million is designated for research and organisational management. </p>
<p><strong>The Greens</strong> have <a href="http://greens.org.au/save-the-reef">pledged</a> A$500 million in new funding, to be spent on improved farming practices and other land restoration projects, plus a A$1.2-billion loan facility to help farmers transition to low-pollution farming methods. Both schemes would be administered over five years.</p>
<p>The Greens have also promised to retain A$370 million in existing funding for water-quality projects, which it says brings its total financial plan for the reef to more than A$2 billion.</p>
<p>The Greens have also promised to use the law to protect the reef, by using the powers of the <a href="https://www.legislation.gov.au/Details/C2016C00551">GBR Marine Park Act of 1975</a> to regulate polluting activities in the reef’s nearby river catchments. Tightening these regulations could <a href="https://theconversation.com/great-barrier-reef-pollution-controls-are-not-enough-heres-what-we-can-do-52861">help to reduce pollution faster</a>, potentially reducing the amount of money needed to hit the reef’s pollution targets.</p>
<p>The Queensland government has also <a href="http://statements.qld.gov.au/Statement/2016/5/25/reef-water-science-taskforce-report-guides-90m-investment">allocated A$90 million</a> to spend on direct water quality improvement measures over the next few years. It will also use its regulatory powers under the state’s <a href="https://www.legislation.qld.gov.au/LEGISLTN/ACTS/2009/09AC042.pdf">Great Barrier Reef Protection Amendment Act of 2009</a> to improve the region’s farming practices.</p>
<h2>Loans and profits</h2>
<p>One large question hanging over the the Coalition and Greens’ loan pledges is whether farmers will be keen to accept this financing, even at “low” interest rates. As many farmers are currently unwilling even to accept grant money to improve practices which provide them with little financial benefit, it is difficult to foresee a wide takeup of a loan facility. </p>
<p>Many environmentally beneficial changes to farm practice bring no net profit for the farmers themselves. Farming lobby group Canegrowers has <a href="http://www.abc.net.au/news/2016-06-13/canegrowers-says-coalition-reef-fund-plan-lacks-detail/7506456">questioned whether this is the best approach</a>, arguing that the industry would rather receive dollar-matching grants than loans.</p>
<p>The Clean Energy Finance Corporation (CEFC) is currently providing loans via the major banks to allow farmers to invest in energy-efficient equipment, with interest rates discounted by up to 70 basis points relative to commercial rates. This would be the model that would most likely be followed for the new proposal. </p>
<p>Future loans doled out under the Coalition’s A$1 billion fund would need to remain within the CEFC’s broad <a href="https://www.legislation.gov.au/Details/F2016L00714">investment mandate</a> of funding projects and technologies that reduce greenhouse emissions. Thus, more efficient fertiliser use, higher-efficiency irrigation pumps, and low-till cropping would all fit the bill. </p>
<p>It is unclear, however, whether other farming improvements that could benefit the reef – such as gully stabilisation or repair – would be judged to come under the mandate of the CEFC loans, or whether they might be excluded.</p>
<p>Regardless, the proposed loan program will still not put nearly enough funds into what is a pressing issue, and a parallel system of focused grants for individual pollution-reduction projects would seem to us to be a sensible approach.</p>
<p>Without stronger regulation (which only the Greens are suggesting) and considerably more funding than any of the main parties is yet willing to provide – not to mention stronger action on emissions reductions throughout the economy – none of these policies promises a particularly rosy future for the Great Barrier Reef.</p>
<p><em>This article was co-written by David Rickards, Managing Director of <a href="http://sefa.com.au/">Social Enterprise Finance Australia</a>.</em></p><img src="https://counter.theconversation.com/content/60927/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jon Brodie receives research funding from the Australian and Queensland Governments, the UN, Bancroft Station Wines, Queensland NRM bodies such as the NQ Dry Tropics NRM Group. </span></em></p>
The Coalition has ramped up the race to fund the Great Barrier Reef’s protection. All three major parties have promised hundreds of millions of dollars, but where from, and what will they be spent on?
Jon Brodie, Chief Research Scientist, Centre for Tropical Water & Aquatic Ecosystem Research (TropWATER), James Cook University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/60329
2016-06-01T08:33:52Z
2016-06-01T08:33:52Z
Australia simmers through hottest autumn on record
<figure><img src="https://images.theconversation.com/files/124756/original/image-20160601-26863-7f0usa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Summer stayed into autumn in many parts of Australia.</span> <span class="attribution"><span class="source">Bondi image from www.shutterstock.com</span></span></figcaption></figure><p>It’s the same old story: with 2016 on track to become the <a href="https://theconversation.com/2016-is-likely-to-be-the-worlds-hottest-year-heres-why-59378">hottest year on record globally</a>, and <a href="https://theconversation.com/what-is-going-on-with-indias-weather-59883">record-breaking heat already evident around the world</a>, Australia has just experienced its hottest autumn on record.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/124755/original/image-20160601-1951-1kya857.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/124755/original/image-20160601-1951-1kya857.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/124755/original/image-20160601-1951-1kya857.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/124755/original/image-20160601-1951-1kya857.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/124755/original/image-20160601-1951-1kya857.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/124755/original/image-20160601-1951-1kya857.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/124755/original/image-20160601-1951-1kya857.png?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">Figures from the Bureau of Meteorology indicate Australia has experienced its hottest autumn on record.</span>
<span class="attribution"><span class="source">Bureau of Meteorology</span></span>
</figcaption>
</figure>
<p>The Bureau of Meteorology has <a href="http://www.bom.gov.au/climate/current/statements/scs56.pdf">reported</a> that for average temperatures across Australia, this has been the hottest March-May period ever recorded – beating the previous record, set in 2005, by more than 0.2°C. </p>
<p>Within this period, March was also the hottest on record, while April and May were each the second-warmest in a series extending back to 1910.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/124754/original/image-20160601-2812-fyiluh.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/124754/original/image-20160601-2812-fyiluh.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=412&fit=crop&dpr=1 600w, https://images.theconversation.com/files/124754/original/image-20160601-2812-fyiluh.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=412&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/124754/original/image-20160601-2812-fyiluh.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=412&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/124754/original/image-20160601-2812-fyiluh.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=518&fit=crop&dpr=1 754w, https://images.theconversation.com/files/124754/original/image-20160601-2812-fyiluh.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=518&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/124754/original/image-20160601-2812-fyiluh.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=518&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Temperatures were well above average across much of the country, especially in the east.</span>
<span class="attribution"><span class="source">Bureau of Meteorology</span></span>
</figcaption>
</figure>
<h2>Why so hot?</h2>
<p>El Niño events tend to cause warmer weather across the east and north of Australia and the major El Niño of 2015-16 undoubtedly contributed to the extreme temperatures experienced across these areas.</p>
<p>However, climate change also played a significant role in our warmest autumn. <a href="http://www.bom.gov.au/amm/docs/2014/lewis2_hres.pdf">Previous work</a>, led by ANU climatologist <a href="https://theconversation.com/profiles/sophie-lewis-22297">Sophie Lewis</a>, indicates that the human influence on the climate has made a record-breakingly hot autumn roughly 20 times more likely. </p>
<p>In other words, without climate change we would be much less likely to experience autumns as warm as this one has been in Australia.</p>
<h2>How we’ll remember autumn 2016</h2>
<p>In the past few months, Australia has seen many extreme hot weather events. Melbourne experienced its <a href="http://www.theage.com.au/victoria/melbourne-weather-melburnians-swelter-as-temperatures-march-into-record-books-20160308-gne1ek.html">warmest March night on record</a>, while Sydney had a run of <a href="https://theconversation.com/sydney-so-hot-right-now-whats-behind-the-citys-record-run-of-warm-weather-55756">39 days with daytime highs above 26°C</a>, as the summer heat continued long into March.</p>
<p>But it’s the <a href="https://theconversation.com/au/topics/2016-coral-bleaching-event">coral bleaching event</a> on the Great Barrier Reef that will likely linger in our memories the longest. Some <a href="https://theconversation.com/great-barrier-reef-bleaching-stats-are-bad-enough-without-media-misreporting-58283">93% of the reef was found to be affected by bleaching</a> and recent surveys have revealed that <a href="https://theconversation.com/how-will-the-barrier-reef-recover-from-the-death-of-one-third-of-its-northern-corals-60186">more than one-third of coral</a> in the northern and central parts of the reef have died. </p>
<p>Without climate change, a bleaching event like this would be <a href="https://theconversation.com/great-barrier-reef-bleaching-would-be-almost-impossible-without-climate-change-58408">virtually impossible</a>.</p>
<p>The extreme heat over Australia this autumn and the associated damage to the reef are also having an effect on the election campaign. As public concern over the future of the reef grows, the parties are being asked to defend their climate change policies. </p>
<p>Both major parties have made election commitments to the reef, with the Coalition announcing an extra A$6 million to tackle crown-of-thorns starfish (adding to a further A$171 million committed under the 2016 budget), and Labor an extra A$377 million over five years (A$500 million in total). While both Labor and the Coalition aim to improve water quality in the reef through their policies, the coral bleaching and death this year is linked with warm seas.</p>
<p>Whether we’ll be able to save parts of the reef largely depends on whether we reduce our greenhouse gas emissions and manage to prevent the rising trend in temperatures from continuing.</p><img src="https://counter.theconversation.com/content/60329/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Andrew King receives funding from the ARC Centre of Excellence for Climate System Science.</span></em></p>
Autumn 2016 was Australia’s hottest, beating the previous record set in 2005.
Andrew King, Climate Extremes Research Fellow, The University of Melbourne
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/59966
2016-05-31T04:56:08Z
2016-05-31T04:56:08Z
Saving Nemo: how climate change threatens anemonefish and their homes
<figure><img src="https://images.theconversation.com/files/123875/original/image-20160525-25205-mbouo5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Nemo is actually a 'false clownfish'.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/the_road_ahead/130768000/">Motoya Kawasaki/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span></figcaption></figure><p>Anemonefish, or clownfish, were made famous by the 2003 Disney-Pixar film <a href="http://www.imdb.com/title/tt0266543/">Finding Nemo</a>, and are about to play a starring role in the sequel, <a href="http://www.imdb.com/title/tt2277860/?ref_=nv_sr_1">Finding Dory</a>. They are well known for their special relationship with anemones, which provide a safe place to call home. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/MKJA-VLpiCo?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
</figure>
<p>But anemonefish face a number of threats. Some researchers have warned of an increase in the <a href="http://www.huffingtonpost.com.au/2016/05/10/the-finding-nemo-effect-is-plundering-wild-clown-fish-stocks/">wild-caught anemonefish trade</a>, as happened following Finding Nemo.</p>
<p>Anemones, on which anemonefish depend, are threatened by <a href="https://theconversation.com/great-barrier-reef-bleaching-would-be-almost-impossible-without-climate-change-58408">warming seas</a> in a similar way to corals. In fact anemones were affected by the recent coral bleaching on the Great Barrier Reef, which recent updates show has left <a href="https://theconversation.com/how-will-the-barrier-reef-recover-from-the-death-of-one-third-of-its-northern-corals-60186">a third of coral colonies dead or dying</a> in the north and central parts of the reef. </p>
<p>So will Nemo be left homeless? </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/124088/original/image-20160526-16665-4lnmbw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/124088/original/image-20160526-16665-4lnmbw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/124088/original/image-20160526-16665-4lnmbw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/124088/original/image-20160526-16665-4lnmbw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/124088/original/image-20160526-16665-4lnmbw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/124088/original/image-20160526-16665-4lnmbw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=565&fit=crop&dpr=1 754w, https://images.theconversation.com/files/124088/original/image-20160526-16665-4lnmbw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=565&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/124088/original/image-20160526-16665-4lnmbw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=565&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 healthy (left) and bleached (right) bubble-tip anemone (<em>Entacmaea quadricolor</em>) on the Great Barrier Reef.</span>
<span class="attribution"><span class="source">Ashley Frisch</span></span>
</figcaption>
</figure>
<h2>Nemo and his 27 cousins</h2>
<p>There are <a href="http://jjgeisler.com/reeftank/anemones/">28 species of anemonefish</a>. Although some people call this group “clownfish”, technically this name is only used for one species, <em>Amphiprion percula</em>. “Nemo” (<em>A. ocellaris</em>) looks similar, but is actually known as the “false clownfish”.</p>
<p>Anemonefish are famous for their special relationship with anemones. Although they can survive in aquariums without anemones, in nature they rely on anemones for protection from predators. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/124091/original/image-20160526-16694-1x09p7t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/124091/original/image-20160526-16694-1x09p7t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/124091/original/image-20160526-16694-1x09p7t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=800&fit=crop&dpr=1 600w, https://images.theconversation.com/files/124091/original/image-20160526-16694-1x09p7t.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=800&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/124091/original/image-20160526-16694-1x09p7t.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=800&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/124091/original/image-20160526-16694-1x09p7t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1005&fit=crop&dpr=1 754w, https://images.theconversation.com/files/124091/original/image-20160526-16694-1x09p7t.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1005&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/124091/original/image-20160526-16694-1x09p7t.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">The pink anemonefish (<em>Amphiprion perideraion</em>) in a bleached anemone (<em>Heteractis magnifica</em>) at Christmas Island.</span>
<span class="attribution"><span class="source">JP Hobbs.</span></span>
</figcaption>
</figure>
<p>In return for providing a safe home, the resident anemonefish will provide nutrients and defend the anemone from predators such as butterflyfish. Both the number and size of anemonefish is linked to the size and number of anemones – and vice versa. Therefore, any decrease in one partner affects the other. </p>
<p>The collection of anemones and anemonefish for the aquarium trade has to be managed properly to <a href="http://link.springer.com/article/10.1007%2Fs00338-016-1401-8">ensure the future of anemonefishes</a>. Anemonefish can be easily bred in captivity and this provides a reliable source for aquarium enthusiasts without impacting wild populations. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/124089/original/image-20160526-16703-1pqkp5a.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/124089/original/image-20160526-16703-1pqkp5a.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/124089/original/image-20160526-16703-1pqkp5a.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/124089/original/image-20160526-16703-1pqkp5a.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/124089/original/image-20160526-16703-1pqkp5a.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/124089/original/image-20160526-16703-1pqkp5a.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/124089/original/image-20160526-16703-1pqkp5a.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/124089/original/image-20160526-16703-1pqkp5a.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">Cinnamon anemonefish (<em>Amphiprion melanopus</em>) in a bleached anemone (<em>Entacmaea quadricolor</em>) on the Great Barrier Reef.</span>
<span class="attribution"><span class="source">Ashley Frisch</span></span>
</figcaption>
</figure>
<p>Ten species of anemones are inhabited by anemonefish. The highest diversity of anemonefish occurs in Indonesia, where anemonefish species outnumber anemones. As a result, different species of anemonefish have <a href="http://rspb.royalsocietypublishing.org/content/283/1827/20160277">learnt to share the same anemone</a>. </p>
<p>In most other locations, anemonefish aggressively prevent other species from entering their anemone. Anemonefish species differ in the number of anemone species they associate with. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/124090/original/image-20160526-16650-rv08y5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/124090/original/image-20160526-16650-rv08y5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/124090/original/image-20160526-16650-rv08y5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=800&fit=crop&dpr=1 600w, https://images.theconversation.com/files/124090/original/image-20160526-16650-rv08y5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=800&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/124090/original/image-20160526-16650-rv08y5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=800&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/124090/original/image-20160526-16650-rv08y5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1005&fit=crop&dpr=1 754w, https://images.theconversation.com/files/124090/original/image-20160526-16650-rv08y5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1005&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/124090/original/image-20160526-16650-rv08y5.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">Clark’s anemonefish (<em>Amphiprion clarkii</em>) in a bleached anemone (<em>Cryptodendrum adhaesivum</em>) at Christmas Island.</span>
<span class="attribution"><span class="source">JP Hobbs.</span></span>
</figcaption>
</figure>
<p>Clark’s anemonefish (<em>A. clarkii</em>) can live in all ten anemone species and is widely distributed throughout the Indian and Pacific Oceans. In contrast, McCulloch’s anemonefish (<em>A. mccullochi</em>) inhabits only one species of anemone and occurs only on reefs around Lord Howe Island. </p>
<p>After hatching, anemonefish larvae use their keen sense of smell to find their preferred anemone species and <a href="http://rspb.royalsocietypublishing.org/content/283/1831/20152694">avoid unhealthy (bleached) anemones</a>.</p>
<h2>Anemones in hot water</h2>
<p>Anemones are closely related to corals and get their colour from microscopic algae (zooxanthellae) that live symbiotically within the tissue of the anemone. Like corals, anemones <a href="http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0070966">expel their algae and turn white</a> when they become stressed. </p>
<p>This process – termed “bleaching” – is usually in response to periods of elevated seawater temperatures. All ten species of anemones are susceptible to bleaching, which can result in a <a href="http://link.springer.com/article/10.1007%2Fs00338-010-0716-0#/page-1">decrease in the size and number of anemonefishes</a> and reduced reproduction. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/124092/original/image-20160526-16706-1xusf4i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/124092/original/image-20160526-16706-1xusf4i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/124092/original/image-20160526-16706-1xusf4i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/124092/original/image-20160526-16706-1xusf4i.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/124092/original/image-20160526-16706-1xusf4i.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/124092/original/image-20160526-16706-1xusf4i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=504&fit=crop&dpr=1 754w, https://images.theconversation.com/files/124092/original/image-20160526-16706-1xusf4i.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=504&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/124092/original/image-20160526-16706-1xusf4i.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=504&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">McCulloch’s anemonefish (<em>Amphiprion mccullochi</em>) in a bleached anemone (<em>Entacmaea quadricolor</em>) at Lord Howe Island.</span>
<span class="attribution"><span class="source">Justin Gilligan.</span></span>
</figcaption>
</figure>
<p>If seawater temperatures remain high for too long, then bleached anemones will die. In 1998, a prolonged period of elevated water temperatures in Japan resulted in mass mortality of bleached anemones and <a href="http://onlinelibrary.wiley.com/doi/10.1046/j.1365-2656.2002.00649.x/abstract">local extinction of anemonefish</a>. </p>
<p>In March 2016, the Great Barrier Reef experienced a severe bleaching event due to elevated water temperatures associated with a strong El Niño event. There was <a href="https://theconversation.com/coral-bleaching-comes-to-the-great-barrier-reef-as-record-breaking-global-temperatures-continue-56570">mass bleaching of both corals and anemones</a>. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/124093/original/image-20160526-16706-z08g9n.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/124093/original/image-20160526-16706-z08g9n.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/124093/original/image-20160526-16706-z08g9n.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=903&fit=crop&dpr=1 600w, https://images.theconversation.com/files/124093/original/image-20160526-16706-z08g9n.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=903&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/124093/original/image-20160526-16706-z08g9n.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=903&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/124093/original/image-20160526-16706-z08g9n.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1135&fit=crop&dpr=1 754w, https://images.theconversation.com/files/124093/original/image-20160526-16706-z08g9n.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1135&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/124093/original/image-20160526-16706-z08g9n.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1135&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Marine biologist Jean-Paul Hobbs studying anemonefish (<em>Amphiprion mccullochi</em>) and their host anemones (<em>Entacmaea quadricolor</em>) at Lord Howe Island.</span>
<span class="attribution"><span class="source">Justin Gilligan.</span></span>
</figcaption>
</figure>
<p>In April 2016, elevated water temperatures also caused mass bleaching of corals and anemones off north-west Australia, including Christmas Island. Bleached anemones have also recently been reported elsewhere in the Pacific Ocean, Indian Ocean and in the Red Sea. </p>
<p>The future of the bleached anemones and their resident anemonefish will depend on how quickly the water temperature returns to normal. If the temperature decreases swiftly, bleached anemones can regain their colour (reabsorb zooxanthellae) and survive. </p>
<p>However, the frequency and intensity of bleaching events are predicted to increase as the climate changes. Consequently, there are serious concerns about the ability of anemones and anemonefish to cope with rising water temperatures. </p>
<p>Reducing global greenhouse gas emissions will limit subsequent bleaching events and help ensure the future of Nemo and its relatives.</p><img src="https://counter.theconversation.com/content/59966/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jean-Paul Hobbs currently receives funding from Curtin University and Christmas Island Divers Association. His past research on anemones and anemonefishes has been funded by James Cook University, ARC Centre of Excellence for Coral Reef Studies, Great Barrier Reef Marine Park Authority, Lord Howe Island Marine Park, Parks Australia, WA Department of Fisheries, Wet n Dry Adventures Christmas Island and the Australian Government Department of the Environment.</span></em></p><p class="fine-print"><em><span>Ashley J Frisch has received funding from the ARC Centre of Excellence for Coral Reef Studies, James Cook University, and the Great Barrier Reef Marine Park Authority.</span></em></p>
The recent severe bleaching on the Great Barrier Reef has also affected anemones, which provide homes for clownfish.
Jean-Paul Hobbs, Research Fellow, Department of Environment and Agriculture, Curtin University
Ashley J Frisch, Postdoctoral Fellow in Marine Ecology, James Cook University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/60186
2016-05-30T20:23:24Z
2016-05-30T20:23:24Z
How will the Barrier Reef recover from the death of one-third of its northern corals?
<p>The problems caused by mass bleaching on the Great Barrier Reef have continued to deepen, with the latest estimates based on results from our surveys showing that <a href="https://www.coralcoe.org.au/media-releases/coral-death-toll-climbs-on-great-barrier-reef">35% of corals are now dead or dying</a> along the northern and central sections of the reef north of Townsville.</p>
<p>We have been tracking this severe bleaching event for months, documenting the damage as abnormally high water temperatures caused the coral to bleach, losing the algae that live within their tissues and supply most of the corals’ energy. </p>
<p>Although corals can recover from bleaching when water temperatures drop, they can also die if they are without their algae for too long. From our surveys, we estimate this has now happened to one-third of the corals on reefs north of Townsville and to half of the corals on reefs that were hit hardest by the bleaching event.</p>
<h2>The scale of the damage</h2>
<p>For this latest survey, my colleagues and I carried out in-water surveys of corals on 84 reefs, spanning 1,300 km from Townsville to the Torres Strait, between mid-March and mid-April this year. We counted the number of coral colonies that were either recently dead, bleached completely white, partially bleached or healthy, as well as quantifying the percentage cover of hard corals and other organisms at each reef. </p>
<p>When you’re underwater, it’s easy to spot corals that have recently died due to bleaching because their white skeletons are coated in a thin film of greenish-brown algae. Over time, the algae grows to form a thick mat that obscures the skeleton – a hallmark of long-dead corals that are not victims of the recent bleaching. Our surveys did not include these colonies. </p>
<p>Corals that are bleached totally white, having lost nearly all of their symbiotic algae, have an extremely low chance of recovering because it takes several months for the algae to come back. In contrast, most corals that are only partially bleached will survive and recover quickly.</p>
<p>In the reef’s central section, between Cairns and Townsville, colonies tended to be partially bleached instead of completely white or dead. We estimate that fewer than 5% of colonies will die on many of these reefs. </p>
<p>But on the reef’s northernmost section, north of Cooktown, we estimate that more than half of the coral colonies on many reefs have died.</p>
<h2>What do these figures really mean?</h2>
<p>Corals are made up of tiny modules, called polyps, that are joined together to form colonies. Most of the polyps in each colony can reproduce, and this obviously means that larger colonies can produce more larvae. </p>
<p>Similarly, reefs with more different colonies living on them can produce more larvae overall, providing a supply of new corals that can disperse to nearby damaged reefs and kick-start their recovery. </p>
<p>In places where corals have died on just a few reefs among many other healthy reefs, the supply of larvae from the neighbouring healthy reefs can facilitate more rapid recovery. </p>
<p>But in places where coral deaths are spread across most of the reefs, such as the stretch north of Cooktown, the coral larvae needed to recolonise the reefs have to travel much longer distances and this slows down the recovery.</p>
<h2>Recovery prospects</h2>
<p>This shows why coral bleaching is particularly damaging to reefs: its effects can be apparent over a scale of thousands of kilometres. Other disturbances, like cyclones, can also kill lots of coral, but their effects are usually more localised, meaning that recovery is easier.</p>
<p>Based on <a href="http://adsabs.harvard.edu/abs/2008ECSS...80..435B">previous bleaching events</a>, it can take several decades before these reefs recover, and much longer before the oldest and largest colonies are able to re-establish themselves. Some areas of the reef that were severely bleached in 1998 still haven’t recovered. The fear is that the time between bleaching events is now shorter than the time needed for reefs to recover.</p>
<p>Ocean currents are crucial to reef recovery, because of the importance of dispersing coral larvae for repopulating damaged reefs. On the Great Barrier Reef, the <a href="https://theconversation.com/can-you-surf-the-east-australian-current-finding-nemo-style-27392">East Australian Current</a> helps to transport larvae from north to south. However, this current begins its southward path at around 18º South (just north of Townsville), meaning that this current will be little help (and will in fact be an active hindrance) to the recovery of the most severely bleached reefs beyond that. </p>
<p>Another factor that impedes recovery is that bleached corals have <a href="http://researchonline.jcu.edu.au/1521/1/Baird_and_Marshall_2002.pdf">lower reproductive output</a> after a bleaching event. This means that even colonies that don’t die this year will contribute fewer larvae in the coming years.</p>
<h2>Fixing the damage?</h2>
<p>Coral bleaching events happen mainly when ocean temperatures are abnormally warm. Consequently, reducing greenhouse gas emissions is the main way we can help to prevent more global bleaching events from striking in the future. </p>
<p><a href="https://theconversation.com/queensland-commits-to-fixing-water-quality-in-the-great-barrier-reef-59827">Improving water quality</a> and controlling outbreaks of <a href="https://theconversation.com/au/topics/crown-of-thorns-starfish">crown-of-thorns starfish</a> are also very important, because reducing coral loss due to these other factors can increase the resilience of the reef to bleaching. </p>
<p>Technological approaches, like shading reefs or artificially restocking reefs, might be considered for specific small reef sites, but they are not feasible for the conservation of the 2,300 km Great Barrier Reef, or for coral reefs on a global scale.</p><img src="https://counter.theconversation.com/content/60186/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Mia Hoogenboom receives funding from Australian Research Council. </span></em></p>
An estimated one-third of corals have now died in the parts of the Great Barrier Reef hit hardest by bleaching, meaning recovery could take years or even decades.
Mia Hoogenboom, Senior Lecturer, Marine Biology and Aquaculture, James Cook University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/60108
2016-05-27T06:26:48Z
2016-05-27T06:26:48Z
Climate change, tourism and the Great Barrier Reef: what we know
<figure><img src="https://images.theconversation.com/files/124287/original/image-20160527-867-gtkevg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Perception is everything when it comes to Great Barrier Reef tourism. </span> <span class="attribution"><span class="source">Reef image from www.shutterstock.com</span></span></figcaption></figure><p>The removal of an <a href="http://www.theguardian.com/environment/2016/may/27/revealed-the-report-on-the-great-barrier-reef-that-australia-didnt-want-the-world-to-see">entire section on the Great Barrier Reef</a> from an <a href="http://www.ucsusa.org/global-warming/global-warming-impacts/world-heritage-tourism-sites-climate-change-risks#.V0fQYpN96X0">international report</a> on World Heritage and climate change has been justified by the Australian government because of the impact on tourism. </p>
<p><a href="http://www.theguardian.com/environment/2016/may/27/australia-scrubbed-from-un-climate-change-report-after-government-intervention">The Guardian</a> reported that all mention of Australia has been removed from the report released on Friday. An Environment Department spokesperson was quoted as saying that “recent experience in Australia had shown that negative commentary about the status of World Heritage properties impacted on tourism”. </p>
<p>Australia is the only populated continent that was not mentioned in the report, which was produced by <a href="http://en.unesco.org/">UNESCO</a>, <a href="http://www.unep.org/">UNEP</a>, and the <a href="http://www.ucsusa.org/">Union of Concerned Scientists</a>. It comes in the wake of one of the Great Barrier Reef’s <a href="https://theconversation.com/great-barrier-reef-bleaching-stats-are-bad-enough-without-media-misreporting-58283">most significant coral bleaching events</a> – one <a href="https://theconversation.com/great-barrier-reef-bleaching-would-be-almost-impossible-without-climate-change-58408">widely attributed to climate change</a>. </p>
<h2>What’s to hide?</h2>
<p>In its purest sense, it could be argued that it is important for the world to know about the impacts climate change is having on some of its most famous natural wonders. This has the potential to precipitate national and global policy change that might ultimately help the reef. </p>
<p>It could also be argued that much of the damage to perceptions of people around the world has already been done. The final episode of <a href="http://iview.abc.net.au/programs/david-attenboroughs-great-barrier-reef/ZW0220A001S00">David Attenborough’s documentary on the Great Barrier Reef</a> – which discusses the widespread bleaching in detail – arguably has far more potential to influence would-be tourists contemplating a visit to the reef. </p>
<p>News coverage of the events has reached audiences as far afield as the <a href="http://www.nytimes.com/2016/04/10/world/asia/climate-related-death-of-coral-around-world-alarms-scientists.html?_r=0">United States</a> and <a href="http://www.bbc.com/news/world-australia-35914009">Britain</a>. And a recent <a href="https://theconversation.com/in-pictures-a-close-up-look-at-the-great-barrier-reefs-bleaching-57495?utm_medium=email&utm_campaign=Latest%20from%20The%20Conversation%20for%20April%2013%202016%20-%204658&utm_content=Latest%20from%20The%20Conversation%20for%20April%2013%202016%20-%204658+CID_7a8b6dbec1dd3aa23c71d69155def9f0&utm_source=campaign_monitor&utm_term=picture%20essay">picture essay</a> on The Conversation provides evidence of the bleaching, observing the phenomenon as “a huge blow to all Australians who cherish this natural wonder and to the tourists who flock here to see the reef”.</p>
<h2>The impact on tourism</h2>
<p>Given that the <a href="https://theconversation.com/au/topics/great-barrier-reef-threats-series">issues on the reef</a> are well known and widely covered, would the UNESCO report really have had an impact? </p>
<p>The Cairns tourism industry is a vital export earner, not only for the region but for the nation. The region has more than <a href="http://media.ttnq.org.au/_documents/9-037775feaa06674b8f58c71ce011be59.pdf">2.4 million visitors per year, contributing A$3.1 billion to the economy</a>, with the Great Barrier Reef as its anchor attraction.</p>
<p>Adding complexity to the issue, there is debate locally as to how widespread the coral bleaching reported by scientists really is.</p>
<p>The tourism industry in Cairns has been quick to counter scientists’ claims with its own. Tour operator Quicksilver has responded with <a href="http://www.quicksilver-cruises.com/information/reefhealth/">Reef Health Updates</a> featuring a marine biologist who claims that as the water cools through winter, many of the coral are likely to regain their colour. </p>
<p>Tourists have also been interviewed for the campaign, emerging from the water amazed and astounded at the diversity of colour and marine life they have seen. </p>
<p>Regional tourism organisation Tourism Tropical North Queensland has also begun a <a href="http://www.ttnq.org.au/great-barrier-reef-colour-to-be-on-show/">campaign</a> to showcase undamaged parts of the reef.</p>
<p>Tourism is a perception-based activity. Expectations of pristine waters and diverse marine life on a World Heritage-listed reef are what drives the Cairns and North Queensland tourism industry in Australia. </p>
<p>We know from <a href="http://www.tandfonline.com/doi/abs/10.1300/J073v23n02_13">past research</a> that perceptions of damage to the natural environment from events such as cyclones do influence travel decisions, but we do not yet know how this translates to coral bleaching events.</p>
<p>Researchers in the region are working to collect data from tourists about how their pre-existing perceptions of coral cover and colour match their actual experiences. </p>
<p>This will provide evidence of the impacts of the bleaching event on the tourist experience and also shed light on what has shaped tourists’ perceptions prior to visiting. Currently, we only have anecdotal evidence from operators and the tourist interviews in the Quicksilver video on what these impacts really are.</p>
<h2>What impact could this have on the reef?</h2>
<p>From another perspective, tourism is particularly valuable to the reef because it is a relatively clean industry that relies on the preservation, rather than depletion, of the resource for its own survival. </p>
<p>The Great Barrier Reef is a resource of value to both tourism and other industries. In the past, the reef has narrowly escaped gas mining, oil spill disasters and overfishing, not to mention the ongoing impacts of land-based industries along the coast that drains to it. </p>
<p>It is important to remember that the original World Heritage listing was “<a href="https://theconversation.com/great-barrier-reef-decision-is-a-u-turn-to-an-inglorious-past-21427">born out of a 12-year popular struggle to prevent the most wondrous coral reef in the world from being destroyed by uncontrolled mining</a>”. This raises questions about whether the comparative economic importance of mining and other industries could increase if tourism declines.</p>
<p>The message about the <a href="https://theconversation.com/au/topics/great-barrier-reef-threats-series">threats to the Great Barrier Reef</a> is already in the public domain. Research is still being done on the true impact of the bleaching event and associated perceptions on the tourism industry, and the results are not yet conclusive. </p>
<p>Rather than bury information that many people globally already have access to, perhaps the Australian government could think more creatively about how it is addressing the issues and promoting this as a positive campaign for <a href="https://www.environment.gov.au/heritage/places/world/gbr">“one of the best managed marine areas in the world”</a>.</p><img src="https://counter.theconversation.com/content/60108/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Allison Anderson does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond the academic appointment above.</span></em></p>
All mention of Australia has been removed from an international report on climate change on the grounds that it would damage tourism. Here’s the evidence.
Allison Anderson, Lecturer in tourism planning and development, CQUniversity Australia
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/59381
2016-05-18T19:46:03Z
2016-05-18T19:46:03Z
This election is our last chance to save the Great Barrier Reef
<figure><img src="https://images.theconversation.com/files/122965/original/image-20160518-9491-136k2ug.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The Great Barrier Reef's health has declined in recent years</span> <span class="attribution"><span class="source">Reef image from www.shutterstock.com</span></span></figcaption></figure><p>The Great Barrier Reef has been in the spotlight thanks to <a href="https://theconversation.com/au/topics/coral-bleaching">severe coral bleaching</a> since March, leaving only 7% of the reef untouched. The bleaching, driven by record-breaking sea temperatures, has been <a href="https://theconversation.com/great-barrier-reef-bleaching-would-be-almost-impossible-without-climate-change-58408">linked to human-caused climate change</a>. </p>
<p>Apart from bleaching, the reef is in serious trouble thanks to <a href="https://theconversation.com/au/topics/great-barrier-reef-threats-series">a variety of threats</a>. <a href="https://research.jcu.edu.au/tropwater/resources/Brodie%20and%20Waterhouse%202012%20a%20critical%20review.pdf">Many species and ecosystems</a> of the Great Barrier Reef are in <a href="http://www.gbrmpa.gov.au/cdn/2014/GBRMPA-Outlook-Report-2014/">serious decline</a>. </p>
<p>It is now overwhelmingly clear that we need to fix these problems to give the reef the best chance in a warming world. In fact, the upcoming election is arguably our last chance to put in place a plan that will save the reef. </p>
<p>In a <a href="http://www.sciencedirect.com/science/article/pii/S0272771416301469">recent paper</a>, we estimate that we need to spend A$10 billion over the next ten years - about five times as much as <a href="https://www.environment.gov.au/marine/gbr/protecting-the-reef">current state and federal governments are spending</a> – to fix up reef water quality before climate change impacts overwhelm it. </p>
<h2>Stop water pollution</h2>
<p>Poor water quality is one of the major threats to the Great Barrier Reef. Sediment and nutrients (such as nitrogen) washed by rivers onto the reef cause waters to become turbid, <a href="http://www.sciencedirect.com/science/article/pii/S0272771416300634">shutting out light for corals and seagrass</a>. It can also encourage algal growth and outbreaks of coral-eating <a href="https://theconversation.com/great-barrier-reef-dying-beneath-its-crown-of-thorns-6383">crown-of-thorns starfish</a>. </p>
<p>The Queensland and Australian governments have made <a href="http://www.environment.gov.au/system/files/resources/d98b3e53-146b-4b9c-a84a-2a22454b9a83/files/reef-2050-long-term-sustainability-plan.pdf">plans with targets to improve water quality</a>, but the main plan - the <a href="https://www.environment.gov.au/marine/gbr/publications/reef-2050-long-term-sustainability-plan">Reef 2050 Long Term Sustainability Plan</a> – is completely inadequate according to the <a href="https://www.science.org.au/supporting-science/science-policy/position-statements/reef-2050-long-term">Australian Academy of Science</a>. Its targets are <a href="https://theconversation.com/current-management-is-not-enough-to-halt-pollution-on-the-great-barrier-reef-49055">unlikely to be met</a>. And <a href="https://theconversation.com/great-barrier-reef-pollution-controls-are-not-enough-heres-what-we-can-do-52861">others</a> have suggested <a href="https://theconversation.com/current-management-is-not-enough-to-halt-pollution-on-the-great-barrier-reef-49055">ways to improve water quality</a> on the Great Barrier Reef. </p>
<p>To provide resilience for the Great Barrier Reef against the current and rapidly increasing climate impacts, water quality management needs to be greatly improved by 2025 to meet the targets and <a href="http://www.gbrmpa.gov.au/__data/assets/pdf_file/0017/4526/GBRMPA_WQualityGuidelinesGBRMP_RevEdition_2010.pdf">guidelines</a>. 2025 is important as it’s likely that climate change effects will be overwhelming after that date. It is also the target date for the Reef 2050 Long Term Sustainability Plan. </p>
<h2>What needs to be done</h2>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/122656/original/image-20160516-11090-19sohox.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/122656/original/image-20160516-11090-19sohox.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/122656/original/image-20160516-11090-19sohox.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=848&fit=crop&dpr=1 600w, https://images.theconversation.com/files/122656/original/image-20160516-11090-19sohox.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=848&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/122656/original/image-20160516-11090-19sohox.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=848&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/122656/original/image-20160516-11090-19sohox.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1066&fit=crop&dpr=1 754w, https://images.theconversation.com/files/122656/original/image-20160516-11090-19sohox.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1066&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/122656/original/image-20160516-11090-19sohox.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1066&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Proposed boundaries of the Greater GBR. The area inside the red line is the GBR World Heritage Area and the shaded area is the proposed Greater GBR management area, including the GBR catchment, the GBRWHA, Torres Strait and Hervey Bay.</span>
<span class="attribution"><span class="source">J Waterhouse, TropWATER. Data for the GBR provided by the Great Barrier Reef Marine Park Authority</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>In our <a href="http://www.sciencedirect.com/science/article/pii/S0272771416301469">recent article</a>, we analysed what we need to do to respond to the current crisis, especially for water quality.</p>
<ol>
<li><p>Refocus management to the “Greater Great Barrier Reef (GBR)” – that is, include management of Torres Strait, Hervey Bay and river catchments that run into the reef as priorities along with the world heritage area. This area is shown in figure above.</p></li>
<li><p>Prioritise management for ecosystems in relatively good condition, such Torres Strait, northern Cape York and Hervey Bay which have the highest current integrity. These areas should still be prioritised despite the recent severe bleaching in the northern Great Barrier Reef.</p></li>
<li><p>Investigate methods of cross-boundary management to achieve simultaneous cost-effective terrestrial, freshwater and marine ecosystem protection in the Greater GBR.</p></li>
<li><p>Develop a detailed, comprehensive, costed water quality management plan for the Greater GBR. In the period 2009-16, more than A$500 million was spent on water quality management (with some success) without a robust comprehensive plan to ensure the most effective use of the funding.</p></li>
<li><p>Use existing federal legislation (the Great Barrier Reef Marine Park Act and the Environment Protection and Biodiversity Conservation Act) to regulate catchment activities that lead to damage to the Greater GBR, together with the relevant Queensland legislation. These rules were established long ago and are immediately available to tackle terrestrial pollutant discharge.</p></li>
<li><p>Fund catchment and coastal management to the required level to largely solve the pollution issues for the Greater GBR by 2025, to provide resilience for the system in the face of accelerating climate change impacts. The funding required is large – of the order of A$1 billion per year over the next ten years but small by comparison to the worth of the Great Barrier Reef – estimated to be of the order of <a href="http://www.sciencedirect.com/science/article/pii/S2212041614001077">A$20 billion per year</a>.</p></li>
<li><p>Continue enforcement of the <a href="http://www.sciencedirect.com/science/article/pii/S0960982215001372">zoning plan</a>.</p></li>
<li><p>Show commitment to protecting the Greater GBR through greenhouse gas emissions control, of a scale to be relevant to protecting the reef (for example those proposed by the <a href="https://www.scribd.com/doc/209541964/Targets-and-Progress-Review-Final-Report-Recommendations">Climate Change Authority</a>), by 2025.</p></li>
</ol>
<p>Unless immediate action is taken to improve water quality, the onset of accelerating climate change impacts mean there is little chance the current decline in reef health can be prevented.</p><img src="https://counter.theconversation.com/content/59381/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jon Brodie has received funding over the last two years from the Australian Government, the Queensland Government, Natural Resource Management groups, WWF, UNEP, Melbourne Water, NSW EPA. </span></em></p><p class="fine-print"><em><span>Richard Pearson has in the past received funding from the Australian Government through the Australian Research Council and the Marine and Tropical Science Research Facility. He is a member of ACF.</span></em></p>
The Great Barrier Reef is in trouble, and the upcoming election is our last chance to lock in plans to save it.
Jon Brodie, Chief Research Scientist, Centre for Tropical Water & Aquatic Ecosystem Research (TropWATER), James Cook University
Richard Pearson, Emeritus Professor, College of Marine & Environmental Sciences, James Cook University
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/58408
2016-04-28T20:14:08Z
2016-04-28T20:14:08Z
Great Barrier Reef bleaching would be almost impossible without climate change
<figure><img src="https://images.theconversation.com/files/120469/original/image-20160428-30970-14f59p1.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Coral Bleaching at Lizard Island on the Great Barrier Reef. </span> <span class="attribution"><span class="source"> © XL Catlin Seaview Survey</span></span></figcaption></figure><p>The worst bleaching event on record has affected corals across the Great Barrier Reef in the last few months. As of the end of March, a whopping 93% of the reef has experienced
<a href="https://theconversation.com/great-barrier-reef-bleaching-stats-are-bad-enough-without-media-misreporting-58283">bleaching</a>. This event has led scientists and high-profile figures such as <a href="https://theconversation.com/david-attenborough-says-the-great-barrier-reef-is-in-grave-danger-its-time-to-step-up-58204">Sir David Attenborough</a> to call for urgent action to protect the reef from annihilation.</p>
<p>There is indisputable evidence that <a href="https://ipcc-wg2.gov/publications/ocean/">climate change is harming the reef</a>. Yet, so far, no one has assessed how much climate change might be contributing to bleaching events such as the one we have just witnessed. </p>
<p>Unusually warm sea surface temperatures are strongly associated with bleaching. Because climate models can simulate these warm sea surface temperatures, we can investigate how climate change is altering extreme warm conditions across the region.</p>
<figure>
<img src="https://cdn.theconversation.com/static_files/files/19/58408-2016-04-28-great-barrier-reef-bleaching-would-be-almost-impossible-without-climate-change-58408-ii_1545b5d5c5faf4e5.gif?1518058990" width="100%">
<figcaption>Daily sea surface temperature anomalies in March 2016 show unusual warmth around much of Australia. Author provided using OSSTIA data from UK Met Office Hadley Centre.</figcaption>
</figure>
<p>We examined the Coral Sea region (shown above) to look at how climate change is altering sea surface temperatures in an area that is experiencing recurring coral bleaching. This area has recorded a big increase in temperatures over the past century, with March 2016 being the warmest on record.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/120466/original/image-20160428-30979-ln4tu4.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/120466/original/image-20160428-30979-ln4tu4.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/120466/original/image-20160428-30979-ln4tu4.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/120466/original/image-20160428-30979-ln4tu4.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/120466/original/image-20160428-30979-ln4tu4.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/120466/original/image-20160428-30979-ln4tu4.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/120466/original/image-20160428-30979-ln4tu4.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/120466/original/image-20160428-30979-ln4tu4.png?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">March sea surface temperatures were the highest on record this year in the Coral Sea, beating the previous 2015 record. Source: Bureau of Meteorology.</span>
</figcaption>
</figure>
<h2>Examining the human influence</h2>
<p>To find out how climate change is changing the likelihood of coral bleaching, we can look at how warming has affected the likelihood of extremely hot March sea temperature records. To do so, we use climate model simulations with and without human influences included. </p>
<p>If we see more very hot March months in simulations with a human influence, then we can say that climate change is having an effect, and we can attribute that change to the human impact on the climate. </p>
<p>This method is similar to analyses we have done for land regions, such as our <a href="https://theconversation.com/a-year-of-records-the-human-role-in-2014s-wild-weather-50208">investigations of recent Australian weather extremes</a>.</p>
<p>We found that climate change has dramatically increased the likelihood of very hot March months like that of 2016 in the Coral Sea. We estimate that there is at least a 175 times increase in likelihood of hot March months because of the human influence on the climate.</p>
<p>The decaying <a href="http://www.bom.gov.au/climate/updates/articles/a008-el-nino-and-australia.shtml">El Niño</a> event may also have affected the likelihood of bleaching events. However, we found no substantial influence for the Coral Sea region as a whole. Sea surface temperatures in the Coral Sea can be warmer than normal for different reasons, including changes in ocean currents (often related to La Niña events) and increased sunshine duration (generally associated with El Niño conditions). </p>
<p>Overall, this means that the influence of El Niño on the Coral Sea as a whole is weak. There have been <a href="http://www.aims.gov.au/docs/research/climate-change/coral-bleaching/bleaching-events.html">severe bleaching events in past El Niño, neutral and La Niña years</a>.</p>
<p>We estimate that climate change has increased temperatures in the hottest March months by just over 1°C. As the effects of climate change worsen we would expect this warming effect to increase, as has been pointed out <a href="http://www.publish.csiro.au/?paper=MF99078">elsewhere</a>.</p>
<p>March 2016 was clearly extreme in the observed weather record, but using climate models we estimate that by 2034 temperature anomalies like March 2016 will be normal. Thereafter events like March 2016 will be cooler than average.</p>
<p>Overall, we’re observing rapid warming in the Coral Sea region that can only be understood if we include human influences. The human effect on the region through climate change is clear and it is strengthening. Surface temperatures like those in March 2016 would be extremely unlikely to occur in a world without humans.</p>
<p>As the seas warm because of our effect on the climate, bleaching events in the Great Barrier Reef and other areas within the Coral Sea are likely to become more frequent and <a href="http://www.publish.csiro.au/?paper=MF99078">more devastating</a>. </p>
<p>Action on climate change may reduce the likelihood of future bleaching events, although not for a few decades as we have already built in warming through our recent greenhouse gas emissions.</p>
<hr>
<p><strong>A note on peer review</strong></p>
<p>We have analysed this coral bleaching event in near-real time, which means the results we present here have not been through peer review.</p>
<p>Recently, we have started undertaking these event attribution analyses immediately after the extreme event has occurred or <a href="https://theconversation.com/its-been-australias-hottest-ever-october-and-thats-no-coincidence-49941">even before it has finished</a>. As we are using a method that has been previously peer-reviewed, we can have confidence in our results.</p>
<p>It is important, however, that these studies go through a peer-review process and these results will be submitted soon. In the meantime we have published a <a href="https://www.climatescience.org.au/content/976-barrier-reef-attribution-study-data-and-methodology">short methods document</a> which provides more detail. </p>
<p>Our results are also consistent with <a href="http://www.publish.csiro.au/?paper=MF99078">previous studies</a> (see also <a href="http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2486.2005.01073.x/full">here</a> and <a href="http://www.nature.com/nclimate/journal/v3/n2/full/nclimate1674.html">here</a>).</p><img src="https://counter.theconversation.com/content/58408/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Andrew King receives funding from the ARC Centre of Excellence for Climate System Science.</span></em></p><p class="fine-print"><em><span>David Karoly receives funding from the Australian Research Council Centre of Excellence for Climate System Science. He also shares in funding from the European Commission for his role as a Research Director in the EU Centre on Shared Complex Challenges at the University of Melbourne. He is a member of the Climate Change Authority and the Wentworth Group of Concerned Scientists.</span></em></p><p class="fine-print"><em><span>Mitchell Black receives funding from the ARC Centre of Excellence for Climate System Science.</span></em></p><p class="fine-print"><em><span>Professor Hoegh-Guldberg undertakes research on coral reef ecosystems and their response to rapid environmental change, which is supported primarily by the Australian Research Council (Canberra), National Oceanic and Atmospheric Administration (Washington, D.C.), Catlin Group (London), and Great Barrier Reef Foundation (Brisbane). He did not receive salary for writing this article.</span></em></p><p class="fine-print"><em><span>Sarah Perkins-Kirkpatrick receives funding from the Australian Research Council.</span></em></p>
This summer’s record-breaking coral bleaching on the Great Barrier Reef was made 175 times more likely thanks to climate change.
Andrew King, Climate Extremes Research Fellow, The University of Melbourne
David Karoly, Professor of Atmospheric Science, The University of Melbourne
Mitchell Black, PhD Candidate, The University of Melbourne
Ove Hoegh-Guldberg, Director, Global Change Institute, The University of Queensland
Sarah Perkins-Kirkpatrick, Research Fellow, UNSW Sydney
Licensed as Creative Commons – attribution, no derivatives.
tag:theconversation.com,2011:article/58283
2016-04-26T20:12:53Z
2016-04-26T20:12:53Z
Great Barrier Reef bleaching stats are bad enough without media misreporting
<figure><img src="https://images.theconversation.com/files/120138/original/image-20160426-1349-72u5a0.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The Great Barrier Reef's northern sections have been hit hardest by bleaching.</span> <span class="attribution"><span class="source">James Kerry/ARC Centre of Excellence for Coral Reef Studies</span></span></figcaption></figure><p>The <a href="https://theconversation.com/coral-bleaching-taskforce-more-than-1-000-km-of-the-great-barrier-reef-has-bleached-57282">widespread bleaching event</a> occurring across the Great Barrier Reef is unprecedented in scale and severity. It has rightly gained global media attention. Sadly, however, some of the headlines it has generated are factually incorrect or misleading: </p>
<blockquote>
<p>Half of Great Barrier Reef “dead or dying” (<a href="http://www.itv.com/news/2016-04-20/half-of-great-barrier-reef-dead-or-dying/">ITV News</a>)</p>
<p>Coral are bleaching along the entire Great Barrier Reef (<a href="http://arstechnica.com/science/2016/04/coral-are-bleaching-along-the-entire-great-barrier-reef/">Ars Technica</a>)</p>
<p>Climate change has destroyed 93% of the Great Barrier Reef (<a href="http://www.redorbit.com/news/science/1113413716/great-barrier-reef-climate-change-042016/">RedOrbit</a>)</p>
</blockquote>
<h2>The aerial surveys</h2>
<p>Most of the recent international coverage was based on a <a href="http://www.coralcoe.org.au/media-releases/only-7-of-the-great-barrier-reef-has-avoided-coral-bleaching">press release</a> from the ARC Centre for Coral Reef Studies at James Cook University. It explained how comprehensive aerial surveys were undertaken on “911 individual reefs … along the full 2,300 km length of the Great Barrier Reef. Of all the reefs we surveyed, only 7% (68 reefs) have escaped bleaching entirely” </p>
<p>The ARC survey assessed nearly one-third of all of the coral reefs on the Great Barrier Reef – a huge sample, analogous to polling 8 million Australians to find out their voting intentions. Underwater teams of scientific divers have confirmed the accuracy of these aerial surveys and are continuing to measure the ongoing impact of the bleaching.</p>
<p>The map below highlights the differences in bleaching patterns between the reef’s northern and southern sections. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/120127/original/image-20160426-1344-1pyvc37.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/120127/original/image-20160426-1344-1pyvc37.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/120127/original/image-20160426-1344-1pyvc37.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=791&fit=crop&dpr=1 600w, https://images.theconversation.com/files/120127/original/image-20160426-1344-1pyvc37.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=791&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/120127/original/image-20160426-1344-1pyvc37.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=791&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/120127/original/image-20160426-1344-1pyvc37.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=994&fit=crop&dpr=1 754w, https://images.theconversation.com/files/120127/original/image-20160426-1344-1pyvc37.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=994&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/120127/original/image-20160426-1344-1pyvc37.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=994&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Results of aerial surveys along the length of the Great Barrier Reef.</span>
<span class="attribution"><span class="source">ARC Centre of Excellence for Coral Reef Studies</span></span>
</figcaption>
</figure>
<p>It is important to recognise that if bleaching was observed on a reef, this does not mean a particular reef has entirely bleached. Indeed, 45% of the reefs assessed had 30% or less bleaching. In the southern section, only 1% of reefs were categorised as “severely bleached”. </p>
<p>Make no mistake: what is happening is very serious. But to state that “<a href="http://www.redorbit.com/news/science/1113413716/great-barrier-reef-climate-change-042016/">climate change has destroyed 93% of the Great Barrier Reef</a>” is a misrepresentation of the situation. </p>
<p>Perhaps the more accurate way to frame the results (and indeed the wording used in the <a href="http://www.coralcoe.org.au/media-releases/only-7-of-the-great-barrier-reef-has-avoided-coral-bleaching">media release</a>) is to say that only 7% of the coral reefs across the Great Barrier Reef have completely avoided bleaching. The situation is bad enough even when sticking to the facts.</p>
<p>There is clear evidence of the extent and severity of the bleaching, which supports the conclusion that the reef is experiencing the worst bleaching event ever seen. The northern half has been hit the hardest, with about 80% categorised as severely bleached.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/120140/original/image-20160426-1355-1w99tg7.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/120140/original/image-20160426-1355-1w99tg7.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/120140/original/image-20160426-1355-1w99tg7.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/120140/original/image-20160426-1355-1w99tg7.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/120140/original/image-20160426-1355-1w99tg7.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/120140/original/image-20160426-1355-1w99tg7.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/120140/original/image-20160426-1355-1w99tg7.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/120140/original/image-20160426-1355-1w99tg7.png?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"></a>
<figcaption>
<span class="caption">The exact extent of bleaching varies from reef to reef.</span>
<span class="attribution"><span class="source">Chris Jones</span></span>
</figcaption>
</figure>
<h2>The context</h2>
<p>Part of the problem is that while many people around the world have heard of the Great Barrier Reef, few know enough about it to put such confronting headlines into context. For instance, it is important to understand the extent to which coral reefs form part of the much larger <a href="http://www.gbrmpa.gov.au/__data/assets/pdf_file/0020/4457/GBR-general-reference-A3-March-2012.PDF">World Heritage Area</a>. </p>
<p>Most of the articles accompanying the above headlines don’t clarify the following key points:</p>
<ul>
<li><p>the World Heritage Area is the size of Italy or Malaysia, but only around 10% of this area is comprised of coral reefs.</p></li>
<li><p>more than 3,000 separate coral reefs collectively comprise the Great Barrier Reef, and these extend north into the Torres Strait, outside the boundaries of both the <a href="http://www.gbrmpa.gov.au/zoning-permits-and-plans/zoning/zoning-maps">GBR Marine Park</a> and the World Heritage Area.</p></li>
<li><p>the surveys show a mixed picture of very severe, moderate and little bleaching that changes dramatically from north to south along the 2,300 km length of the reef. </p></li>
<li><p>a <a href="https://s-media-cache-ak0.pinimg.com/736x/03/9f/d0/039fd0a0d3b28fbccb70d381274f81fb.jpg">bleached coral is not necessarily a dead coral</a>, and the true extent of dead coral across the Great Barrier Reef will only become clear over the coming months.</p></li>
<li><p>while coral reefs are a key component of the ecosystem, they are <a href="http://www.gbrmpa.gov.au/managing-the-reef/threats-to-the-reef/climate-change/what-does-this-mean-for-habitats">not the only habitats</a> suffering from the impacts of climate change.</p></li>
</ul>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/120134/original/image-20160426-1344-g6a7oi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/120134/original/image-20160426-1344-g6a7oi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/120134/original/image-20160426-1344-g6a7oi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=449&fit=crop&dpr=1 600w, https://images.theconversation.com/files/120134/original/image-20160426-1344-g6a7oi.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=449&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/120134/original/image-20160426-1344-g6a7oi.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=449&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/120134/original/image-20160426-1344-g6a7oi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=564&fit=crop&dpr=1 754w, https://images.theconversation.com/files/120134/original/image-20160426-1344-g6a7oi.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=564&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/120134/original/image-20160426-1344-g6a7oi.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=564&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Anemones have been bleaching too.</span>
<span class="attribution"><span class="source">Justin Marshall/CoralWatch</span></span>
</figcaption>
</figure>
<h2>Tourism in damage control</h2>
<p>At the other end of the scale, some tourism operators and politicians have questioned the impacts of the bleaching, claiming that the effects are overstated.</p>
<p>This has given rise to a social media campaign involving pictures of healthy corals posted under the #GBRtoday hashtag, and has generated headlines such as:</p>
<blockquote>
<p>Tourism industry pushes back against bleaching claims (<a href="http://www.4ca.com.au/news/local-news/51369-tourism-industry-pushes-back-against-bleaching-claims">Radio 4CA</a>)</p>
<p>Tourism officials not panicking about coral bleaching on Far North Queensland reefs (<a href="http://www.cairnspost.com.au/business/tourism-officials-not-panicking-about-coral-bleaching-on-far-northern-reefs/news-story/8e9b010596329790ccc793ffec5fec12">Cairns Post</a>)</p>
</blockquote>
<p>An <a href="http://rrrc.org.au/wp-content/uploads/2016/04/Coral-Bleaching-Assessment-on-Key-Tourism-Sites-between-Lizard-Island-and-Cairns-Z.pdf">independent survey</a> by tour operators using federal funding was co-ordinated by the Reef and Rainforest Research Centre (RRRC) in Cairns. This involved 402 surveys on reefs between Cairns and the northern Ribbon Reefs. It found 31% of their survey sites had not bleached, with the remaining 69% of the surveys showing varying levels of bleaching. </p>
<p>At 16 of the RRRC survey sites, 85% or more of the surveyed area was bleached to varying extents, ranging from moderate bleaching to coral death (bleaching levels 2-4, see page 8 of the <a href="http://rrrc.org.au/wp-content/uploads/2016/04/Coral-Bleaching-Assessment-on-Key-Tourism-Sites-between-Lizard-Island-and-Cairns-Z.pdf">report</a> for more details). </p>
<p>At several of the Ribbon Reefs, between 30-40% of the corals at the surveyed site were dead. These results are not dissimilar to those of the ARC scientists.</p>
<h2>The real picture</h2>
<p>In summary, the level of bleaching of the coral reefs is catastrophic in the northern sector. Along the length of the Great Barrier Reef from north to south, there is a gradient of decreasing severity, from very severe to no sign of bleaching.</p>
<p>The magnitude of this bleaching, the worst ever to hit the reef, cannot be overstated. This is a massive blow to the UNESCO World Heritage site considered to be the most biodiverse on the planet. </p>
<p>Experts are predicting high levels of coral death across some parts of the Great Barrier Reef. Close to <a href="http://www.coralcoe.org.au/media-releases/only-7-of-the-great-barrier-reef-has-avoided-coral-bleaching">50% mortality</a> of bleached corals has already been measured north of Port Douglas. However, the wider impacts on the Great Barrier Reef ecosystem, and on the industries and communities that depend on a healthy reef, will not be fully apparent for months.</p><img src="https://counter.theconversation.com/content/58283/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jon C. Day 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 statistic that bleaching has been seen in 93% of surveyed areas of the Great Barrier Reef has sparked worldwide coverage - not all of it accurate.
Jon C. Day, PhD candidate, ARC Centre of Excellence for Coral Reef Studies, James Cook University
Licensed as Creative Commons – attribution, no derivatives.