tag:theconversation.com,2011:/uk/topics/indian-ocean-9556/articlesIndian Ocean – The Conversation2024-03-27T01:14:51Ztag:theconversation.com,2011:article/2265132024-03-27T01:14:51Z2024-03-27T01:14:51ZThese extraordinary Australian islands are teeming with life – and we must protect them before it’s too late<p>In the Southern Ocean about 4,000 kilometres from Perth lies a truly extraordinary place. Known as the Heard Island and McDonald islands, they are among the most remote places on Earth: a haven for marine life amid the vast ocean, virtually undisturbed by human pressures.</p>
<p>But as our <a href="https://research-repository.uwa.edu.au/en/publications/understanding-the-marine-ecosystems-surrounding-heard-island-and-">report</a> released today reveals, this special place in Australia’s territory is at risk. In particular, climate change is warming the waters around the islands, threatening a host of marine life.</p>
<p>More than 20 years ago, a marine reserve was declared over the islands and parts of the surrounding waters. At the time, it was a significant step forward in environmental protection. But since then, science has progressed and the threats have worsened. </p>
<p>Our report reviewed these protections and found they are no longer adequate. The marine reserve surrounding the Heard and McDonald islands must urgently be expanded. </p>
<h2>Spotlight on the reserve system</h2>
<p>The Heard and McDonald islands are just a tiny tip of the Kerguelen Plateau – a huge underwater mass rising high above the surrounding ocean basins. </p>
<p>The plateau intercepts the Antarctic Circumpolar Current, the strongest current system in the world. When the current hits the plateau, deep, nutrient-rich waters are pushed to the surface. This supports a food chain ranging from tiny plankton to fish, invertebrates, seabirds and marine mammals such as elephant seals and sperm whales.</p>
<p>On Heard Island, Mawson’s Peak is officially Australia’s highest mountain. It is 2,745 metres high and forms the summit of an active volcano known as Big Ben. Heard Island and McDonald Islands also host valuable fisheries for Patagonian toothfish and mackerel icefish.</p>
<p>The marine reserve around the islands was declared in 2002 and extended in 2014. It now covers 17% of what is known as the “exclusive economic zone” – the area of the sea in which a nation (in this case, Australia) has exclusive rights to resources such as fish and minerals.</p>
<p>The original reserve was primarily designed for waters shallower than 1,000m, because in 2002 little was known about the area’s deeper waters. A review of the reserve system is due this year.</p>
<p>Our report draws on more than 20 years’ of research conducted since the reserve was first declared. It highlights new scientific understanding of the region and the need to expand its protection.</p>
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<h2>Climate pressures on the plateau</h2>
<p>Climate change poses wicked threats for the Heard and McDonald islands and surrounding marine environment. </p>
<p>We found the shelf area is <a href="https://www.nature.com/articles/s41467-020-20781-1">becoming warmer</a>. This potentially threatens species adapted to cold polar waters, such as the mackerel icefish. This species lives in shallow water and is an important food source for fur seals and other predators. </p>
<p>No other sub-antarctic shelf exists to the south of Heard Island, which means the region is a vital animal habitat. Maintaining the islands’ biodiversity in the face of climate change is best achieved by extending the existing marine reserve to cover more shallow waters, as well as protecting currently unprotected deeper waters.</p>
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Read more:
<a href="https://theconversation.com/australias-only-active-volcanoes-and-a-very-expensive-fish-the-secrets-of-the-kerguelen-plateau-123351">Australia's only active volcanoes and a very expensive fish: the secrets of the Kerguelen Plateau</a>
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<h2>Protecting deep-water species</h2>
<p>The Patagonian toothfish is a top predator species that connects different parts of the food web. Commercial fishing in the islands’ economic zone targets toothfish using “<a href="https://www.fisheries.noaa.gov/national/bycatch/fishing-gear-bottom-longlines">bottom longlines</a>” which are weighted to the seafloor at depths down to 2,000m. The footprint of fishing operations has expanded over the past 30 years.</p>
<p>Our report suggests protecting <a href="https://www.sciencedirect.com/science/article/pii/S0304380016303325">spawning grounds</a> of toothfish will reduce risks to this species and help ensure the fishery does not deplete fish stock.</p>
<p>Fishing is managed in such a way to eliminate the accidental catching (or by-catch) of seabirds. But there is still significant by-catch of a number of non-target fish species, especially skates. </p>
<p>Keeping fishing out of some areas can reduce pressure on vulnerable species. Important areas for achieving this are in the deeper waters to the southeast of Heard Island. </p>
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Read more:
<a href="https://theconversation.com/climate-risk-index-shows-threats-to-90-per-cent-of-the-worlds-marine-species-190221">Climate risk index shows threats to 90 per cent of the world's marine species</a>
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<h2>Sustaining biodiversity into the future</h2>
<p>Our analysis reveals an updated understanding of the marine ecosystems surrounding Heard and McDonald islands.</p>
<p>Scientists now know more about where <a href="https://www.sciencedirect.com/science/article/abs/pii/S1470160X16302977">marine mammals and birds forage</a> – particularly in the important period when parents are feeding their young. We found some species that breed on Heard Island, including king penguins and fur seals, rely on areas not protected by the marine reserve during these times.</p>
<p>Our analysis also reveals a complex mosaic of productive habitats in shallow water, and less productive habitats in deeper water. This in turn affects the distribution of animal species.</p>
<p>Increased protection for the areas in the west, south, and southeast of the economic zone will be needed to protect animals in these habitats.</p>
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<img alt="Increased protections are needed to protect biodiversity in the region." src="https://images.theconversation.com/files/298059/original/file-20191022-28092-12ocbi6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/298059/original/file-20191022-28092-12ocbi6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/298059/original/file-20191022-28092-12ocbi6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/298059/original/file-20191022-28092-12ocbi6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/298059/original/file-20191022-28092-12ocbi6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/298059/original/file-20191022-28092-12ocbi6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/298059/original/file-20191022-28092-12ocbi6.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">Bird activity behind a research vessel near the Kerguelen Plateau.</span>
<span class="attribution"><span class="source">Paul Tixier</span></span>
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<h2>Looking ahead</h2>
<p>The current marine reserve covering Heard and McDonald islands is not sufficient. It should cover deeper water ecosystems and provide protection for foraging areas of resident seals, penguins and albatross. </p>
<p>Protecting spawning grounds of toothfish and areas important to cold-adapted species, such as mackerel icefish, will help ensure these species have the best chance against continuing warming of the ocean. </p>
<p>Extending the protections would help Australia meet its domestic policy and international agreements. For example, the federal government has committed to protecting <a href="https://theconversation.com/weve-committed-to-protect-30-of-australias-land-by-2030-heres-how-we-could-actually-do-it-217795">at least 30%</a> of ocean ecosystems by 2030.</p>
<p>It would also ensure our marine protected areas are <a href="https://www.dcceew.gov.au/environment/marinereservesreview/resources/representative-system">nationally representative</a> – a key national objective Australia has committed to.</p>
<p>By extending adequate protection of Heard and McDonald islands, Australia has the chance to show global leadership in conserving this precious natural asset in the Southern Ocean.</p><img src="https://counter.theconversation.com/content/226513/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The report underpinning this article was part-funded by Pew Charitable Trusts and the Australian Marine Conservation Society.</span></em></p>A new report has found the marine reserve covering the Heard and McDonald islands must urgently be expanded.Ian Cresswell, Adjunct professor, The University of Western AustraliaAndrew J Constable, Adviser, Antarctica and Marine Systems, Science & Policy, University of TasmaniaKeith Reid, Honorary Research Associate, Institute for Marine and Antarctic Studies, University of TasmaniaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2230252024-03-11T13:07:21Z2024-03-11T13:07:21ZTechnology to protect South Africa’s oceans: experts find that a data-driven monitoring system is paying off<figure><img src="https://images.theconversation.com/files/577893/original/file-20240226-24-qjmkpc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A fishing boat launching into South African waters at dawn.</span> <span class="attribution"><span class="source">Justin Klusener Photos</span></span></figcaption></figure><p>Nine years ago South Africa put in place an innovative information management system designed to monitor and protect its seas. The country is surrounded by the Atlantic and Indian oceans on its southern, eastern and western borders. </p>
<p>The oceans are an <a href="https://www.tandfonline.com/doi/abs/10.1080/19480881.2015.1066555">important source of income and employment</a>. The ocean economy <a href="https://www.dffe.gov.za/sites/default/files/docs/publications/oceans-economy-summary-progress-report-June2019.pdf">contributed about R110 billion</a> (around US$5.7 billion) to South Africa’s GDP in 2010. A 2019 government report <a href="https://www.dffe.gov.za/sites/default/files/docs/publications/oceans-economy-summary-progress-report-June2019.pdf">projected</a> that, by 2033, this would rise to R177 billion (US$9.2 billion), as well as creating just over one million jobs. The main sectors in ocean industries are maritime transport, fisheries and aquaculture, mineral resource exploitation and tourism. The potential for economic growth is also reflected in the country’s <a href="https://www.gov.za/sites/default/files/gcis_document/201706/saoceaneconomya.pdf">Operation Phakisa Oceans Economy plan</a>.</p>
<p>But, while the sheer extent of its maritime domain presents many opportunities, it also comes with governance challenges. It’s hard to monitor and plan for ocean-related economic development and conservation.</p>
<p>That’s where the National Oceans and Coastal Information Management System (<a href="https://ocims.environment.gov.za/About.html">OCIMS</a>) comes in. It was conceptualised within the country’s Department of Forestry, Fisheries and the Environment in 2012 and officially launched in 2015 in partnership with the Council for Scientific and Industrial Research (CSIR). </p>
<p>While the system is tailored to South Africa’s national priorities, it was inspired by other mature ocean information systems around the world, such as those in <a href="https://imos.org.au/">Australia</a> and the <a href="https://coastwatch.noaa.gov/cwn/index.html">US</a>.</p>
<p>The system brings ocean observations made by various national agencies into one platform. The major users are also partners who contribute to the system by sharing data and expertise.</p>
<p>For example, data capture apps on the system are used to share measurements made on aquaculture farms and inform users on the potential risk of <a href="https://oceanservice.noaa.gov/facts/redtide.html">red tides</a> (a common name used for harmful algal bloom). Boat-based whale watching operators contribute their marine species sightings data towards biodiversity assessments. All this data can be analysed by scientists and their findings used to advise on policy options or compliance and enforcement actions.</p>
<p>In a <a href="https://doi.org/10.1016/j.jenvman.2024.120255">recent paper</a> we looked at how the system emerged and why it’s been important for the protection of the country’s oceans. We found that it was providing value for money: it helped mitigate environmental or security risks, resulting in significant cost savings for the public and private sectors. It also promoted dialogue across government departments, non-profit organisations and the private sector. This facilitates a coordinated approach to ocean governance.</p>
<p>The approach taken to establish the system could benefit other countries looking to build their own ocean and coastal system knowledge platforms.</p>
<h2>Data-driven</h2>
<p>As the COVID pandemic demonstrated, informed decisions cannot occur without access to data. Historical and operational data provides situational awareness, informs policy and supports long-term planning and management.</p>
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Read more:
<a href="https://theconversation.com/how-african-countries-can-harness-the-huge-potential-of-their-oceans-77889">How African countries can harness the huge potential of their oceans</a>
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<p>To this end, the Department of Forestry, Fisheries and the Environment, working with the <a href="https://www.saeon.ac.za/">South African Environmental Observations Network</a>, created the <a href="https://data.ocean.gov.za/">Marine Information Management System</a>. It’s an essential component of the overall OCIMS system. It preserves, discovers and disseminates long-term data. It is internationally accredited and bound by best international standards and practices. </p>
<p>The system also makes data more accessible by providing <a href="https://ica-abs.copernicus.org/articles/6/275/2023/ica-abs-6-275-2023.pdf">user-specific data capture applications</a>, complemented by data visualisation platforms such as webmaps and dashboards. </p>
<h2>Supporting decisions</h2>
<p>Another of the system’s aims is to provide tools for supporting decisions. Such tools can be used for coordination and response (for example, monitoring <a href="https://ica-abs.copernicus.org/articles/6/275/2023/ica-abs-6-275-2023.pdf">avian influenza</a>). They can also be used in compliance and enforcement initiatives, such as tracking vessels.</p>
<p>The Fisheries and Aquaculture tool, for instance, supports both the public and private sectors by providing warnings on potentially harmful algal blooms, a phenomenon that can threaten aquaculture farms or affect fish and lobster populations. It detects algal blooms through satellite observations; this satellite data is complemented by information from those in the field, combining to create an active, interactive decision-making tool.</p>
<p>Then there’s the Integrated Vessel Tracking tool. It monitors vessels’ movements and is used daily by the institutions mandated to enforce security at sea, such as intelligence services and the navy, to detect or intercept illegal activities at sea. <a href="https://issafrica.org/research/books-and-other-publications/south-africas-maritime-domain-awareness-a-capability-baseline-assessment">Researchers say</a> the tool has worked to prevent illegal fishing and marine pollution. It’s also been instrumental in the interception of drug-loaded vessels.</p>
<h2>Collaboration</h2>
<p>All of these successes have been made possible by secure, sustained funding by the South African government. That has instilled a sense of security in collaborators and partners; they provide invaluable co-funding, expertise and data, saving money and building resilience into the system.</p>
<p>Some of the system’s tools have been shared with other countries in the <a href="https://marcosio.org/">southern African</a> and Indian Ocean regions. </p>
<p>As the project’s visibility increases, new opportunities for collaborations are emerging. Government departments, non-profit organisations and the private sector are coming forward with offers to share data. The system is also being proposed for use by academic scientists in their proposals.</p>
<p>One of the main lessons emerging from our research, which may be of interest to other countries wanting to launch similar initiatives, is that it’s crucial to involve a system’s major users in development from the start. Formalised stakeholder interactions ensure that the system directly responds to major user needs. That makes it immediately relevant and useful.</p><img src="https://counter.theconversation.com/content/223025/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Marjolaine Krug works for the South African Department of Forestry, Fisheries and the Environment, Oceans and Coast Branch.
The OCIMS is funded through Operation Phakisa Marine Protection Services and Ocean Governance workstream and is a partnership between the Department of Forestry, Fisheries and the Environment, the Department of Science and Innovation, the Council for Scientific and Industrial Research, the South African Environmental Observation Network and the South African Weather Services. </span></em></p><p class="fine-print"><em><span>Ashley Naidoo was the Chief Director for the Oceans and Coasts Science Programs at the Department of Forestry Fisheries and the Environment until January 2024.</span></em></p><p class="fine-print"><em><span>Lauren Williams works for the Department of Forestry, Fisheries and the Environment (South Africa). She has been involved in the development of the Oceans and Coastal Information Management System (OCIMS) since its inception. </span></em></p>South Africa’s ocean information management system is helping to mitigate security and environmental risks.Marjolaine Krug, Senior Scientific Advisor, University of Cape TownLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2252922024-03-08T11:34:27Z2024-03-08T11:34:27ZFlight MH370 is still missing after ten years – forensic experts explain what we know and why we haven’t found the plane<p>It has been ten years since Malaysian airlines flight MH370, carrying 239 passengers and crew on board, disappeared less than one hour after taking off from Kuala Lumpur on 8 March 2014. It has become one of the great unsolved mysteries of modern times and is a puzzle that has remained resolutely unsolved. </p>
<p>Theories abound on the flight’s disappearance and current location of the wreckage. Unusually, all communications aboard the plane were switched off shortly after take-off. </p>
<p>Intermittent satellite location information subsequently suggested <a href="https://slate.com/technology/2014/06/inmarsat-releases-data-showing-mh370-definitely-went-south.html">it was flown south on a very different flight path</a> than expected, to a remote and deep ocean area of the Southern Indian Ocean before contact was lost.</p>
<p>When actively searching for MH370, sophisticated international surveillance aircraft initially conducted over 300 flights to visually look for plane debris on the surface. Then surface and submersible vehicles conducted further surveys, searching over 120,000 sq km of ocean before ending the search in 2017. </p>
<p>The effort to find MH370 became one of the <a href="https://www.telegraph.co.uk/news/worldnews/asia/malaysia/10863605/MH370-search-becomes-most-expensive-aviation-hunt-in-history-yet-still-no-clues.html">most expensive aviation searches in history</a>. These surveys used both <a href="https://en.wikipedia.org/wiki/Sonar">sonar</a> (active acoustic instruments to image the sea floor to locate the aircraft), and also listening devices to pick up the aircraft’s <a href="https://en.wikipedia.org/wiki/Flight_recorder">flight data recorder</a>. </p>
<p>Confirmed MH370 plane debris were found on Reunion Island in July 2015, and off the coast of Mozambique in February 2016, which was consistent with what we know about ocean currents. In 2018, OceanInfinity, a private exploration company, <a href="https://oceaninfinity.com/ocean-infinity-to-continue-search-for-missing-malaysian-airlines-flight-mh370/">also searched 25,000 sq km</a> but without success.</p>
<p>Since then, a mixture of highly trained experts and members of the public have sought to assist the <a href="https://www.mh370search.com/">search</a>. These efforts have varied from simple to really advanced data analysis. They have attempted to map the locations and timings of plane debris, and other maritime debris, as well as model drift currents. In doing so, they are attempting to reconstruct where these may have originated from, which is no small task. </p>
<p>Analysis of the MH370 flight path has been pieced together from two different types of radar – primary and secondary – as well as the intermittent data “pings” from the plane to the <a href="https://en.wikipedia.org/wiki/Inmarsat">Inmarsat</a> satellite. The results suggest that it <a href="https://www.bbc.co.uk/news/science-environment-27870467">diverted south from its intended flight path</a>.</p>
<p>Another technique called weak signal propagation (<a href="https://en.wikipedia.org/wiki/WSPR_(amateur_radio_software)">WSPR</a> data (a way of using radio emission to track objects such as planes), had defined a specific but very large search area, some of which has already been searched.</p>
<p>Available hydroacoustic data (based on the way sound propagates in water) of the sea floor has also been analysed. However, only a relatively small area was covered and the marine sea floor in this region can be very rugged. There are deep <a href="https://www.sciencedirect.com/science/article/pii/S007966112200163X">submarine canyons</a> that can hide objects much bigger than a plane. </p>
<p>Lessons from studying past flight disasters also informed the search. These included the 2009 Yemenia plane crash in the Indian Ocean.</p>
<h2>Recovery operation</h2>
<p>For inland or coastal water searches, a phased investigation strategy is suggested as <a href="http://dx.doi.org/10.1016/j.earscirev.2017.04.012">best practice</a>, where investigators look to identify water depths, major current strengths and directions, together with pre-existing site information, before specialist search teams are employed using methods, equipment configurations and personnel that have all been accredited.</p>
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Read more:
<a href="https://theconversation.com/how-science-is-helping-the-police-search-for-bodies-in-water-73931">How science is helping the police search for bodies in water</a>
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<p>However this reliance on technology can be problematic. Even in small waterways, the presence of vegetation in the search area or a target buried by sediment can make these searches difficult.</p>
<p>Much of the Southern Indian Ocean sea floor is rugged and relatively unmapped, with <a href="https://www.bgs.ac.uk/news/deepest-points-of-the-indian-ocean-and-southern-ocean-revealed/">water depths of up to 7.4km</a>. It’s away from regular shipping lanes and commercial flight patterns, with few fishing boats, no significant land masses and some of the worst winds and weather in the world. These factors also make it a very challenging area to search. </p>
<p>In deep water (more than 2km to 3km) deploying sonar is cumbersome and prohibitively expensive. It also takes a long time to generate data. A major challenge for scanning technologies is achieving accuracy at these kinds of depths due to the scattering of the signal caused by uneven, especially rocky substrates on the sea floor.</p>
<p>The development of more advanced autonomous submersible vehicles may hold the
key to finding MH370 in the Southern Indian Ocean, along with post-processing of
raw data which can clarify what can be attributed to rocks as well as sea-floor
hummocks and pockets. </p>
<p>This can distinguish between the sea floor and the objects being searched for. However, the area where MH370 disappeared is vast, meaning future searches will remain just as challenging as when the plane first went missing in 2014.</p><img src="https://counter.theconversation.com/content/225292/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jamie Pringle receives funding from the HLF, the Nuffield Foundation, Royal Society, NERC, EPSRC and EU Horizon2020. He is affiliated with the Geological Society of London. Jamie works for Keele University.</span></em></p><p class="fine-print"><em><span>Alastair Ruffell receives funding from: ProjectBoost (IntertradeIreland); Arts & Humanities Research Council; Natural Environment Research Council; Engineering & Physical Sciences Research Council.</span></em></p><p class="fine-print"><em><span>Ruth Morgan has received funding from the UK Arts and Humanities Research Council and the UK Engineering and Physical Sciences Research Council.</span></em></p>Despite advanced technology and search techniques the rugged seafloor can hide objects much larger than a plane.Jamie Pringle, Reader in Forensic Geoscience, Keele UniversityAlastair Ruffell, Reader, School of Natural and Built Environment, Queen's University BelfastRuth Morgan, Vice Dean Engineering (Interdisciplinarity Entrepreneurship), Professor of Crime and Forensic Science, UCLLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2249542024-03-05T05:07:21Z2024-03-05T05:07:21ZMH370 disappearance 10 years on: can we still find it?<p>It has been ten years since Malaysia Airlines passenger flight MH370 <a href="https://theconversation.com/lessons-to-learn-despite-another-report-on-missing-flight-mh370-and-still-no-explanation-100764">disappeared on March 8 2014</a>. To this day it remains one of the biggest aviation mysteries globally.</p>
<p>It’s unthinkable that a modern Boeing 777-200ER jetliner with 239 people on board can simply vanish without any explanation. Yet multiple searches in the past decade have still not yielded the main wreckage or the bodies of the victims.</p>
<p>At a remembrance event held earlier this week, the Malaysian transport minister announced <a href="https://www.reuters.com/world/asia-pacific/malaysia-says-mh370-search-must-go-10-years-after-plane-vanished-2024-03-03/">a renewed push for another search</a>.</p>
<p>If approved by the Malaysian government, the survey will be conducted by United States seabed exploration firm Ocean Infinity, whose efforts were unsuccessful in 2018. </p>
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Read more:
<a href="https://theconversation.com/lessons-to-learn-despite-another-report-on-missing-flight-mh370-and-still-no-explanation-100764">Lessons to learn, despite another report on missing flight MH370 and still no explanation</a>
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<h2>What happened to MH370?</h2>
<p>The flight was scheduled to fly from Kuala Lumpur to Beijing. Air traffic control lost contact with the aircraft within 60 minutes into the flight over the South China Sea.</p>
<p>Subsequently, it was tracked by military radar crossing the Malay Peninsula and was last located by radar over the Andaman Sea in the northeastern Indian Ocean.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/579774/original/file-20240305-18-vdbysn.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A map of the region showing the initial search areas on 8-16 March." src="https://images.theconversation.com/files/579774/original/file-20240305-18-vdbysn.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/579774/original/file-20240305-18-vdbysn.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=375&fit=crop&dpr=1 600w, https://images.theconversation.com/files/579774/original/file-20240305-18-vdbysn.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=375&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/579774/original/file-20240305-18-vdbysn.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=375&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/579774/original/file-20240305-18-vdbysn.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=471&fit=crop&dpr=1 754w, https://images.theconversation.com/files/579774/original/file-20240305-18-vdbysn.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=471&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/579774/original/file-20240305-18-vdbysn.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=471&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 planned route, final route and initial search area for MH370 in Southeast Asia.</span>
<span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/Timeline_of_Malaysia_Airlines_Flight_370#/media/File:MH370_initial_search_Southeast_Asia.svg">Andrew Heenen/Wikimedia Commons</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Later, automated satellite communications between the aircraft and British firm’s Inmarsat telecommunications satellite indicated that the plane ended up in the southeast Indian Ocean <a href="https://hub.arcgis.com/datasets/4c94d33cfc144f7d8b78943dee56e29b/explore">along the 7th arc</a> (an arc is a series of coordinates).</p>
<p>This became the basis for defining the initial search areas by the Australian Air Transport Safety Bureau. Initial air searches were conducted in the South China Sea and the Andaman Sea.</p>
<p>To date, we still don’t know what caused the aircraft’s change of course and disappearance.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/579749/original/file-20240305-25-p456o1.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/579749/original/file-20240305-25-p456o1.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/579749/original/file-20240305-25-p456o1.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/579749/original/file-20240305-25-p456o1.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/579749/original/file-20240305-25-p456o1.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/579749/original/file-20240305-25-p456o1.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/579749/original/file-20240305-25-p456o1.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/579749/original/file-20240305-25-p456o1.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Location of the 7th arc and the origin of debris locations for simulations undertaken by the University of Western Australia.</span>
<span class="attribution"><span class="source">Google Earth/Author provided</span></span>
</figcaption>
</figure>
<h2>What have searches for MH370 found so far?</h2>
<p>On March 18 2014, ten days after the disappearance of MH370, a search in the southern Indian Ocean <a href="https://www.atsb.gov.au/publications/2014/considerations-on-defining-the-search-area-mh370">was led by Australia</a>, with participation of aircraft from several countries. This search continued until April 28 and covered an area of 4,500,000 square kilometres of ocean. No debris was found. </p>
<p>Two underwater searches of the Indian Ocean, 2,800km off the coast of Western Australia, have also failed to find any evidence of the main crash site. </p>
<p>The initial seabed search, led by Australia, covered 120,000 square kilometres and extended 50 nautical miles across the 7th arc. It took 1,046 days and was suspended on January 17 2017.</p>
<p>A second search by Ocean Infinity in 2018 <a href="https://oceaninfinity.com/conclusion-of-current-search-for-malaysian-airlines-flight-mh370/">covered over 112,000 square kilometres</a>. It was completed in just over three months but also didn’t locate the wreckage.</p>
<h2>What about debris?</h2>
<p>While the main crash site still hasn’t been found, several pieces of debris have washed up in the years since the flight’s disappearance. </p>
<p>In fact, in June 2015 officials from the Australian Air Transport Safety Bureau determined that debris might arrive in Sumatra, contrary to the ocean currents in the region.</p>
<p>The strongest current in the Indian Ocean is the South Equatorial Current. It flows east to west between northern Australia and Madagascar, and debris would be able to cross it. </p>
<p>Indeed, on July 30 2015 a large piece of debris – a <a href="https://en.wikipedia.org/wiki/Flaperon">flaperon</a> (moving part of a plane wing) – washed up on Reunion Island in the western Indian Ocean. It was later confirmed to belong to MH370.</p>
<p>Twelve months earlier, using an oceanographic drift model, our University of Western Australia (UWA) modelling team had predicted that any debris originating from the 7th arc would end up in the western Indian Ocean.</p>
<p>In subsequent months, additional aircraft debris was found in the western Indian Ocean in Mauritius, Tanzania, Rodrigues, Madagascar, Mozambique and South Africa.</p>
<p>The UWA drift analysis accurately predicted where floating debris from MH370 would beach in the western Indian Ocean. It also guided American adventurer Blaine Gibson and others to directly recover several dozen pieces of debris, three of which <a href="https://www.newsweek.com/where-blaine-gibson-now-malaysia-airlines-mh370-debris-hunter-1787369">have been confirmed</a> to be from MH370, while several others <a href="https://www.airlineratings.com/news/mh370-debris-now-for-the-facts/">are deemed likely</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/579756/original/file-20240305-22-q62h9n.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A detailed satellite map showing locations of debris found on the shores of Africa and Madagascar." src="https://images.theconversation.com/files/579756/original/file-20240305-22-q62h9n.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/579756/original/file-20240305-22-q62h9n.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=602&fit=crop&dpr=1 600w, https://images.theconversation.com/files/579756/original/file-20240305-22-q62h9n.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=602&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/579756/original/file-20240305-22-q62h9n.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=602&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/579756/original/file-20240305-22-q62h9n.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=757&fit=crop&dpr=1 754w, https://images.theconversation.com/files/579756/original/file-20240305-22-q62h9n.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=757&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/579756/original/file-20240305-22-q62h9n.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=757&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Predicted locations of landfall from results of University of Western Australia drift modelling. The white dots indicate predicted landfall of the debris. The aggregation of many dots, particularly close to land, is an indication of the density of particles – higher probability of debris making landfall. These are highlighted by red circles.</span>
<span class="attribution"><span class="source">Charitha Pattiaratchi/UWA, Author provided</span></span>
</figcaption>
</figure>
<p>To date, these debris finds in the western Indian ocean are the only physical evidence found related to MH370.</p>
<p>It is also independent verification that the crash occurred close to the 7th arc, as any debris would initially flow northwards and then to the west, transported by the prevailing ocean currents. These results are consistent with other drift studies undertaken by independent researchers globally.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/ocean-currents-suggest-where-we-should-be-looking-for-missing-flight-mh370-63100">Ocean currents suggest where we should be looking for missing flight MH370</a>
</strong>
</em>
</p>
<hr>
<h2>Why a new search for MH370 now?</h2>
<p>Unfortunately, the ocean is a chaotic place, and even oceanographic drift models cannot pinpoint the exact location of the crash site.</p>
<p>The proposed new search by Ocean Infinity has significantly narrowed down the target area within latitudes 36°S and 33°S. This is approximately 50km to the south of the locations where UWA modelling indicated the release of debris along the 7th arc. If the search does not locate the wreckage, it could be extended north.</p>
<p>Since the initial underwater searches, technology has tremendously improved. Ocean Infinity is using a fleet of autonomous underwater vehicles with improved resolution. The proposed search will also use remotely controlled surface vessels.</p>
<p>In the area where the search is to take place, the ocean is around 4,000 metres deep. The water temperatures are 1–2°C, with low currents. This means that even after ten years, the debris field would be relatively intact.</p>
<p>Therefore, there is a high probability that the wreckage can still be found. If a future search is successful, this would bring closure not just to the families of those who perished, but also the thousands of people who have been involved in the search efforts.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/mh370-new-underwater-sound-wave-analysis-suggests-alternative-travel-route-and-new-impact-locations-110664">MH370: New underwater sound wave analysis suggests alternative travel route and new impact locations</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/224954/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Charitha Pattiaratchi receives funding from Integrated Marine Observing System research institute, the Australian Research Council and the West Australian Marine Science Institution.</span></em></p>It remains one of the biggest aviation mysteries – the tragic disappearance of passenger flight MH370. But a new, targeted search of the seabed could still yield answers.Charitha Pattiaratchi, Professor of Coastal Oceanography, The University of Western AustraliaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2189022024-01-11T13:25:55Z2024-01-11T13:25:55ZTo protect endangered sharks and rays, scientists are mapping these species’ most important locations<figure><img src="https://images.theconversation.com/files/565884/original/file-20231214-27-kjjzka.jpg?ixlib=rb-1.1.0&rect=60%2C0%2C6720%2C4426&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A tiger shark swims among surgeonfish off Fuvahmulah Atoll, Maldives, in the Indian Ocean.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/tiger-shark-with-shoal-of-fish-surgeonfishes-indian-royalty-free-image/1262279323">imageBROKER/Norbert Probst via Getty Images</a></span></figcaption></figure><p>All of the saltwater bodies on Earth make up <a href="https://oceanservice.noaa.gov/facts/howmanyoceans.html">one big ocean</a>. But within it, there is infinite variety – just ask any scuba diver. Some spots have more coral, more sea turtles, more fish, more life. </p>
<p>“I’ve been diving in many places around the world, and there are few locations like the <a href="https://visitfuvahmulah.mv/discover-fuvahmulah/">Fuvahmulah Atoll</a> in the Maldives,” Amanda Batlle-Morera, a research assistant with the <a href="https://sharkrayareas.org/">Important Shark and Ray Areas project</a>, told me. “You can observe tiger sharks, thresher sharks, scalloped hammerheads, oceanic manta rays and more, without throwing out bait to attract them.” </p>
<p>Identifying areas like Fuvahmulah that are especially important to certain species is a <a href="https://www.fws.gov/sites/default/files/documents/critical-habitat-fact-sheet.pdf">long-standing strategy</a> for protecting threatened land animals, birds and marine mammals, such as whales and dolphins. Now our team of marine conservation scientists at the <a href="https://sharkrayareas.org/">Important Shark and Ray Areas project</a> is using it to help protect sharks and their relatives. </p>
<p>I am a <a href="https://scholar.google.com/citations?user=xb7noGAAAAAJ&hl=en">marine conservation biologist</a> and the project’s communications officer. This initiative is working to identify locations that are critical for sharks and rays, so that these zones can be flagged for future protection or fisheries management measures. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/0mPBvhGvZLI?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Divers get close views of tiger sharks at Fuvahmulah, an offshore island in the southern Maldives. Six threatened shark species and one threatened ray species appear regularly in the area.</span></figcaption>
</figure>
<h2>Where the sharks are</h2>
<p>Sharks and their relatives are some of the most imperiled animals on Earth: More than one-third of all known species are <a href="https://doi.org/10.1016/j.cub.2021.08.062">threatened with extinction</a>. Many of these animals play vital roles in their ecosystems. Losing marine predators <a href="https://doi.org/10.1016/j.tree.2008.01.003">can destabilize entire food webs</a> and the ecosystems that these food webs depend on.</p>
<p>In recent years, the management of sharks and their relatives, rays and chimaeras, has largely focused on curbing the impacts of fisheries and trade on these species. But their populations <a href="https://doi.org/10.1016/j.cub.2021.08.062">are still declining rapidly</a>, so new strategies are needed. </p>
<p>To effectively protect these important and threatened animals, my colleagues and I believe it is vital to identify and protect parts of the ocean, plus some freshwater habitats, that are especially significant for their lives. Some areas, for example, are important migratory pathways, or feeding or mating grounds, or places to lay eggs. </p>
<p>Our team has created a <a href="https://doi.org/10.3389/fmars.2022.968853">list of technical criteria</a> so that zones around the world can be examined and potentially designated as Important Shark and Ray Areas. We modeled these criteria on similar approaches that are already in use, such as <a href="https://doi.org/10.1641/0006-3568(2004)054%5B1110:KBAASC%5D2.0.CO;2">important marine mammal areas</a>, which we adapted to the specific needs and biology of sharks and their relatives. </p>
<p>We are now hosting a series of 13 regional workshops around the world and inviting local experts to nominate preliminary areas of interest for evaluation by our team and an independent expert review panel. So far, we’ve completed three workshops, one focusing on the Central and South American Pacific, another on the Mediterranean and Black seas, and the third on the Western Indian Ocean, with a workshop for Asia planned for early 2024. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/568049/original/file-20240105-14-7s4g8o.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A world map shows zones that scientists have identified as Important Shark and Ray Areas in the Pacific and Indian oceans and the Mediterranean Sea." src="https://images.theconversation.com/files/568049/original/file-20240105-14-7s4g8o.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/568049/original/file-20240105-14-7s4g8o.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=308&fit=crop&dpr=1 600w, https://images.theconversation.com/files/568049/original/file-20240105-14-7s4g8o.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=308&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/568049/original/file-20240105-14-7s4g8o.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=308&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/568049/original/file-20240105-14-7s4g8o.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=387&fit=crop&dpr=1 754w, https://images.theconversation.com/files/568049/original/file-20240105-14-7s4g8o.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=387&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/568049/original/file-20240105-14-7s4g8o.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=387&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 current version of the online atlas of Important Shark and Ray Areas. The atlas is organized by region, showing which parts of the world’s oceans and coasts have been assessed.</span>
<span class="attribution"><a class="source" href="https://sharkrayareas.org/">Important Shark and Ray Areas initiative</a>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>After the workshops and expert reviews, each finalized Important Shark and Ray Area will be added to our e-atlas, which <a href="https://sharkrayareas.org/e-atlas/">can be viewed online</a>. Each region’s Important Shark and Ray Areas are published in a formal compendium, and the whole global process will be repeated every 10 years. This cycle will allow us to consider changes to areas that have already been mapped, such as new fishery policies or impacts from climate change, and to take into account new research that can help us identify new areas. </p>
<h2>Informing conservation policies</h2>
<p>We recently published our <a href="https://sharkrayareas.org/download/mediterranean-and-black-seas-regional-compendium-of-important-shark-and-ray-areas/">Mediterranean and Black seas region compendium</a>, which reflects input from over 180 experts from around the region. It identifies 65 Important Shark and Ray Areas that range widely in size and habitat type. Our <a href="https://sharkrayareas.org/download/western-indian-ocean-regional-compendium-of-important-shark-and-ray-areas/">western Indian Ocean compendium</a> includes over 125 areas. </p>
<p>These zones are important for species like the critically endangered <a href="https://www.fisheries.noaa.gov/species/blackchin-guitarfish">blackchin guitarfish</a> (<em>Glaucostegus cemiculus</em>), as well as heavily fished shark species like the <a href="https://www.sharks.org/smoothhound-mustelus-mustelus">common smoothhound shark</a> (<em>Mustelus mustelus</em>). </p>
<p>Some of these areas, such as <a href="https://sharkrayareas.org/portfolio-item/benidorm-island-isra/">Benidorm Island</a> off Spain’s Mediterranean coast, are in shallow coastal zones. Others, like the <a href="https://sharkrayareas.org/wp-content/uploads/isra-factsheets/12CentralSouthPacific/Cocos-Galapagos-Swimway-12CentralSouthPacific.pdf">Cocos-Galapagos Swimway</a> off Costa Rica and Ecuador, reach into deep ocean waters. </p>
<p>The smallest area identified so far, Israel’s <a href="https://sharkrayareas.org/wp-content/uploads/isra-factsheets/03MedBlackSeas/Palmahim-Brine-Pools-03MedBlackSeas.pdf">Palmahim brine pools</a> in the southeast Mediterranean, measures just 0.03 square miles (0.09 square kilometers) – about half the size of New York City’s Grand Central station. <a href="https://eol.org/pages/46560072">Blackmouth catsharks</a>
(<em>Galeus melastomus</em>) breed and lay eggs there, and threatened <a href="https://eol.org/pages/46560287">angular rough sharks</a> (<em>Oxynotus centrina</em>) feed there, including on blackmouth catshark eggs. </p>
<p>The largest area is the <a href="https://sharkrayareas.org/wp-content/uploads/isra-factsheets/03MedBlackSeas/Strait-of-Sicily-and-Tunisian-Plateau-03MedBlackSeas.pdf">Strait of Sicily and Tunisian Plateau</a>, which extends over 77,000 square miles (200,000 square kilometers) – about the size of Great Britain – in the Mediterranean between Sicily, Malta, western Libya and Tunisia. This zone supports at least 32 species of sharks, rays and chimaeras, including many that are at risk of extinction, in habitats ranging from shallow seagrass beds to deep ocean trenches.</p>
<p><div data-react-class="InstagramEmbed" data-react-props="{"url":"https://www.instagram.com/p/CsHnxebvcsp/?utm_source=ig_web_copy_link\u0026igsh=MzRlODBiNWFlZA==","accessToken":"127105130696839|b4b75090c9688d81dfd245afe6052f20"}"></div></p>
<p>Identifying a location as an Important Shark and Ray Area does not mean it will automatically be protected. Our goal is to inform countries’ existing spatial planning and fisheries management processes and other conservation planning. Eventually, these zones may be incorporated into <a href="https://oceanexplorer.noaa.gov/facts/mpas.html">marine protected areas</a> or other types of ocean preserves.</p>
<p>Sharks and their relatives need human help to survive and maintain their important biological roles in the ocean. Through the Important Shark and Ray Areas project, hundreds of scientists and other experts are helping to identify special places for these species that we believe need some extra attention.</p>
<p><em>Dr. Rima Jabado, chair of the IUCN Species Survival Commission Shark Specialist Group, contributed to this article.</em></p><img src="https://counter.theconversation.com/content/218902/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>David Shiffman 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 their academic appointment.</span></em></p>A new initiative is pinpointing areas in the world’s oceans that are key habitats for sharks and their relatives, so that governments can consider protecting these areas.David Shiffman, Faculty Research Associate in Marine Biology, Arizona State UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1983502023-02-01T06:12:08Z2023-02-01T06:12:08ZSeychelles is becoming overwhelmed by marine plastic – we now know where it comes from<figure><img src="https://images.theconversation.com/files/507320/original/file-20230131-12-y5egtu.jpg?ixlib=rb-1.1.0&rect=15%2C0%2C5087%2C3396&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A green turtle on Aldabra entangled in abandoned fishing gear.</span> <span class="attribution"><span class="source">Rich Baxter</span>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span></figcaption></figure><p>More than 1,000km southwest of Mahé, the main inhabited island in Seychelles, lies a ring of coral islands called the <a href="https://en.wikipedia.org/wiki/Aldabra">Aldabra Atoll</a>. The islands are a <a href="https://whc.unesco.org/en/list/185/">Unesco world heritage site</a> and support a huge diversity of marine species including manta rays and tiger sharks. The atoll is also a <a href="https://theconversation.com/how-we-discovered-that-sea-turtles-in-seychelles-have-recovered-from-the-brink-179041">breeding site</a> for endangered <a href="https://www.worldwildlife.org/species/green-turtle">green turtles</a>.</p>
<p>Aldabra has long been <a href="http://www.sif.sc/aldabra">protected</a> from threats to its biodiversity by its remoteness. But now plastic debris is strewn across Aldabra’s coastlines, threatening nearby marine ecosystems. <a href="https://doi.org/10.1126/science.aar3320">Research</a> finds the likelihood of coral disease increases from 4% to 89% when coral are in contact with plastic.</p>
<p>The <a href="http://sif.sc/">Seychelles Islands Foundation</a>, who are responsible for managing Aldabra, conducted a plastic clean-up operation in partnership with <a href="https://www.ox.ac.uk/news/2020-09-10-millions-dollars-clean-tuna-nets-and-flip-flops-island-state">Oxford University</a> in 2019. Roughly 25 tonnes of plastic waste were removed from the islands. </p>
<p>A <a href="https://doi.org/10.1016/j.marpolbul.2022.114497">new study</a> that we co-authored modelled the flow of plastic debris in the Indian Ocean between 1993 and 2019 and traced it to its source. We found that none of the plastic that washes up on Aldabra comes from the islands themselves. </p>
<figure class="align-center ">
<img alt="An aerial shot of the Aldabra Atoll." src="https://images.theconversation.com/files/507332/original/file-20230131-7253-8kr9t0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/507332/original/file-20230131-7253-8kr9t0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=596&fit=crop&dpr=1 600w, https://images.theconversation.com/files/507332/original/file-20230131-7253-8kr9t0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=596&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/507332/original/file-20230131-7253-8kr9t0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=596&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/507332/original/file-20230131-7253-8kr9t0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=749&fit=crop&dpr=1 754w, https://images.theconversation.com/files/507332/original/file-20230131-7253-8kr9t0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=749&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/507332/original/file-20230131-7253-8kr9t0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=749&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The Aldabra Atoll, part of the Seychelles’ Outer Islands.</span>
<span class="attribution"><span class="source">Seychelles Islands Foundation</span>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<h2>Simulating plastic flow</h2>
<p>Using data on plastic waste generation and fishing activity, we generated hundreds of billions of virtual plastic particles entering the Indian ocean. We then simulated their movement based on ocean currents, waves and winds.</p>
<p>Bottle caps and other low-buoyancy items sink fast and plastic loses buoyancy as it fragments or becomes <a href="https://www.sciencedirect.com/science/article/pii/S0269749116300264">covered in waterborne organisms</a>. Items that remain buoyant for longer are transported further distances. To reach Aldabra from the eastern Indian Ocean, our model estimates that debris must be floating for at least six months.</p>
<p>We determined the likelihood that this debris would wash up on the coast by analysing the rate at which <a href="https://www.aoml.noaa.gov/phod/gdp/index.php">scientific “drifters”</a> (instruments that record ocean currents) and <a href="https://www.sciencedirect.com/science/article/pii/S0006320720309976">GPS-tracked floating fishing devices</a> become “beached”. Free-floating instruments such as these behave well as proxies for floating plastic. These observations indicate that around 3% of the debris that is within 10km of a coast beaches each day.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/ma0wlFfA6dI?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Four-year simulation of highly buoyant marine debris transport in the Indian Ocean.</span></figcaption>
</figure>
<h2>Island under siege</h2>
<p>Our model predicts that Indonesia is responsible for most of the plastic debris, including as flip-flops and plastic packaging, that beaches across Seychelles. Various other countries including India, Sri Lanka and the Philippines are also major sources.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/506216/original/file-20230125-11-441nau.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A figure showing the sources of marine debris across the Indian Ocean." src="https://images.theconversation.com/files/506216/original/file-20230125-11-441nau.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/506216/original/file-20230125-11-441nau.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=770&fit=crop&dpr=1 600w, https://images.theconversation.com/files/506216/original/file-20230125-11-441nau.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=770&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/506216/original/file-20230125-11-441nau.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=770&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/506216/original/file-20230125-11-441nau.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=968&fit=crop&dpr=1 754w, https://images.theconversation.com/files/506216/original/file-20230125-11-441nau.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=968&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/506216/original/file-20230125-11-441nau.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=968&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Sources of marine debris for Seychelles and other remote islands in the western Indian Ocean (1993-2014).</span>
<span class="attribution"><a class="source" href="https://creativecommons.org/licenses/by/4.0/">Vogt-Vincent et al. (2023)</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<p>But Seychelles is also contaminated with plastic waste from other places. </p>
<p>Almost half of the plastic bottles found on Aldabra during the initial clean-up had been manufactured in China. But ocean currents do not flow directly between China and the western Indian Ocean. It is thus unlikely that a large number of bottles could float from China to Seychelles. </p>
<p>But Seychelles is close to a <a href="https://www.marinetraffic.com/en/ais/home/centerx:63.4/centery:-8.7/zoom:4">major shipping lane</a> that connects southeast Asia to the Atlantic. If bottles were discarded from ships crossing the Indian Ocean then they would likely beach across Seychelles. </p>
<p><a href="https://doi.org/10.1038/s41598-020-71444-6">Research</a> that we conducted in 2020 estimated that the fishing industry was responsible for 83% of the plastic waste on Aldabra. Most of the fishing gear abandoned by <a href="https://www.msc.org/what-we-are-doing/our-approach/fishing-methods-and-gear-types/purse-seine">“purse seine” fisheries</a> (a method of fishing that employs large nets to catch tuna) likely relates to regional fishing activity around Seychelles. But abandoned gear from longline fisheries may have drifted in from as far afield as western Australia.</p>
<p>Perhaps most importantly, our modelling also suggests that the rates at which plastic debris will beach in the Indian Ocean will follow strong seasonal cycles. </p>
<p>Winds tend to have a <a href="https://iridl.ldeo.columbia.edu/maproom/Global/Climatologies/Vector_Winds.html?bbox=bb%3A15.12%3A-39.110%3A132.52%3A35.656%3Abb&T=Jul">southerly (northward) component</a> during the Indian Ocean’s summer monsoon season. But major debris sources such as Indonesia and India share similar, or more northerly, latitudes with Seychelles. During this period, debris from these sources tends to miss Seychelles and is transported further north. </p>
<p>By contrast, the winds reverse during the <a href="https://iridl.ldeo.columbia.edu/maproom/Global/Climatologies/Vector_Winds.html?bbox=bb%3A15.12%3A-39.110%3A132.52%3A35.656%3Abb&T=Jan">winter monsoons</a> and transport debris directly towards Seychelles. We expect plastic debris accumulation to peak in Seychelles shortly after the winter monsoons (February to April). In the southernmost islands, almost all of the debris that beaches will do so at this point. </p>
<figure class="align-center ">
<img alt="A map showing the direction of ocean currents in the Indian Ocean across different seasons." src="https://images.theconversation.com/files/506218/original/file-20230125-12-c6pgwb.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/506218/original/file-20230125-12-c6pgwb.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=392&fit=crop&dpr=1 600w, https://images.theconversation.com/files/506218/original/file-20230125-12-c6pgwb.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=392&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/506218/original/file-20230125-12-c6pgwb.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=392&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/506218/original/file-20230125-12-c6pgwb.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=493&fit=crop&dpr=1 754w, https://images.theconversation.com/files/506218/original/file-20230125-12-c6pgwb.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=493&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/506218/original/file-20230125-12-c6pgwb.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=493&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Schematic of ocean currents in the Indian Ocean.</span>
<span class="attribution"><a class="source" href="https://creativecommons.org/licenses/by/4.0/">Vogt-Vincent et al. (2023)</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<h2>Planning effective mitigation</h2>
<p>Seychelles is not responsible for generating this waste but face mounting environmental and economic costs. For example, <a href="https://doi.org/10.1038/s41598-020-71444-6">500 tonnes</a> of litter remained following the initial clean-up of Aldabra’s coasts, which may cost up to US$5 million (£4 million) to remove.</p>
<p>The United Nations last year <a href="https://www.unep.org/news-and-stories/story/what-you-need-know-about-plastic-pollution-resolution">agreed</a> to establish a <a href="https://www.plasticstreaty.org/">global plastic treaty</a> that will tackle plastic pollution at its roots. But negotiations only began recently and it may be a long time before the treaty has any meaningful impact. </p>
<figure class="align-center ">
<img alt="An aerial shot of a group of people removing litter from a beach." src="https://images.theconversation.com/files/506404/original/file-20230125-22-6nbe1u.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/506404/original/file-20230125-22-6nbe1u.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/506404/original/file-20230125-22-6nbe1u.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/506404/original/file-20230125-22-6nbe1u.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/506404/original/file-20230125-22-6nbe1u.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/506404/original/file-20230125-22-6nbe1u.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/506404/original/file-20230125-22-6nbe1u.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A team from the Seychelles Islands Foundation removing litter from the coastline of Aldabra.</span>
<span class="attribution"><span class="source">Seychelles islands Foundation</span>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<p>Until then our modelling may help to establish other strategies to reduce the accumulation of plastic debris in Seychelles. </p>
<p>We identified fishing gear and shipping as being responsible for the majority of plastic pollution on Seychelles. Better enforcement of existing laws such as the 1983 ban on the disposal of plastic into the sea under the <a href="https://www.imo.org/en/about/Conventions/Pages/International-Convention-for-the-Prevention-of-Pollution-from-Ships-(MARPOL).aspx">Marpol Convention</a> should reduce the amount of plastic entering the Indian Ocean.</p>
<p>Predicting the peak of plastic accumulation in Seychelles will also maximise the effectiveness of beach clean-ups. Removing litter shortly after its arrival will minimise the time debris spends being broken down into unmanageable fragments.</p>
<p>Remote Indian Ocean islands are increasingly affected by plastic waste generated overseas. But by modelling the flow of plastic debris, we now have the chance to develop more effective strategies to reduce plastic accumulation and strengthen demands for stronger commitments under the global plastic treaty. </p>
<hr>
<figure class="align-right ">
<img alt="Imagine weekly climate newsletter" src="https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
</figcaption>
</figure>
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<p class="fine-print"><em><span>Noam Vogt-Vincent receives funding from the Natural Environment Research Council (NERC). </span></em></p><p class="fine-print"><em><span>April Burt works with Seychelles Islands Foundation, who manage Aldabra Atoll</span></em></p>Remote islands in the Indian Ocean are now strewn with plastic waste – the origin of this waste has until now not been established.Noam Vogt-Vincent, DPhil Candidate in Earth Sciences, University of OxfordApril Burt, Research Associate, University of OxfordLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1972152023-01-09T17:10:21Z2023-01-09T17:10:21ZInvasive rats are changing fish behaviour on coral reefs – new study<figure><img src="https://images.theconversation.com/files/503231/original/file-20230105-1808-63w6g0.jpg?ixlib=rb-1.1.0&rect=14%2C0%2C4866%2C2744&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Invasive rats can fundamentally alter the functioning of surrounding marine ecosystems.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/funny-image-three-positions-running-rat-48864871">Bluerain/Shutterstock</a></span></figcaption></figure><p>Coral reefs are degrading rapidly to the extent that their marine inhabitants must either adapt or die. For many animals, including reef fish, <a href="https://www.nature.com/articles/s41558-018-0314-7">behaviour</a> is one of the first responses to changes in environmental conditions.</p>
<p>Behavioural changes may be critical for predicting the future survival of many animal species. This is encouraging marine scientists to study how, why or when these changes happen. </p>
<p>Much of the existing research into the impact of environmental change on reef fish species tends to focus on increasing sea temperatures and ocean acidification. But some coral reef ecosystems are also threatened by one, more surprising source. An invasive species – the black rat – has overrun many islands in the <a href="https://commons.wikimedia.org/wiki/File:Chagos_map.PNG">Chagos Archipelago</a>, a remote group of small islands in the Indian Ocean. The rats are altering the functioning of surrounding marine ecosystems. </p>
<p><a href="https://www.nature.com/articles/s41559-022-01931-8">Recent research</a> that we co-authored alongside colleagues from Lakehead University in Canada revealed that these rats are affecting the territorial behaviour of fish by reducing the flow of nutrients from bird droppings into the ocean. </p>
<p>We focused on the <a href="https://seaunseen.com/jewel-damselfish/">jewel damselfish</a>, a small fish that aggressively defends patches of edible algae it cultivates through a process known as “farming”. Our research surveyed coral reefs both around islands with high seabird densities and without rats, and islands with low seabird densities and many rats. Jewel damselfish in the seas surrounding rat-infested islands were less aggressive and defended larger territories than those surrounding rat-free islands. </p>
<h2>Invasive rats</h2>
<p>The rats, many of which arrived on the Chagos Archipelago on ships in the 18th century, prey on small seabirds and their eggs. This has decimated seabird populations on these islands. Seabird densities are up to <a href="https://www.nature.com/articles/s41586-018-0202-3">760 times smaller</a> on rat-infested islands than on islands without rats. </p>
<p>But seabirds are a key component of the nutrient cycle. They feed in the ocean and return to the islands to roost and breed where they deposit large quantities of droppings. Their droppings, which are rich in nutrients, are then washed into the sea and onto nearby coral reefs. </p>
<p>By supplementing coral reefs with additional natural nutrients, seabirds are able to fertilise these ecosystems. Rat predation has disrupted this cycle and removed the nutrients provided by seabirds to coral ecosystems. </p>
<figure class="align-center ">
<img alt="A bird in flight against the backdrop of the ocean." src="https://images.theconversation.com/files/503224/original/file-20230105-18-vbjshz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/503224/original/file-20230105-18-vbjshz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/503224/original/file-20230105-18-vbjshz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/503224/original/file-20230105-18-vbjshz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/503224/original/file-20230105-18-vbjshz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/503224/original/file-20230105-18-vbjshz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/503224/original/file-20230105-18-vbjshz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Brown booby, a seabird species found in the Chagos.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/full-stretch-flight-juvenile-brown-bobby-1311357596">sushil20087817/Shutterstock</a></span>
</figcaption>
</figure>
<h2>Aggressive economics</h2>
<p>We found that algae in jewel damselfish territories next to rat-free islands were richer in nutrients than in territories next to rat-infested islands. However, the total amount of algae within the territories was unaffected. </p>
<p>This means that the quality, but not the quantity, of the food resources available to the jewel damselfish is higher in the waters surrounding rat-free islands. The fish in these territories get “more for their money” when foraging. The quality of nutrients means that fish are able to find all the food they need in smaller territories than fish around rat-infested islands. </p>
<p>But this carries behavioural consequences. We found that jewel damselfish in reefs surrounding rat-free islands were five times more likely to be more aggressive and 70 times more likely to hold smaller territories than those next to rat-infested islands.</p>
<p>The additional nutrients from seabird droppings in seas around islands with large seabird populations raise the quality of jewel damselfish territories and make them worth defending. The quality of nutrients in these locations means that the nutritional benefits of defending a territory are higher than the energy costs expended by aggressively defending them. </p>
<p>This is not the case for jewel damselfish in seas around rat-infested islands. The disruption to the nutrient cycle here results in lower quality territories that are less worth defending. </p>
<h2>Small fish, big impact</h2>
<p>By disrupting the nutrient cycle, invasive rats have directly reduced the aggressive tendencies of damselfish. But this behavioural change may alter the wider coral ecosystem. </p>
<p>The social organisation of <a href="https://www.nationalgeographic.com/animals/fish/facts/blue-tang">blue tangs</a>, a fish native to coral reefs in the Indo-Pacific, can be influenced by the territoriality of farming damselfish. Tangs tend to form schools in areas of the reef with high densities of territorial damselfish. This is likely because it allows “safety in numbers” when accessing defended algae and increases competition for algal food resources. But <a href="https://doi.org/10.1007/s10641-004-2861-1">research</a> has found that where damselfish densities are low, tangs rarely form schools. </p>
<figure class="align-center ">
<img alt="A school of blue fish swimming through a coral reef." src="https://images.theconversation.com/files/503247/original/file-20230105-18-yexznc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/503247/original/file-20230105-18-yexznc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/503247/original/file-20230105-18-yexznc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/503247/original/file-20230105-18-yexznc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/503247/original/file-20230105-18-yexznc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/503247/original/file-20230105-18-yexznc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/503247/original/file-20230105-18-yexznc.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">Invasive rats may indirectly affect the social organisation of some species.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/school-blue-tang-136660415">Isabelle Kuehn/Shutterstock</a></span>
</figcaption>
</figure>
<p>Algal productivity (grams of biomass per square metre) can also be affected by territorial damselfish. Algae within farming damselfish territories can, for example, be <a href="https://www.int-res.com/articles/meps/40/m040p041.pdf">up to 3.4 times</a> more productive than algae growing outside of the territories.</p>
<p>Territorial damselfish can also impact the density of coral within an area and therefore the structure of a reef. In Kenya, <a href="https://doi.org/10.1007/s00338-014-1229-z">research</a> has shown that the density of juvenile coral is lower inside farming damselfish territories than that in non-defended areas. Invasive rats may therefore affect coral replenishment and the functioning of the wider ecosystem.</p>
<p>By establishing the link between fish behaviour and the seabird nutrient cycle, our study highlights the potential for rat eradication to restore territorial fish behaviour. Measures to eradicate invasive rats from tropical islands have slowly been introduced across the Indian Ocean over the past 16 years. <a href="https://doi.org/10.1016/j.cub.2021.03.104">Evidence</a> suggests that these measures have contributed to the return of seabird nutrients to tropical islands and coral reefs. </p>
<p>Animal behaviour is an important but understudied aspect of biological research into ecological responses to environmental change and should be a focal point for future studies.</p><img src="https://counter.theconversation.com/content/197215/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Sally Keith receives funding from NERC. </span></em></p><p class="fine-print"><em><span>This research was supported by the Natural Environment Research Council (Rachel L. Gunn, grant number NE/L002604/1), with Rachel L. Gunns studentship through the Envision Doctoral Training Partnership.</span></em></p>Rats are disrupting the flow of nutrients towards the sea on many tropical islands – this has consequences for fish behaviour and the wider ecosystem.Sally Keith, Senior Lecturer, Lancaster UniversityRachel Gunn, Postdoctoral researcher in the Animal Evolutionary Ecology, University of TübingenLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1958302022-12-05T14:01:27Z2022-12-05T14:01:27ZWhy Britain should immediately withdraw from Mauritius’ Chagos Islands<figure><img src="https://images.theconversation.com/files/498697/original/file-20221202-12-ij0794.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Demonstrators from the Chagos Islands protest for Britain to end its "illegal occupation".
</span> <span class="attribution"><span class="source">Photo by JEAN MARC POCHE/AFP via Getty Images</span></span></figcaption></figure><p>Britain is on the cusp of decolonising Mauritius – again. The first attempt at decolonisation took place in 1968 but went unfulfilled when London kept hold of an island group that had long been regarded as Mauritian territory: the Chagos Archipelago.</p>
<p>In recent years, the international community has handed down a clear and consistent view that Britain’s occupation of the Chagos Islands is <a href="https://theconversation.com/britains-ownership-of-the-chagos-islands-has-no-basis-mauritius-is-right-to-claim-them-177461">illegal</a>. Now, London and Port Louis are engaged in <a href="https://www.theguardian.com/world/2022/nov/03/uk-agrees-to-negotiate-with-mauritius-over-handover-of-chagos-islands">talks</a> over the future of the islands – the final act, perhaps, in the decolonisation of Mauritius.</p>
<p>Britain’s foreign secretary, James Cleverly, <a href="https://questions-statements.parliament.uk/written-statements/detail/2022-11-03/hcws354">has suggested</a> that an agreement on the status of the Chagos Archipelago will come “by early next year”. </p>
<p>But what might a settlement look like?</p>
<p>The answer depends almost entirely on what can be agreed about the future of Diego Garcia, the largest island of the Chagos group. It’s the site of a critical US military base that Britain has dutifully hosted for the past 50 years.</p>
<h2>The American elephant</h2>
<p>It is hard to overstate the legal and political pressure that Britain faces to withdraw from the Chagos Islands. No fewer than <a href="https://www.theguardian.com/world/2019/may/22/uk-suffers-crushing-defeat-un-vote-chagos-islands">116 national governments</a>, the <a href="https://press.un.org/en/2019/ga12146.doc.htm">UN General Assembly</a>, the <a href="https://www.reuters.com/article/us-britain-mauritius/african-union-urges-britain-to-cede-chagos-islands-end-colonial-rule-idUSKBN1XW1GG">African Union</a> and the <a href="https://www.ejiltalk.org/icj-delivers-chagos-advisory-opinion-uk-loses-badly/">International Court of Justice</a> have called upon Britain to cease its occupation of the islands. The <a href="https://www.theguardian.com/world/2021/jan/28/un-court-rejects-uk-claim-to-chagos-islands-in-favour-of-mauritius">settled opinion</a> of the international community is that Diego Garcia and the rest of the Chagos Archipelago belong to Mauritius, not the United Kingdom. This is not much of a grey area.</p>
<p>But complying with international law is a voluntary act. </p>
<p>For a long time, Britain’s policy was that the Chagos Islands would be returned to Mauritius when they were <a href="https://www.gov.uk/government/speeches/questions-on-the-british-indian-ocean-territory-have-long-been-a-bilateral-matter-between-the-uk-and-mauritius#:%7E:text=When%20we%20no%20longer%20need,needed%20them%20for%20defence%20purposes.">no longer needed</a> “for defence purposes”. In his written statement to announce talks with Port Louis, Cleverly appeared to reaffirm this commitment by insisting that “any agreement between our two countries will ensure the continued effective operation” of the base on Diego Garcia.</p>
<p>The elephant in the room is that Britain does not now need – and, in fact, has never truly depended upon – the Chagos Archipelago for military purposes. Only a handful of British military personnel cycle through Diego Garcia. What, then, is London waiting for?</p>
<p>In reality, it is US forces that use the island of Diego Garcia as a logistics hub and staging post for military actions across the Indo-Pacific. As they negotiate with Mauritius, British leaders are therefore mostly interested in securing guarantees that America’s military interests will not be harmed by a transfer of authority to Port Louis. </p>
<p>This is what will shape negotiations over the territory’s future.</p>
<h2>Difficult talks ahead</h2>
<p>Four scenarios stand out as realistic.</p>
<p>First, Britain could relinquish its claim to the Chagos Archipelago without delay, and with few or no strings attached. This would be the “cleanest” way to uphold London’s obligations to Mauritius under international law. It would then be up to Port Louis and Washington to decide upon the future of the base on Diego Garcia.</p>
<p>Second, London could suggest a <a href="https://www.lowyinstitute.org/the-interpreter/finding-compromise-chagos-islands-saga">staged approach</a> to decolonisation. The opening phase would see Britain return the so-called “Outer” Chagos Islands to Mauritius – that is, the 57 islands of the archipelago that have never been used for military purposes, which are scattered around 100 miles north and west of Diego Garcia. But in exchange, Port Louis would grant London temporary sovereignty over Diego Garcia (a rump British Indian Ocean Territory) so that the base there could continue its operations uninterrupted for a specified amount of time.</p>
<p>Another variant of this option would be for Britain to acknowledge Mauritian sovereignty over the entire Chagos Archipelago – including Diego Garcia – but negotiate to access rights for itself and the United States.</p>
<p>Finally, talks could break down altogether. This is a real possibility. Decision-makers in London are unlikely to agree to anything that Washington cannot support.</p>
<h2>The case for full decolonisation</h2>
<p>Strictly bilateral talks might not be the best way to resolve the Chagos dispute. The United States must be engaged in the process, too.</p>
<p>Indeed, finding a long-term agreement between Washington and Port Louis is complicated by Britain’s persistent attempts to serve as an intermediary. Colonialism and illegality are hard to accommodate in diplomatic accords, after all.</p>
<p>Britain ought to announce the full and unconditional decolonisation of the territory as a backdrop to Mauritius and the United States discussing the issues that concern the two of them: basing rights, a status of forces agreement, and support for a resettled Chagossian community, to name three.</p>
<p>America’s military is hosted by a diverse cast of national governments on every continent. Dealing with Mauritius should be no more difficult than negotiating with Australia, Poland, Saudi Arabia, or South Korea.</p>
<p>Either way, London has no constructive role to play in these discussions, which concern the territory’s future rather than its past.</p><img src="https://counter.theconversation.com/content/195830/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Peter Harris 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>As they negotiate with Mauritius, British leaders are mostly interested in securing guarantees that America’s military interests will not be harmed by a transfer of authority to Port Louis.Peter Harris, Associate Professor of Political Science, Colorado State UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1921952022-11-14T18:53:05Z2022-11-14T18:53:05ZRestoring Mayotte’s lagoon: when a newly born volcano meets human resilience<figure><img src="https://images.theconversation.com/files/494711/original/file-20221110-25-4vo9et.jpg?ixlib=rb-1.1.0&rect=0%2C15%2C2048%2C1263&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Mayotte's surrounding coral reef is made up of three different structures more than 350 kilometers long. The lagoon they form is threatened by climate change and erosion. </span> <span class="attribution"><a class="source" href="https://commons.wikimedia.org/w/index.php?curid=77558219">Axelspace </a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>One of France’s five overseas departments, Mayotte is the southernmost island of the Comoros Archipelago, located Indian ocean between Madagascar and the African mainland. The island is the centrepiece of a coral-reef structure that was created over hundreds of thousands of years through volcanic episodes, subsidence and sea-level shifts. Made up of three different structures more than 350 kilometres long, the reef encloses a lagoon with a surface area of 1,100 square kilometres that shelters an opulent biodiversity that includes 2,300 known living species.</p>
<p>One of just ten such coral-reef systems on Earth, Mayotte lagoon was classified as a marine natural park in 2010, and the government has long hoped that it would be <a href="https://outremers360.com/planete/mayotte-vise-lunesco">added to the list of UNESCO World Heritage sites</a>.</p>
<h2>Birth of a giant</h2>
<p>On May 10, 2018, however, an event took place that no one could have predicted: 50 kilometres off Mayotte’s east coast, an underwater volcano was born. The natural phenomena that underlay the volcano’s birth and the chain of events that it has set off have forever altered the undersea landscape and the island itself, and will continue to do so for millennia.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/494698/original/file-20221110-23-8dqi79.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/494698/original/file-20221110-23-8dqi79.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/494698/original/file-20221110-23-8dqi79.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=171&fit=crop&dpr=1 600w, https://images.theconversation.com/files/494698/original/file-20221110-23-8dqi79.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=171&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/494698/original/file-20221110-23-8dqi79.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=171&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/494698/original/file-20221110-23-8dqi79.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=215&fit=crop&dpr=1 754w, https://images.theconversation.com/files/494698/original/file-20221110-23-8dqi79.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=215&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/494698/original/file-20221110-23-8dqi79.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=215&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Left: 2014, before new volcano’s birth. Right: 2019, after its discovery.</span>
<span class="attribution"><span class="source">BGRM</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>As the volcano’s growth continued, scientists recorded 800 micro-tremors that occurred several times a day over three weeks. From May 2018 to June 2019, a <a href="https://archimer.ifremer.fr/doc/00632/74401/74104.pdf">series of 32 earthquakes</a> of 5 or more on the Richter scale struck the island. In its short life, the volcano has already ejected <a href="https://www.brgm.fr/en/news/press-release/mayotte-volcano-largest-underwater-eruption-ever-documented">more than 5 km³ of lava</a>, by far the most ever observed, transforming the underwater landscape.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/494700/original/file-20221110-21-qh9jz8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/494700/original/file-20221110-21-qh9jz8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/494700/original/file-20221110-21-qh9jz8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=359&fit=crop&dpr=1 600w, https://images.theconversation.com/files/494700/original/file-20221110-21-qh9jz8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=359&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/494700/original/file-20221110-21-qh9jz8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=359&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/494700/original/file-20221110-21-qh9jz8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=451&fit=crop&dpr=1 754w, https://images.theconversation.com/files/494700/original/file-20221110-21-qh9jz8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=451&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/494700/original/file-20221110-21-qh9jz8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=451&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">In 2018 and 2019, a swarm of earthquakes took place 15 kilometres to the east of Mayotte.</span>
<span class="attribution"><span class="source">BGRM</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>The volcano’s growth will continue for millennia, as it’s part of a natural cycle of island building, destruction and rebuilding. Indeed, just 12,000 years ago, Mayotte was <a href="https://www.mayottehebdo.com/actualite/dossier/il-y-a-12-000-ans-mayotte-etait-cinq-fois-plus-grande/">five times larger than it is today</a>.</p>
<p>While Mayotte’s subsidence is natural, since 2018 it has witnessed the equivalent of a sprint in geologic time – in just four years, the island has moved 20 centimetres to the east and dropped by 15 centimetres.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/494701/original/file-20221110-24-k1393e.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/494701/original/file-20221110-24-k1393e.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/494701/original/file-20221110-24-k1393e.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=355&fit=crop&dpr=1 600w, https://images.theconversation.com/files/494701/original/file-20221110-24-k1393e.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=355&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/494701/original/file-20221110-24-k1393e.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=355&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/494701/original/file-20221110-24-k1393e.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=446&fit=crop&dpr=1 754w, https://images.theconversation.com/files/494701/original/file-20221110-24-k1393e.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=446&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/494701/original/file-20221110-24-k1393e.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=446&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Subsidence of Mayotte in 2019, just a year after the volcano’s emergence.</span>
<span class="attribution"><span class="source">BGRM</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>The volcano’s birth triggered a series of natural disasters that have been exacerbated by the island’s natural geography and ongoing climate change. Mahorans have long lived with the rainy season, known as <em>Kashkazi</em>, but a series of torrential storms have caused landslides, significant erosion and accelerated coastal retreat. All have tested Mahorans’ resilience and raised questions about how they can best adapt to the changing world around them.</p>
<p>The volcano also disrupted the island’s political, economic and social order. Mayotte has been a French department since 2011 and a special territory of the European Union since 2014, and until the volcano’s birth, its <a href="https://www.mayotte.gouv.fr/content/download/5164/43644/file/Mayotte%202025%20Une%20ambition%20pour%20la%20R%C3%A9publique%20-%20document%20strat%C3%A9gique.pdf">2025 roadmap</a> pointed toward the need for more effective institutions, improved education, development, health care and housing, and sustainable management of natural resources, in that order. After 2018, managing the environmental situation became top priority.</p>
<h2>Accelerating erosion</h2>
<p>During Mayotte’s monsoon season, rain naturally causes erosion, and the soil released is carried into the sea as silt. With the volcano’s eruption and associated swarm of earthquakes, intensifying rains and poor land management have caused erosion to rise. Forty years ago, 5,000 tons of sediment was released annually; by 2018, the rate was 20,000 tons per year, an eightfold increase. The end result is a vast flow of soil into the lagoon.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/494702/original/file-20221110-18-5dt7kz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/494702/original/file-20221110-18-5dt7kz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/494702/original/file-20221110-18-5dt7kz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=320&fit=crop&dpr=1 600w, https://images.theconversation.com/files/494702/original/file-20221110-18-5dt7kz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=320&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/494702/original/file-20221110-18-5dt7kz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=320&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/494702/original/file-20221110-18-5dt7kz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=402&fit=crop&dpr=1 754w, https://images.theconversation.com/files/494702/original/file-20221110-18-5dt7kz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=402&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/494702/original/file-20221110-18-5dt7kz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=402&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Increasing rains and poor land-management techniques have led to a dramatic increase in siltation of the lagoon.</span>
<span class="attribution"><span class="source">BGRM</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>For scientists, the volcano’s birth was <a href="https://leblob.fr/en/mayotte-birth-underwater-volcano">one of the first that could be witnessed first-hand</a>, with many more research missions set to enrich scientific databases in the coming decades. One of the most important is <a href="https://www.brgm.fr/en/reference-completed-project/leselam-action-against-soil-erosion-lagoon-siltation-mayotte">LESELAM</a>, which was launched by the BRGM in 2018. Its aim is to better understand the phenomenon of erosion and siltation of Mayotte lagoon, and so be able to better combat it.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/494703/original/file-20221110-16-nqqly2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/494703/original/file-20221110-16-nqqly2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/494703/original/file-20221110-16-nqqly2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=848&fit=crop&dpr=1 600w, https://images.theconversation.com/files/494703/original/file-20221110-16-nqqly2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=848&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/494703/original/file-20221110-16-nqqly2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=848&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/494703/original/file-20221110-16-nqqly2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1066&fit=crop&dpr=1 754w, https://images.theconversation.com/files/494703/original/file-20221110-16-nqqly2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1066&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/494703/original/file-20221110-16-nqqly2.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">Erosive basins and annual sedimentation flux (ton/year) in 2018.</span>
<span class="attribution"><a class="source" href="https://www.brgm.fr/en/reference-completed-project/leselam-action-against-soil-erosion-lagoon-siltation-mayotte">BGRM</a>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Mayotte is densely populated, and humans have long transformed its topography to facilitate agriculture and livestock ranching. The combination of the island’s volcanic soil, steep slopes, and “slash and burn” farming techniques have left behind many deforested areas known as <a href="https://fr.wikipedia.org/wiki/Padza"><em>padzas</em></a>. With the rise in the island’s population, the uncontrolled growth of shantytowns has contributed increasing amounts of urban runoff that pollutes the lagoon.</p>
<p>Today, scientists and associations are working to raise awareness on the importance of environmental conservation. <a href="https://enrd.ec.europa.eu/projects-practice/fighting-against-soil-erosion-mayotte-leselam_en">Stakeholder collaborations advance</a> but require continued effort. Given the immense challenges, initial enthusiasm can suffer when quick results aren’t obtained.</p>
<p>In 2021 France declared Mayotte to be suffering from a <a href="https://www.legifrance.gouv.fr/jorf/id/JORFTEXT000044289624">natural disaster</a>, but such statements are no longer sufficient. What is needed is bringing international attention to the environmental crisis that is taking place on Mayotte. To revive the island’s economy, raise hope among the population, and preserve this magnificent island, the following actions were carried out:</p>
<ul>
<li><p><strong>Researching</strong>. On 27 January 2022, an international conference detailed the significant risks that Mayotte faces in the coming years due to global warming and emphasised the importance of nature conservation.</p></li>
<li><p><strong>Campaigning</strong>. On 18 May 2022, an international campaign was launched protect and restore Mayotte lagoon and advocate for change and push for action, the lagoon desilting project is registered in this environmental protection campaign.</p></li>
<li><p><strong>Economic planning</strong>. Restoring the lagoon isn’t just a matter of removing the silt, but also establishing a circular-economy model to reemploy it. On an island where the unemployment rate is 30%, creating green jobs is a high priority. Salt extracted from the silt could be marketed, while the salt-free earth could be transformed into building material, supporting an existing economic sector and reducing the importation of building materials. With the lagoon’s health restored, green tourism would serve as a channel for sustainable economic growth.</p></li>
<li><p><strong>Educating</strong>. First, while the volcano’s birth of the coast of Mayotte upended the island’s plan to have the lagoon inscribed as an endangered <a href="https://documentation.outre-mer.gouv.fr/Record.htm?idlist=1&record=19142156124919603389">UNESCO World Heritage Site</a> in Danger list. Second, the desilting project should be registered on the 2022-2025 strategic plan of the <a href="https://icriforum.org/cordap-strategic-plan-2022-2025/">Coral Research and Development Platform</a>.</p></li>
</ul>
<p>The 2018 eruption of the volcano off the coast of Mayotte and the chain of natural disasters that it set off have made it crystal clear that the island’s coral reefs, lagoon and mangroves aren’t just natural gifts to be enjoyed. It is urgent for them to be protected, and so safeguard for future generations the rich biodiversity, ecosystem services, coastline protection, and natural beauty that they provide.</p>
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<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/485372/original/file-20220919-20-pguqfq.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/485372/original/file-20220919-20-pguqfq.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=305&fit=crop&dpr=1 600w, https://images.theconversation.com/files/485372/original/file-20220919-20-pguqfq.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=305&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/485372/original/file-20220919-20-pguqfq.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=305&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/485372/original/file-20220919-20-pguqfq.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=383&fit=crop&dpr=1 754w, https://images.theconversation.com/files/485372/original/file-20220919-20-pguqfq.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=383&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/485372/original/file-20220919-20-pguqfq.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=383&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption"></span>
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<p><em><a href="https://whc.unesco.org/en/next50/">50th anniversary of the World Heritage Convention</a> (16 November 2022): World Heritage as a source of resilience, humanity and innovation.</em></p><img src="https://counter.theconversation.com/content/192195/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Noro Ravoavahy est membre de l'Alliance HQE-GBC France. </span></em></p>Mayotte is no exception to the adage “small islands, big problems”. A newly born volcano combined with poor land management and accelerating climate change has put its fabled lagoon at risk.Noro Ravoavahy, Architecte, Labex AE&CC, Ecole Nationale Supérieure d’Architecture de Grenoble, Conservatoire national des arts et métiers (CNAM)Licensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1913402022-09-27T06:06:12Z2022-09-27T06:06:12ZAbout 200 dead whales have been towed out to sea off Tasmania – and what happens next is a true marvel of nature<figure><img src="https://images.theconversation.com/files/486684/original/file-20220927-14-7mqf23.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C4025%2C3024&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Department of Natural Resources and Environment Tasmania </span></span></figcaption></figure><p>Australians watched in horror last week as 230 pilot whales became stranded at a beach near Macquarie Harbour on Tasmania’s west coast. Some whales were saved, but the vast majority died. This left a big problem: what to do with all the rotting whale carcasses?</p>
<p>Authorities decided to tow the dead animals out to sea, hoping they’ll eventually sink to the seafloor. </p>
<p>Such mass whale strandings are sad to witness. But in this case, the aftermath presents a fascinating opportunity for scientific discovery. </p>
<p>As the dead whales decompose, an astonishing and rare chain of events is likely to flow through the marine ecosystem – ultimately leading to an explosion of activity and new life.</p>
<figure class="align-center ">
<img alt="aerial view of beach with whales stranded in line" src="https://images.theconversation.com/files/486685/original/file-20220927-16-b7es39.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/486685/original/file-20220927-16-b7es39.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/486685/original/file-20220927-16-b7es39.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/486685/original/file-20220927-16-b7es39.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/486685/original/file-20220927-16-b7es39.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/486685/original/file-20220927-16-b7es39.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/486685/original/file-20220927-16-b7es39.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Authorities decided to tow the dead animals out to sea, hoping they’ll eventually sink to the seafloor.</span>
<span class="attribution"><span class="source">Department of Natural Resources and Environment Tasmania</span></span>
</figcaption>
</figure>
<h2>A 600-tonne problem</h2>
<p>Mass whale strandings happen fairly regularly – especially in Tasmania – yet no one really knows why.</p>
<p>Days before this latest incident, <a href="https://www.abc.net.au/news/2022-09-20/sperm-whales-stranded-off-king-island-tasmania/101457406">14 sperm whales</a> became stranded off King Island, northwest of Tasmania.</p>
<p>And in 2020, about 470 pilot whales <a href="https://theconversation.com/like-trying-to-find-the-door-in-a-dark-room-while-hearing-your-relatives-scream-for-help-tasmanias-whale-stranding-tragedy-explained-146674">became stranded</a> at Macquarie Harbour. While many were pulled out to sea, some of those carcasses washed up and were left to rot on the beach – an entirely natural process. </p>
<p>However, pilot whales are big animals. Males weigh up to 2,300kg, which means they take a long time to decompose. The smell of two tonnes of rotting whale blubber soon becomes unbearable, so carcasses are frequently buried. </p>
<p>This time around, authorities <a href="https://www.abc.net.au/news/2022-09-25/whale-carcasses-towed-out-to-sea-after-mass-stranding/101471166">decided to tow</a> the dead animals out to sea. The ABC reported local salmon farm workers took almost 11 hours to dispose of 204 dead whales with a combined weight of between 500 and 600 tonnes.</p>
<p>They were tied to a 400 metre-long rope and towed by boats for 40 kilometres, before being dropped into deep water in the Indian Ocean.</p>
<p>Some carcasses may wash back to shore, but most are likely to disperse with the tides and currents. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/curious-kids-why-dont-whales-have-teeth-like-we-do-186727">Curious kids: why don’t whales have teeth like we do?</a>
</strong>
</em>
</p>
<hr>
<figure class="align-center ">
<img alt="Two men in high-vis stand in front of tractor and trailer carrying a whale" src="https://images.theconversation.com/files/486686/original/file-20220927-12-he77l6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/486686/original/file-20220927-12-he77l6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/486686/original/file-20220927-12-he77l6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/486686/original/file-20220927-12-he77l6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/486686/original/file-20220927-12-he77l6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/486686/original/file-20220927-12-he77l6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/486686/original/file-20220927-12-he77l6.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">Mass whale strandings happen fairly regularly, yet no one really knows why.</span>
<span class="attribution"><span class="source">Department of Natural Resources and Environment Tasmania</span></span>
</figcaption>
</figure>
<h2>Shark bait? Probably not</h2>
<p>The big question is: what happens to all that whale mass dumped at sea?</p>
<p>Initially, a dead whale tends to float to the surface as it begins to decompose and its innards expand with gas. As this happens, ocean scavengers such as sharks and seabirds are likely to feast on the remains.</p>
<p>Some people <a href="https://www.abc.net.au/news/2019-04-14/do-buried-whale-carcasses-really-attract-sharks/10996512">can be concerned</a> that whale carcasses attract sharks that might pose a risk to humans. </p>
<p>Granted, encounters between sharks and humans, are <a href="https://theconversation.com/fatal-shark-attacks-are-at-a-record-high-deterrent-devices-can-help-but-some-may-be-nothing-but-snake-oil-150845">on the rise</a> in Australia and elsewhere. But they’re still very rare. </p>
<p>A <a href="https://parks.des.qld.gov.au/__data/assets/pdf_file/0024/167613/swim-humpback-whales-risks-sharks.pdf">report</a> to the Western Australian government in 2012 found whale carcasses were a risk factors associated with shark attacks, and said caution should be exercised near a dead whale in the water.</p>
<p>But the same report noted that of 26 shark attacks investigated, the highest number occurred more than a kilometre offshore. While there is no doubt <a href="https://doi.org/10.1016/j.gecco.2019.e00655">sharks are attracted to dead whales</a>, the data is <a href="https://hakaimagazine.com/news/beached-whales-are-a-lure-for-hungry-sharks/">not clear</a> on whether a whale carcass leads directly to an increase in shark attacks on people. </p>
<p>Research <a href="https://www.sciencedirect.com/science/article/pii/S2351989419301854?via%3Dihub">has shown</a> the likelihood of whale carcasses washing towards shore, where shark scavenging can be observed, is low. So as long as the carcass is taken far from shore and people keep their distance from it, the threat to humans from shark encounters appears to be exceedingly low. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/why-do-whales-keep-getting-tangled-in-shark-nets-and-what-should-you-do-if-you-see-it-happen-186468">Why do whales keep getting tangled in shark nets? And what should you do if you see it happen?</a>
</strong>
</em>
</p>
<hr>
<figure class="align-center ">
<img alt="Rescue boat next to the carcass of a large white whale" src="https://images.theconversation.com/files/486688/original/file-20220927-27-owyv43.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/486688/original/file-20220927-27-owyv43.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/486688/original/file-20220927-27-owyv43.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/486688/original/file-20220927-27-owyv43.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/486688/original/file-20220927-27-owyv43.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/486688/original/file-20220927-27-owyv43.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/486688/original/file-20220927-27-owyv43.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">Dead floating whales provide a feast for animal scavengers. Pictured: seabirds feed on a large whale carcass floating off Spain in 2018.</span>
<span class="attribution"><span class="source">EFE/SASEMAR</span></span>
</figcaption>
</figure>
<h2>From death comes new life</h2>
<p>Inevitably, the whale carcass will start to sink. Most life in the ocean is found fairly close to the sea surface, so if the water is relatively shallow much of what’s left of the carcass will be quickly eaten by scavengers once it reaches the sea floor. </p>
<p>But these carcasses have been disposed of in deep water. The deep ocean can be a barren place, where rich food sources are rare. So the appearance of a single whale carcass can supercharge an entire ecosystem. </p>
<p>New life and activity can erupt around the dead animal in very little time. This process is known as “whale fall” and has been studied by scientists, sometimes using remotely operated vehicles. On the seafloor of the North Pacific, whale fall has been found to <a href="https://www.frontiersin.org/articles/10.3389/fevo.2022.885572/full">support the survival</a> of at least 12,490 organisms of 43 species. </p>
<p>Deep sea sharks will make the most of the carcass. <a href="https://www.youtube.com/watch?v=CZzQhiNQXxU">A host of other animals</a> including hagfish, octopus, crabs, lobsters, worms and sea cucumbers will join in too. All the while bacteria work away quietly in the background. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/is-migaloo-dead-as-climate-change-transforms-the-ocean-the-iconic-white-humpback-has-been-missing-for-two-years-184256">Is Migaloo ... dead? As climate change transforms the ocean, the iconic white humpback has been missing for two years</a>
</strong>
</em>
</p>
<hr>
<p><a href="https://www.nhm.ac.uk/discover/what-happens-when-whales-die.html">According to</a> Britain’s Natural History Museum, a single whale can provide animals with food for up to two years during the scavenging stage. </p>
<p>Other animals and bacteria survive off the chemicals produced from the rotting carcass.</p>
<p>These organisms, known as “chemotrophs” were thought to be unique to underwater volcanic vents, where they use hydrogen sulphide as the principal energy source. <a href="https://doi.org/10.1098/rspb.2016.2337">Research</a> has shown a similar suite of animals recruit around dead and decaying whales – generating a completely independent ecosystem based on a gas that <a href="https://www.nhm.ac.uk/discover/what-happens-when-whales-die.html">smells like rotten eggs</a>.</p>
<p>Only a few organisms can break down the bones that remain, in a process that might take up to ten years. </p>
<p>So take a moment to consider the effect of 204 whale falls in a small part of the ocean off Tasmania. Right now, they are probably generating interconnected marine metropolises, the likes of which are rarely seen.</p><img src="https://counter.theconversation.com/content/191340/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Culum Brown receives funding from Australian Research Council, Taronga Zoo, Sea World Research and Rescue Foundation</span></em></p>As the dead whales decompose, an astonishing and rare chain of events is likely to flow through the marine ecosystem – ultimately leading to an explosion of activity and new life.Culum Brown, Professor, Macquarie UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1906782022-09-20T13:09:02Z2022-09-20T13:09:02ZSouth Africa is surrounded by sea but doesn’t have a plan to protect it: three steps to get one<figure><img src="https://images.theconversation.com/files/484551/original/file-20220914-13-kerp1i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Kalk Bay, Western Cape, South Africa.</span> <span class="attribution"><span class="source">Education Images/Universal Images Group via Getty Images</span></span></figcaption></figure><p>South Africa is surrounded by 2,798km of coastline. Yet, oddly, the country doesn’t have a coherent maritime strategy underpinned by a related national strategy to safeguard its maritime interests.</p>
<p>This omission was underscored again recently by an evolving <a href="https://www.westerncape.gov.za/assets/departments/economic-development-tourism/draft_discussion_document_towards_an_oceans_economy_master_plan__0.pdf">master plan for South Africa’s oceans</a>. The document is significant as it puts the importance of South Africa’s oceans into sharper focus. But this shouldn’t obscure the fact that government’s commitment to comprehensively harness the ocean to help arrest economic decline has been disappointing.</p>
<p>The document also underscores the absence of a coherent and comprehensive policy. In countries where this has been done well – such as <a href="https://www.transport.govt.nz/area-of-interest/resilience-and-security/maritime-security-strategy/#:%7E:text=The%20Maritime%20Security%20Strategy%20ensures%20New%20Zealand%20has,more%20efficient%20and%20effective%20maritime%20security%20sector%20that%3A%20%22%22">New Zealand</a> and <a href="https://theconversation.com/ghana-has-developed-a-maritime-policy-here-is-what-it-means-188381">Ghana</a> – policies have been developed that encompass the economic value of a country’s oceans, as well as the vulnerability they present from a security point of view.</p>
<p>There are solutions. </p>
<p>A three step process would put South Africa’s maritime security house in order. The first would be to create a well-designed government-led process that includes a high-office body and core stakeholders. This would lead directly into the second step – the mapping of the country’s national maritime interests as well as the threats it faces. The third step would be creation of an integrated national maritime strategy.</p>
<p>The growing trend internationally is for countries to be explicit about their maritime interests and back this with dedicated institutional commitments to promote, develop and defend them if required. It’s time South Africa followed suit.</p>
<h2>What’s missing</h2>
<p>Some efforts have been made at getting a policy framework in place. The most recent is the <a href="http://www.governmentpublications.lib.uct.ac.za/news/framework-document-south-africa%E2%80%99s-national-interest-and-its-advancement-global-environment">Draft Framework on South Africa’s National Interest</a>.</p>
<p>The evolving master plan and <a href="https://www.operationphakisa.gov.za/Pages/Home.aspx">Operation Phakisa</a> – launched by the country’s presidency in July 2014 to hasten solutions to “critical development issues” – stress the critical importance of the oceans economy to South Africa’s overall economic interests. </p>
<p>The master plan also outlines good statistics on the potential contribution the oceans economy holds for the country.</p>
<p>But neither of these adds up to an integrated and credible maritime security plan for the country. The overall picture is one of working in silos, seemingly without coordination.</p>
<p>A recent communiqué from the <a href="https://www.sadc.int/speeches-communiques">Southern African Development Community Heads of State meeting</a> in the DR Congo noted that maritime security of Southern Africa is not what it should be and that a regional maritime strategy must be implemented. </p>
<p>There are examples South Africa could learn form. There are sound strategies on maritime security emerging among Gulf of Guinea countries, <a href="https://www.kenyanews.go.ke/govt-develops-comprehensive-maritime-security-strategy/">Kenya</a> in the Horn region, and the emphasis by <a href="https://www.defenceweb.co.za/featured/maritime-security-the-seychelles-way/#:%7E:text=The%20Seychelles%20has%20committed%20to%20protecting%20up%20to,and%20preserve%20economic%20opportunities%20in%20tourism%20and%20fishing">Seychelles</a> on security to harness the economic potential of its maritime territories.</p>
<p>Countries like <a href="https://www.defenceweb.co.za/sea/sea-sea/ghana-has-developed-a-maritime-policy-here-is-what-it-means/">Ghana</a>, <a href="https://www.defenceweb.co.za/featured/nigeria-launches-deep-blue-maritime-security-project/">Nigeria</a>, Kenya, Seychelles and Mauritius have made strides.</p>
<p>Beyond Africa, the UK recently launched its <a href="https://www.gov.uk/government/publications/national-maritime-security-strategy">national maritime security strategy</a>. For its part, China has turned its attention to the importance of the oceans <a href="https://www.stripes.com/theaters/africa/2021-12-06/china-military-guinea-djibouti-africom-3875711.html">in pursuit of its national interests</a>. This ambition features alongside the <a href="https://www.sipri.org/publications/2019/sipri-background-papers/foreign-military-presence-horn-africa-region">military buildup in the western Indian Ocean</a> with a focus on the Horn region and southern strands to Madagascar, Mauritius, Seychelles and Maldives.</p>
<p>The naval profile unfolds alongside a much larger oceans agenda made up of security, safety, climate change, functional connectivity, and a thriving blue economy.</p>
<h2>Prioritising South Africa’s maritime interests</h2>
<p>A first step is to appoint a high-level entity to oversee maritime affairs in South Africa. A Department of Maritime Affairs is an attractive idea. But a powerful steering committee reporting to the presidency is probably a more attainable start. </p>
<p>This practice is growing. <a href="https://www.transport.govt.nz/area-of-interest/resilience-and-security/maritime-security-strategy/#:%7E:text=The%20Maritime%20Security%20Strategy%20ensures%20New%20Zealand%20has,more%20efficient%20and%20effective%20maritime%20security%20sector%20that%3A">New Zealand</a> and Ghana have taken this approach. </p>
<p>Next there needs to be a detailed mapping of interests on existing and new domains. An example is the security of underwater cable infrastructure – locally and regionally. </p>
<p>The maritime domain has essentially become too important to leave within a vague and broad set of statements like South Africa’s <a href="http://www.governmentpublications.lib.uct.ac.za/news/framework-document-south-africa%E2%80%99s-national-interest-and-its-advancement-global-environment">recent framework document</a>. Clearly articulated national interests with a maritime underpinning should inform an integrated national maritime security strategy. </p>
<p>In my view this is imperative for three reasons.</p>
<p>First, existing plans and documents are too vague about a credible security foundation for South Africa’s dependence on, and use of, the oceans. This leaves too much room for ambiguity about what must be secured.</p>
<p>Second, the absence of a strategy inherently forfeits the value in planning for shifts in maritime interests as well as the dynamic modern strategic maritime environment.</p>
<p>A third aspect stems from the value of a maritime security strategy to inform collaboration with regional and international partners (other African countries). Having a maritime strategy presents opportunities for maritime diplomacy – whether coercive, cooperative or more persuasive in kind.</p>
<p>South Africa is also very explicit in its foreign policy about commitment to the Southern African Development Community and Africa. The African Union’s <a href="https://view.officeapps.live.com/op/view.aspx?src=https%3A%2F%2Fau.int%2Fweb%2Fsites%2Fdefault%2Ffiles%2Fdocuments%2F30928-doc-2050_aim_strategy_eng.doc">AIMS-2050</a> and <a href="https://au.int/en/treaties/african-charter-maritime-security-and-safety-and-development-africa-lome-charter">Lomé Charter</a> as well as <a href="https://au.int/en/agenda2063">Agenda 2063</a> alongside the <a href="https://sdgs.un.org/goals">UN Sustainable Development Goals</a> have explicit maritime objectives that call for cooperation. Collectively, these framework documents guide and expect South Africa to be in step with its own strategies.</p>
<p>The question is: what does South Africa bring to the maritime table?</p>
<p>Not a great deal, is the answer. This means it can’t support and cooperate with higher order African maritime architectures. It seemingly remains up to academia, NGOs, individual state departments and agencies to play many of the constructive maritime roles on the international stage.</p>
<p>South Africa comes across as being out of touch with maritime security developments on the continent and beyond. There is no doubt that encouraging work is being done on South Africa’s ocean landscapes. This work unfortunately stems more from collections of actors in national departments, agencies, NGOs, and academia shining the light on the country’s critical maritime interests. </p>
<p>But this hasn’t been translated into a coherent strategy. The ultimate responsibility rests with the higher echelons of government. It is national government that must orchestrate the opportunities, actors and beneficiaries that will give expression to Operation Phakisa’s extensive oceans agenda.</p><img src="https://counter.theconversation.com/content/190678/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Francois Vreÿ receives funding from Stellenbosch University. He is affiliated with Stellenbosch University. </span></em></p>The trend globally is for countries to be explicit about their maritime interests, underpinned by a sound security strategy.Francois Vreÿ, Research Coordinator, Security Institute for Governance and Leadership in Africa, Stellenbosch UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1840802022-06-07T15:33:01Z2022-06-07T15:33:01ZFour novelists, one ocean: how Indian Ocean literature can remap the world<figure><img src="https://images.theconversation.com/files/467495/original/file-20220607-26-j47u9f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A dhow ship in Stonetown Zanzibar.</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>Novels make worlds. They create an intuitive sense and mental image of a place. And the senses of space produced by fiction shape how readers see the world itself, just like maps do. </p>
<p>For early postcolonial literature, the world of the novel was often the nation. Postcolonial novels were usually set within national borders and concerned in some way with national questions. Sometimes the whole story of the novel was taken as an <a href="https://www.jstor.org/stable/466475">allegory of the nation</a>, whether India or Tanzania. This was important for supporting anti-colonial nationalism, but could also be limiting – land-focused and inward-looking.</p>
<p>My new book <a href="https://link.springer.com/book/10.1007/978-3-030-87116-1"><em>Writing Ocean Worlds</em></a> explores another kind of world of the novel: not the village or nation, but the Indian Ocean world.</p>
<p>The book describes a set of novels in which the Indian Ocean is at the centre of the story. It focuses on the novelists Amitav Ghosh, Abdulrazak Gurnah, Lindsey Collen and Joseph Conrad. Ghosh is a writer based between India and the US whose work includes historical fiction of the Indian Ocean; Gurnah is a novelist from Zanzibar, who was awarded the 2021 <a href="https://www.dw.com/en/abdulrazak-gurnah-nobel-for-literature-2021/a-59436226#:%7E:text=Abdulrazak%20Gurnah%20awarded%20Nobel%20Prize,gulf%20between%20cultures%20and%20continents.%22">Nobel Prize for Literature</a>; Collen is an author and activist based in Mauritius; and Joseph Conrad, is a key figure of the English literary canon.</p>
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<a href="https://theconversation.com/nobel-winner-abdulrazak-gurnahs-fiction-traces-small-lives-with-wit-and-tenderness-169585">Nobel winner Abdulrazak Gurnah's fiction traces small lives with wit and tenderness</a>
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<p>These four authors are notable for having centred the Indian Ocean world in the majority of their novels. Each also covers an important region of the Indian Ocean: <a href="https://www.amitavghosh.com/">Ghosh</a> the eastern part, <a href="https://literature.britishcouncil.org/writer/abdulrazak-gurnah">Gurnah</a> the western part, <a href="https://amheath.com/authors/lindsey-collen/">Collen</a> the islands and <a href="https://www.britannica.com/biography/Joseph-Conrad">Conrad</a> an imperial outsider’s view. </p>
<p>Their work reveals a world that is outward-looking – full of movement, border-crossing and south-south interconnection. They’re all very different – from colonially inclined (Conrad) to radically anti-capitalist (Collen), but together draw on and shape a wider sense of Indian Ocean space through themes, images, metaphors and language. This has the effect of remapping the world in the reader’s mind, as centred in the interconnected global south. </p>
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Read more:
<a href="https://theconversation.com/exploring-the-indian-ocean-as-a-rich-archive-of-history-above-and-below-the-water-line-133817">Exploring the Indian Ocean as a rich archive of history – above and below the water line</a>
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<p>As the Kenyan novelist <a href="https://www.penguinrandomhouse.com/authors/159826/yvonne-adhiambo-owuor/">Yvonne Adhiambo Owuor</a> <a href="https://www.youtube.com/watch?v=FbHKNvqYPnE">has said</a>, the narrative of particularly Africa’s interconnection with the world “seems to have been lost in our post-independence, postcolonial imagination”. As she says, “so much of Africa lies hidden in the sea”. </p>
<p>My book aims to tempt readers to dive into the fiction where it can be found.</p>
<h2>The Indian Ocean connection</h2>
<p>The Indian Ocean world is a term used to describe the very long-lasting <a href="https://www.indianoceanhistory.org/Maps.aspx">connections</a> among the coasts of east Africa, the Arab coasts, and South and East Asia. These connections were made possible by the <a href="https://iowmaterialhistorieswebinar.org/s/Material-Histories/page/home">geography</a> of the Indian Ocean. </p>
<p>For much of history, travel by sea was much easier than by land, which meant that port cities very far apart were often more easily connected to each other than to much closer inland cities. <a href="https://www.hurstpublishers.com/book/dhow-cultures-of-the-indian-ocean/">Historical and archaeological evidence</a> suggests that what we now call <a href="https://epress.lib.uts.edu.au/journals/index.php/TfC/article/view/920">globalisation first appeared</a> in the Indian Ocean. This is the interconnected oceanic world referenced and produced by the novels in my book. </p>
<p>The Indian Ocean novel in English is a small but substantial genre, including works also by <a href="https://www.mgvassanji.com/">MG Vassanji</a>, <a href="https://literature.britishcouncil.org/writer/michael-ondaatje">Michael Ondaatje</a>, <a href="https://www.romeshg.com/">Romesh Gunesekera</a>, and many others. </p>
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Read more:
<a href="https://theconversation.com/literature-sheds-light-on-the-history-and-mystery-of-the-southern-ocean-122664">Literature sheds light on the history and mystery of the Southern Ocean</a>
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<p>For their part Ghosh, Gurnah, Collen and even Conrad reference a different set of histories and geographies than the ones most commonly found in fiction in English. Those are mostly centred in Europe or the US, assume a background of Christianity and whiteness, and mention places like Paris and New York. </p>
<p>The novels in the book highlight instead a largely Islamic space, feature characters of colour, and centralise the ports of Malindi, Mombasa, Aden, Java and Bombay.</p>
<p>To take one example, in Gurnah’s novel <a href="https://books.google.co.za/books/about/By_the_Sea.html?id=13lsEAAAQBAJ&printsec=frontcover&source=kp_read_button&hl=en&redir_esc=y#v=onepage&q&f=false">By the Sea</a>, a teacher in Zanzibar is showing his young students their place in the world, and he draws a long continuous line around the east coast of Africa, up and around to India, and through the Malay and Indonesian archipelagos, all the way to China. This, he says, is where we are, circling Zanzibar and pointing eastwards and out to sea. Just outside the classroom:</p>
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<p>crowds of sailing ships lie plank to plank in the harbour, the sea between them glistening with slicks of their waste … the streets thronged with Somalis or Suri Arabs or Sindhis, buying and selling and breaking into incomprehensible fights, and at night camping in the open spaces, singing cheerful songs and brewing tea…</p>
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<p>It is a densely imagined, richly sensory image of a <a href="https://www.routledge.com/Convivial-Worlds-Writing-Relation-from-Africa/Steiner/p/book/9780367554163">southern cosmopolitan culture</a> which provides for an enlarged sense of place in the world. </p>
<h2>Representing Africa</h2>
<p>This remapping is particularly powerful for the representation of Africa. In the fiction, sailors and travellers are not all European. And Africa is not portrayed as a hydrophobic continent which only receives rather than sends out explorers. African as well as Indian and Arab characters are traders, nakhodas (dhow ship captains), runaways, villains, missionaries, activists. </p>
<p>This does not mean that Indian Ocean Africa is romanticised. Migration is often a matter of force; travel is portrayed as abandonment rather than adventure; freedoms are kept from women; and slavery is rife. </p>
<p>What it does mean is that the African part of the Indian Ocean world plays an active role in its long, rich history, and therefore in that of the wider world.</p><img src="https://counter.theconversation.com/content/184080/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Charne Lavery 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 work of the authors reveals a world that is outward-looking, full of movement, border-crossing and south-south interconnection.Charne Lavery, Lecturer and Research Associate, University of PretoriaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1760502022-02-02T14:43:03Z2022-02-02T14:43:03ZKiller whales taking food from fishing lines reveal something intriguing about human evolution<p>Who would go off to try and catch a fish if a sushi buffet had been laid on? Not me. Nor killer whales, according to <a href="https://doi.org/10.1098/rsbl.2021.0328">new research</a> that vividly illustrates the allure for these animals of the easy pickings provided by longline fisheries for Patagonian toothfish in the Indian Ocean. </p>
<p>In their study, French fisheries researcher Morgane Amelot and her colleagues examined over 119,000 photographs of individual killer whales taken between 2003 and 2018 around the Crozet Islands in the southern Indian Ocean. They produced an identity parade of whales caught red-handed (or finned) taking fish from baited hooks attached to a long main line. </p>
<p>Killer whales have been known to do this since the mid-1990s, but this analysis showed how the behaviour has spread through the population. The number of whales spotted around the fishing vessels suggest that by the end of the study period, the entire population was taking advantage of the buffet. </p>
<p>Humans, with the inexorable expansion of our fishing fleets, have inadvertently provided the whales with a new source of food, allowing them to expand their niche (the term ecologists use to described a species’ role in an ecosystem). This creates problems for both killer whales and toothfish that require more research to solve, but understanding how this behaviour spreads through populations also leads us into deeper intellectual waters. Might the way killer whales open up new niches mirror early human evolution?</p>
<h2>Toothfish to go</h2>
<p>It is estimated that the whales now take around 163 tonnes of toothfish every year. We don’t know if the toothfish were part of the whales’ diet before they discovered the longlines, but the foraging method is undoubtedly new. </p>
<p>It’s not hard to see the attraction. Instead of all that tiresome swimming around, finding and then chasing the fish, the longliners are kind enough to gather and slowly wind them up from the depths and present them one by one for consumption – the open ocean equivalent of the conveyor belt in a sushi bar.</p>
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<img alt="A black-and-white photo of fishermen preparing a length of rope with hundreds of metal hoops attached." src="https://images.theconversation.com/files/444016/original/file-20220202-17-3uk1mf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/444016/original/file-20220202-17-3uk1mf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=478&fit=crop&dpr=1 600w, https://images.theconversation.com/files/444016/original/file-20220202-17-3uk1mf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=478&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/444016/original/file-20220202-17-3uk1mf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=478&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/444016/original/file-20220202-17-3uk1mf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=601&fit=crop&dpr=1 754w, https://images.theconversation.com/files/444016/original/file-20220202-17-3uk1mf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=601&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/444016/original/file-20220202-17-3uk1mf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=601&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Longlining is a commercial fishing method which can catch hundreds of fish on a single main line.</span>
<span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/Longline_fishing#/media/File:Gangions_used_in_salmon_longlining.jpg">NOAA Photo Library</a></span>
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<p>This isn’t confined to the Indian Ocean. In the northern Pacific, both killer and sperm whales have been exploiting longline fisheries <a href="https://wildwhales.org/2020/06/23/whale-depredation-sneaking-an-easy-snack/">for decades</a>. In all these cases there is evidence that <a href="https://press.uchicago.edu/ucp/books/book/chicago/C/bo12789830.html">cultural transmission</a> is behind <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0109079">the spread</a>. In other words, the whales were learning about the new opportunity from seeing others taking advantage of it. Given that we know killer whales are capable of <a href="https://link.springer.com/article/10.1007%2Fs10071-012-0546-2">highly precise imitation</a> of each other’s behaviour, it seems likely that cultural transmission, the foundation of killer-whale culture, underlies the spread of this behaviour in the Indian Ocean too.</p>
<p>What this research shows is an accelerated version of a process that has played out throughout the evolutionary history of the killer whale. In recent decades, we’ve learned more about how wild populations are divided into what are called <a href="https://uk.whales.org/whales-dolphins/meet-the-different-types-of-orcas/">ecotypes</a> – different forms of killer whale, with distinct appearances, vocal behaviour, and often (but not always) highly specialised prey preferences. </p>
<p>Most famous are the fish-eating killer whales of the north-east Pacific, where for some populations, fully 80% of their diet can be comprised of <a href="https://www.int-res.com/abstracts/meps/v316/p185-199/">a single salmon species</a>. New specialisations are still being described – for example, <a href="https://www.sciencedaily.com/releases/2022/01/220131110513.htm">another study</a> published recently documented the cooperative tactics some groups use to take down blue whales. </p>
<h2>The whale within</h2>
<p>The origins of these ecotypes lie in the discovery of new ecological opportunities and the subsequent spread of new hunting tactics through cultural transmission – just like the spread of longline foraging. Sometimes the passing of these specialisations down generations has given rise to lineages of tradition so stable and separate that the distinctive diets have started affecting natural selection – the genomes of whales in separate lineages <a href="https://www.nature.com/articles/ncomms11693">are diverging</a>. </p>
<p>As a result, killer whales pose a conundrum for biologists, challenging the species concept itself. Are they one species, with sub-types, or should they be considered separate species? The debate <a href="https://genome.cshlp.org/content/20/7/908">rages on</a> unresolved. The interaction between cultural traditions and genetic evolution that has produced this conundrum is called gene-culture co-evolution.</p>
<p>We know this process from <a href="https://www.americanscientist.org/article/gene-culture-coevolution-and-human-diet">our own societies</a>. If you are an adult who is lactose tolerant, your <a href="https://bmcresnotes.biomedcentral.com/articles/10.1186/s13104-015-1833-1">genetic ancestry</a> is intertwined at some point with a <a href="https://www.nature.com/articles/ng1263">dairy farming culture</a>. </p>
<p>The parallels to our own history go deeper, however. The story of human evolution has been a moving target in recent years. In contrast to the standard single-African-population origin story, we now know that what have been classified as multiple <em>Homo</em> species co-existed with modern humans. But were they <a href="https://www.livescience.com/how-many-human-species.html">separate species</a>? Or could they better be described as ecotypes, specialised on diverse niches?</p>
<p>This relates to a provocative <a href="https://doi.org/10.1016/j.tree.2018.05.005">new view</a> of human evolution, termed African multi-regionalism. It suggests that modern humans evolved as sets of interlinked groups throughout Africa, with divisions between groups being primarily related to ecology – different niches for different groups. </p>
<p>My colleagues and I <a href="https://www.nature.com/articles/s41467-019-10293-y">have argued</a> that culturally transmitted ecological specialisations may have led to diversification in humans in the same way as in killer whales. So perhaps the spread of killer whales taking fish from longlines can indeed help us understand how we ourselves came to be.</p><img src="https://counter.theconversation.com/content/176050/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Luke Rendell 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>To a group of hungry killer whales, a longline fishing boat looks like an all-you-can-eat buffet.Luke Rendell, MASTS Lecturer in Biology, University of St AndrewsLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1684132021-10-03T08:34:32Z2021-10-03T08:34:32ZSouth Africa’s massive ‘sardine run’ leads fish into an ecological trap<figure><img src="https://images.theconversation.com/files/422355/original/file-20210921-27-ufpuee.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Steven Benjamin/Not for reuse</span></span></figcaption></figure><p>One of the world’s most spectacular marine migrations is the KwaZulu-Natal sardine run. The so-called “<a href="https://edition.cnn.com/travel/article/greatest-shoal-on-earth-south-africa-sardine-run-c2e-spc-intl-scn/index.html">greatest shoal on Earth</a>” takes place during the southern hemisphere’s winter. It involves the movement of tens to hundreds of millions of sardines from the warm-temperate waters of South Africa’s south coast to the subtropical waters of the east coast, over a thousand kilometres away.</p>
<p>This annual mass migration, <a href="https://www.oceansafrica.com/sardine-run/">first reported in 1853</a>, is triggered by cold water <a href="https://oceanservice.noaa.gov/education/tutorial_currents/03coastal4.html">upwelling</a> on South Africa’s south-east coast. In this process, cold, nutrient-rich water rises up from the deep, creating a highly productive food web. The migration attracts vast numbers of <a href="https://www.youtube.com/watch?v=6zOarcL1BSc">predators</a>: the sardine schools are followed northwards by seabirds, sharks, seals, dolphins and even large baleen whales. These devour as many of the helpless sardines as they can, which is made easier by the fact that their prey is sandwiched between dry land and the hot, tropical waters of the southward-flowing Agulhas Current, which exceed the sardines’ physiological tolerances. </p>
<p>To make matters worse, those fish that survive the predation still don’t have it easy: the journey is so strenuous that the sardines which eventually arrive on the east coast are emaciated. This goes against what scientists understand about <a href="https://www.nature.com/scitable/knowledge/library/animal-migration-13259533/">animal migrations</a> – such large-scale population movements normally provide some “<a href="https://academic.oup.com/bioscience/article/57/2/165/228565">selective advantage</a>” by allowing animals to make optimal use of environmental resources. </p>
<p>Surely the obvious negatives of participating in the sardine run must be hugely outweighed by some fitness benefits to make it all worthwhile? The answer, our <a href="https://www.science.org/doi/10.1126/sciadv.abf4514">new research</a> suggests, is “no” – and the reasons for the sardines’ behaviour lies in their genes. </p>
<h2>A distinct east coast population?</h2>
<p>One popular explanation for why the sardine run occurs is that the migration might be a relic of spawning behaviour dating back to <a href="https://www.britannica.com/science/Last-Glacial-Maximum">the last glacial period</a>, about 10,000 years ago. What is now subtropical Indian Ocean habitat may have been an important nursery area with cooler waters. </p>
<p>When the ice age ended, the sardines would have physiologically adapted to tolerate the subtropical conditions in this region, and evolved into a distinct east coast population that continues to spawn there to this day. These sardines mix with south coast sardines during summer, then separate from them in winter as they migrate up the east coast. The presence of sardine eggs in the plankton confirms that spawning does occur in this region. </p>
<p>Surprisingly, we discovered that sardines participating in the migration are not part of a distinct east coast population. Instead, they primarily originate from the colder waters off South Africa’s Atlantic west coast. Why would these sardines migrate to the opposite end of the country, only to end up in habitat that is obviously too warm for them? We suggest that the fish are drawn into what amounts to an ecological trap – a rare example of a mass migration that has no obvious fitness benefits.</p>
<h2>Genomic analyses</h2>
<p>Our research started from the assumption that the sardine run represents the spawning migration of a distinct stock of sardines that is physiologically well adapted to tolerate subtropical conditions. </p>
<p>Physical characteristics and other data indicate that sardines on the east coast are indeed distinct. But this may result from different environmental pressures, including the stress of participating in the migration. We knew that understanding the sardines’ heritable genetic traits would provide stronger evidence for this hypothesis – or debunk it.</p>
<p>So we used thousands of genetic markers from across the genomes of hundreds of sardines captured throughout the species’ South African range. Although most of these markers showed little differentiation, a suite of genetic markers with a signal of adaptation to water temperature showed regional differences.</p>
<p>We found evidence for two regional populations – but it was not the east coast sardines that were distinct. Instead, we found genetic differences within the species’ temperate core range: one population was associated with South Africa’s cool-temperate west coast (Atlantic Ocean) and the other with the warm-temperate south coast (Indian Ocean). </p>
<p>The strong affiliation with water temperature suggests that thermal adaptation maintains these regional patterns; each population cluster is adapted to the temperature range that it experiences in its native region.</p>
<p>The sardines participating in the run showed a clear affiliation with the west coast population. Not only are these sardines not well adapted to subtropical conditions, but they actually prefer the colder, upwelled waters of the south-eastern Atlantic Ocean.</p>
<h2>Major riddles solved</h2>
<p>This study solves some of the major riddles concerning the sardine run, which make perfect sense in the light of the new evidence. </p>
<p>Our findings explain why only a small fraction of the sardines present on the south coast participates in the run. The bulk of those sardines are native to this region and are adapted to warm-temperate conditions. Because of this, they show little interest in the cold, upwelled water.</p>
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<img alt="An illustration explaining how sardine migration is influenced by genetic adaptations to water temperature" src="https://images.theconversation.com/files/422354/original/file-20210921-23-1lsuz8q.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/422354/original/file-20210921-23-1lsuz8q.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=395&fit=crop&dpr=1 600w, https://images.theconversation.com/files/422354/original/file-20210921-23-1lsuz8q.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=395&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/422354/original/file-20210921-23-1lsuz8q.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=395&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/422354/original/file-20210921-23-1lsuz8q.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=496&fit=crop&dpr=1 754w, https://images.theconversation.com/files/422354/original/file-20210921-23-1lsuz8q.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=496&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/422354/original/file-20210921-23-1lsuz8q.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=496&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">This illustration examines some of the factors at play in the sardine migration.</span>
<span class="attribution"><span class="source">Supplied by authors</span></span>
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<p>The results also provide an explanation why no sardine runs occur in years when there is no cold water upwelling. The upwelling on the south-east coast attracts west coast sardines that have dispersed to the south coast, but that are not well adapted to the warmer water temperatures in this region. They essentially consider the upwelling regions in the south-east to be west coast habitat. For a short time, it is as if they are back home in the Atlantic – but when the upwelling ends and water temperatures rise, their fateful error is revealed.</p>
<p>At this point, the predators have gotten wind of their presence, and as the sardines try to escape, they travel ever farther north into unbearably warm subtropical habitat. The fate of the fish that survive the sardine run is uncertain.</p>
<p>Our genomic explanation shows that much still remains to be discovered about how marine life interacts with its environment. A great deal of integrative, multidisciplinary research is still needed before humans can efficiently and sustainably benefit from the incredible diversity of life and the resources available in the sea.</p><img src="https://counter.theconversation.com/content/168413/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Peter Teske receives research funding from the University of Johannesburg and the National Research Foundation.</span></em></p><p class="fine-print"><em><span>Christopher David McQuaid receives funding from Rhodes University and the National Research Foundation of South Africa.. </span></em></p><p class="fine-print"><em><span>Luciano Beheregaray receives funding from the Australian Research Council.</span></em></p><p class="fine-print"><em><span>Carl van der Lingen 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>Sardines from the cold waters off South Africa’s Atlantic coast are attracted to cold water upwelling in the Indian Ocean. When the upwelling ends, they are trapped in water that is too warm for them.Peter Teske, Professor of Marine Genomics, University of JohannesburgCarl van der Lingen, Honorary Research Associate, University of Cape TownChristopher David McQuaid, Distinguished Professor, Rhodes UniversityLuciano Beheregaray, Professor of Biodiversity Genomics, Flinders UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1673702021-09-09T08:34:33Z2021-09-09T08:34:33ZHow climate change contributed to Madagascar’s food crisis<figure><img src="https://images.theconversation.com/files/419622/original/file-20210906-27-1s0845m.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A baby scale hangs on a tree branch during a malnutrition screening session in Ifotaka, southern Madagascar.</span> <span class="attribution"><span class="source">RIJASOLO/AFP via Getty Images</span></span></figcaption></figure><p><em>The UN has announced that Madagascar is on the brink of experiencing the world’s first <a href="https://www.bbc.co.uk/news/world-africa-58303792">“climate change famine”</a>. Tens of thousands of people are suffering “catastrophic” levels of hunger. Climate hazard scientist, Chris Funk, provides insights into the causes.</em></p>
<h2>How significant has the drought been in Madagascar?</h2>
<p>Out of the last six years in Madagascar, five years have had poor or very bad rainy seasons. </p>
<p>My colleagues and I were able to track this because of the satellite-gauge rainfall data that we developed – the <a href="https://www.chc.ucsb.edu/data/chirps">Climate Hazards Group’s Infrared Precipitation with Stations (CHIRPS)</a> system – to monitor droughts in regions like southern Madagascar. The focus of my work has been on sea temperatures between Australia and Hawaii – the Indo-Pacific – and the impacts variations have on southern and eastern Africa.</p>
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Read more:
<a href="https://theconversation.com/novel-use-of-satellite-data-is-helping-africa-cope-with-natural-disasters-56161">Novel use of satellite data is helping Africa cope with natural disasters</a>
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<p>Our data suggests that since 2015, with the exception of the 2018 - 2019 rains, seasonal rainfall (which usually falls from from October to May in southern Madagascar) has been low. This fall within the driest 10% of years since 1981.</p>
<p>Other <a href="https://www.giss.nasa.gov/">data</a> <a href="https://www.ecmwf.int/en/forecasts/datasets/reanalysis-datasets/era5">suggests</a> that the past six years have also been exceptionally warm. Warmer air can hold more water vapour which leads to vapour deficits. These deficits can exacerbate droughts by drying out vegetation, because the drier air pulls moisture out of the plants.</p>
<p>Looking back over Indo-Pacific sea temperatures, I am really struck at how extreme conditions have been since 2014. </p>
<p>The Indo-Pacific is dominated by three types of extreme weather events; El Niño, La Niña and the Indian Ocean dipole. These all occur when certain parts of the ocean become exceptionally warm.
El Niño is influenced by the eastern Pacific, La Niña by the western Pacific and the Indian Ocean Dipole by the western Indian Ocean. </p>
<p>When these events happen, wind patterns shift to support heavy rainfall over whichever region is extremely warm. These shifts, in turn, can disturb rainfall conditions over eastern and southern Africa. </p>
<p><a href="https://origin.cpc.ncep.noaa.gov/products/analysis_monitoring/ensostuff/ONI_v5.php">Every year</a> since 2014, there has been either a La Niña or El Niño, except for 2019 to 2020. But that year was an exceptionally strong Indian Ocean Dipole event. </p>
<p>This is consistent with my view that climate change is increasing “climate volatility” by increasing the frequency of extreme sea surface temperatures – extreme sea surface temperatures create these extreme weather events.</p>
<h2>What have been the implications?</h2>
<p>Repetitive drought shocks have led to severe vegetation stress.</p>
<p>While I don’t have any expertise as a food security analyst, the <a href="https://fews.net/southern-africa/madagascar">Famine Early Warning Systems Network</a> is tracking conditions in Madagascar very closely. They report below-average rice, maize, and pulse production in the main producing areas of the highlands as well as across eastern and southern Madagascar. There is also very poor cassava production, a staple food.</p>
<p>Our satellite imagery confirms this – we see that the droughts have really dried out <a href="https://earlywarning.usgs.gov/fews/product/450">vegetation</a>. </p>
<p>In general, this type of persistent drought stress weakens the resilience of poor households. It can also lead to higher food prices.</p>
<h2>The lack of rain has been connected to climate change. Why?</h2>
<p>In my work on <a href="https://scholar.google.com/citations?user=q7sk2bAAAAAJ&hl=en">climate hazards</a>, it has become clear that we need to recognise how and when climate change is exacerbating natural climate and weather extremes. </p>
<p>The specific links between sea surface temperature conditions and the recent dry conditions in Madagascar are not well understood but the link between climate change and more extreme Indo-Pacific sea surface temperatures is quite clear. </p>
<p>Our <a href="https://rmets.onlinelibrary.wiley.com/doi/full/10.1002/qj.3266">research</a>, supporting famine early warning, for example, has described how climate change is amplifying the magnitude of natural variations, such as <a href="https://doi.org/10.1175/BAMS-D-16-0167.1">El Niños</a> and <a href="https://doi.org/10.1175/BAMS-D-18-0108.1">La Niñas</a>. This <a href="https://www.cambridge.org/core/books/drought-flood-fire/96E0EB1519F5175B68079D294D0B0E93">contributed</a> to post-2014 increases in eastern and southern African food insecurity. </p>
<p>From 2019 to 2021, we saw exceptionally warm ocean conditions in the Indian Ocean and western Pacific. And, as mentioned earlier, warmer air can hold more water vapour which leads to deficits.</p>
<p>In two recent papers, one focused on a <a href="https://iopscience.iop.org/article/10.1088/1748-9326/ab4a6c">global drought analysis</a> and one focused on <a href="https://esd.copernicus.org/articles/12/17/2021/">East Africa</a>, we argue that these warmer temperatures have amplified the impact of precipitation deficits, especially in arid regions. </p>
<p>Data for southern Madagascar suggest that large increases in atmospheric water demand due to warmer air temperatures have occurred there during many recent droughts.</p>
<h2>What are the projections for the future?</h2>
<p>The just-released Intergovernmental Panel on Climate Change <a href="https://www.ipcc.ch/report/ar6/wg1/downloads/report/IPCC_AR6_WGI_Chapter_04.pdf">report</a> suggests a near-term and persistent El Niño-like shift in the climate. This could be associated with warmer eastern Pacific ocean conditions, warmer air temperatures and more frequent droughts over southern Madagascar.</p>
<p>My perspective on “projections,” however, is that we need to reject the idea that climate change is some “external” process. There is no physical process that causes all the sea surface temperatures and air temperatures to slowly warm at very similar rates. </p>
<p>Energy <a href="https://blog.chc.ucsb.edu/?p=1003">is building up</a> in the ocean and atmosphere and then converging in specific locations, creating more extreme weather and climate. </p>
<p>I think we can safely project that what we are seeing happen will continue. We will <a href="https://www.climate.gov/news-features/understanding-climate/climate-change-ocean-heat-content">continue to see</a> increased Indo-Pacific volatility that will bring more frequent, strong El Niño, La Niñas, and Indian Ocean Dipole events. Alongside this, much warmer air temperatures will both increase desiccation during droughts and contribute to more extreme rainfall during storms and cyclones.</p>
<p>To respond to these changes, we are racing to develop improved early warning systems. </p>
<h2>Which other countries in Africa are at risk from the same?</h2>
<p>My expertise focuses on southern and eastern Africa, so my concerns also apply in many of those countries. </p>
<p>In southern Africa, we have seen many recent <a href="https://blog.chc.ucsb.edu/?p=695">poor rainy seasons</a> in Zimbabwe. In East Africa, climate change-enhanced conditions contributed to droughts in <a href="https://doi.org/10.1175/BAMS-D-18-0108.1">2016 - 2017</a> and 2020 - 2021. </p>
<p>We were able to anticipate those shocks many months in advance <a href="https://blog.chc.ucsb.edu/?p=904">based</a>, in part, on <a href="https://blog.chc.ucsb.edu/?p=757">exceptionally warm west Pacific sea surface</a> temperatures.</p>
<p>We are now very concerned about the potential of another sequence of poor rains in East Africa from 2021 - 2022. Current forecasts appear very similar to recent drought years. This could be especially concerning for Ethiopia, where <a href="https://data.chc.ucsb.edu/people/diego/Ethiopia_dekadal_monitoring_reports/Ethiopia%20Kiremt_long_rains%20seasons%20special%20report%20dekad%2024%202021.pdf">very poor rains</a> have led to low <a href="https://cropmonitor.org/documents/EWCM/reports/EarlyWarning_CropMonitor_202006.pdf">crop production outcomes</a>. Poor rains, combined with food price increases, conflict, political division, have led to crisis levels of <a href="https://fews.net/east-africa/ethiopia/food-security-outlook/june-2021">food insecurity</a>.</p>
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Read more:
<a href="https://theconversation.com/ethiopias-tigray-region-has-seen-famine-before-why-it-could-happen-again-150181">Ethiopia's Tigray region has seen famine before: why it could happen again</a>
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<p>We have <a href="https://www.frontiersin.org/articles/10.3389/fclim.2021.716568/full">also</a> shown in <a href="https://esd.copernicus.org/articles/12/17/2021/">recent papers</a> that in east African regions, dry seasons are getting drier in already-arid places. Both increased Indo-Pacific sea surface temperatures and increased terrestrial air temperatures are increasing climate risk. </p>
<p>But, we are not helpless. </p>
<p>There are vital efforts being made to build resilience. For example, the social enterprise <a href="https://tatirano.org/">Tatirano</a> (“to collect water” in Malagasy) aims to increase the adoption of rainwater harvesting techniques by communities. In the drier, arid drought-stricken areas rainwater harvesting can increase water retention for agriculture by increasing the amount of rain absorbed by the soil. Larger scale nature-based rainwater harvesting collection and storage (natural rock reservoirs for example) can help mitigate more variable rainfall and take advantage of extreme precipitation events, which appear to be more frequent.</p>
<p>I am excited about the possibility of <a href="https://chc.ucsb.edu/">Climate Hazards Center</a> observations and forecasts feeding into local decision-support tools, like Tatirano’s <a href="https://stats.tatirano.org/dashboard">data systems</a>. </p>
<p>In addition, improvements in early warning and early action, water resource management, safety net and risk management systems, and agricultural development are offering and, will offer, pathways to improved climate resilience.</p><img src="https://counter.theconversation.com/content/167370/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Chris Funk receives funding from the United States Agency for International Development.</span></em></p>Out of the last six years in Madagascar, five years have had poor or very bad rainy seasons.Chris Funk, Director of the Climate Hazards Center, University of California, Santa BarbaraLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1602842021-05-23T10:43:13Z2021-05-23T10:43:13ZTanzania’s ‘forgotten’ cyclones and concerns for the future<figure><img src="https://images.theconversation.com/files/401575/original/file-20210519-23-chbwo0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Cyclone Kenneth caused significant damage to Mozambique, the Comoros Islands and Tanzania in 2019.</span> <span class="attribution"><span class="source">EMIDIO JOZINE/AFP via Getty Images</span></span></figcaption></figure><p>A cyclone, known as Jobo, <a href="https://www.garda.com/crisis24/news-alerts/471166/tanzania-tropical-depression-jobo-makes-landfall-and-continues-tracking-west-update-4">made landfall</a> near Dar es Salaam in late April. By this point it had weakened to a tropical depression and impacts were, thankfully, minimal. </p>
<p>Land-falling tropical cyclones are rare in Tanzania so past events are outside the memory of most. It had even been suggested that Cyclone Kenneth, which occurred in 2019, was the <a href="https://theconversation.com/why-the-indian-ocean-is-spawning-strong-and-deadly-tropical-cyclones-116559">first tropical cyclone to make landfall in Tanzania</a>. The largest impacts of cyclone Kenneth were felt further south where at least <a href="https://reliefweb.int/disaster/tc-2019-000038-moz">38 lives were lost and almost 35,000 homes were damaged or destroyed</a>.</p>
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<p>However, we recently published <a href="https://rmets.onlinelibrary.wiley.com/doi/full/10.1002/wea.3921">research</a> which recounts the events of two tropical cyclones which made land-fall in Tanzania, in 1872 and 1952. Using eyewitness accounts from <a href="https://trove.nla.gov.au/newspaper/article/8926435">news articles</a>, the <a href="https://microform.digital/boa/collections/72/volumes/495/miscellaneous-1907-1964">British Online Archives</a> and meteorological observations, we show what a devastating impact these storms had.</p>
<p>We hope that by documenting these cyclones in Tanzania, it will encourage further investigation into the drivers of tropical cyclones in the southwest Indian Ocean which, to date, have received little research attention. </p>
<p>Our concern is that, with a changing climate, these events could become more intense.</p>
<h2>Rare cyclones</h2>
<p>Tropical cyclones – also known as hurricanes in the Atlantic and typhoons in the Pacific – typically form over the ocean when the sea surface temperature is at least 26.5°C and where there is a sufficiently strong Coriolis effect. The Coriolis effect arises because of the earth’s spin around its axis. It <a href="https://www.nationalgeographic.org/encyclopedia/coriolis-effect/">drives the circular rotation of winds in a cyclone</a>. </p>
<p>Countries closer to the equator, north of Tanzania, won’t experience tropical cyclones directly. The Coriolis effect is too weak to sustain them, though there can be complex indirect effects of tropical cyclones occurring further south. This can range from delaying onset of rainy seasons, as with <a href="https://rmets.onlinelibrary.wiley.com/doi/full/10.1002/wea.3824">Cyclone Idai in 2019</a>, to actually increasing the chance of heavy rainfall, as with <a href="https://rmets.onlinelibrary.wiley.com/doi/full/10.1002/qj.3698">cyclones during 2018</a>.</p>
<p>Around Tanzania, tropical cyclones are rare, but they’ve happened before. In 1872 and 1952 the country was hit by devastating cyclones that made landfall in the far north and south respectively. </p>
<p>Meteorological records of these events are limited, but there are eyewitness accounts which provide interesting and important information on tropical cyclones along the coast of Tanzania.</p>
<p>In 1872, a tropical cyclone <a href="https://rmets.onlinelibrary.wiley.com/doi/full/10.1002/wea.3921">tracked across</a> Zanzibar and Bagamoyo, a town to the north of Dar es Salaam. The storm destroyed all of the Sultan’s boats in Zanzibar harbour, the Catholic Mission Hospital at Bagamoyo, and two thirds of coconut and clove crops on Zanzibar. </p>
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<img alt="A sketch of the effects of the hurricane at Zanzibar, Tanzania" src="https://images.theconversation.com/files/401281/original/file-20210518-17-h12mqi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/401281/original/file-20210518-17-h12mqi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=407&fit=crop&dpr=1 600w, https://images.theconversation.com/files/401281/original/file-20210518-17-h12mqi.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=407&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/401281/original/file-20210518-17-h12mqi.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=407&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/401281/original/file-20210518-17-h12mqi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=512&fit=crop&dpr=1 754w, https://images.theconversation.com/files/401281/original/file-20210518-17-h12mqi.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=512&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/401281/original/file-20210518-17-h12mqi.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=512&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">Effects of the cyclone at Zanzibar, Tanzania, from a sketch by Henn, illustration from the magazine The Illustrated London News, volume LX, June 1, 1872.</span>
<span class="attribution"><span class="source">DEA / BIBLIOTECA AMBROSIANA / Contributor/GettyImages</span></span>
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<p>An eye-witness account from Zanzibar describes how his window shutters were blasted open as “torrents of water swept in. It was salt water and sand carried by the hurricane”.</p>
<p>In 1952 another <a href="https://rmets.onlinelibrary.wiley.com/doi/full/10.1002/wea.3921">cyclone hit</a>, this time further south, over Lindi. This was reported by the East African Meteorological Department. It caused over US$100 million of damage in today’s terms. This included half the buildings in Lindi losing their roof. An account by a ship captain caught in the storm says there were “gusts of well-nigh indescribable fury” with “limited visibility to about 20 metres”.</p>
<p>There are concerns that changes in the weather could make these events even more intense.</p>
<h2>More intense?</h2>
<p>With the warming of sea surface temperatures, <a href="https://link.springer.com/chapter/10.1007/978-981-15-4327-2_10">especially</a> the rapidly warming Indian Ocean, intense cyclones are expected to become more prevalent. </p>
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Read more:
<a href="https://theconversation.com/southern-africa-must-brace-itself-for-more-tropical-cyclones-in-future-103641">Southern Africa must brace itself for more tropical cyclones in future</a>
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<p>With rising sea levels, storm surges (resulting from the strong winds of cyclones) will cause more wide spread damage. Once-a-century extreme sea-level events, which can result from these storm surges, <a href="https://www.ipcc.ch/srocc/chapter/summary-for-policymakers/">could</a> strike the East African coastline every year by 2050. </p>
<p>In addition, as the air over the ocean warms, <a href="https://journals.ametsoc.org/view/journals/clim/33/7/jcli-d-19-0328.1.xml">more moisture can be transported</a> with storms such as tropical cyclones, driving an increase in maximum rainfall intensity. </p>
<h2>Forecasting</h2>
<p>Once a cyclone is on its way, there is no changing where it will hit, nor how it could intensify, but we can see it coming and take precautions to greatly reduce the harm that it does.</p>
<p>With satellite imagery and modern weather forecasting, cyclones are often observed many days in advance of landfall. Even before a cyclone is present there are activities which can either increase or decrease the ability of locations to cope with impacts. For example, the destruction of mangroves <a href="https://www.unep.org/news-and-stories/story/tanzania-locals-and-officials-band-together-save-mangroves">decreases</a> the natural protection against ocean storm surges.</p>
<p>The severity of past events should give impetus to build knowledge of the potential impacts of extreme weather amongst decision-makers, disaster management authorities and the general public.</p>
<p><em>Dr Caroline Wainwright (Post-Doctoral Research Assistant, University of Reading) and Dr Sam Hardy (Research Fellow, University of Leeds) contributed to the research in this article.</em></p><img src="https://counter.theconversation.com/content/160284/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Declan Finney works for the University of Edinburgh. He previously received funding from the Natural Environment Research Council. </span></em></p><p class="fine-print"><em><span>Hellen Msemo receives funding from the Global Challenges Research Fund (GCRF) African SWIFT Project (NE/P021077/1). She is also affiliated with Tanzania Meteorological Authority</span></em></p><p class="fine-print"><em><span>John Marsham receives funding from the Natural Environment Research Council, the Weather and Climate Science for Service Partnership Programme, the Foreign and Commonwealth Development Office and UK Research and Innovation as part of the Global Challenges Research Fund. He is Met Office joint chair at the University of Leeds, a position part funded by the Met Office. </span></em></p>Land-falling tropical cyclones are rare in Tanzania so past events are outside the memory of most.Declan Finney, Project Manager of Climate Research, The University of EdinburghHellen Msemo, PhD candidate, University of LeedsJohn Marsham, Academic Research Fellow, Institute for Climate and Atmospheric Science (ICAS), University of LeedsLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1597922021-04-29T14:38:49Z2021-04-29T14:38:49ZWatching a coral reef die as climate change devastates one of the most pristine tropical island areas on Earth<figure><img src="https://images.theconversation.com/files/397728/original/file-20210429-13-1cf9nq9.jpg?ixlib=rb-1.1.0&rect=0%2C8%2C1917%2C1212&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The Chagos Reef was vibrant before the heat wave.</span> <span class="attribution"><a class="source" href="https://www.livingoceansfoundation.org/publication/global-reef-expedition-chagos-archipelago-final-report/">Ken Marks/Khaled bin Sultan Living Oceans Foundation</a></span></figcaption></figure><p>The <a href="https://en.wikipedia.org/wiki/Chagos_Archipelago#/media/File:Chagos_map.PNG">Chagos Archipelago</a> is one of the most remote, seemingly idyllic places on Earth. Coconut-covered sandy beaches with incredible bird life rim tropical islands in the Indian Ocean, hundreds of miles from any continent. Just below the waves, coral reefs stretch for miles along an <a href="https://www.researchgate.net/figure/Satellite-bathymetry-map-of-the-western-Indian-Ocean-basin-Approximate-aerial-extent-of_fig1_320835153">underwater mountain chain</a>.</p>
<p>It’s a paradise. At least it was before the heat wave.</p>
<p>When I first explored the Chagos Archipelago 15 years ago, the underwater view was incredible. Schools of brilliantly colored fish in blues, yellows and oranges darted among the corals of a vast, healthy reef system. Sharks and other large predators swam overhead. Because the archipelago is so remote and sits in one of the largest <a href="https://chagos-trust.org/chagos/overview">marine protected areas</a> on the planet, it has been sheltered from industrial fishing fleets and other activities that can harm the coastal environment.</p>
<p>But it can’t be protected from climate change.</p>
<figure class="align-center ">
<img alt="A diver carries a plastic pipe for measuring while swimming over a variety of corals" src="https://images.theconversation.com/files/397204/original/file-20210426-15-ng6gsy.jpg?ixlib=rb-1.1.0&rect=480%2C586%2C1097%2C689&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/397204/original/file-20210426-15-ng6gsy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/397204/original/file-20210426-15-ng6gsy.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/397204/original/file-20210426-15-ng6gsy.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/397204/original/file-20210426-15-ng6gsy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/397204/original/file-20210426-15-ng6gsy.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/397204/original/file-20210426-15-ng6gsy.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A diver documents the coral reefs in the Chagos Archipelago.</span>
<span class="attribution"><a class="source" href="https://www.livingoceansfoundation.org/publication/global-reef-expedition-chagos-archipelago-final-report/">Khaled bin Sultan Living Oceans Foundation</a></span>
</figcaption>
</figure>
<p>In 2015, a marine heat wave struck, harming coral reefs worldwide. <a href="https://people.miami.edu/profile/spurkis@rsmas.miami.edu">I’m a marine biologist</a> at the University of Miami’s Rosenstiel School of Marine and Atmospheric Science, and I was with a team of researchers on a <a href="https://www.livingoceansfoundation.org/global-reef-expedition/global-reef-expedition-final-reports/">10-year global expedition to map the world’s reefs</a>, led by the <a href="https://www.livingoceansfoundation.org/">Khaled bin Sultan Living Oceans Foundation</a>, wrapping up our work in the Chagos Archipelago at the time. Our report on the state of the reefs there <a href="https://www.livingoceansfoundation.org/publication/global-reef-expedition-chagos-archipelago-final-report/">was just published</a> in spring 2021.</p>
<p>As the water temperature rose, the corals began to bleach. To the untrained eye, the scene would have looked fantastic. When the water heats up, corals become stressed and they expel the tiny algae called dinoflagellates that live in their tissue. Bleaching isn’t as simple as going from a living coral to a bleached white one, though. After they expel the algae, the corals turn fluorescent pinks and blues and yellows as they produce chemicals to <a href="https://doi.org/10.1016/j.cub.2020.04.055">protect themselves from the Sun’s harmful rays</a>. The entire reef was turning psychedelic colors.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/397178/original/file-20210426-13-v15dqm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Two bright pink coral mounds" src="https://images.theconversation.com/files/397178/original/file-20210426-13-v15dqm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/397178/original/file-20210426-13-v15dqm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/397178/original/file-20210426-13-v15dqm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/397178/original/file-20210426-13-v15dqm.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/397178/original/file-20210426-13-v15dqm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/397178/original/file-20210426-13-v15dqm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/397178/original/file-20210426-13-v15dqm.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">Just before they turned white, the corals turned abnormally bright shades.</span>
<span class="attribution"><a class="source" href="https://www.livingoceansfoundation.org/publication/global-reef-expedition-chagos-archipelago-final-report/">Phil Renaud/Khaled bin Sultan Living Oceans Foundation</a></span>
</figcaption>
</figure>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/397198/original/file-20210426-21-txmdaj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Large fish and schools of fish swimming above the reef" src="https://images.theconversation.com/files/397198/original/file-20210426-21-txmdaj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/397198/original/file-20210426-21-txmdaj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/397198/original/file-20210426-21-txmdaj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/397198/original/file-20210426-21-txmdaj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/397198/original/file-20210426-21-txmdaj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/397198/original/file-20210426-21-txmdaj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/397198/original/file-20210426-21-txmdaj.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 Chagos archipelago is home to some 800 species of fish, including rays, skates and dozens of varieties of shark.</span>
<span class="attribution"><a class="source" href="https://www.livingoceansfoundation.org/publication/global-reef-expedition-chagos-archipelago-final-report/">Phil Renaud/Khaled bin Sultan Living Oceans Foundation</a></span>
</figcaption>
</figure>
<p>That explosion of color is rare, and it doesn’t last long. Over the following week, we watched the corals turn white and start to die. It wasn’t just small pieces of the reef that were bleaching – it was happening across hundreds of square miles.</p>
<p>What most people think of as a coral is actually many tiny colonial polyps that build calcium carbonate skeletons. With their algae gone, the coral polyps could still feed by plucking morsels out of the water, but their metabolism slows without the algae, which provide more nutrients <a href="https://oceanservice.noaa.gov/education/tutorial_corals/coral02_zooxanthellae.html">through photosynthesis</a>. They were left desperately weakened and more vulnerable to diseases. We could see diseases taking hold, and that’s what finished them off.</p>
<p>We were witnessing the death of a reef.</p>
<figure class="align-center ">
<img alt="A large mushroom-shaped coral structure, half of it turned white from bleaching" src="https://images.theconversation.com/files/397197/original/file-20210426-19-2eyjzx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/397197/original/file-20210426-19-2eyjzx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/397197/original/file-20210426-19-2eyjzx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/397197/original/file-20210426-19-2eyjzx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/397197/original/file-20210426-19-2eyjzx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/397197/original/file-20210426-19-2eyjzx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/397197/original/file-20210426-19-2eyjzx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Corals beginning to bleach in the Chagos archipelago.</span>
<span class="attribution"><a class="source" href="https://www.livingoceansfoundation.org/publication/global-reef-expedition-chagos-archipelago-final-report/">Phil Renaud/Khaled bin Sultan Living Oceans Foundation</a></span>
</figcaption>
</figure>
<h2>Rising temperatures increase the heat wave risk</h2>
<p>The devastation of the Chagos Reef wasn’t happening in isolation.</p>
<p>Over the past century, <a href="https://www.ncdc.noaa.gov/cag/global/time-series/globe/ocean/ytd/12/1880-2017">sea surface temperatures</a> have risen by an average of <a href="https://www.epa.gov/climate-indicators/climate-change-indicators-sea-surface-temperature">about 0.13 degrees Celsius</a> (0.23 F) per decade as the oceans absorb the vast majority of greenhouse gas emissions from human activities, largely from the burning of fossil fuels. The temperature increase and changing ocean chemistry affects sea life of all kinds, from <a href="https://www.pmel.noaa.gov/co2/story/What+is+Ocean+Acidification%3F">deteriorating the shells of oysters and tiny pteropods</a>, an essential part of the food chain, to causing fish populations to migrate to cooler water. </p>
<p>Corals can become stressed when temperatures around them <a href="https://coralreefwatch.noaa.gov/satellite/methodology/methodology.php">rise just 1 C</a> (1.8 F) above their tolerance level. With water temperature elevated from global warming, even a minor heat wave can become devastating.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/IEWJAEkGeNk?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
</figure>
<p>In 2015, the ocean heat from a strong <a href="https://oceanservice.noaa.gov/facts/ninonina.html">El Niño</a> event triggered the mass bleaching in the Chagos reefs and <a href="https://www.climate.gov/news-features/event-tracker/survey-photos-reveal-damage-year%E2%80%99s-global-coral-bleaching-event">around the world</a>. It was the third global bleaching on record, following events in <a href="http://www.reefcheck.org/wp-content/uploads/2020/07/Ambio1999.pdf">1998</a> and <a href="https://www.climate.gov/news-features/videos/coral-bleaching-alarm-2010">2010</a>.</p>
<p>Bleaching doesn’t just affect the corals – entire reef systems and the fish that feed, spawn and live among the coral branches suffer. One <a href="https://doi.org/10.1073/pnas.0401277101">study of reefs</a> around Papua New Guinea in the southwest Pacific found that about 75% of the reef fish species declined after the 1998 bleaching, and many of those species declined by more than half.</p>
<figure class="align-center ">
<img alt="Two bright orange fish with white bands swim past an anemone" src="https://images.theconversation.com/files/397200/original/file-20210426-21-24e0zc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/397200/original/file-20210426-21-24e0zc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/397200/original/file-20210426-21-24e0zc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/397200/original/file-20210426-21-24e0zc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/397200/original/file-20210426-21-24e0zc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/397200/original/file-20210426-21-24e0zc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/397200/original/file-20210426-21-24e0zc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Most corals are brown or green. Fish and anemones bring color to the reefs.</span>
<span class="attribution"><a class="source" href="https://www.livingoceansfoundation.org/publication/global-reef-expedition-chagos-archipelago-final-report/">Ken Marks/Khaled bin Sultan Living Oceans Foundation</a></span>
</figcaption>
</figure>
<figure class="align-center ">
<img alt="Starfish on a coral" src="https://images.theconversation.com/files/397603/original/file-20210428-19-1j2eryy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/397603/original/file-20210428-19-1j2eryy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/397603/original/file-20210428-19-1j2eryy.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/397603/original/file-20210428-19-1j2eryy.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/397603/original/file-20210428-19-1j2eryy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/397603/original/file-20210428-19-1j2eryy.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/397603/original/file-20210428-19-1j2eryy.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Noduled sea stars are among the reef’s diverse species.</span>
<span class="attribution"><a class="source" href="https://www.livingoceansfoundation.org/global-reef-expedition/">Ken Marks/Khaled bin Sultan Living Oceans Foundation</a></span>
</figcaption>
</figure>
<p>Research shows marine heat waves are now about <a href="http://doi.org/10.1126/science.aba0690">20 times more likely</a> than they were just four decades ago, and they tend to be hotter and last longer. We’re at the point now that some places in the world are anticipating coral bleaching every couple of years.</p>
<p>That increasing frequency of heat waves is a death knell for reefs. They don’t have time to recover before they get hit again.</p>
<p><iframe id="IS1fT" class="tc-infographic-datawrapper" src="https://datawrapper.dwcdn.net/IS1fT/4/" height="400px" width="100%" style="border: none" frameborder="0"></iframe></p>
<h2>Where we saw signs of hope</h2>
<p>During the <a href="https://www.livingoceansfoundation.org/global-reef-expedition/global-reef-expedition-final-reports/">Global Reef Expedition</a>, we visited over 1,000 reefs around the world. Our mission was to conduct standardized surveys to assess the state of the reefs and map the reefs in detail so scientists could document and hopefully respond to changes in the future. With that knowledge, countries can plan more effectively to protect the reefs, important national resources, providing <a href="https://reefresilience.org/value-of-reefs/">hundreds of billions of dollars a year</a> in economic value while also <a href="https://oceanservice.noaa.gov/facts/coral_protect.html">protecting coastlines</a> from waves and storms.</p>
<p>We saw damage almost everywhere, from the <a href="https://www.livingoceansfoundation.org/global-reef-expedition/atlantic-ocean/inaguas-bahamas/">Bahamas</a> to the <a href="https://www.youtube.com/watch?v=7yisyMO-Xi0">Great Barrier Reef</a>.</p>
<p>Some reefs are able to survive heat waves better than others. Cooler, stronger currents, and even storms and cloudier areas can help prevent heat building up. But the global trend is not promising. The world has already <a href="https://www.nationalacademies.org/news/2019/06/protecting-coral-reefs-in-a-deteriorating-environment">lost 30% to 50% of its reefs</a> in the last 40 years, and scientists have warned that most of the remaining reefs <a href="https://www.ipcc.ch/2018/10/08/summary-for-policymakers-of-ipcc-special-report-on-global-warming-of-1-5c-approved-by-governments/">could be gone within decades</a>.</p>
<figure class="align-center ">
<img alt="Flat corals turning white as they bleach" src="https://images.theconversation.com/files/397202/original/file-20210426-21-nq77pb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/397202/original/file-20210426-21-nq77pb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/397202/original/file-20210426-21-nq77pb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/397202/original/file-20210426-21-nq77pb.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/397202/original/file-20210426-21-nq77pb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/397202/original/file-20210426-21-nq77pb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/397202/original/file-20210426-21-nq77pb.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Table corals bleaching in the Chagos Reef.</span>
<span class="attribution"><a class="source" href="https://www.livingoceansfoundation.org/publication/global-reef-expedition-chagos-archipelago-final-report/">Derek Manzello/Khaled bin Sultan Living Oceans Foundation</a></span>
</figcaption>
</figure>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/397179/original/file-20210426-21-1l2ahj7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Diver with large sea turtle swimming over corals." src="https://images.theconversation.com/files/397179/original/file-20210426-21-1l2ahj7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/397179/original/file-20210426-21-1l2ahj7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/397179/original/file-20210426-21-1l2ahj7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/397179/original/file-20210426-21-1l2ahj7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/397179/original/file-20210426-21-1l2ahj7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/397179/original/file-20210426-21-1l2ahj7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/397179/original/file-20210426-21-1l2ahj7.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 author, Sam Purkis, dives near a hawksbill turtle in the Chagos Archipelago.</span>
<span class="attribution"><a class="source" href="https://www.livingoceansfoundation.org/publication/global-reef-expedition-chagos-archipelago-final-report/">Derek Manzello/Khaled bin Sultan Living Oceans Foundation</a></span>
</figcaption>
</figure>
<p>While we see some evidence that certain marine species are <a href="https://phys.org/news/2021-04-climate-marine-species-poleward.html">moving to cooler waters</a> as the planet warms, a reef takes thousands of years to establish and grow, and it is limited by geography.</p>
<p>In the areas where we saw glimmers of hope, it was mostly due to good management. When a region can control other harmful human factors – such as overfishing, extensive coastal development, pollution and runoff – the <a href="https://blogs.scientificamerican.com/observations/a-bulwark-against-reef-destruction-in-a-warming-world/">reefs are healthier</a> and better able to handle the global pressures from climate change.</p>
<p>Establishing large marine protected areas is one of the most effective ways I’ve seen to <a href="http://doi.org/10.1098/rstb.2015.0210">protect coral reefs</a> because it limits those other harms.</p>
<figure class="align-center ">
<img alt="Pointed-nose fish among coral branches" src="https://images.theconversation.com/files/397195/original/file-20210426-19-7dtogm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/397195/original/file-20210426-19-7dtogm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/397195/original/file-20210426-19-7dtogm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/397195/original/file-20210426-19-7dtogm.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/397195/original/file-20210426-19-7dtogm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/397195/original/file-20210426-19-7dtogm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/397195/original/file-20210426-19-7dtogm.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">Coral reefs are fish nurseries and feeding grounds. They also protect coast lines from storms and waves.</span>
<span class="attribution"><a class="source" href="https://www.livingoceansfoundation.org/publication/global-reef-expedition-chagos-archipelago-final-report/">Stephan Andrews/Khaled bin Sultan Living Oceans Foundation</a></span>
</figcaption>
</figure>
<figure class="align-center ">
<img alt="Brilliant blue fish swim in a coral reef" src="https://images.theconversation.com/files/397205/original/file-20210426-15-15m16st.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/397205/original/file-20210426-15-15m16st.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/397205/original/file-20210426-15-15m16st.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/397205/original/file-20210426-15-15m16st.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/397205/original/file-20210426-15-15m16st.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/397205/original/file-20210426-15-15m16st.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/397205/original/file-20210426-15-15m16st.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Some of the diversity of the Chagos Reef.</span>
<span class="attribution"><a class="source" href="https://www.livingoceansfoundation.org/publication/global-reef-expedition-chagos-archipelago-final-report/">Derek Manzello/Khaled bin Sultan Living Oceans Foundation</a></span>
</figcaption>
</figure>
<p>The Chagos marine protected area covers 640,000 square kilometers (250,000 square miles) with only one island currently inhabited – Diego Garcia, which houses a U.S. military base. The British government, which created the marine protected area in 2010, has been <a href="https://www.lawfareblog.com/chagos-archipelago-dispute-law-diplomacy-and-military-basing">under pressure to turn over control of the region</a> to the country of Mauritius, where former Chagos residents now live and which won a challenge over it in the International Court of Justice in 2020. Whatever happens with jurisdiction, the region would benefit from maintaining a high level of marine protection.</p>
<h2>A warning for other ecosystems</h2>
<p>The Chagos reefs could potentially recover – if they are spared from more heat waves. Even a 10% recovery would make the reefs stronger for when the next bleaching occurs. But recovery of a reef is measured in decades, not years.</p>
<p>So far, research missions that have returned to the Chagos reefs have found only meager recovery, if any at all.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/397198/original/file-20210426-21-txmdaj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Large fish and schools of fish swimming above the reef" src="https://images.theconversation.com/files/397198/original/file-20210426-21-txmdaj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/397198/original/file-20210426-21-txmdaj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/397198/original/file-20210426-21-txmdaj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/397198/original/file-20210426-21-txmdaj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/397198/original/file-20210426-21-txmdaj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/397198/original/file-20210426-21-txmdaj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/397198/original/file-20210426-21-txmdaj.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 Chagos Archipelago is home to some 800 species of fish, including rays, skates and dozens of varieties of shark.</span>
<span class="attribution"><a class="source" href="https://www.livingoceansfoundation.org/publication/global-reef-expedition-chagos-archipelago-final-report/">Phil Renaud/Khaled bin Sultan Living Oceans Foundation</a></span>
</figcaption>
</figure>
<p>We knew the reefs weren’t doing well under the insidious march of climate change in 2011, when the global reef expedition started. But it’s nothing like the intensity of worry we have now in 2021.</p>
<p>Coral reefs are the canary in the coal mine. Humans have collapsed other ecosystems before through overfishing, overhunting and development, but this is the first unequivocally tied to climate change. It’s a harbinger of what can happen to other ecosystems as they reach their survival thresholds.</p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/369797/original/file-20201117-13-180ibt9.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/369797/original/file-20201117-13-180ibt9.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/369797/original/file-20201117-13-180ibt9.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/369797/original/file-20201117-13-180ibt9.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/369797/original/file-20201117-13-180ibt9.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=504&fit=crop&dpr=1 754w, https://images.theconversation.com/files/369797/original/file-20201117-13-180ibt9.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=504&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/369797/original/file-20201117-13-180ibt9.png?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">
<figcaption>
<span class="caption"></span>
</figcaption>
</figure>
<p><strong><em>This story is part of <a href="https://theconversation.com/uk/topics/oceans-21-96784">Oceans 21</a></em></strong>
<br><em>Our series on the global ocean opened with <a href="https://oceans21.netlify.app/">five in-depth profiles</a>. Look for new articles on the state of our oceans in the lead-up to the U.N.’s next climate conference, COP26. The series is brought to you by The Conversation’s international network.</em></p><img src="https://counter.theconversation.com/content/159792/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Sam Purkis 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 their academic appointment.</span></em></p>Scientists watched in real time as rising ocean heat transformed the sprawling reef. It was a harbinger for ecosystems everywhere as the planet warms.Sam Purkis, Professor and Chair of the Department of Marine Sciences, University of MiamiLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1515482020-12-06T10:04:00Z2020-12-06T10:04:00ZThe world’s ocean is bearing the brunt of a changing climate. Explore its past and future in our new series<figure><img src="https://images.theconversation.com/files/373170/original/file-20201205-19-1454wc2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">shutterstock</span> </figcaption></figure><p><em>Oceans 21 is a Conversation international series examining the history and future of the world’s ocean.</em></p>
<p><em>Five profiles open our series on the global ocean, delving into ancient Indian Ocean trade networks, Pacific plastic pollution, Arctic light and life, Atlantic fisheries and the Southern Ocean’s impact on global climate.</em></p>
<p><em>Explore the series in the link below.</em></p>
<hr>
<p><a href="https://oceans21.netlify.app" target="_blank"><img src="https://images.theconversation.com/files/373165/original/file-20201205-23-zcoc96.png" width="100%"></a></p>
<hr>
<p><em>Thanks to Hannah Hoag, Jack Marley, Nicole Hasham, Fidelis Satriastanti, Jennifer Weeks, Jennifer Gallé, Nontobeko Mtshali, Veronika Meduna, Wes Mountain, Lucía Caballero.</em></p><img src="https://counter.theconversation.com/content/151548/count.gif" alt="The Conversation" width="1" height="1" />
Oceans 21 is a Conversation international series examining the history and future of the world’s ocean.Wes Mountain, Social Media + Visual Storytelling EditorLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1449542020-08-25T14:25:27Z2020-08-25T14:25:27ZMauritius oil spill: how coral reefs, mangroves and seagrass could be affected<figure><img src="https://images.theconversation.com/files/354570/original/file-20200825-25-gudszl.jpg?ixlib=rb-1.1.0&rect=0%2C667%2C7636%2C4450&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/volunteers-clean-ocean-coast-oil-after-1801591885">Ohrim/Shutterstock</a></span></figcaption></figure><p>Sometimes bad things happen in the worst possible places – like the MV Wakashio running aground on shallow reefs off the south-east coast of Mauritius on July 25. The wreck of the bulk carrier ship began leaking oil in front of a nature reserve island (Ile aux Aigrettes), a couple of kilometres from a marine park (Blue Bay), and close to an internationally important wetland area (Pointe d’Esny Ramsar Site). </p>
<p>The MV Wakashio was carrying 4,000 tonnes of oil, which hardly compares to the 400,000 tonnes spilled in the Deepwater Horizon disaster of 2010. But it was the vessel’s proximity to the globally recognised cluster of ecosystems in Mauritius that means this spill could have long lasting consequences.</p>
<p>Mauritius is a biodiversity hotspot and much of the island’s unique wildlife depends on intricate connections between the reefs, lagoons, seagrass meadows and mangroves, so pollution in one habitat can have a devastating ripple effect.</p>
<p>With that in mind, what does the recent oil spill mean for the environment here?</p>
<h2>What happens during an oil spill?</h2>
<p>As soon as oil enters the ocean, lighter compounds in the fuel evaporate and the surrounding air can become toxic to wildlife and even harmful to human health. Oil slicks form on the sea surface and are carried away from the spill site.</p>
<p>When reefs and other habitats are nearby, it’s this early window that is most crucial for preventing damage. Containing the spill with booms or collecting the oil while it is on the surface with <a href="https://www.epa.gov/emergency-response/skimmers">skimmers</a> can help stop it spreading. </p>
<p>As the lighter components of the oil evaporate, a heavy sludge forms and can be carried by the tide towards the coastline. Washed up, it effectively smothers any organism it touches, including corals, fish and seabirds, while toxic compounds accumulate in their tissues. Eventually, microbes will break down the remaining oil, but this may take many years.</p>
<h2>Connections in coastal ecosystems</h2>
<p>More than 500 metres of coral reef are thought to have been <a href="https://www.scientificamerican.com/article/mauritians-launch-rescue-to-save-wildlife-from-oil-spill/">destroyed</a> by the ship as it ran aground, but this is just the beginning. </p>
<p>As the oil sinks, it can cover more of the reef. Corals depend on sunlight for sustenance but they also eat floating microorganisms called zooplankton. Aside from clouding the water and reducing sunlight, oil pollution has been shown to <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3696092/">kill zooplankton</a>, while the toxic chemicals in crude oil weaken the ability of corals to photosynthesise. Deep water corals coated in oil experienced <a href="https://www.pnas.org/content/pnas/109/50/20303.full.pdf">tissue swelling and ruptures</a>.</p>
<p>In the years following an oil spill, growth and reproduction is reduced, leaving less live coral <a href="https://www.int-res.com/articles/meps/105/m105p231.pdf">on reefs</a>. In spite of this, coral reefs are resilient ecosystems and can recover to pre-disaster conditions over several decades, as long-term research following an oil spill in 1986 off the coast of <a href="https://link.springer.com/article/10.1007/s12526-020-01057-9">Panama</a> showed. </p>
<p>Key to that recovery are the efforts of local species. Parrotfish, for example, provide an <a href="https://www.int-res.com/articles/ab2012/15/b015p087.pdf">essential service</a> to reefs on the south-east coast of Mauritius by eating seaweeds that could otherwise choke and consume the coral when it’s weakened by pollution. But they don’t spend their whole lives doing this, they’re born and raised in nearby mangroves and seagrass beds. </p>
<figure class="align-center ">
<img alt="Colourful parrotfish nibble seaweed on a tropical coral reef." src="https://images.theconversation.com/files/354589/original/file-20200825-20-1fp5476.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/354589/original/file-20200825-20-1fp5476.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/354589/original/file-20200825-20-1fp5476.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/354589/original/file-20200825-20-1fp5476.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/354589/original/file-20200825-20-1fp5476.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/354589/original/file-20200825-20-1fp5476.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/354589/original/file-20200825-20-1fp5476.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Adult parrotfish graze coral reefs to keep them healthy, but they depend on other habitats to raise their young.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/colorful-parrotfish-feeding-on-tropical-coral-1266791950">Richard Whitcombe/Shutterstock</a></span>
</figcaption>
</figure>
<p>Mangrove forests are coastal wetlands comprised of a dense jumble of trees that thrive in salt water. Their tangled roots form almost impenetrable mazes that offer nursery habitats for parrotfish, snappers, jacks, barracudas and even sharks. Here, young reef fish can grow up safe beyond the reach of larger predators. </p>
<p>Seagrass form underwater plains of flowering plants. They are another kind of nursery refuge for ocean life, but, <a href="https://www.taylorfrancis.com/books/e/9781315368597">like mangroves</a>, they struggle to <a href="http://www.prppg.ufpr.br/ppgecologia/wp-content/uploads/2016/08/duke_2016.pdf">recover</a> from oil pollution. Both habitats tend to flourish where waves and tides are gentle. Sediment builds up around them and so does oil sludge. </p>
<figure class="align-center ">
<img alt="A juvenile lemon shark swims between mangrove roots in shallow coastal water." src="https://images.theconversation.com/files/354591/original/file-20200825-20-1ncyh15.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/354591/original/file-20200825-20-1ncyh15.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=404&fit=crop&dpr=1 600w, https://images.theconversation.com/files/354591/original/file-20200825-20-1ncyh15.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=404&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/354591/original/file-20200825-20-1ncyh15.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=404&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/354591/original/file-20200825-20-1ncyh15.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=508&fit=crop&dpr=1 754w, https://images.theconversation.com/files/354591/original/file-20200825-20-1ncyh15.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=508&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/354591/original/file-20200825-20-1ncyh15.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=508&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The ocean’s large predators often start life in shallow habitats like mangrove forests.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/juvenile-lemon-shark-swimming-shallow-clear-1218561280">Anita Kainrath/Shutterstock</a></span>
</figcaption>
</figure>
<p>Aside from nurturing future generations of coral reef fish, mangroves and seagrass meadows trap material that runs off the land, providing clearer coastal waters over reefs. In turn, reefs absorb the energy of waves from the open ocean, protecting mangroves and beaches from erosion.</p>
<p>Marine life in places like Mauritius rely on all three ecosystems, and species often reside in one while feeding in another. This ensures a steady flow of nutrients between them. Seabirds nesting in mangroves feed on seagrass meadows and their organic waste is carried onto reefs where it nourishes organisms there. </p>
<p>These connections mean that if one ecosystem is damaged, the others are also affected. This ensures that the effects of oil spills are often more severe than they might first appear. Only by monitoring and protecting each of these ecosystems can there be any hope for long-term recovery in the region.</p><img src="https://counter.theconversation.com/content/144954/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>John Turner has received collaborative funding from the British Council, Mauritius Research Council, Waste Water Management Authority and Royal Geographical Society. </span></em></p><p class="fine-print"><em><span>Ronan Roche and Sivajyodee Sannassy Pilly do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Marine wildlife rarely remain in one habitat. Most species rely on a healthy network of ecosystems to raise their young and catch their food.Sivajyodee Sannassy Pilly, PhD Candidate in Marine Ecology, Bangor UniversityJohn Turner, Professor of Marine Biology and Head of School of Ocean Sciences, Bangor UniversityRonan Roche, Research Fellow in Marine Science, Bangor UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1447492020-08-19T14:31:10Z2020-08-19T14:31:10ZPasha 77: Explainer: the oil spill in Mauritius<figure><img src="https://images.theconversation.com/files/353594/original/file-20200819-24-d65qyn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">GettyImages</span> </figcaption></figure><p>This is not the first time a ship has run aground in Mauritius, the island nation 2,000 kilometres off the south-east coast of Africa. But how and why did it happen again? Could the government have done more to prevent the spillage that is wreaking havoc on the coastal systems? What will the impact be for the biodiversity? What will it take to clean up this mess and avoid situations like these in the future? </p>
<p>In today’s episode of Pasha, Adam Moolna, a lecturer in environment and sustainability at Keele University, answers these and other questions on the Mauritian oil spill disaster. </p>
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Read more:
<a href="https://theconversation.com/mauritius-is-reeling-from-a-spreading-oil-spill-and-people-are-angry-with-how-the-government-has-handled-it-144288">Mauritius is reeling from a spreading oil spill – and people are angry with how the government has handled it</a>
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<p><strong>Photo:</strong>
“A picture taken on August 15, 2020 shows the partially submerged Japanese owned Panama-flagged bulk carrier MV Wakashio as the mid section of the vessel broke in two near Blue Bay Marine Park off the coast of south-east Mauritius. Rough seas have since hampered efforts to stop fuel leaking from the bulk carrier and staining pristine waters in an ecologically protected marine area. By <a href="https://www.gettyimages.com/detail/news-photo/picture-taken-on-august-15-2020-shows-the-partially-news-photo/1228058064?adppopup=true">Getty Images</a></p>
<p><strong>Music</strong>
"Happy African Village” by John Bartmann, found on <a href="http://freemusicarchive.org/music/John_Bartmann/Public_Domain_Soundtrack_Music_Album_One/happy-african-village">FreeMusicArchive.org</a> licensed under <a href="https://creativecommons.org/publicdomain/zero/1.0/">CC0 1</a>.</p>
<p>“Sad_Drama_Romantic_Stinger” by SoundFlakes, found on <a href="https://freesound.org/people/SoundFlakes/sounds/413732/">Freesound</a> licensed under <a href="http://creativecommons.org/licenses/by/3.0/">Attribution license</a>.</p><img src="https://counter.theconversation.com/content/144749/count.gif" alt="The Conversation" width="1" height="1" />
After the oil spill, the usual sight of families strolling by the sea was quickly replaced by volunteers working hard in a concerted effort to protect their coast.Ozayr Patel, Digital EditorLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1424872020-08-10T13:02:39Z2020-08-10T13:02:39ZKenya’s coast is losing huge amounts of seagrass. But all isn’t lost<figure><img src="https://images.theconversation.com/files/346898/original/file-20200710-26-dbju1p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Seagrasses support a wide variety of life</span> <span class="attribution"><span class="source">Reinhard Dirscherl/ullstein bild via Getty Image</span></span></figcaption></figure><p><em>The UN environmental programme has released <a href="https://www.unenvironment.org/resources/report/out-blue-value-seagrasses-environment-and-people#:%7E:text=Portugu%C3%AAs-,Out%20of%20the%20Blue%3A%20The%20Value%20of%20Seagrasses,the%20Environment%20and%20to%20People&text=They%20contribute%20to%20community%20well,or%20carbon%20sequestration%20and%20storage.">a report</a> warning that fishing trawlers, seaweed farming, and tourism off the coast of Kenya is threatening the survival of seagrasses. Moina Spooner, from The Conversation Africa, asked Lillian Daudi to explain why the grasses are important and what must be done to protect them.</em></p>
<p><strong>What is seagrass and why is it important?</strong></p>
<p>Seagrasses are flowering marine plants that have adapted to survive in marine conditions. They are mostly found in shallow sandy bottom habitats and can form dense extensive meadows. </p>
<p>There are about <a href="https://ocean.si.edu/ocean-life/plants-algae/seagrass-and-seagrass-beds">72 seagrass species</a> distributed across the world’s temperate and tropical oceans. These meadows trap sediment, absorb nutrients and give us clear waters.</p>
<p>They’re a source of food, shelter and nursery areas for many organisms, including commercially important fish. This means that they provide food security for coastal communities by supporting artisanal fisheries and are an integral part of coastal livelihoods. They also support a number of endangered species such as dugongs, sea turtles and sea horses. </p>
<p>Seagrass meadows are also <a href="https://medium.com/@FORESIGHT_ClimateEnergy/seagrass-beats-rainforests-as-carbon-sink-736815319121">important carbon sinks</a>, capable of trapping carbon from the atmosphere 40 times faster than tropical rainforests and storing it for hundreds of years. </p>
<p><strong>What’s happening to it along the coast of Kenya?</strong></p>
<p>There are <a href="https://www.researchgate.net/publication/305402549_The_Seagrasses_of_Kenya_and_Tanzania">about 12 species</a> of seagrasses distributed along the Kenyan coast. According to the <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6283928/">latest research</a> (published about two years ago), seagrasses along the Kenyan coast covers an area of about 317km². </p>
<p>But these meadows are subject to frequent disturbance. For instance people disturb sediment on the seabed which suffocates the seagrass, or they damage the seagrass by trampling it. There are also natural disturbances, such as grazing by sea urchins. In some areas this has led to the total loss of seagrass. </p>
<p>Overgrazing, in particular by the collector sea urchin, has been a <a href="https://www.int-res.com/articles/meps/226/m226p255.pdf">major factor</a> in how seagrass is distributed along the Kenyan coast. This is because there’s been a fast rise in <a href="https://link.springer.com/article/10.1007/BF00317561">sea urchin populations</a> which I believe is due to overfishing. Fish, such as the parrot fish, are the natural predators of sea urchins. </p>
<p>When urchin populations are high (about eight or more urchins per m²), they move in aggregations and can clear seagrass shoots <a href="https://www.int-res.com/articles/meps/226/m226p255.pdf">at the rate of</a> five shoots per day per urchin. In Kenya, they have been reported to move in aggregations of up to 137 urchins per 10m², consuming huge <a href="https://www.int-res.com/articles/meps2002/226/m226p255.pdf">amounts</a> of seagrass. </p>
<p>For instance, in Kenya’s north-coast area of Watamu and Malindi <a href="https://www.oceandocs.org/bitstream/handle/1834/7803/ktf000e4.pdf?sequence=1">about</a> 4.6% of seagrass is lost each year to urchins. </p>
<p><strong>Is there any indication of how much is being lost and what type of effects will this loss have?</strong></p>
<p>Between 1986 and 2016 – a period of 30 years – Kenya lost <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6283928/">about</a> 21% of its seagrass cover. The intensity and frequency of seagrass loss varies along the coastline. Some areas show signs of natural recovery while others have become altered habitats with a different composition of seagrass species. </p>
<p>The disturbance of seagrass meadows has caused fragmentation of continuous seagrass beds. These shallow ecosystems support most artisanal fishermen along the Kenyan coast, providing important habitats for fish, including rabbit and seagrass parrot fish. </p>
<p>Ongoing <a href="https://www.kmfri.co.ke/index.php/about-us/research-centres/mombasa-research-centre">research work</a> in my department at the Kenya Marine and Fisheries Research Institute shows that these losses may, in the long term, affect the dynamics of the food webs, especially the fish supported by these meadows, such as parrot fish.</p>
<p><strong>Is enough being done to protect these grasses?</strong></p>
<p>There are several efforts towards the protection of seagrasses.</p>
<p>Over the last decade researchers at the <a href="https://www.kmfri.co.ke/">Kenya Marine and Fisheries Research Institute</a> have been conducting research on seagrasses. This research supports the activities of various organisations responsible for the protection of seagrasses. </p>
<p>For five years, there have been <a href="https://www.nairobiconvention.org/CHM%20Documents/WIOSAP/WIOSAP%20docs%20for%20website/Third%20WIOSAP%20PSC/Seagrass%20Restoration%20Guideline_v06_REVISION.pdf">efforts</a> to protect seagrasses through restoration trials carried out by the Kenya Marine and Fisheries Research Institute. These trials provided data on the best species to use, the most cost effective ways and implications of restoration efforts. These trials are important to recolonise areas that have lost grass and increasing meadows. So far, the one that’s shown the greatest success involved planting seagrass seedlings in punched holes in large bags on the ocean floor.</p>
<p>Kenya’s seagrass rehabilitation efforts are commendable and <a href="http://nairobiconvention.org/Meeting%20Documents/June%202019/WIOSAP%20Third%20Project%20Steering%20Committee%20Meeting/Day%202%20Presentations/Seagrass%20Restoration%20Guideline_FINAL_26062019.pdf">contributed to</a> the development of seagrass ecosystem restoration guidelines for the Western Indian Ocean region, supported by the United Nations Environment Programme. </p>
<p>There are also encouraging signs from government as there are <a href="https://www.pd.co.ke/lifestyle/conserving-neglected-yet-vital-seagrass-38801/">currently efforts</a> to review and implement the national coral reef and seagrass conservation and management strategy.</p>
<p>There are still some challenges when it comes to managing and protecting seagrasses, because we’re still not sure of the distribution and actual cover estimates of seagrass along the coast. This requires sound techniques such as remote sensing and remotely operated vehicles that are now underway to enable mapping and monitoring of changes to seagrass beds over time. Until this happens, there’s no certainty about which conservation strategies do or don’t work.</p>
<p>The future is bright since the capacity in seagrass research has grown over the years, especially as more scientists have developed a passion for exploring these unique habitats.</p><img src="https://counter.theconversation.com/content/142487/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Lillian Daudi receives funding from the Kenyan Government and donors affiliated to Kenya Marine and Fisheries Research Institute. </span></em></p>Between 1986 and 2016, Kenya lost about 21 of its seagrasses.Lillian Daudi, Scientist, Kenya Marine and Fisheries Research InstituteLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1338172020-06-07T08:53:26Z2020-06-07T08:53:26ZExploring the Indian Ocean as a rich archive of history – above and below the water line<figure><img src="https://images.theconversation.com/files/339216/original/file-20200602-133866-18vt4bh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>On many beaches around the Indian Ocean, keen observers may spot bits of broken pottery. Washed smooth by the ocean, these shards are in all likelihood hundreds of years old, from centres of ceramic production like the <a href="https://en.wikipedia.org/wiki/Abbasid_Caliphate">Middle Eastern Abbasid caliphate</a> and the <a href="https://www.history.com/topics/ancient-china/ming-dynasty">Chinese Ming dynasty</a>. </p>
<p>Originally destined for Indian Ocean port cities, this pottery would have been purchased by merchant elites accustomed to eating off fine plates. These traders formed part of <a href="https://en.wikipedia.org/wiki/Indian_Ocean_trade">vast commercial networks</a> that crisscrossed the Indian Ocean arena and beyond, from East Africa to Indonesia, the Middle East and China. </p>
<p>These trade networks stretched back thousands of years, powered by the monsoon winds. Reversing direction in different seasons, these winds have long shaped the rhythm of life around the ocean, bringing rain to farmers, filling the sails of dhows and enabling trade between different ecological zones.</p>
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<p><strong><em>This story is part of <a href="https://theconversation.com/uk/topics/oceans-21-96784">Oceans 21</a></em></strong>
<br><em><a href="https://oceans21.netlify.app/">Five profiles open our series on the global ocean</a>, delving into ancient <a href="https://theconversation.com/exploring-the-indian-ocean-as-a-rich-archive-of-history-above-and-below-the-water-line-133817">Indian Ocean</a> trade networks, <a href="https://theconversation.com/it-might-be-the-worlds-biggest-ocean-but-the-mighty-pacific-is-in-peril-150745">Pacific</a> plastic pollution, <a href="https://theconversation.com/arctic-ocean-climate-change-is-flooding-the-remote-north-with-light-and-new-species-150157">Arctic</a> light and life, <a href="https://theconversation.com/the-atlantic-the-driving-force-behind-ocean-circulation-and-our-taste-for-cod-146534">Atlantic</a> fisheries and the <a href="https://theconversation.com/an-ocean-like-no-other-the-southern-oceans-ecological-richness-and-significance-for-global-climate-151084">Southern Ocean</a>’s impact on global climate. Look out for new articles in the lead up to COP26. Brought to you by The Conversation’s international network.</em></p>
<p>The monsoon wind pattern makes the Indian Ocean relatively easy to cross both ways. In the Atlantic, by contrast, winds blow in one direction all year round. That’s why the Indian Ocean is the world’s oldest long-distance trans-oceanic trading arena, and is sometimes known as the <a href="https://books.google.co.za/books/about/Indian_Ocean_Studies.html?id=_Yu7CGaIWkEC&redir_esc=y">cradle of globalisation</a>.</p>
<p>This cosmopolitan world has long fascinated scholars and has become a vibrant domain of research. Yet this work has had little to say about the sea itself. Its focus is on human movement with the ocean as a passive backdrop. In the age of <a href="https://theconversation.com/half-of-worlds-sandy-beaches-could-disappear-due-to-sea-level-rise-by-2100-132688">rising sea levels and climate change</a>, it’s important to learn more about the sea from a material and ecological point of view.</p>
<p>Over the past few years, this situation has started to shift. In this article we survey both the older and the newer forms of Indian Ocean studies, of surface and depth.</p>
<h2>Surface histories of the Indian Ocean</h2>
<p>Given the long millennia of trade and exchange, one key concern of Indian Ocean studies has been a focus on cultural interaction. Cities on the shores have sustained deep forms of material, intellectual and cultural exchange, so that the denizens of these ports had more in common with each other than with their fellows inland. </p>
<p>This early cosmopolitan world has famously been explored in Amitav Ghosh’s <a href="https://www.penguinrandomhouse.com/books/59434/in-an-antique-land-by-amitav-ghosh/"><em>In an Antique Land</em></a>, which traces the travels of Abram bin Yiju, a 12th century Jewish Tunisian merchant based in Cairo and later in Mangalore, India. The book contrasts the rigidity of borders in the 1980s with the relative ease of movement in the late medieval Indian Ocean. </p>
<p>The Swahili coast provides another famed example of Indian Ocean cosmopolitanism. Stretching a thousand miles from Somalia to Mozambique, Swahili society arose from centuries of interaction between Africa, the Middle East and Asia. </p>
<p>Centred on coastal city states like Kilwa, Zanzibar and Lamu, Swahili trade networks reached far inland to present day <a href="https://www.metmuseum.org/toah/hd/mapu/hd_mapu.htm">Zimbabwe</a> and outward to Persia, India and China. After reaching their height from the <a href="https://en.wikipedia.org/wiki/Swahili_coast">12th to the 15th</a> centuries, these city states were eventually undone by the Portuguese, who arrived from the early 16th century, seeking to establish a monopoly of the spice trade. </p>
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<img alt="" src="https://images.theconversation.com/files/339226/original/file-20200602-133933-1lsl2xr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/339226/original/file-20200602-133933-1lsl2xr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=247&fit=crop&dpr=1 600w, https://images.theconversation.com/files/339226/original/file-20200602-133933-1lsl2xr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=247&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/339226/original/file-20200602-133933-1lsl2xr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=247&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/339226/original/file-20200602-133933-1lsl2xr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=311&fit=crop&dpr=1 754w, https://images.theconversation.com/files/339226/original/file-20200602-133933-1lsl2xr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=311&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/339226/original/file-20200602-133933-1lsl2xr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=311&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">Zanzibar, Tanzania.</span>
<span class="attribution"><span class="source">GettyImages</span></span>
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<p>Central to these histories of mobility and exchange in the Indian Ocean has been the spread of Islam across land and sea from the <a href="http://www.oxfordislamicstudies.com/article/opr/t253/e17">7th century CE</a>. By the 14th century, mercantile networks around the Indian Ocean were almost entirely in the hands of Muslim traders. </p>
<p>In their wake came scholars, theologians, pilgrims, clerks, legal pundits and Sufi divines. Together, these groups created a shared economic, spiritual and legal frameworks. Sufism, a mystical form of Islam is an important strand in the Indian Ocean histories, as is the centrifugal power of the <a href="https://www.bbc.co.uk/newsround/24566691">Hajj</a> pilgrimage to Mecca. </p>
<h2>European Colonisation along the Indian Ocean</h2>
<p>When the Portuguese rounded the Cape in the late 15th century, they entered what many have termed a Muslim Lake, dominated in the north by the Turkish Ottoman, Persian Safavid and Indian Mughal empires. When the Dutch arrived in the Indian Ocean in the <a href="https://books.google.co.za/books?id=R6cwDwAAQBAJ&pg=PA98&lpg=PA98&dq=they+were+able+to+go+from+one+end+of+it+to+another+by+carrying+letters+of+introduction+from+Muslim+sultans+on+various+shores&source=bl&ots=SqIZVHCG_O&sig=ACfU3U2NefNFKvhTRJp_6HV0dirVQFjtew&hl=en&sa=X&ved=2ahUKEwik2djp0KHoAhUOuRoKHRWkDT8Q6AEwAHoECAgQAQ#v=onepage&q=they%20were%20able%20to%20go%20from%20one%20end%20of%20it%20to%20another%20by%20carrying%20letters%20of%20introduction%20from%20Muslim%20sultans%20on%20various%20shores&f=false">17th century,</a> “they were able to go from one end of it to another by carrying letters of introduction from Muslim sultans on various shores”.</p>
<p>As Engseng Ho has <a href="https://books.google.co.za/books?id=YMcZU0VHdG0C&printsec=frontcover&source=gbs_ge_summary_r&cad=0#v=onepage&q&f=false">indicated</a>, these sprawling networks of Muslim commerce operated <a href="https://books.google.co.za/books?id=YMcZU0VHdG0C&pg=PR21&lpg=PR21&dq=The+Portuguese,+Dutch+and+English+in+the+Indian+Ocean+were+strange+new+traders+who+brought+their+states+with+them.+They+created+militarised+trading-post+empires+in+the+Indian+Ocean,+following+Venetian+and+Genoese+precedents+in+the+Mediterranean,+and+were+wont+to+do+business+at+the+point+of+a+gun&source=bl&ots=oVswsYMqAj&sig=ACfU3U1hc_GR8YBw-GO2OQgM1WhG7bOabA&hl=en&sa=X&ved=2ahUKEwj385C90aHoAhURaBoKHfPhCn8Q6AEwAHoECAkQAQ#v=onepage&q=The%20Portuguese%2C%20Dutch%20and%20English%20in%20the%20Indian%20Ocean%20were%20strange%20new%20traders%20who%20brought%20their%20states%20with%20them.%20They%20created%20militarised%20trading-post%20empires%20in%20the%20Indian%20Ocean%2C%20following%20Venetian%20and%20Genoese%20precedents%20in%20the%20Mediterranean%2C%20and%20were%20wont%20to%20do%20business%20at%20the%20point%20of%20a%20gun&f=false">without the backing</a> of an army or a state. </p>
<blockquote>
<p>The Portuguese, Dutch and English in the Indian Ocean were strange new traders who brought their states with them. They created militarised trading-post empires in the Indian Ocean, following Venetian and Genoese precedents in the Mediterranean, and were wont to do business at the point of a gun. </p>
</blockquote>
<p>Early European entrants to the Indian Ocean world initially had to adapt to the trading orders that they encountered. But by the 19th century, European empires <a href="https://en.wikipedia.org/wiki/New_Imperialism">dominated</a>. Their military, transport and communication infrastructure intensified the movement of people across the Indian Ocean world. </p>
<p>As Clare Anderson has <a href="https://books.google.co.za/books/about/Legible_Bodies.html?id=1LkEAQAAIAAJ&redir_esc=y">demonstrated</a>, much of this mobility was forced and conscripted. It involved slaves, indentured labourers, political exiles and prisoners who were transported between regions. At times, these systems built on existing foundations of labour exploitation. As recent research <a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1478-0542.2006.00346.x">indicates</a>, South Asian indentured labour was often taken from regions in India where slavery existed. Old and new systems of unfree labour produced an archipelago of prisons, plantations and penal colonies. </p>
<p>As an archive, the Indian Ocean provides a new way of looking at world history, that has previously been dominated by European accounts. The age of European empires is only one tiny sliver of time in a much longer arc. A view from the Indian Ocean unsettles ideas of the relationship between European colonisers and colonised groups. </p>
<p>As historians like Engseng Ho and Sugata Bose have <a href="https://books.google.co.za/books/about/A_Hundred_Horizons.html?id=BPpZJDc6LIMC&redir_esc=y">argued</a>, the Indian Ocean world was an arena of competing claims. </p>
<p>The ambitions of British imperialism, for example, were countered by the equally grand visions of Islam. Indeed, the Indian Ocean arena produced a rich repertoire of transoceanic ideologies, including Hindu reformism and pan-Buddhism. </p>
<p>Such ideologies eventually acquired an anti-imperial character which also fed into ideas of Afro-Asian solidarity and non-alignment. These arose from the <a href="https://en.wikipedia.org/wiki/Bandung_Conference">Bandung Conference</a> in 1955 at which 29 newly independent nations gathered to forge a new path rather than falling in line with either of the rival camps in the emerging Cold War. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/339238/original/file-20200602-133924-1l7rs6c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/339238/original/file-20200602-133924-1l7rs6c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=343&fit=crop&dpr=1 600w, https://images.theconversation.com/files/339238/original/file-20200602-133924-1l7rs6c.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=343&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/339238/original/file-20200602-133924-1l7rs6c.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=343&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/339238/original/file-20200602-133924-1l7rs6c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=431&fit=crop&dpr=1 754w, https://images.theconversation.com/files/339238/original/file-20200602-133924-1l7rs6c.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=431&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/339238/original/file-20200602-133924-1l7rs6c.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=431&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The Belt and Road Initiative.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>In the 21st century, these older alliances have come under pressure as China and India elbow each other for dominance in the Indian Ocean. China’s ambitious <a href="https://en.wikipedia.org/wiki/Belt_and_Road_Initiative">Belt and Road Initiative</a> involves massive transport and port infrastructure and aims to extend China’s footprint across much of the Indian Ocean arena. In response, New Delhi has <a href="https://carnegieindia.org/2018/08/21/india-s-answer-to-belt-and-road-road-map-for-south-asia-pub-77071">bolstered</a> its economic and military activity in this domain. </p>
<h2>Deep histories of the Indian Ocean</h2>
<p>While the uniquely well-travelled surface of the Indian Ocean has received much attention, its depths barely register in the cultural or historical imagination. Its waters constitute <a href="https://www.ngdc.noaa.gov/mgg/global/etopo1_ocean_volumes.html">nearly 20%</a> of the ocean’s total volume, and its deepest point, the Sunda Deep of the Java Trench, lies nearly 8km below the surface. Yet its seafloor, like much of the world’s oceans, is <a href="https://www.smithsonianmag.com/science-nature/first-complete-map-ocean-floor-stirring-controversial-waters-180963993/">largely unmapped</a>. </p>
<p>Seafloor features determine weather patterns, fish concentrations and tsunami dynamics. Initial explorations by mining companies <a href="https://www.nature.com/articles/d41586-019-02242-y">revealed</a> mineral-rich deposits on submarine volcanic vents, while new species are <a href="https://www.hakaimagazine.com/news/less-than-a-fifth-of-deep-sea-life-is-identifiable/">continually</a> being discovered. </p>
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Read more:
<a href="https://theconversation.com/how-many-undiscovered-creatures-are-there-in-the-ocean-86705">How many undiscovered creatures are there in the ocean?</a>
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<p>The deep Indian Ocean is far <a href="https://aslopubs.onlinelibrary.wiley.com/doi/full/10.1002/lob.10149">less studied</a> than the depths of the other oceans, for economic reasons: it is ringed by underdeveloped countries. The second <a href="https://iioe-2.incois.gov.in/">International Indian Ocean Expedition</a> was launched only in 2015, fifty years after the first. It aims to increase understanding about the oceanographic and biological characteristics of this undersampled ocean, as well as the ways in which it is changing. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/339229/original/file-20200602-133886-13ap6zq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/339229/original/file-20200602-133886-13ap6zq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/339229/original/file-20200602-133886-13ap6zq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/339229/original/file-20200602-133886-13ap6zq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/339229/original/file-20200602-133886-13ap6zq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/339229/original/file-20200602-133886-13ap6zq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/339229/original/file-20200602-133886-13ap6zq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Maldives Indian Ocean coral reef.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>Paying attention to the submarine world is becoming increasingly important in a time of climate change prompted by human activities. The Indian Ocean is warming faster than any of the other oceans, holding more than 70% of all the heat absorbed by the upper ocean <a href="https://www.nature.com/news/indian-ocean-may-be-key-to-global-warming-hiatus-1.17505">since 2003</a>. Indian Ocean islands – the <a href="https://www.reuters.com/article/us-maldives-environment/maldives-sends-climate-sos-with-undersea-cabinet-idUSTRE59G0P120091017">Maldives</a> being a well-known example – are already being submerged by rising global sea levels. </p>
<p>Cyclone patterns are <a href="https://theconversation.com/why-the-indian-ocean-is-spawning-strong-and-deadly-tropical-cyclones-116559">shifting further south and happening more often</a> as a result of the ocean’s rising temperature. The monsoon, which underpinned the Indian Ocean’s shipping networks and the rainfall patterns on its coastlines, is losing its power and predictability. </p>
<h2>Deities, spirits and ancestors</h2>
<p>While the Indian Ocean’s depths are in many ways opaque, they are not unpopulated in people’s imaginations. The ocean bustles with water deities, djinns, mermaids and ancestral spirits – a mythical submarine world that reflects the cosmopolitanism of its land populations. </p>
<p>In southern Africa this mix is especially rich: Khoisan/ First Nation water sprites, Muslim djinns introduced by South East Asian slaves, African ancestors, one of whose domains is the ocean, and British imperial ideas about the romance of the sea. </p>
<p>These ideas encounter each other and turn bodies of water into rich sites of memory and history. They have been explored by the <a href="https://www.oceanichumanities.com/">Oceanic Humanities for the Global South project</a>. Work by Confidence Joseph, Oupa Sibeko, Mapule Mohulatsi and Ryan Poinasamy explores the literary and artistic imaginations of southern Africa’s creolised waters. </p>
<p>Afrofuturist science fiction is also turning to the deep Indian Ocean. Mohale Mashigo’s <a href="https://go.xprize.org/oceanstories/floating-rugs/"><em>Floating Rugs</em></a> is situated in a submarine community on South Africa’s east coast. Mia Couto’s <a href="https://books.google.co.za/books/about/Rain.html?id=AR0HtAEACAAJ&source=kp_book_description&redir_esc=y">stories</a> from the Mozambican coastline have long paired myths of mermaids with marine biology. Yvonne Adhiambo Owuor’s novel <a href="https://www.nytimes.com/2019/05/09/books/review/dragonfly-sea-yvonne-adhiambo-owuor.html"><em>The Dragonfly Sea</em></a> links contemporary Afro-Asian networks to the undersea. </p>
<h2>Deep sea mining</h2>
<p>Some exploration of the deep ocean can seem science-fictional, but isn’t. </p>
<p>The <a href="https://www.isa.org.jm/">International Seabed Authority</a>, a branch of the United Nations in operation since 2001 and responsible for parcelling out potential marine mining areas, has granted contracts for mining exploration in the Indian Ocean. At the same time, researchers are <a href="https://www.nature.com/articles/srep39158">discovering</a> an astonishing number of new deep ocean species on the <a href="https://www.smithsonianmag.com/smart-news/six-new-species-sea-creatures-discovered-region-slated-underwater-mining-180961480/">same sites</a>. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/339237/original/file-20200602-133933-1sktdjv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/339237/original/file-20200602-133933-1sktdjv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/339237/original/file-20200602-133933-1sktdjv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/339237/original/file-20200602-133933-1sktdjv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/339237/original/file-20200602-133933-1sktdjv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/339237/original/file-20200602-133933-1sktdjv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/339237/original/file-20200602-133933-1sktdjv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Underwater pearl farm.</span>
<span class="attribution"><span class="source">GettyImages</span></span>
</figcaption>
</figure>
<p>The submarine world has long been plundered for riches. Histories of <a href="https://books.google.co.za/books/about/Pearls_People_and_Power.html?id=NwyYwgEACAAJ&redir_esc=y">pearl diving</a> in the Indian Ocean – as in a central scene of Jules Verne’s <a href="https://www.goodreads.com/book/show/33507.Twenty_Thousand_Leagues_Under_the_Sea"><em>Twenty Thousand Leagues under the Sea</em></a> – are continued in today’s <a href="https://theconversation.com/first-steps-to-tackling-south-africas-abalone-poaching-106957">illegal abalone trade</a>. Poachers on the coast of South Africa don scuba gear to harvest abalone to trade with Asian markets, linking the undersea to Indian Ocean criminal underworlds, along the same lines as the ancient trade networks. </p>
<p>At times these networks are the source of treasure. On the Island of Mozambique, for instance, the shards of blue pottery that were <a href="http://www.unesco.org/new/en/member-states/single-view/news/training_on_underwater_archaeology_for_african_countries_tak/">traded</a> around the Indian Ocean are one of the objects of the active treasure hunting trade today. While some of the treasures are sold by dealers in antiquities, others provide crucial evidence for <a href="https://www.iol.co.za/news/africa/sunken-treasure-brings-tidal-wave-of-trouble-214643">maritime archaeological research</a>. Recently, the <a href="https://nmaahc.si.edu/explore/initiatives/slave-wrecks-project">Slave Wrecks Project</a> has discovered slave shipwrecks that provide concrete symbols of the transatlantic slave trade and link it to histories of Indian Ocean slavery and indenture. </p>
<p>The old waterfronts of East African port cities like Mombasa, Zanzibar and Lamu are dominated by buildings with a pure white finish. This present-day architecture echoes a centuries-old tradition of building houses, mosques and tombs from white coral stone and dressed with lime plaster. Made from shells and corals that began their life under the sea, this luminous plaster made port cities visible from afar to incoming vessels. </p>
<p>The ocean’s submarine life and its human histories are always entangled. And now writers, artists and scholars are increasingly drawing attention to their connectedness.</p><img src="https://counter.theconversation.com/content/133817/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Isabel Hofmeyr receives funding from the National Research Foundation. </span></em></p><p class="fine-print"><em><span>Charne Lavery 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 Indian Ocean provides a new way of looking at world history that has been dominated by European accounts.Isabel Hofmeyr, Professor of African Literature, University of the WitwatersrandCharne Lavery, Senior Lecturer, University of PretoriaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1332762020-03-17T14:31:23Z2020-03-17T14:31:23ZWhy an Indian ocean deep sea mission will help the Maldives and Seychelles manage their oceans<figure><img src="https://images.theconversation.com/files/319535/original/file-20200310-61113-iwcl08.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The submersible will allow scientists to film the seabed and take samples</span> <span class="attribution"><span class="source">NEKTON</span></span></figcaption></figure><p>Oceans cover over <a href="https://www.ecowatch.com/world-oceans-day-healthy-oceans-healthy-planet-1891167205.html">70%</a> of our “blue” planet and are vital to its health. For instance <a href="https://www.sciencelearn.org.nz/resources/689-the-ocean-and-the-carbon-cycle">carbon moves</a> in and out of the ocean and can be stored there for thousands of years. Oceans are also <a href="https://www.unenvironment.org/nairobiconvention/news/story/blue-economy-indian-ocean-governance-perspectives-sustainable-development-region">a source of food</a> and livelihood to millions of people, and to the economies of coastal countries.
They are also the <a href="https://science.nasa.gov/earth-science/oceanography/living-ocean">largest habitable</a> space on the planet and house many different organisms. </p>
<p>But there’s a great deal that scientists still don’t know about the world’s oceans. </p>
<p>The “deep sea” is <a href="https://oceanservice.noaa.gov/facts/light_travel.html">traditionally defined</a> as below 200m. Usually light from the sun can’t reach these depths and they are home to organisms that have special adaptations to live here. These waters are often in remote areas, and are beyond the reach of all but specialist technologies, therefore much of the deep sea remains under-explored. </p>
<p>Exploration is <a href="https://www.mapress.com/j/zt/article/view/zootaxa.4664.1.2">always revealing</a> species that are new to science. Many of these could be directly important to humans, for example some <a href="https://www.mdpi.com/1660-3397/18/2/107">contain specific</a> compounds that may aid medicinal advances. </p>
<p>The Seychelles and the Maldives are now jointly launching a new deep-sea scientific mission in the Indian Ocean that is focused on seamounts – large land-forms that rise from the ocean floor but don’t reach the surface. Because of a limit in equipment and experts, there have not been any systematic biological surveys of this region at these depths before. Historically, this type of research has been near countries with better access to resources, such as those on the shores of the Atlantic and Pacific Oceans.</p>
<p>The mission of the <a href="https://nektonmission.org/missions/first-descent-midnight-zone">“First Descent: Midnight Zone”</a> is to understand what lives in the water, from the surface to the seabed. We also want to know how this changes from waters in the Seychelles to the Maldives.</p>
<p>This information will eventually be available on open access databases, building on the global knowledge of the deeper ocean for other scientists and policy makers.
We hope that this information enables countries to understand how to manage their oceans better. </p>
<h2>Equipment</h2>
<p>Our expedition is made up of scientists from many different disciplines who are coming together to document biological, physical and chemical parameters. This will provide us with valuable baseline data which can also be used to predict life in other sites that we couldn’t explore.</p>
<p>The gear we will use ranges from traditional oceanographic technologies to newly developed equipment. </p>
<p>For example we will use a <a href="https://www.youtube.com/watch?v=OCJKWU99UVg">multibeam echo-sounder</a> – a type of sonar – to visualise the shape and depth of the seamounts. Sensors and water samplers will examine water columns – imagine columns of water from the surface of the ocean to the bottom. <a href="https://aquaticbiotechnology.com/en/plankton-nets/neuston-net">Neuston nets</a> – like a net between two floats – are used to sample zooplankton and microplastics in the “neuston layer”, or top few centimetres of the ocean.</p>
<p>The most advanced piece of technology we will use is the full depth submersible, it looks like an underwater pod that can go to extreme depths. This enables us to explore the steep slopes of the seamounts. This will allow us to film and record transects of the seabed and also take samples of specific organisms of interest with the manipulator arm. We expect to find cold water coral reefs and gardens of soft corals and sponges – all home to diverse life.</p>
<p>This expedition will take five weeks, operating 24 hours a day.</p>
<h2>Exploration sites</h2>
<p>We are exploring six seamounts that were prioritised by stakeholders – such as government ministries – from the Seychelles and Maldives. </p>
<p>Seamounts are interesting to explore because they are <a href="https://oceanexplorer.noaa.gov/facts/seamounts-biodiv.html">a hotspot</a> for marine life. This is because they rise up from the seafloor and push deep, cold nutrient rich waters up around and over them to the surface. Also, because they’re hard and sediment can’t settle on the slopes and vertical surfaces, organisms can attach to them. In the deep sea the seabed is mostly rock, covered by a thick layer of sediment. </p>
<p>In addition to this information, by visiting locations east and west of the Central Indian Ridge, we hope to investigate whether the ridge is a potential barrier to organisms moving. This is important to help the understanding of genetic connectivity across the region. Genetic connectivity can help us understand where isolated, and therefore more vulnerable, populations of organisms are.</p>
<h2>Useful data</h2>
<p>Seychelles is to announce its massive project <a href="https://www.bbc.com/news/world-africa-47925193">to protect</a> 30% of their waters. Data from the expedition will help inform this process. This protection includes both no-take zones and the banning of some activities.</p>
<p>In the Maldives a process of marine spatial planning – ocean zoning to remove or include specific activities – has just started. Documenting life in the deep waters enables us to ground assumptions on life made at these depths, and could show areas that need future protection.</p>
<p>Finally some of the seamounts that we will visit are in the high seas. This area is beyond national jurisdiction and is currently receiving international attention because of a <a href="https://www.un.org/bbnj/">UN treaty</a> that’s being negotiated. Shining a spotlight on seamount life could help galvanise action by the parties and the new knowledge that comes from the data collected could help future management of the region.</p>
<p><em>Sheena Talma, a key scientist working on the mission, also contributed to this article.</em></p><img src="https://counter.theconversation.com/content/133276/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Lucy Woodall receives funding from the Nekton Foundation</span></em></p>Unless we know what is in the ocean, we can’t protect the biggest part of the planet.Lucy Woodall, Senior Research Fellow, University of OxfordLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1321882020-02-24T19:00:33Z2020-02-24T19:00:33ZWhy drought-busting rain depends on the tropical oceans<p>Recent <a href="https://www.theguardian.com/world/2020/feb/07/massive-relief-torrential-rain-douses-bushfires-across-parts-of-australia">helpful rains</a> dampened fire grounds and gave many farmers a reason to cheer. But much of <a href="https://theconversation.com/rain-has-eased-the-dry-but-more-is-needed-to-break-the-drought-131660">southeast Australia remains in severe drought</a>.</p>
<p>Australia is no stranger to drought, but the current one stands out when looking at rainfall records over the past 120 years. This drought has been marked by <a href="http://www.bom.gov.au/climate/change/#tabs=Tracker&tracker=timeseries&tQ=graph%3Drain%26area%3Dmdb%26season%3D0608%26ave_yr%3D0">three consecutive extremely dry winters</a> in the Murray-Darling basin, which rank in the driest 10% of winters since 1900.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/316381/original/file-20200220-92493-1fl9g08.gif?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/316381/original/file-20200220-92493-1fl9g08.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/316381/original/file-20200220-92493-1fl9g08.gif?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=412&fit=crop&dpr=1 600w, https://images.theconversation.com/files/316381/original/file-20200220-92493-1fl9g08.gif?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=412&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/316381/original/file-20200220-92493-1fl9g08.gif?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=412&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/316381/original/file-20200220-92493-1fl9g08.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=518&fit=crop&dpr=1 754w, https://images.theconversation.com/files/316381/original/file-20200220-92493-1fl9g08.gif?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=518&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/316381/original/file-20200220-92493-1fl9g08.gif?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"></a>
<figcaption>
<span class="caption">Despite recent rainfall the southeast of Australia remains in the grip of a multi-year drought.</span>
<span class="attribution"><span class="source">Bureau of Meteorology</span></span>
</figcaption>
</figure>
<p>So what’s going on?</p>
<p>There has been much discussion on whether human-caused climate change is to blame. <a href="https://nature.com/articles/s41558-020-0718-z">Our new study</a> explores Australian droughts through a different lens. </p>
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<em>
<strong>
Read more:
<a href="https://theconversation.com/rain-has-eased-the-dry-but-more-is-needed-to-break-the-drought-131660">Rain has eased the dry, but more is needed to break the drought</a>
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<p>Rather than focusing on what’s causing the dry conditions, we investigated why it’s been such a long time since we had widespread drought-breaking rain. And it’s got a lot to do with how the temperature varies in the Pacific and Indian Ocean.</p>
<p><a href="https://nature.com/articles/s41558-020-0718-z">Our findings</a> suggest <a href="https://theconversation.com/is-australias-current-drought-caused-by-climate-change-its-complicated-97867">that while climate change does contribute to drought</a>, blame can predominately be pointed at the absence of the Pacific Ocean’s La Niña and the negative Indian Ocean Dipole – climate drivers responsible for bringing wetter weather.</p>
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<iframe width="440" height="260" src="https://www.youtube.com/embed/J6hOVatamYs?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Understanding the Indian Ocean Dipole.</span></figcaption>
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<h2>What’s the Indian Ocean Dipole?</h2>
<p>As you may already know, <a href="https://www.abc.net.au/news/2017-10-19/what-el-nino-la-nina-mean-australian-weather/9053464">the Pacific Ocean</a> influences eastern Australia’s climate through El Niño conditions (associated with drier weather) and La Niña conditions (associated with wetter weather).</p>
<p>The lesser known cousin of El Niño and La Niña across the Indian Ocean is called the <a href="https://www.bbc.com/news/science-environment-50602971">Indian Ocean Dipole</a>. This refers to the difference in ocean temperature between the eastern and western sides of the Indian Ocean. It modulates <a href="http://www.bom.gov.au/climate/iod/">winter and springtime rainfall</a> in southeastern Australia. </p>
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Read more:
<a href="https://theconversation.com/dipole-the-indian-nino-that-has-brought-devastating-drought-to-east-africa-74011">Dipole: the 'Indian Niño' that has brought devastating drought to East Africa</a>
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</p>
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<p>When the Indian Ocean Dipole is “negative”, there are warmer ocean temperatures in the east Indian Ocean, and we see more rain over much of Australia. The opposite is true for “positive” Indian Ocean Dipole events, which bring less rain.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/316782/original/file-20200224-24680-1de3dmg.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/316782/original/file-20200224-24680-1de3dmg.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/316782/original/file-20200224-24680-1de3dmg.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=314&fit=crop&dpr=1 600w, https://images.theconversation.com/files/316782/original/file-20200224-24680-1de3dmg.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=314&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/316782/original/file-20200224-24680-1de3dmg.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=314&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/316782/original/file-20200224-24680-1de3dmg.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=394&fit=crop&dpr=1 754w, https://images.theconversation.com/files/316782/original/file-20200224-24680-1de3dmg.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=394&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/316782/original/file-20200224-24680-1de3dmg.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=394&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 Murray-Darling Basin experiences high rainfall variability, with decade-long droughts common since observations began. The graph shows seasonal rainfall anomalies from a 1961-1990 average with major droughts marked.</span>
<span class="attribution"><span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>What does it mean for the drought?</h2>
<p>When the drought started to take hold in 2017 and 2018, we didn’t experience an El Niño or strongly positive Indian Ocean Dipole event. These are two dry-weather conditions we might expect to see at the start of a drought.</p>
<p>Rather, conditions in the Pacific and Indian Oceans were near neutral, with little to suggest a drought would develop. </p>
<p>So why are we in severe, prolonged drought?</p>
<p>The problem is we haven’t had either a La Niña or a negative Indian Ocean Dipole event since winter 2016. Our study shows the lack of these events helps explain why eastern Australia is in drought. </p>
<p>For the southeast of Australia in particular, La Niña or negative Indian Ocean Dipole events provide the atmosphere with suitable conditions for persistent and widespread rainfall to occur. So while neither La Niña or a negative Indian Ocean Dipole guarantee heavy rainfall, they do increase the chances.</p>
<h2>What about climate change?</h2>
<p>While climate drivers are predominately causing this drought,<a href="https://theconversation.com/is-australias-current-drought-caused-by-climate-change-its-complicated-97867"> climate change also contributes</a>, though more work is needed to understand what role it specifically plays.</p>
<p>Drought is more complicated and multidimensional than simply “not much rain for a long time”. It can be measured with a raft of metrics beyond rainfall patterns, including metrics that look at humidity levels and evaporation rates. </p>
<p>What we do know is that climate change can exacerbate some of these metrics, which, in turn, can affect drought. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/is-australias-current-drought-caused-by-climate-change-its-complicated-97867">Is Australia's current drought caused by climate change? It's complicated</a>
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</em>
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<p>Climate change might also influence climate drivers, though right now it’s hard to tell how. A 2015 study suggests that under climate change, <a href="https://www.nature.com/articles/nclimate2492">La Niña events will become more extreme</a>. Another study from earlier this month suggests climate change is driving more <a href="https://www.abc.net.au/news/2020-02-13/indian-ocean-dipole-linked-to-global-warming-in-new-research/11943178">positive Indian Ocean Dipole events</a>, bringing even more drought. </p>
<p>Unfortunately, regional-scale projections from climate models aren’t perfect and we can’t be sure how the ocean patterns that increase the chances of drought-breaking rains will change under global warming. What is clear is there’s a risk they will change, and strongly affect our rainfall.</p>
<h2>Putting the drought in context</h2>
<p>Long periods when a La Niña or a negative Indian Ocean Dipole event were absent characterised Australia’s past droughts. This includes two periods of more than three years that brought us the Second World War drought and the Millennium drought.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/316772/original/file-20200224-116114-1n445kn.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/316772/original/file-20200224-116114-1n445kn.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/316772/original/file-20200224-116114-1n445kn.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=211&fit=crop&dpr=1 600w, https://images.theconversation.com/files/316772/original/file-20200224-116114-1n445kn.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=211&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/316772/original/file-20200224-116114-1n445kn.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=211&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/316772/original/file-20200224-116114-1n445kn.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=266&fit=crop&dpr=1 754w, https://images.theconversation.com/files/316772/original/file-20200224-116114-1n445kn.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=266&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/316772/original/file-20200224-116114-1n445kn.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=266&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 longer the time without a La Niña or negative Indian Ocean Dipole event, the more likely the Murray-Darling Basin is in drought.</span>
</figcaption>
</figure>
<p>In the above graph, the longer each line continues before stopping, the longer the time since a La Niña or negative Indian Ocean Dipole event occurred. The lower the lines travel, the less rainfall was received in the Murray Darling basin during this period. This lets us compare the current drought to previous droughts.</p>
<p>During the current drought (black line) we see how the rainfall deficit continues for several years, almost identically to how the Millennium drought played out. </p>
<p>But then the deficit increases strongly in late 2019, when we had a <a href="https://www.abc.net.au/news/2019-05-16/positive-indian-ocean-dipole-bad-news-for-drought-crippled-areas/11120566">strongly positive Indian Ocean Dipole</a>. </p>
<h2>So when will this drought break?</h2>
<p>This is a hard question to answer. While recent rains have been helpful, we’ve developed a long-term rainfall deficit in the Murray-Darling Basin and elsewhere that will be hard to recover from without either a La Niña or negative Indian Ocean Dipole event.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/weather-bureau-says-hottest-driest-year-on-record-led-to-extreme-bushfire-season-129447">Weather bureau says hottest, driest year on record led to extreme bushfire season</a>
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</em>
</p>
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<p>The most recent <a href="http://www.bom.gov.au/climate/outlooks/#/overview/summary/">seasonal forecasts</a> don’t predict either a negative Indian Ocean Dipole or La Niña event forming in the next three months. However, accurate forecasts are difficult at this time of year as we approach the “<a href="https://www.climate.gov/news-features/blogs/enso/spring-predictability-barrier-we%E2%80%99d-rather-be-spring-break">autumn predictability barrier</a>”. </p>
<p>This means, for the coming months, the drought probably won’t break. After that, it’s anyone’s guess. We can only hope conditions improve.</p><img src="https://counter.theconversation.com/content/132188/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Andrew King receives funding from the Australian Research Council. </span></em></p><p class="fine-print"><em><span>Andy Pitman receives funding from the Australian Research Council</span></em></p><p class="fine-print"><em><span>Anna Ukkola receives funding from the ARC Centre of Excellence for Climate Extremes. </span></em></p><p class="fine-print"><em><span>Ben Henley receives funding from an Australian Research Council Linkage Project with Melbourne Water, the Victorian Department of Environment, Land, Water and Planning, and the Bureau of Meteorology. </span></em></p><p class="fine-print"><em><span>Josephine Brown receives funding from the National Environmental Science Program and the Australian Research Council.</span></em></p>The absence of climate drivers – specifically, the Indian Ocean Dipole and La Niña – explains why Australia has gone so long without heavy rains.Andrew King, ARC DECRA fellow, The University of MelbourneAndy Pitman, Director of the ARC Centre of Excellence for Climate System Science, UNSW SydneyAnna Ukkola, Research Fellow, Australian National UniversityBen Henley, Research Fellow in Climate and Water Resources, The University of MelbourneJosephine Brown, Lecturer, The University of MelbourneLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1247182019-11-05T14:23:11Z2019-11-05T14:23:11ZMalawi’s dream of a waterway to the Indian Ocean may yet come true<figure><img src="https://images.theconversation.com/files/299688/original/file-20191031-187898-1ytiywh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A small boat carries passengers across the Zambezi river. </span> <span class="attribution"><span class="source">Wikimedia Commons</span></span></figcaption></figure><p>Malawi’s landlocked status places a huge <a href="https://www.africanwaterfacility.org/fileadmin/uploads/awf/Projects/AWF-Project-appraisal-report-MULTIN-SHIREZAMBEZI.pdf">burden on its economy</a>. This makes imports and exports expensive. Because of time-consuming and poor-quality rail and road transport, the country’s transport costs are <a href="http://repository.uneca.org/pdfpreview/bitstream/handle/10855/23017/b11560861.pdf?sequence=1">among the highest in Africa</a>. </p>
<p>The search for a solution has dominated Malawi’s foreign policy since independence in 1964. Malawi relies on four main trade corridors: the ports of Dar es Salaam in Tanzania; Beira and Nacala in Mozambique and Durban in South Africa. </p>
<p>An alternative route is a waterway to the Indian Ocean through Mozambique. It was first proposed in 1891. The now <a href="http://www.iese.ac.mz/lib/publication/livros/des2015/IESE-Desafios2015_16_ConSob.pdf">controversial idea</a> was revived in 2005 by Malawi’s third president, Bingu wa Mutharika (2004-2012) as a signature foreign policy project. It was known as the Shire-Zambezi Waterway. </p>
<p>Believing it would be an important legacy of his presidency, he <a href="https://www.voanews.com/africa/malawi-zambia-seek-trade-waterway-mozambique">consistently</a> claimed that using the route from Nsanje in Malawi to Chinde in Mozambique would drastically reduce Malawi’s transport costs and boost economic growth.</p>
<p>Malawi’s <a href="http://www.nsomalawi.mw/index.php?option=com_wrapper&view=wrapper&Itemid=110">main exports</a> are tobacco, tea, sugar. It imports oils, consumer goods and fertilisers.</p>
<p>But Malawi has so far failed to get access to the Indian Ocean. Our <a href="https://www.sum.uio.no/english/research/publications/2019/happy-kayuni-dan-banik-joseph-chunga-the-perils-of-megaphone-diplomacy-malawian-mozambican-relations-following-the-shire-zambezi-waterway-project.html">research</a> suggests this is because of two important factors: Malawi’s diplomatic strategy and the absence of Mozambique’s buy-in. </p>
<p>We found that for the project to happen, Malawi must change its diplomatic approach and the two countries must ensure that their national interests in the project are closely aligned.</p>
<p>Yet there may be renewed hope for the project. This is because there are recent signs that the two countries do in fact have interests in common and can collaborate on a project. </p>
<h2>The Shire-Zambezi waterway</h2>
<p>Malawi’s diplomatic relations with Mozambique have not been harmonious since independence. Historically, Malawi was aligned to apartheid South Africa, which provided support to the Renamo rebel movement during Mozambique’s 16-year <a href="https://sites.tufts.edu/atrocityendings/2015/08/07/mozambique-civil-war/">civil war</a>. </p>
<p>Mozambique’s leaders therefore showed little interest in Mutharika’s vision of a waterway running through its territory. The other factor was Mozambique would likely lose out on the toll or freight charges for foreign vehicles that use its transport network. Instead, in 2009 they announced plans to <a href="http://www.iese.ac.mz/lib/publication/Dibben,Pauline_tranport.pdf">rehabilitate the port of Beira</a>, rather than Chinde’s, and improve the country’s road network.</p>
<p>Still, Mutharika pursued the waterway project. First, beginning in 2005, he sought <a href="http://www.scoop.co.nz/stories/WL0610/S01566/cablegate-the-shire-zambezi-waterway-gods-highway-or-bingus.htm">support from other African leaders</a> at meetings of the African Union, Southern African Development Community (SADC) and New Partnership For Africa’s Development (NEPAD). </p>
<p>Second, he bolstered the credibility of the project by formally and informally <a href="https://www.timalawi.nl/LaatsteNieuws/NsanjeInlandPort.htm">including</a> Zambia, Zimbabwe and the Democratic Republic of Congo. As a former Secretary General of the Preferential Trade Area of East and Central Africa (PTA), he believed that a regional integration component would win his project favour. </p>
<p>Third, Mutharika insisted that the project be <a href="http://www.scoop.co.nz/stories/WL0610/S01566/cablegate-the-shire-zambezi-waterway-gods-highway-or-bingus.htm">completed quickly</a>, even in the absence of Mozambican approval. He may have reasoned that if he demonstrated his commitment, Mozambique would be forced to comply for the sake of neighbourly relations.</p>
<h2>Megaphone diplomacy</h2>
<p>Mutharika’s strategy demonstrated the shortcomings of <a href="https://www.saiia.org.za/wp-content/uploads/2008/05/16-Dlamini.pdf">“megaphone diplomacy”</a> in international relations. Megaphone diplomacy is generally understood as the use of mass media to advance contentious diplomatic aims. This is the opposite of “quiet diplomacy” through traditional diplomatic channels. </p>
<p>Without consulting the Mozambican government and after almost a year in power, Mutharika organised a highly publicised groundbreaking ceremony in Nsanje port in southern Malawi in October 2005. Subsequently, his administration engaged a private Portuguese company to begin phase one of the construction of the port. </p>
<p>This phase was quickly completed and Mutharika’s government went ahead to publicise the official opening of the waterway. Billboards went up across the country emblazoned with the words </p>
<blockquote>
<p>“The dream becomes reality: Nsanje Port opens October 2010”. </p>
</blockquote>
<p>The presidents of Zambia and Zimbabwe were invited to the public ceremony to celebrate the planned arrival of a barge carrying 60 tonnes of imported fertiliser. Mozambican authorities, however, <a href="https://www.pressreader.com/south-africa/daily-news-south-africa/20101026/282531539771813">impounded the barge and detained </a> four Malawians for navigating the river without authorisation. </p>
<p>Mozambique objected to the project on grounds that no economic feasibility study or environmental impact assessment had been carried out. It also claimed that Malawi had not even requested official clearance of the barge. </p>
<p>The final blow for Malawi’s diplomatic debacle was the publication of the feasibility report commissioned by the SADC. The 2013 report <a href="http://www.engineeringnews.co.za/PRINT-VERSION/SHIRE-ZAMBEZI-2016-02-19">concluded</a> that the project is </p>
<blockquote>
<p>“technically feasible but not financially viable.”</p>
</blockquote>
<p>Although the waterway is Malawi’s shortest route to the sea, the report <a href="https://clubofmozambique.com/news/shire-zambezi-waterway-not-viable-insists-transport-ministry-of-mozambique/">concluded</a> that only 273,200 tonnes per year could be transported through the waterway. Annual dredging and removal of aquatic plants would cost 80 million US dollars per year, the report further said. </p>
<h2>Mozambican response</h2>
<p>The report provided a legitimate reason for Mozambique’s withdrawal from the project, but failed diplomacy undoubtedly led to the collapse of the waterway project. Mozambique was operating from a position of power as it controls access to the sea. And it was unlikely to benefit much from the Shire-Zambezi Waterway. If Malawi changes its diplomatic approach, the project may ultimately see the light of day. </p>
<p>Indeed, Malawi’s tactics appeared to reinforce Mozambique’s opposition to the project, which it felt undermined its national interests. </p>
<p>In recent months, Malawi’s current president Peter Mutharika (Bingu Mutharika’s brother) has been drumming up support for the project again. Mozambique continues to ignore such signals. </p>
<p>But the two countries recently <a href="https://southerntimesafrica.com/site/news/world-bank-funding-malawi-mozambique-interconnection">signed an agreement</a> that will allow the Electricity Supply Corporation of Malawi to purchase 200 megawatts of power from Mozambique starting in 2022. This is a clear case of a successful partnership with both countries sharing a common national interest on power generation and supply. </p>
<p>Despite the African Union’s <a href="https://au.int/en/agenda2063/flagship-projects">talk of globalisation, regional integration and partnerships</a>, national interest continues to rule in international diplomacy. For the Shire-Zambezi project to go ahead, Malawi and Mozambique must have a frank discussion about how they could both benefit from it.</p><img src="https://counter.theconversation.com/content/124718/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Happy Kayuni receives funding from the Research Council of Norway and the Norwegian Agency for Development Cooperation (Norad). </span></em></p><p class="fine-print"><em><span>Dan Banik receives funding from the Research Council of Norway and the Norwegian Agency for Development Cooperation (Norad). </span></em></p><p class="fine-print"><em><span>Joseph Chunga receives funding from the Research Council of Norway and the Norwegian Agency for Development Cooperation (Norad). </span></em></p>Malawi must change its diplomatic approach and align its national interests with Mozambique’sHappy Kayuni, Professor, University of MalawiDan Banik, Professor of political science, Director of the Oslo SDG Initiative, Host of "In Pursuit of Development" podcast, University of OsloJoseph Chunga, Lecturer & Research fellow, University of Cape TownLicensed as Creative Commons – attribution, no derivatives.