tag:theconversation.com,2011:/us/topics/tasman-sea-19932/articlesTasman Sea – The Conversation2019-01-24T18:41:35Ztag:theconversation.com,2011:article/1104422019-01-24T18:41:35Z2019-01-24T18:41:35ZThe stubborn high-pressure system behind Australia’s record heatwaves<figure><img src="https://images.theconversation.com/files/255325/original/file-20190124-135136-p47dl4.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C2041%2C1032&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Parts of Australia have broken multiple heat records over the past week.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/mundoo/6894022268/in/photolist-bvcECU-dYT8nc-93PFVW-gmKuQn-44HVEn-GgRxet-g3adJw-cLjsHJ-LZekm-dWPfET-KWTNX-k1qN11-feGhCu-czVdNf-4GfwhE-8VLE8y-6Tp8JH-4Vvvdx-d2iVYf-siXMo-e97Ffd-d7vAsN-e1DbrK-p34mwi-HHHHv-2KQWyJ-cbVXEu-HHB97-Urn7jF-K4AFE-6NWv93-77LPN4-8KpG95-4QETmL-cS3AEJ-6S4cbG-k3rzSQ-8jsop7-dmRttb-ot3psy-7Duwmv-dYSyUz-8BnpjD-8vVKSj-8T3e67-pQz8G7-bRuGcM-dbKpSv-HUXF7-8qLj9Z">Vicki/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/">CC BY-NC-SA</a></span></figcaption></figure><p>If you think the weather this month has been like Groundhog Day (albeit much hotter), you’d probably be right! Much like a stuck record, weather systems seem to have stalled over most of the country.</p>
<p><a href="https://www.brisbanetimes.com.au/national/queensland/brisbane-facing-longest-dry-spell-in-12-years-20120821-24jwh.html">Brisbane</a> residents are questioning the lack of rain, storms and heat. <a href="https://www.abc.net.au/news/2019-01-21/monsoon-late-to-territory-but-expected-to-dump-rain-for-few-days/10733120">Darwin</a> has just endured its second-latest monsoon onset on record after weeks of heat and humidity. <a href="https://www.sbs.com.au/news/nine-days-over-45c-queensland-outback-town-smashes-heat-record">Interior towns</a> and cities have experienced significantly hot weather with a number of new maximum and minimum temperature records broken, along with records for consecutive days over 35°C. </p>
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Read more:
<a href="https://theconversation.com/coastal-seas-around-new-zealand-are-heading-into-a-marine-heatwave-again-110028">Coastal seas around New Zealand are heading into a marine heatwave, again</a>
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<p>Perth has largely escaped the heat so far this summer, while Sydney and Hobart have had a mixed bag. Coastal sea breezes have tempered conditions in the south and southeast of the continent. However, <a href="https://www.theguardian.com/australia-news/live/2019/jan/24/australia-extreme-heatwave-south-australia-45c-tasmania-bushfires-victoria-temperature-nsw-weather-forecast-live-news-updates">heatwaves</a> are forecast for Melbourne and much of the southeast, with the arrival of strong, hot northerly winds. This will also bring extreme or severe fire weather conditions in many areas, <a href="https://www.abc.net.au/news/2019-01-24/what-makes-a-horror-fire-danger-day/10685918">including Tasmania</a>. Adelaide, meanwhile, has sweltered through the <a href="https://www.abc.net.au/news/2019-01-24/sa-heating-up-with-records-expected-to-be-broken/10745220">hottest day on record for any Australian capital</a>.</p>
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<a href="https://images.theconversation.com/files/255320/original/file-20190124-135154-1lmq5pb.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/255320/original/file-20190124-135154-1lmq5pb.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/255320/original/file-20190124-135154-1lmq5pb.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=415&fit=crop&dpr=1 600w, https://images.theconversation.com/files/255320/original/file-20190124-135154-1lmq5pb.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=415&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/255320/original/file-20190124-135154-1lmq5pb.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=415&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/255320/original/file-20190124-135154-1lmq5pb.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=521&fit=crop&dpr=1 754w, https://images.theconversation.com/files/255320/original/file-20190124-135154-1lmq5pb.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=521&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/255320/original/file-20190124-135154-1lmq5pb.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=521&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"><span class="source">Bureau of Meteorology</span></span>
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<p>These weather patterns across the country are largely due to a stubborn blocking high-pressure system that has remained over the Tasman Sea since early January, affecting weather on both sides of the ditch. This type of <a href="http://www.bom.gov.au/watl/about-weather-and-climate/australian-climate-influences.shtml?bookmark=blockinghigh">strong high-pressure system</a> typically forms further south than usual, and remains almost stationary for an extended period, thus blocking the west-to-east progression of weather systems across southern Australia. </p>
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Read more:
<a href="https://theconversation.com/australias-deadliest-natural-hazard-whats-your-heatwave-plan-90165">Australia's 'deadliest natural hazard': what's your heatwave plan?</a>
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<p>Sometimes, these blocking highs position themselves over the Great Australian Bight. They can occur at any time of year, and can stay in the Australian region from several days to several weeks.</p>
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<a href="https://images.theconversation.com/files/255319/original/file-20190124-135160-n1y4qc.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/255319/original/file-20190124-135160-n1y4qc.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/255319/original/file-20190124-135160-n1y4qc.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=501&fit=crop&dpr=1 600w, https://images.theconversation.com/files/255319/original/file-20190124-135160-n1y4qc.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=501&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/255319/original/file-20190124-135160-n1y4qc.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=501&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/255319/original/file-20190124-135160-n1y4qc.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=630&fit=crop&dpr=1 754w, https://images.theconversation.com/files/255319/original/file-20190124-135160-n1y4qc.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=630&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/255319/original/file-20190124-135160-n1y4qc.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=630&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">This schematic shows a ‘blocking high’ preventing weather systems moving across Australia.</span>
<span class="attribution"><a class="source" href="https://www.climatechangeinaustralia.gov.au/media/ccia/2.1.6/cms_page_media/168/CCIA_2015_NRM_TR_Chapter%204.pdf">Understanding Climate Change in Australia report</a></span>
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<p><a href="http://www.bom.gov.au/lam/Students_Teachers/pressure.shtml">Winds rotate anticlockwise</a> around high-pressure systems in the Southern Hemisphere. On the northern flank of the blocking high, southeast trade winds have been affecting northern New South Wales and eastern Queensland due to a persistent ridge of high pressure. These winds have been largely cool and dry, with only the far north of Queensland experiencing significant showers. The ridge has kept the <a href="https://www.mla.com.au/globalassets/mla-corporate/blocks/research-and-development/qld-climate-drivers.pdf">inland trough</a> further west over inland NSW and Queensland, preventing normal afternoon thunderstorm activity in the inland, and adding to the woes of the extended drought.</p>
<p>Cool, moist weather from the Southern Ocean is being displaced southeast by the blocking high, resulting in prolonged continental heatwaves and lack of rain. On the western flank of the blocking high, hot dry northerly winds from the arid centre are pushing through South Australia and Victoria, generating heatwave conditions.</p>
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Read more:
<a href="https://theconversation.com/why-were-hardwired-to-ignore-safety-advice-during-a-heatwave-99805">Why we're hardwired to ignore safety advice during a heatwave</a>
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<p>Across the ditch, cooler and drier southerly winds are <a href="https://www.newshub.co.nz/home/new-zealand/2019/01/dry-summer-wet-weather-set-to-be-short-lived.html">affecting much of New Zealand</a>. Only the southwest of the South Island is getting any significant rain due to persistent moist westerlies on the southern flank of the blocking high.</p>
<p>An unusually strong ridge of high pressure across Queensland, extending up to Cape York, has kept the monsoon trough north of the continent. This pattern is forecast to change as a deep tropical depression forms in the Gulf of Carpentaria over the coming days and moves south into northern Queensland. Unfortunately, the stubborn ridge of high pressure over central Queensland is likely to block the rain-bearing low from moving much further south over drought-stricken parts of inland Queensland and NSW.</p>
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Read more:
<a href="https://theconversation.com/coping-with-heat-waves-5-essential-reads-99495">Coping with heat waves: 5 essential reads</a>
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<p>While parts of the country have sweltered, the far <a href="https://thewest.com.au/news/weather/perth-weather-rainfall-records-smashed-in-cape-leeuwin-witchcliffe-as-wa-drenched-ng-b881082190z">southwest of Australia</a> has experienced cooler and wetter than average conditions this month. Cape Leeuwin, Australia’s most southwesterly point, set a 123-year daily rainfall record for January, recording a massive 57mm of rainfall.</p>
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<a href="https://images.theconversation.com/files/255321/original/file-20190124-135151-1agarc6.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/255321/original/file-20190124-135151-1agarc6.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/255321/original/file-20190124-135151-1agarc6.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=406&fit=crop&dpr=1 600w, https://images.theconversation.com/files/255321/original/file-20190124-135151-1agarc6.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=406&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/255321/original/file-20190124-135151-1agarc6.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=406&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/255321/original/file-20190124-135151-1agarc6.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=511&fit=crop&dpr=1 754w, https://images.theconversation.com/files/255321/original/file-20190124-135151-1agarc6.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=511&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/255321/original/file-20190124-135151-1agarc6.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=511&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"><span class="source">Bureau of Meteorology</span></span>
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<p>In the short term, there is no indication that the blocking high will break down or move eastward. Forecasters on both sides of the Tasman expect the pattern to continue until February at least.</p>
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Read more:
<a href="https://theconversation.com/are-heatwaves-worsening-and-have-hot-days-doubled-in-australia-in-the-last-50-years-79337">Are heatwaves 'worsening' and have 'hot days' doubled in Australia in the last 50 years?</a>
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<img src="https://counter.theconversation.com/content/110442/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Steve Turton has previously received funding from the Australian Government.</span></em></p>Much of Australia is sweltering due to a high pressure system parked over the Tasman Sea – and there’s no sign it’s moving any time soon.Steve Turton, Adjunct Professor of Environmental Geography, CQUniversity AustraliaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1100282019-01-22T04:38:28Z2019-01-22T04:38:28ZCoastal seas around New Zealand are heading into a marine heatwave, again<figure><img src="https://images.theconversation.com/files/254689/original/file-20190121-100292-m58bim.jpg?ixlib=rb-1.1.0&rect=243%2C263%2C3877%2C2426&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">This summer, coastal seas to the north and east of New Zealand are even warmer than during last year's marine heat wave.</span> <span class="attribution"><span class="source">from www.shutterstock.com</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span></figcaption></figure><p>As New Zealanders are enjoying their days at the beach, unusually warm ocean temperatures look to be a harbinger of another marine heatwave. </p>
<p>Despite the exceptional conditions during last year’s <a href="https://www.abc.net.au/news/2018-03-27/bom-and-nz-body-issue-joint-statement-on-marine-heatwave/9593618">heatwave in the Tasman Sea</a>, this summer’s sea surface temperatures to the north and <a href="https://www.stuff.co.nz/environment/climate-news/109811451/consecutive-marine-heatwaves-could-be-on-the-way">east of New Zealand</a> are even warmer.</p>
<p>The <a href="https://www.niwa.co.nz/climate/sea-surface-temperature-update/16-january-2019">latest NIWA climate assessment</a> shows that sea surface temperatures in coastal waters around New Zealand are well above average. Marine heatwave conditions are already occurring in parts of the Tasman Sea and the ocean around New Zealand and looking to <a href="https://www.newshub.co.nz/home/new-zealand/2018/12/marine-heatwave-will-the-tasman-sea-temperature-rise-again.html">become the new normal</a>. </p>
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Read more:
<a href="https://theconversation.com/marine-heatwaves-are-getting-hotter-lasting-longer-and-doing-more-damage-95637">Marine heatwaves are getting hotter, lasting longer and doing more damage</a>
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<p><img width="100%" src="https://media.giphy.com/media/3kE6xmZMXZ5WD5HjfI/giphy.gif">
</p><figure><figcaption>Changing sea surface temperature anomalies (conditions compared to average) in the oceans around New Zealand during the first two weeks of January - comparing 2009 to 2019. Source: NIWA</figcaption></figure><p></p>
<h2>What’s in a name</h2>
<p>Currently, <a href="https://www.niwa.co.nz/climate/sea-surface-temperature-update/16-january-2019">marine heatwaves are defined</a> as periods that last for five or more days with temperatures warmer than the 90th percentile based on a 30-year historical baseline. Given we are likely to <a href="https://www.sciencedirect.com/science/article/pii/S0079661116000057">experience many more such events</a> as the oceans continue to warm, it is time to understand and categorise the intensity of marine heat.</p>
<p>The names Hurricane Katrina, tropical cyclone Giselle (which sank the <a href="https://interactives.stuff.co.nz/2018/04/wahine/">ferry Wahine 50 years ago</a>), tropical cyclone Winston give a malevolent personality to geophysical phenomena. Importantly they get graded into categories, so we can rapidly assess their potential impact.</p>
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Read more:
<a href="https://theconversation.com/winston-strikes-fiji-your-guide-to-cyclone-science-55134">Winston strikes Fiji: your guide to cyclone science</a>
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<p>An Australian team has <a href="https://tos.org/oceanography/article/categorizing-and-naming-marine-heatwaves">developed a classification scheme</a> for marine heatwaves. The team used an approach similar to that used for hurricanes and cyclones – changing conditions can be slotted into to a sequence of categories. At the moment it looks like we are in marine heat wave category one conditions, but potentially entering category two if it continues to warm. </p>
<h2>Turning the heat up on marine life</h2>
<p>A marine heatwave is <a href="https://www.nzherald.co.nz/nz/news/article.cfm?c_id=1&objectid=12187629">potentially devastating for marine ecosystems</a>. It is also an indication that the hidden buffer in the climate system – the fact that the oceans have absorbed 93% of the excess heat – is <a href="http://science.sciencemag.org/content/363/6423/128">starting to change</a>. Individual warm seasons have always occurred, but in future there will be more of them and they will <a href="https://doi.org/10.1080/00288330.2017.1390772">keep getting warmer</a>.</p>
<p>The Great Barrier Reef has already been hit hard by a succession of marine heatwave events, bleaching the iconic corals and changing the structure of the ecosystem it supports.</p>
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Read more:
<a href="https://theconversation.com/the-2016-great-barrier-reef-heatwave-caused-widespread-changes-to-fish-populations-100455">The 2016 Great Barrier Reef heatwave caused widespread changes to fish populations</a>
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<p>Further south, off Tasmania’s east coast, a number of species that normally occur in tropical waters have <a href="https://doi.org/10.1016/j.gloenvcha.2014.12.003">extended their range further south</a>. A number of fish species, lobster and octopus species have also taken up residence along the Tasmanian coast, displacing some of the species that call this coast home. Mobile species can escape the warmer temperatures, but sedentary plants and animals are hardest hit. </p>
<p>In New Zealand, aquaculture industries will find it <a href="https://www.nature.com/articles/s41559-018-0669-1">more difficult to grow fish or mussels</a> as <a href="https://doi.org/10.1080/00288330.2017.1390772">coastal waters continue to warm</a>. If the same trends seen off Tasmania occur here, areas with substantial kelp canopies will struggle and start to be replaced by <a href="https://doi-org.ezproxy.auckland.ac.nz/10.1016/j.pocean.2018.02.007">species normally seen further north</a>. But the impacts will likely be very variable because the warming will be heavily influenced by wind and ocean currents and different locations will feel changes to a greater or lesser extent.</p>
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<span class="caption">NIWA’s research vessel Kaharoa has deployed Argo floats in the Southern Ocean and in waters around New Zealand.</span>
<span class="attribution"><span class="source">NIWA</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
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<h2>Predicting the seasons</h2>
<p>As important as it is to identify a marine heatwave at the time, reliable predictions of developing conditions would help fishers, aquaculture companies and local authorities – and in fact anyone living and working around the ocean.</p>
<p>Seasonal forecasting a few months ahead is difficult. It falls between weather and climate predictions. In a collaboration between the <a href="https://www.niwa.co.nz/">National Institute of Water and Atmospheric Research</a> and the <a href="http://www.bom.gov.au/">Australian Bureau of Meteorology</a>, we are examining how well long-term <a href="https://www.tandfonline.com/doi/full/10.1080/00288330.2018.1538052">forecasts of ocean conditions around New Zealand stack up</a>. Early forecasts suggested this summer would not be as warm as last year. But it now looks like this summer will again be very warm in the ocean.</p>
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Read more:
<a href="https://theconversation.com/this-summers-sea-temperatures-were-the-hottest-on-record-for-australia-heres-why-56906">This summer's sea temperatures were the hottest on record for Australia: here’s why</a>
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<p>One of the important points to keep in mind is that when we are at the beach, we are sampling only the surface temperature. The same is true of satellites – they monitor less than the top millimetre of the ocean. </p>
<p>Sea surface temperatures are several degrees above normal at the moment. But in deeper waters, because of the high heat content of water, even a tenth of a degree is significant. Temperature in the deeper ocean is monitored by a <a href="http://imos.org.au/facilities/nationalmooringnetwork/">network of moored buoys</a> on and off the continental shelf along the Australian coast. New Zealand has almost nothing that would be comparable. </p>
<h2>Measuring temperature in real time</h2>
<p>What we can look to, in the absence of moored buoys, is a fleet of ocean robots that monitor temperature in real time. <a href="http://www.whoi.edu/oceanrobots/index.html#home">Argo floats</a> drift with ocean currents, sink to two kilometres every ten days and then collect data as they return to the surface. </p>
<p>These data allowed us to identify that the 2017/18 marine heatwave around New Zealand remained shallow. Most of the warmer water was in the upper 30 metres. Looking at the present summer conditions, one Argo robot off New Zealand’s west coast shows it is almost four degrees above normal in the upper 40 metres of the ocean. On the east coast, near the Chatham Islands, another float shows warmed layers to 20 metres deep. To the south, the warming goes deeper, down to almost 80 metres. </p>
<p>Our work using the Australian Bureau of Meteorology forecast model highlights how <a href="https://www.tandfonline.com/doi/full/10.1080/00288330.2018.1538052">variable the ocean around New Zealand is</a>. Different issues emerge in different regions, even if they are geographically close. </p>
<p>The research on categories of marine heatwaves shows we will have to keep <a href="https://tos.org/oceanography/assets/docs/31-2_hobday.pdf">shifting</a> what we regard as a heat wave as the ocean continues to warm. None of this should come as a surprise. We have known for some time that the world’s oceans are storing most of the additional heat and the impacts of a warming ocean will be <a href="http://science.sciencemag.org/content/355/6332/eaai9214">serious</a>.</p><img src="https://counter.theconversation.com/content/110028/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Craig Stevens receives funding from the Marsden Fund managed by Royal Society Te Apārangi as well as the MBIE-funded Sustainable Seas National Science Challenge. He is on the council of the New Zealand Association of Scientists. </span></em></p><p class="fine-print"><em><span>Ben Noll 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>Marine heatwaves may become the new normal for the Tasman Sea and the ocean around New Zealand, and oceanographers are developing models to better predict their intensity.Craig Stevens, Associate Professor in Ocean Physics, National Institute of Water and Atmospheric ResearchBen Noll, Meteorologist/forecaster, National Institute of Water and Atmospheric ResearchLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1089862018-12-18T19:13:59Z2018-12-18T19:13:59ZExploring Australia’s ‘other reefs’ south of Tasmania<figure><img src="https://images.theconversation.com/files/251125/original/file-20181217-27779-1tg4cyr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Solenosmilia coral reef with unidentified solitary yellow corals.</span> <span class="attribution"><span class="source">CSIRO</span></span></figcaption></figure><p>Off southern Tasmania, at depths between 700 and 1,500 metres, more than 100 undersea mountains provide rocky pedestals for deep-sea coral reefs.</p>
<p>Unlike shallow tropical corals, deep-sea corals live in a cold environment without sunlight or symbiotic algae. They feed on tiny organisms filtered from passing currents, and protect an assortment of other animals in their intricate structures.</p>
<p>Deep-sea corals are fragile and slow-growing, and vulnerable to human activities such as fishing, mining and climate-related changes in ocean temperatures and acidity.</p>
<p>This week we returned from a month-long research voyage on CSIRO vessel <em>Investigator</em>, part of Australia’s Marine National Facility. We criss-crossed many seamounts in and near the Huon and Tasman Fracture marine parks, which are home to both pristine and previously fished coral reefs. These two parks are part of a larger network of Australian Marine Parks that surround Australia’s coastline and protect our offshore marine environment.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/251126/original/file-20181218-27776-x0p4qp.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/251126/original/file-20181218-27776-x0p4qp.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/251126/original/file-20181218-27776-x0p4qp.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=373&fit=crop&dpr=1 600w, https://images.theconversation.com/files/251126/original/file-20181218-27776-x0p4qp.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=373&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/251126/original/file-20181218-27776-x0p4qp.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=373&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/251126/original/file-20181218-27776-x0p4qp.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=469&fit=crop&dpr=1 754w, https://images.theconversation.com/files/251126/original/file-20181218-27776-x0p4qp.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=469&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/251126/original/file-20181218-27776-x0p4qp.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=469&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 RV Investigator criss-crossed the Huon and Tasman Fracture marine parks.</span>
<span class="attribution"><span class="source">CSIRO</span></span>
</figcaption>
</figure>
<p>The data we collected will answer our two key research questions: what grows where in these environments, and are corals regrowing after more than 20 years of protection?</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/explainer-the-rv-investigators-role-in-marine-science-35239">Explainer: the RV Investigator’s role in marine science</a>
</strong>
</em>
</p>
<hr>
<h2>Our eyes on the seafloor</h2>
<p>Conducting research in rugged, remote deep-sea environments is expensive and technically challenging. It’s been a test of patience and ingenuity for the 40 ecologists, technicians and marine park managers on board, and the crew who provide electronics, computing and mechanical support.</p>
<p>But now, after four weeks of working around-the-clock shifts, we’re back in the port of Hobart. We have completed 147 transects covering more 200 kilometres in length and amassed more than 60,000 stereo images and some 300 hours of video for analysis.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/251127/original/file-20181218-27752-18i8j3r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/251127/original/file-20181218-27752-18i8j3r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/251127/original/file-20181218-27752-18i8j3r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/251127/original/file-20181218-27752-18i8j3r.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/251127/original/file-20181218-27752-18i8j3r.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/251127/original/file-20181218-27752-18i8j3r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/251127/original/file-20181218-27752-18i8j3r.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/251127/original/file-20181218-27752-18i8j3r.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">The deep tow camera system weighs 350 kilos and has four cameras, four lights and a control unit encased in high-strength aluminium housings.</span>
<span class="attribution"><span class="source">CSIRO</span></span>
</figcaption>
</figure>
<p>A deep-tow camera system designed and built by CSIRO was our eye on the seafloor. This 350 kilogram system has four cameras, four lights and a control unit encased in high-strength aluminium housings.</p>
<p>An operations planner plots “flight-paths” down the seamounts, adding a one-kilometre run up for the vessel skipper to land the camera on each peak. The skipper navigates swell, wind and current to ensure a steady course for each one-hour transect.</p>
<p>An armoured fibre optic tow cable relays high-quality, real-time video back to the ship. This enables the camera “pilot” in the operations room to manoeuvre the camera system using a small joystick, and keep the view in focus, a mere two metres off the seafloor.</p>
<p>This is an often challenging job, as obstacles like large boulders or sheer rock walls loom out of the darkness with little warning. The greatest rapid ascent, a near-vertical cliff 45m in height, resulted in highly elevated blood pressure and one broken camera light!</p>
<h2>Reaching into their world</h2>
<p>Live imagery from the camera system was compelling. As well as the main reef-building stony coral <em>Solenosmilia variabilis</em>, we saw hundreds of other animals including feathery solitary soft corals, tulip-shaped glass sponges and crinoids. Their colours ranged from delicate creams and pinks to striking purples, bright yellows and golds.</p>
<p>To understand the make-up of coral communities glimpsed by our cameras, we also used a small net to sample the seafloor animals for identification. For several of the museum taxonomists onboard, this was their first contact with coral and mollusc species they had known, and even named, only from preserved specimens.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/251165/original/file-20181218-27749-186e3ah.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/251165/original/file-20181218-27749-186e3ah.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/251165/original/file-20181218-27749-186e3ah.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=323&fit=crop&dpr=1 600w, https://images.theconversation.com/files/251165/original/file-20181218-27749-186e3ah.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=323&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/251165/original/file-20181218-27749-186e3ah.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=323&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/251165/original/file-20181218-27749-186e3ah.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=406&fit=crop&dpr=1 754w, https://images.theconversation.com/files/251165/original/file-20181218-27749-186e3ah.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=406&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/251165/original/file-20181218-27749-186e3ah.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=406&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 deepwater hippolytid shrimp with large hooked claw, which it uses to clean coral and get food.</span>
<span class="attribution"><span class="source">CSIRO</span></span>
</figcaption>
</figure>
<p>We found a raft of undescribed species, as expected in such remote environments. In many cases this is likely to be the only time these species are ever collected. We also found animals living among the corals, hinting at their complex interdependencies. This included brittlestars curled around corals, polychaete worms tunnelling inside corals, and corals growing on shells.</p>
<p>We used an oceanographic profiler to sample the chemical properties of the water to 2,000m. Although further analysis is required, our aim here is to see whether long-term climate change is impacting the living conditions at these depths.</p>
<p>A curious feature of one of the southern seamounts is that it hosts the world’s only known aggregation of deep-water eels. We have sampled these eels twice before and were keen to learn more about this rare phenomenon.</p>
<p>Using an electric big-game fishing rig we landed two egg-laden female eels from a depth of 1,100 metres: a possible first for the record books.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/251129/original/file-20181218-27776-nx1qei.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/251129/original/file-20181218-27776-nx1qei.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/251129/original/file-20181218-27776-nx1qei.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/251129/original/file-20181218-27776-nx1qei.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/251129/original/file-20181218-27776-nx1qei.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/251129/original/file-20181218-27776-nx1qei.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/251129/original/file-20181218-27776-nx1qei.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/251129/original/file-20181218-27776-nx1qei.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">Dave Logan of Parks Australia with an eel landed from more than a kilometre under the sea.</span>
<span class="attribution"><span class="source">Fraser Johnston/CSIRO</span></span>
</figcaption>
</figure>
<p>In a side-project, a team of observers recorded 42 seabird species and eight whale and dolphin species. They have one more set of data towards completing the first circum-Australia survey of marine birds and mammals.</p>
<h2>More coral pedestals than we realise</h2>
<p>An important finding was that living <em>S. variabilis</em> reefs extended between the seamounts on raised ridges down to about 1,450m. This means there is more of this important coral matrix in the Huon and Tasman Fracture marine parks than we previously realised.</p>
<p>In areas that were revisited to assess the regrowth of corals after two decades of protection from fishing, we saw no evidence that the coral communities are recovering. But there were signs that some individual species of corals, featherstars and urchins have re-established a foothold.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/sludge-snags-and-surreal-animals-life-aboard-a-voyage-to-study-the-abyss-79924">Sludge, snags, and surreal animals: life aboard a voyage to study the abyss</a>
</strong>
</em>
</p>
<hr>
<p>In coming months we will work through a sub-sample of our deep-sea image library to identify the number and type of organisms in certain areas. This will give us a clear, quantitative picture of where and at what depth different species and communities live in these marine parks, and a foundation for predicting their likely occurrence both in Australia and around the world.</p>
<p><br></p>
<hr>
<p><em>The seamount corals survey involved 10 organisations: CSIRO, the National Environmental Science Program Marine Biodiversity Hub, Australian Museum, Museums Victoria, Tasmanian Museum and Art Gallery, NIWA (NZ), three Australian universities and Parks Australia.</em></p><img src="https://counter.theconversation.com/content/108986/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Nic Bax receives funding from CSIRO and the Australian Government National Environmental Science Program, Marine Biodiversity Hub </span></em></p><p class="fine-print"><em><span>Alan Williams receives funding from CSIRO, NESP Biodiversity Hub, Parks Australia
</span></em></p>In the cold southern oceans, underwater mountains support deep-sea reefs.Nic Bax, Director, NERP Marine Biodiversity Hub, CSIROAlan Williams, Researcher, CSIROLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/467402015-08-31T20:06:16Z2015-08-31T20:06:16ZSeabirds are eating plastic litter in our oceans – but not only where you’d expect<figure><img src="https://images.theconversation.com/files/93131/original/image-20150827-368-192m6mo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Had a gutful of plastic rubbish affecting wildlife?</span> <span class="attribution"><span class="source">Britta Denise Hardesty</span>, <span class="license">Author provided</span></span></figcaption></figure><p>Many of you may have already seen the photograph above, of an albatross carcass full of undigested plastic junk. But how representative is that of the wider issue facing seabirds?</p>
<p>To help answer that question, we carried out the first worldwide analysis of the threat posed by plastic pollution to seabird species worldwide. </p>
<p>Our study, <a href="http://www.pnas.org/cgi/doi/10.1073/pnas.1502108112">published today in Proceedings of the National Academy of Sciences</a>, found that nearly 60% of all seabird species studied so far have had plastic in their gut. This figure is based on reviewing previous reports in the scientific literature, but if we use a statistical model to infer what would be found at the current time and include unstudied species, we expect that more than 90% of seabirds have eaten plastic rubbish. </p>
<h2>Rising tide of plastic</h2>
<p>Our analysis of published studies shows that the amount of plastic in seabird’s stomachs has been climbing over the past half-century. In 1960, plastic was found in the stomachs of less than 5% of seabirds, but by 2010 this had risen to 80%. We predict that by 2050, 99% of the world’s seabird species will be accidentally eating plastic, unless we take action to clean up the oceans. </p>
<p>Perhaps surprisingly, we also found that the area with the worst expected impact is at the boundary of the Southern Ocean and the Tasman Sea, between Australia and New Zealand. While this region is far away from the subtropical gyres, dubbed “ocean garbage patches”, that collect the highest densities of plastic, the highest threat is in areas where plastic rubbish overlaps with large numbers of different seabird species – such as the Southern Ocean off Australia.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/93265/original/image-20150828-17435-140ee9d.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/93265/original/image-20150828-17435-140ee9d.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/93265/original/image-20150828-17435-140ee9d.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=413&fit=crop&dpr=1 600w, https://images.theconversation.com/files/93265/original/image-20150828-17435-140ee9d.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=413&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/93265/original/image-20150828-17435-140ee9d.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=413&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/93265/original/image-20150828-17435-140ee9d.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=519&fit=crop&dpr=1 754w, https://images.theconversation.com/files/93265/original/image-20150828-17435-140ee9d.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=519&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/93265/original/image-20150828-17435-140ee9d.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=519&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Expected number of seabird species ingesting plastic.</span>
<span class="attribution"><a class="source" href="http://www.pnas.org/cgi/doi/10.1073/pnas.1502108112">PNAS</a></span>
</figcaption>
</figure>
<p>Seabirds are excellent indicators of ecosystem health. The high estimates of plastic in seabirds we found were not so surprising, considering that members of our research team have previously found nearly 200 pieces of plastic in a single seabird. These items include a wide range of things most of us would recognise: bags, bottle caps, bits of balloons, cigarette lighters, even toothbrushes and plastic toys. </p>
<p>Seabirds can have surprising amounts of plastic in their gut. Working on islands off Australia, we have found birds with plastics making up 8% of their body weight. Imagine a person weighing 62 kg having almost 5 kg of plastic in their digestive tract. And then think about how large that lump would be, given that many types of plastic are designed to be as lightweight as possible.</p>
<p>The more plastic a seabird encounters, the more it tends to eat, which means that one of the best predictors of the amount of plastic in a seabird’s gut is the concentration of ocean plastic in the region where it lives. This finding points the way to a solution: reducing the amount of plastic that goes into the ocean would directly reduce the amount that seabirds (and other wildlife) accidentally eat. </p>
<p>That might sound obvious, but as we can see from the stomach contents of the birds, many of the items are things people use every day, so the link to human rubbish is clear. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/93410/original/image-20150831-29524-d82uzn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/93410/original/image-20150831-29524-d82uzn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/93410/original/image-20150831-29524-d82uzn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=451&fit=crop&dpr=1 600w, https://images.theconversation.com/files/93410/original/image-20150831-29524-d82uzn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=451&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/93410/original/image-20150831-29524-d82uzn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=451&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/93410/original/image-20150831-29524-d82uzn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/93410/original/image-20150831-29524-d82uzn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/93410/original/image-20150831-29524-d82uzn.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">Plastic from a dead flesh-footed shearwater, amounting to 8% of the bird’s body weight.</span>
<span class="attribution"><span class="source">Britta Denise Hardesty</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Our study suggests that improving waste management would directly benefit wildlife. There are several actions we could take, such as reducing packaging, banning single-use plastic items or charging an extra fee to use them, and introducing deposits for recyclable items like drink containers. </p>
<p>Many of these types of policies are already proving to be locally effective in reducing waste lost into the environment, a substantial portion of which ends up polluting the ocean. </p>
<p>One <a href="http://www.sciencedirect.com/science/article/pii/S0269749115001104">recent study</a> of industrial practices in Europe found that improved management of plastic led to a clear reduction in the number of plastic items found in seabirds in the North Sea within a few decades. This is encouraging, as it suggests not only that the solutions are effective, but also that they work in a relatively short time. </p>
<p>Given that most of these items were in someone’s hands at some point, it seems that a simple behaviour change can reduce a global impact to our seabirds, and to other marine species as well.</p>
<p><em>This work was carried out as part of a national marine debris project supported by CSIRO and Shell’s Social investment program, as well as the marine debris working group at the <a href="https://www.nceas.ucsb.edu/">US National Center for Ecological Analysis and Synthesis</a>, University of California, Santa Barbara, with support from <a href="http://www.oceanconservancy.org">Ocean Conservancy</a>.</em></p><img src="https://counter.theconversation.com/content/46740/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Chris Wilcox receives funding from CSIRO, Shell Social Investment Fund</span></em></p><p class="fine-print"><em><span>Britta Denise Hardesty received funding for this work from CSIRO and Shell’s Social investment program .</span></em></p><p class="fine-print"><em><span>Erik van Sebille receives funding from the Australian Research Council and the Engineering and Physical Sciences Research Council.</span></em></p>By 2050, 99% of the world’s seabird species will be accidentally eating plastic, unless we take action to clean up the oceans. And some of the highest risk to wildlife is in the Southern Ocean off Australia.Chris Wilcox, Senior Research Scientist, CSIROBritta Denise Hardesty, Senior Research Scientist, Oceans and Atmosphere Flagship, CSIROErik van Sebille, Lecturer in oceanography and climate change, Imperial College LondonLicensed as Creative Commons – attribution, no derivatives.