tag:theconversation.com,2011:/global/topics/lake-victoria-38138/articlesLake Victoria – The Conversation2023-09-21T12:03:56Ztag:theconversation.com,2011:article/2137782023-09-21T12:03:56Z2023-09-21T12:03:56ZInvasive alien species are a serious threat to the planet: 4 key messages for Africa<p>Climate change has negatively – and irreversibly, in some cases – affected ecosystems around the globe. Sadly, though, it is not the only phenomenon that’s altering our natural world.</p>
<p>In 2019, the Intergovernmental Science Policy Platform on Biodiversity and Ecosystem Services (IPBES) Global Assessment Report <a href="https://www.ipbes.net/sites/default/files/inline/files/ipbes_global_assessment_report_summary_for_policymakers.pdf">confirmed</a> invasive alien species as one of the five most important direct drivers of biodiversity loss. The others were climate change, land and sea use, direct exploitation of species, and pollution. </p>
<p><a href="https://www.ipbes.net/">IPBES</a>, an independent intergovernmental body, was established in 2012. It now has 144 member countries; Somalia, the newest member, joined in mid-September. Its major objective is to strengthen the interface between science and policy to conserve and sustainably use biodiversity. </p>
<p>The 2019 assessment found that more than 37,000 alien species had been introduced by many human activities to regions and biomes around the world, most in the past 100 years. A <a href="https://www.ipbes.net/IASmediarelease">new report</a> by the organisation, focused on alien invasive species, suggests this number is rising fast, with new alien species being recorded at an unprecedented rate of approximately 200 annually. It also reveals that the global economic cost of invasive alien species exceeded US$423 billion annually. Costs have at least quadrupled every decade since 1970.</p>
<p>But the new report doesn’t just concentrate on problems. It also offers solutions. It outlines key responses and policy options that governments may take for prevention, early detection and effective control of invasive alien species. Doing so will help to safeguard nature and its contributions to people. This will ensure a better quality of life for all.</p>
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<a href="https://theconversation.com/the-true-damage-of-invasive-alien-species-was-just-revealed-in-a-landmark-report-heres-how-we-must-act-211893">The true damage of invasive alien species was just revealed in a landmark report. Here's how we must act</a>
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<p>I am an invasion biologist whose <a href="https://www.ru.ac.za/centreforbiologicalcontrol/people/researchstaff/juliecoetzee/">research</a> focuses on the ecology and management of invasive aquatic plants. Here, I elaborate on the four key messages highlighted by the report that African countries should heed if the continent is to successfully tackle the threats posed by invasive species.</p>
<h2>Key messages</h2>
<p><em><strong>1: Invasive alien species are a major threat to nature, its contributions to people, and good quality of life.</strong></em></p>
<p>In Africa, invasive species threaten food security by negatively affecting fish production, agricultural productivity, grazing and water supplies. </p>
<p>The introduction of the Nile perch, <em>Lates niloticus</em>, into East Africa’s Lake Victoria in 1954 is one of the most extreme examples. Predation by this species caused the extinction of approximately 200 species of cichlids from the lake. It <a href="https://www.jstor.org/stable/2386700">is considered</a> to represent the largest extinction event among vertebrates during the 20th century. </p>
<p>The invasion also resulted in the shallow lake becoming enriched with nutrients as people came to fish for Nile perch. This resulted in the widespread invasion of the lake by water hyacinth. The plant restricted access to the lake, which prevented transport and fishing. </p>
<p><em><strong>2: Globally, invasive alien species and their impacts are increasing rapidly and are predicted to continue rising in the future. Accurate data is crucial.</strong></em></p>
<p>A <a href="https://www.sciencedirect.com/science/article/pii/S0048969721003041">2021 research study</a> highlighted that the reported economic costs of invasive aquatic species were unevenly distributed across geographic regions. Africa, the Oceania-Pacific Islands and the Antarctic-Subantarctic, combined, accounted for only 0.6% of the US$345 billion global estimate. That’s not because the costs are really that low. The data simply isn’t being recorded, so we’re not getting the full picture. </p>
<p>African countries need to <a href="https://healthtimes.co.zw/2023/09/19/zim-scales-up-efforts-to-control-invasive-alien-species/">partner with their neighbours</a> in better quantifying the situation. </p>
<p><em><strong>3: Invasive alien species and their negative impact can only be prevented and mitigated through effective management.</strong></em></p>
<p>In 2011 the Convention on Biological Diversity released its <a href="https://www.cbd.int/sp/targets/">Aichi Biodiversity Targets</a>. The 20 targets were designed to address and mitigate biodiversity loss across the globe. Target 9 stated that, by 2020, invasive alien species and pathways should be identified and prioritised. Priority species should be controlled or eradicated, and measures taken to block new pathways.</p>
<p>But none of those targets were met. And there has been little or no progress recorded in some African countries. Today, invasive species <a href="https://www.thelancet.com/journals/lanplh/article/PIIS2542-5196(20)30174-1/fulltext">are reported</a> to be adversely affecting livelihoods in more than 70% of African countries. </p>
<p>Constrained financial resources and the lack of legal frameworks and related operational systems are largely to blame for the lack of progress. For example, there is a <a href="https://link.springer.com/chapter/10.1007/978-3-030-32394-3_12">huge lack of capacity</a>, mainly at ports of entry – which are the most crucial step in preventing invasions. </p>
<p>Many regions still have to enhance their management plans for effective control of invasive species, starting with identification of common invasive species.</p>
<p><em><strong>4: There are success stories on the continent – lessons should be shared across borders.</strong></em></p>
<p>In South Africa, the management of alien plant invasions has been actively supported by the government’s <a href="https://www.dws.gov.za/wfw/">Working for Water</a> programme since 1995. </p>
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<a href="https://theconversation.com/invasive-alien-plants-in-south-africa-pose-huge-risks-but-they-can-be-stopped-94186">Invasive alien plants in South Africa pose huge risks, but they can be stopped</a>
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<p>A study in 2022 <a href="https://www.sciencedirect.com/science/article/abs/pii/S0006320722002944">estimated</a> that an average of R310 million (adjusted to 2020 values) had been spent every year on work that covered 2.7 million hectares across more than 76,000 sites. This doesn’t mean plant invasions are totally under control. But it is clear that, without this kind of programme, the situation would be far worse.</p>
<p>The study recommended that the programme’s future efforts must focus on clearly defined priority sites, improving planning and monitoring, and increasing operational efficiency. These are all valuable lessons for other African countries.</p>
<h2>An African lens</h2>
<p>Its new report did not focus on any one part of the world, but IPBES has previously been clear about the importance of biodiversity to African nations. In a 2018 <a href="https://www.ipbes.net/assessment-reports/africa">regional assessment</a> on Biodiversity and Ecosystem Services For Africa, the organisation wrote that</p>
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<p>biodiversity and nature’s contributions in Africa are economically, socially and culturally important, essential in providing the continent’s food, water, energy, health and secure livelihood, and represent a strategic asset for sustainable development and achievement of the Sustainable Development Goals.</p>
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<p>Most of the data in the newest report comes from the northern hemisphere, as this is where most of the research is conducted, and where the majority of funding comes from. </p>
<p>Different countries and regions will have different needs. That’s where the value of regional coordination and knowledge-sharing becomes clear.</p><img src="https://counter.theconversation.com/content/213778/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Julie Coetzee receives funding from the National Research Foundation SARCHi and the Natural
Resource Management Programme of the South African Department of Forestry, Fisheries, and the Environment. Any opinion, conclusion or recommendation in this material is that of the authors and the NRF does not accept any liability in this regard.</span></em></p>The new report on alien invasive species doesn’t just concentrate on problems. It also offers solutions.Julie Coetzee, Researcher, Rhodes UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1907192022-10-07T07:26:15Z2022-10-07T07:26:15ZUganda’s Owen Falls dam: a colonial legacy that still stings, 67 years later<figure><img src="https://images.theconversation.com/files/485174/original/file-20220918-52595-ss59az.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The sluice gates open at the Owen Falls dam across the White Nile in Uganda on 14 October 1962. </span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/the-sluice-gates-open-at-the-owen-falls-dam-later-the-news-photo/1365173292?adppopup=true">McCabe/Express/Hulton Archive via Getty Images</a></span></figcaption></figure><p>Uganda’s Owen Falls hydropower plant has a rich history that predates the country’s independence in 1962. The plant is located across the White Nile and sits between the towns of Jinja and Njeru on the shores of Lake Victoria. It is about 85 kilometres east of Kampala.</p>
<p>Uganda was a protectorate of the British empire from 1894 to 1962. In 1947, English engineer Charles Redvers Westlake recommended the construction of a hydroelectric dam at Owen Falls that was supposed to be East Africa’s largest power project. </p>
<p>The governor of the Protectorate of Uganda, Sir Andrew Cohen, <a href="https://www.archive.observer.ug/features/spec/spec200805011.php">wrote</a> at the time that the Owen Falls dam would open new horizons of opportunity and prosperity for Uganda and all who lived there. Cohen went on to note: </p>
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<p>Despite its technical complexity and the fact that we have had to draw upon skill and experience from many parts of the world, it belongs to Uganda and to Uganda’s people. The power which the dam will provide and the industries it will make possible will bring solid benefit to everybody in the shape of increased wealth; above all, it will bring new opportunities to Africans.</p>
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<p>At its completion in 1954, the dam <a href="https://www.tandfonline.com/doi/full/10.1080/17531055.2021.1950751">immediately expanded</a> Uganda’s electricity supply capacity from 1MW to 150MW. But the expected boom in electricity consumption didn’t happen. One textile mill and a copper smelter were the only industrial establishments to crop up. </p>
<p>The Uganda Electricity Board (UEB) – which was established on <a href="https://www.monitor.co.ug/uganda/special-reports/110-years-of-electricity-in-uganda-1751826">15 January 1948</a> – resorted to selling between one third and one half of the electricity generated to Kenya.</p>
<p>The institutional arrangements for constructing the dam left a damaging legacy that is still felt today. The British established governance arrangements for Nile waters that effectively granted Egypt veto power over all construction projects on the Nile. This legal regime continues to cause conflict between Nile riparian states to this day.</p>
<p>Owen Falls’ construction has to be seen as part of a racist colonial project, the sole objective of which was the exploitation of peoples and their resources to maximise British interests. </p>
<h2>Empire’s twisted logic</h2>
<p>At the end of World War II there were protests throughout the British empire as demands for independence began picking up pace. </p>
<p>In Uganda, the country’s new colonial governor, <a href="https://www.monitor.co.ug/uganda/magazines/people-power/building-of-owen-falls-dam-begins-in-jinja-1636524">Sir John Hathorn Hall</a>, was forced to take action. Some of the steps he took were informed by the need for the colonial government to show restless and poverty-stricken Ugandans that it was interested in promoting economic growth, industrialisation and development.</p>
<p>The dam was supposed to help Ugandans utilise their own natural resource – the water in Lake Victoria – to provide themselves with a significant level of energy independence.</p>
<p>But, in the twisted logic of the empire, achieving this goal was constrained by London trying to achieve interests elsewhere. In this case, British agricultural interests in Egypt. </p>
<p>In 1929, Egypt and Britain had signed the <a href="https://treaties.fcdo.gov.uk/awweb/pdfopener?md=1&did=64266">Anglo-Egyptian Treaty</a>, which was designed to harness the waters of the Nile River and its tributaries to produce raw materials, notably cotton, for British industries.</p>
<p>The treaty, which created what are today known as historically acquired rights, was concluded without input from Uganda or other <a href="https://www.brookings.edu/blog/africa-in-focus/2015/04/28/the-limits-of-the-new-nile-agreement/#:%7E:text=%5B2%5D%20The%20Nile%20River%20riparian,Sudan%20are%20downstream%20riparian%20states">Nile riparian states</a>. </p>
<p>These rights allocate virtually all Nile waters to Egypt and Sudan. They also grant Egypt veto power over all construction projects on the Nile River and its tributaries.</p>
<p>As Ugandans would later find out, the British had, without their permission, placed Egyptian officials in a position to <a href="https://theconversation.com/colonial-era-treaties-are-to-blame-for-the-unresolved-dispute-over-ethiopias-dam-133538">veto</a> development projects in Uganda and other upstream Nile Basin states.</p>
<p><strong>The Nile Basin states</strong></p>
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<p>Despite the fact that the Owen Falls dam was to be constructed on the White Nile in Uganda, Uganda was forced to obtain permission for its construction from <a href="https://www.monitor.co.ug/uganda/magazines/people-power/building-of-owen-falls-dam-begins-in-jinja-1636524">Egypt</a>. </p>
<h2>Source of tension and conflict</h2>
<p>The 1929 Anglo-Egyptian Treaty and the <a href="https://treaties.un.org/doc/Publication/UNTS/Volume%20453/volume-453-I-6519-English.pdf">1959 Nile Treaty</a> – which was a bilateral agreement between Egypt and Sudan – continue to fuel conflict between the downstream and upstream states in the Nile Basin. </p>
<p>In fact, Ethiopia’s refusal to abide by and be bounded by these colonial anachronisms has forced officials in Cairo to <a href="https://www.businessinsider.com/hacked-stratfor-emails-egypt-could-take-military-action-to-protect-its-stake-in-the-nile-2012-10">threaten to go to war</a> to maintain Egypt’s acquired rights. </p>
<p>In accordance with the spirit of the 1929 Anglo-Egyptian Treaty, colonial Uganda was forced to submit the documents for constructing the Owen Falls dam to Cairo for approval.</p>
<p>The construction of the dam would be the responsibility of the UEB, which was also to administer and maintain the project. However, the interests of Egypt were to be represented at the construction site by an Egyptian resident engineer, who would instruct the UEB on the discharges to be passed through the dam.</p>
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<a href="https://theconversation.com/nile-basin-at-a-turning-point-as-ethiopian-dam-starts-operations-178267">Nile basin at a turning point as Ethiopian dam starts operations</a>
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<p>It is no wonder that when Ethiopia announced its intention in 2011 to construct a <a href="https://www.brookings.edu/blog/africa-in-focus/2020/08/05/the-controversy-over-the-grand-ethiopian-renaissance-dam/">dam on the Blue Nile</a>, Egypt sought similar concessions. Just as it had demanded of colonial Uganda, Egypt sought to maintain technical staff at the site of Ethiopia’s dam to monitor its operations.</p>
<h2>Racism on site</h2>
<p>The racist foundations of colonialism were quite evident at the Owen Falls dam site. For example, after estimating that the job would require a labour force of 2,000, the UEB built labour quarters for Europeans and Asians, complete with a club, community centre and swimming pool, at the Amberly Estate north of Jinja. </p>
<p>But it chose to house all African staff in quarters located across the bridge in Njeru. </p>
<p>These discriminatory economic and social policies would spill into the post-independence period and be exploited by dictator <a href="https://theconversation.com/thousands-of-recently-discovered-photographs-document-life-in-uganda-during-idi-amins-reign-119131">Idi Amin</a> for his personal interests.</p>
<p>When <a href="https://www.bbc.com/news/uk-61585886">she died on 8 September 2022</a>, some Ugandans remembered Queen Elizabeth II as the young monarch who, in 1954, inaugurated the Owen Falls dam as a symbol of energy independence and ushered in a new era of industrialisation and economic development in Uganda. </p>
<p>But others remember her as the person who, over 70 years, presided over a country that reminds them of brutal exploitation, including the theft of their resources.</p><img src="https://counter.theconversation.com/content/190719/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>John Mukum Mbaku is affiliated with Weber State University (Ogden, Utah, USA) and The Brookings Institution (Washington, D.C.)</span></em></p>The mega dam in Jinja was meant to give Uganda energy independence, but this was constrained by Britain’s agricultural interests in Egypt.John Mukum Mbaku, Professor, Weber State UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1391392020-06-09T14:37:58Z2020-06-09T14:37:58ZLake Victoria could burst its banks more often in the future. What can be done<figure><img src="https://images.theconversation.com/files/336755/original/file-20200521-102678-1fa4gq1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Parts of Kenya have flooded as a result of Lake Victoria's rising levels</span> <span class="attribution"><span class="source">Photo by CASMIR ODUOR/AFP via Getty Images</span></span></figcaption></figure><p>In recent weeks, water levels in Lake Victoria have reached unprecedented heights as a result of heavy rains in the East African region which started in August 2019. <a href="https://reliefweb.int/report/ethiopia/eastern-africa-region-floods-and-locust-outbreak-snapshot-may-2020">Some say</a> the lake’s levels have not been this high for 50 years. According to the Lake Victoria Basin Commission, the lake hit a <a href="https://www.theeastafrican.co.ke/news/ea/Lake-Victoria-water-rises-to-historic-levels/4552908-5556404-n0j7crz/index.html">new record</a> level of 13.42 meters – marginally higher than the 13.41 meter mark recorded in 1964.</p>
<p>Nestled between Rwanda, Burundi, Uganda, Kenya and Tanzania, Lake Victoria supports the livelihoods of over <a href="https://books.google.co.ke/books?id=msJADwAAQBAJ&pg=PA206&lpg=PA206&dq=35+million+people+livelihoods+lake+victoria&source=bl&ots=ze_URRD5p8&sig=ACfU3U0_NP894P3hs6m7X1eEpUtFBeGZJw&hl=en&sa=X&ved=2ahUKEwj87PWj9MTpAhWmzYUKHXVxDzIQ6AEwAXoECAkQAQ#v=onepage&q=35%20million%20people%20livelihoods%20lake%20victoria&f=false">35 million</a> people and is crucial for many sectors. The rising water levels have been devastating, particularly for those that live close to the lake and depend on it. </p>
<p>The lake supports fisheries, agriculture (through providing irrigation), hydropower (mainly for Uganda), domestic water supply and industry.</p>
<p>The lake is also an important tourist destination and provides the habitat for many key species – such as endemic cichlid fishes, birds and sitatunga antelopes.</p>
<p>Because of the floods, it’s <a href="https://www.theeastafrican.co.ke/news/ea/Lake-Victoria-water-rises-to-historic-levels/4552908-5556404-n0j7crz/index.html">been reported</a> that over 200,000 people have been displaced in Kenya, Uganda and Tanzania.</p>
<p>The floods have destroyed infrastructure, farmland and crops, and property around the lake. They have also increased the spread of pollution. This is increasing water treatment costs and affecting those living in the surrounding areas. There are now concerns that there will be <a href="https://theconversation.com/lockdown-and-flooding-raise-the-risk-of-a-spike-in-mosquito-borne-diseases-in-kenya-139129">outbreaks</a> of vector borne diseases – such as malaria and bilharzia – and gastrointestinal diseases such as cholera.</p>
<h2>Heavy rains</h2>
<p>The rains the region received were unusually heavy and attributable to the <a href="https://theconversation.com/kenya-is-experiencing-strange-weather-whats-behind-it-131480">Indian Ocean Dipole</a> – a weather phenomenon caused by differences in sea surface temperatures between the eastern and western tropical Indian Ocean. Last year, the differences in temperatures were higher than usual, causing much more rainfall over East Africa from September to January. </p>
<p>Though the rain caused by the dipole have ended, the region then moved into its rainy season which typically runs from March to May. </p>
<p>Lake Victoria has an enormous surface area of 68,800sqkm. Rainfall is very important for the lake as it <a href="https://www2.meteo.uni-bonn.de/bibliothek/Flohn_Publikationen/K321-K349_1985-1990/K321.pdf">accounts for</a> 80% of its recharge. The 23 rivers that recharge the lake <a href="https://www2.meteo.uni-bonn.de/bibliothek/Flohn_Publikationen/K321-K349_1985-1990/K321.pdf">account for only</a> 20% of its input. </p>
<p>From <a href="https://www.mdpi.com/2073-4441/11/7/1449">research</a> my colleagues and I have done – examining the projected changes in weather in the Lake Victoria basin – we’ve found that these high water levels will be more frequent in the future because there’ll be much more rainfall. </p>
<p>The aim of our study was to look at how the rivers that drain into the Lake Victoria basin will change as a result of <a href="https://www.ipcc-data.org/guidelines/pages/glossary/glossary_r.html">increased</a> greenhouse gases in the atmosphere.</p>
<p>We show that, between 2036 and 2065, there will be 25% more annual rainfall in the eastern part of the lake Victoria catchment (Kenya and Tanzania side) area and between 5 and 10% in the western part of the catchment (Rwanda and Burundi side). </p>
<p>Our models use data from the <a href="https://www.smhi.se/en/research/research-departments/climate-research-rossby-centre2-552/about-rossby-centre-1.8341#:%7E:text=The%20regional%20climate%20models%20developed,vegetation%20processes%2C%20RCA%2DGUESS.">Rossby Center Regional Atmospheric Model</a> along with the global climate model from the <a href="https://www.wcrp-climate.org/news/wcrp-newsletter/wcrp-news-articles/1347-wcrp-spotlight-the-coordinated-regional-climate-downscaling-experiment-cordex#:%7E:text=The%20Coordinated%20Regional%20Climate%20Downscaling%20Experiment%20(CORDEX)%20is%20a%20Programme,climate%20downscaling%20through%20global%20partnerships.">Coordinated Regional Climate Downscaling Experiment project</a>. </p>
<p>We coupled this with information on how much greenhouse gas there could be in the future. There are a series of scenarios – known as <a href="https://www.ipcc-data.org/guidelines/pages/glossary/glossary_r.html">Representative Concentration Pathways</a> – which represent what could happen in the future based on different emission trajectories. The more pessimistic scenarios, for instance, assume that no climate change policies are implemented and so there is an increase in greenhouse gases. These, more pessimistic, scenarios are what we based our models on.</p>
<p>Our data shows how much rain there could be. Lake Victoria is an open lake meaning whenever the lake level rises, spill-off should occur – this makes it hard to predict how much the lake will rise because the control of the spillover is through manmade dams in Jinja. </p>
<p>When the lake’s levels do get high, there are measures that countries affected can take to mitigate the effects – but they are not easy. They require careful planning and availability of funds.</p>
<h2>What can be done</h2>
<p>It’s all about managing the inputs and outputs and developing floodplain regulations.</p>
<p>The first step will be to plan how to reduce the flow of water into the lake by creating <a href="https://training.fema.gov/hiedu/docs/fmc/chapter%207%20-%20flood%20damage%20reduction%20strategies%20and%20tools.pdf">storage</a> within the catchments – such as dams or reservoirs – or finding ways <a href="https://training.fema.gov/hiedu/docs/fmc/chapter%207%20-%20flood%20damage%20reduction%20strategies%20and%20tools.pdf">to divert</a> the water – for instance through the use of canals or spillways.</p>
<p>However this will only manage 20% of what goes into the lake, as most of the recharge is because of rainfall. So we need to also consider outputs.</p>
<p>The only surface outlet of the lake is through the Victoria Nile river which forms the upper section of the Nile River. The Kiira and Nalubale dams, in Jinja, control the outflow of Lake Victoria into this river. Dam management scenarios that regulate the outflow to mimic natural lake level fluctuations are needed. </p>
<p>There are <a href="https://www.nation.co.ke/news/experts-point-accusing-finger-at-Uganda/1056-5560152-gve7y4/index.html">currently tensions</a> over this, as there are accusations that Uganda could have done more to prevent the current floods by regulating the dams better. More must be done to ensure this does not happen again and that countries have strict agreements in place. </p>
<p>In addition to managing the lake’s levels through inputs and outputs, its extremely important that the region increases investments in monitoring systems that provide national early warning and communication. This will alert residents in a timely manner.</p><img src="https://counter.theconversation.com/content/139139/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Lydia Olaka 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 flooding has affected water resources, agriculture and food security, health and sanitation, fisheries, and energy and infrastructure.Lydia Olaka, Lecturer, University of NairobiLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1293612020-01-26T09:53:04Z2020-01-26T09:53:04ZIn 100 000 years Lake Victoria has dried up three times. It could happen again<figure><img src="https://images.theconversation.com/files/310208/original/file-20200115-151862-1yh9nzx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Lake Victoria</span> <span class="attribution"><span class="source">Aleksandr Stezhkin/Shutterstock</span></span></figcaption></figure><p>Lake Victoria, in East Africa, is the world’s largest tropical freshwater lake. At <a href="https://www.researchgate.net/publication/229541663_Management_issues_in_the_Lake_Victoria_watershed">68,800km²</a>, it’s also the second largest freshwater lake in the world after Lake Superior in North America. On a clear day you cannot see the other side of Lake Victoria, yet this vast body of water <a href="https://science.sciencemag.org/content/331/6022/1299">has dried up</a> several times in the past – and it could happen again. </p>
<p>Over the past 100,000 years, the lake has completely dried up <a href="https://www.sciencedirect.com/science/article/pii/S0012821X19305758?via%3Dihub">at least</a> three times. Each time it was probably replaced by a vast grassland.</p>
<p>My colleagues and I <a href="https://www.sciencedirect.com/science/article/pii/S0012821X19305758?via%3Dihub">found that</a> the lake could dry up again in as little as 500 years because of changes in temperature, rainfall and orbital forcing – the effect on climate of slow changes in the tilt of the Earth’s axis. Our predictions are based on historical and geologic data from the last 100,000 years. </p>
<p>Inadequate and conflicting data on long term weather trends make it hard to be conclusive. And we can’t be sure of how climate will change in the future due to human actions without more data. Over the past few decades, the frequency of drought in East Africa <a href="https://earthobservatory.nasa.gov/images/51411/severe-drought-causes-famine-in-east-africa">has increased</a> but <a href="https://agupubs.onlinelibrary.wiley.com/doi/10.1002/9781119068020.ch16">climate models</a> project an overall increase in rainfall over the next century for this area. </p>
<p>Previous studies on Lake Victoria’s future water levels have been done, but didn’t have evidence for past changes in rainfall or include orbital forcing.</p>
<p>Based on historical and geologic observations, our findings show that Lake Victoria can dry up very quickly with small decreases in annual rainfall. Knowing whether rainfall is going to increase or decrease over the next 100 years becomes very important. </p>
<p>Today about <a href="https://earthobservatory.nasa.gov/features/Victoria/victoria2.php">30 million</a> people in Rwanda, Burundi, Uganda, Kenya and Tanzania rely on the lake for fishing, irrigation, drinking water and, in Uganda, electricity. Lake Victoria is also the source of one of the River Nile’s major tributaries, the White Nile. About <a href="https://theconversation.com/in-the-future-there-will-be-more-rain-but-less-water-in-the-nile-basin-129360">250 million people</a> rely on the Nile in Ethiopia, Uganda, South Sudan, Sudan and Egypt. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/in-the-future-there-will-be-more-rain-but-less-water-in-the-nile-basin-129360">In the future there will be more rain, but less water, in the Nile Basin</a>
</strong>
</em>
</p>
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<p><a href="https://www.tralac.org/news/article/13721-east-africa-the-fastest-growing-region-in-africa-with-people-leading-longer-and-healthier-lives.html">Huge population growth</a> is expected in the region. All these people will increasingly rely on the lake because the region <a href="https://www.ipcc.ch/report/ar5/wg2/">is warming</a> and may receive <a href="https://www.ipcc.ch/report/ar5/wg2/">less annual rainfall</a> due to global climate change.</p>
<h2>Factors that affect the lake level</h2>
<p>For our research, we needed to examine all the factors that could affect the size and level of Lake Victoria, including rainfall, temperature, evaporation and rivers flowing into and out of the lake. </p>
<p>The main inflow is the Kagera River, which drains the highlands of Rwanda and Burundi. The White Nile flows out of the lake. It also loses a lot of water to evaporation which, at the equator, is very high due to intense sunlight – <a href="https://www.tandfonline.com/doi/abs/10.1080/02626669809492173">almost equal</a> to the amount of rainfall falling on the lake.</p>
<p>From <a href="https://science.sciencemag.org/content/331/6022/1299">previous research</a> we knew that the lake dried up twice, at 17,000 and 15,000 years ago.</p>
<p>To reconstruct lake levels as far back as 18,000 years, scientists examined diatoms (a type of algae) collected from the bottom of the lake to see how fresh or brackish the water used to be. Brackish diatoms indicate lower lake levels because the water becomes saltier as the water evaporates. </p>
<p>Our <a href="https://www.sciencedirect.com/science/article/pii/S0012821X19305758?via%3Dihub">new research</a> examined the chemistry of fossil soils along the edge of the lake to understand past changes in the amount of rainfall. Because the orbit of the Earth around the sun has varied, we also looked at how sunlight reaching the Earth has changed, and will change. </p>
<p>Using all this information we were able to create a model of the lake’s past, present, and future. </p>
<h2>Drying up</h2>
<p>Our findings <a href="https://www.sciencedirect.com/science/article/pii/S0012821X19305758?via%3Dihub">show that</a> the amount of annual rainfall in the Lake Victoria Basin must continue to be at least 75% of current rainfall amounts (105 cm each year) or the lake will disappear.</p>
<p>Once the lake has dried up rainfall needs to be at least 131 cm every year to refill the lake. Depending on other changes in the weather, this could take between hundreds and thousands of years. If there was less than 94% of today’s rainfall, it would take at least 10,000 years to refill.</p>
<p>Climate models <a href="https://www.ipcc.ch/report/ar5/wg2/">all predict</a> an increase in temperature over the next 100 years, which will affect evaporation for this region. </p>
<p>Previous drops in lake levels over the last 60 years were caused by a natural decrease in annual rainfall and by Uganda releasing more than the agreed upon water to generate electricity. We found that if previously observed natural rates of lake level fall are projected into the future, the White Nile could stop flowing out of Lake Victoria in as little as 10 years at the fastest rates. But we need more research to know just how likely this is. </p>
<h2>Delicate balance</h2>
<p>Our research shows just how delicate the balance is between rainfall and evaporation for Lake Victoria. The lake could dry up in as little as 500 years. But the consequences of falling levels for people living around it would begin much sooner.</p>
<p>For Uganda, this would mean the loss of its <a href="https://energypedia.info/wiki/Uganda_Energy_Situation#Energy_demand">primary source</a> of electricity. The White Nile also <a href="https://www.hydrol-earth-syst-sci.net/22/5509/2018/">sustains</a> the Nile during the dry seasons.</p>
<p>In as little as 100 years, the major port cities around Lake Victoria could lose access because the lake has shrunk. Currently these cities depend on the income generated from the fishing industry and fresh water.</p>
<p>Kenya could lose all access to the lake in 400 years. This sets up a potentially dangerous dynamic between Kenya and Uganda, which already fight over fishing rights – very lucrative due to the <a href="https://www.aljazeera.com/indepth/inpictures/migingo-island-africas-smallest-war-190217150742518.html">1 million pounds</a> of fish harvested from the lake every year.</p>
<h2>Increased monitoring</h2>
<p>There is an urgent need for a greater understanding of how rainfall will change in this region. Lake Victoria’s continued existence is directly related to rain and evaporation. </p>
<p>We need to increase monitoring of temperatures, precipitation and other weather data, such as humidity, in the region. We must also measure the water flowing into and out of Lake Victoria via all the rivers. </p>
<p>A greater understanding of the lake’s history would also improve our ability to understand any patterns in the lake drying up. Deeper drilling for sediment samples would provide information to help us predict and prepare for the potential future of Lake Victoria.</p><img src="https://counter.theconversation.com/content/129361/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Emily J. Beverly receives funding from the National Science Foundation, National Geographic, and the Leakey Foundation. </span></em></p>Lake Victoria’s past is key to understanding its future.Emily J. Beverly, Assistant Professor, University of HoustonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1126412019-03-10T09:24:42Z2019-03-10T09:24:42ZCage farming can protect Lake Victoria’s fish. But regulations need tightening<figure><img src="https://images.theconversation.com/files/261865/original/file-20190304-110123-zekigp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Cage farming is when fish are raised and harvested in a netted enclosure.</span> <span class="attribution"><span class="source">Ranko Maras/Shutterstock</span></span></figcaption></figure><p>Lake Victoria’s fish stocks are <a href="https://www.businessdailyafrica.com/news/counties/Lake-Victoria-Nile-Perch-stocks-drop-over-pollution/4003142-4141910-qex4b6z/index.html">struggling</a> to keep up with demand.
For instance, stocks and catches of Nile perch <a href="https://theconversation.com/how-corruption-encourages-illegal-fishing-on-lake-victoria-97812">have reduced</a>, from 340,000 tons in 1990 to about 251,000 in 2014. Though there’s no official figure, from our discussions with fisheries stakeholders we know that the tonnage on the Kenyan side now stands at about 99,000.</p>
<p>Nestled between Tanzania, Uganda, Kenya, Burundi and Rwanda, millions of people depend on the lake. In 2010 there were <a href="https://www.researchgate.net/publication/256096790_Using_New_Methods_and_Data_to_Assess_and_Address_Population_Fertility_and_Environment_links_in_the_Lake_Victoria_Basin">about</a> 42.4 million and it’s <a href="https://www.researchgate.net/publication/256096790_Using_New_Methods_and_Data_to_Assess_and_Address_Population_Fertility_and_Environment_links_in_the_Lake_Victoria_Basin">projected</a> that by 2030 there will be almost double – about 76.5 million. About 3 million people rely directly on fisheries for food, and <a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1440-1770.2007.00358.x">about</a> 30 million from the East African region rely on them for their livelihoods. </p>
<p>There’s also international demand for the Lake’s fish. Catches of leading commercial species – Nile perch and Nile tilapia – are now <a href="https://slate.com/news-and-politics/2015/03/lake-victoria-is-in-grave-danger-africas-largest-lake-is-threatened-by-pollution-and-overfishing.html">primarily</a> caught for export, mostly going to Europe and Asia. </p>
<p>These challenges to natural fish stocks <a href="https://doi.org/10.1111/fme.12283">are</a> compounded by over-fishing and illegal and unregulated fishing activities.</p>
<p>In <a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/fme.12334">our research</a>, we argue that cage aquaculture or farming, where fish are raised and harvested in a netted enclosure in an existing water system, could provide an alternative to how fish are produced. This could increase fishery production without damaging wild stocks. </p>
<p>Cage farmers in Kenya – where most of Lake Victoria’s cage activity is based – <a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/fme.12334">currently produce</a> about 40,000 tons of fish per year. By comparison, 99,000 tons of wild fish were landed in Kenya in 2016. </p>
<p>Catching wild fish, with nets or lines, and cage farming are the only two ways fish are harvested from the lake. But for both production mechanisms to remain in harmony, there needs to be proper regulations on cage farming. These will improve coordination and collaboration between everyone involved, and ensure that the harvesting of fish is done without harming the environment. </p>
<h2>Cage farming</h2>
<p>Cage farming is when a netted enclosure is suspended in an aquatic environment – like a sea or lake. This enclosure houses fish or other aquatic products. </p>
<p>The practice <a href="https://www.researchgate.net/publication/230167317_Cage_culture_development_and_its_role_in_aquaculture_in_China">dates back</a> many centuries in China, though in <a href="http://www.fao.org/3/a-i5555e.pdf">most</a> African countries it’s a new technology. </p>
<p>In the case of Lake Victoria, it’s been there for about 13 years and involves private sector players, development agencies – like the EU funded cage farming <a href="https://cordis.europa.eu/project/rcn/81317/reporting/en">project</a> – and small-scale fisheries. </p>
<p>Today cages are concentrated along the Kenyan side of Lake Victoria. And the industry is quickly <a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/fme.12334">gaining ground</a>. Currently, there are about 4,000 cages of varying sizes, but mainly of 2 by 2 by 2 square metres in the lake under 60 different owners. Most of the cages are individually owned (62%), while groups (38%) own others.</p>
<p>As <a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/fme.12334">an alternative</a> to traditional pond culture systems on land, cage farming can overcome some of the conventional fish farming constraints. This has helped it to grow in popularity.</p>
<p>These <a href="https://www.researchgate.net/publication/287293649_Tilapia_Culture">include</a>: </p>
<ul>
<li><p>There’s very high production of fish per unit volume of water </p></li>
<li><p>Relatively less investment is needed per unit of production <a href="http://article.sciencepublishinggroup.com/pdf/10.11648.j.aff.20180702.12.pdf">compared to</a> pond or land culture. The cost of starting up a cage industry – including cage material, feeds, fingerlings, security, a boat for accessing the cages, and labour – <a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/fme.12334">can range</a> between US$4,300 to US$590,000. There is a huge variation in cost because the cages, source of materials and size of the operations vary greatly. </p></li>
<li><p>Use of existing water bodies reduces water demands on land and also means the industry is less affected by drought.</p></li>
<li><p>Ease of relocation of cages from one site to another and there’s also ease of accessibility for operational practices, such as feeding and cleaning the nets.</p></li>
</ul>
<p>Ultimately, the profitability of cage farming depends, among other things, on which species is cultured, management level, input costs, and market prices. </p>
<h2>Challenges</h2>
<p>But cage farming does have its challenges – and so it’s vital that proper policies are in place to address these. </p>
<p>In the long-run, cage farming may create new environmental challenges. These <a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/fme.12334">include</a> the discharge of nutrients from the fish feed and excretions which could lead to <a href="https://doi.org/10.1111/fme.12283">changes</a> in the ecosystem. </p>
<p>Farmed fish may also escape and interact with other fish in the wild which can spread disease and parasites. </p>
<p>These impacts can, in turn, decrease local catch of wild fish, creating a conflict between cage culture and fishermen. This is already a delicate situation because of competition over lake space.</p>
<p>It’s important that proper regulation is put in so that cage culture reduces poverty, provides food and boosts the income of the fishers, while reducing pressure on capture fisheries. </p>
<p>Guidelines by the East African Community for cage farming <a href="http://www.lvfo.org/sites/default/files/Final%20FMP%20III%202016%20to%202020_0.pdf">already exist</a>, but these must be enforced and other regulations developed. These include: </p>
<ul>
<li><p>Moving the cages to deep waters (about 10 metres depth) where there’s more oxygen and the flow of water helps them to “self-clean”</p></li>
<li><p>Farmers must have access to mapping tools so they know the right place to install their cages. This will protect navigation of other boats, and natural fish breeding zones and fishing areas to avoid conflicts.</p></li>
<li><p>Cleaning cage netting regularly to avoid fouling and clogging.</p></li>
<li><p>Use of floating feeds to avoid excessive accumulation of uneaten feeds.</p></li>
<li><p>Develop business plans for cage enterprises to track their operations, monitor progress, and make adjustments for improved performance.</p></li>
<li><p>Involve a good number of vulnerable communities – like women – by giving them start-up capital</p></li>
<li><p>Insuring operations against risks and losses.</p></li>
</ul>
<p>With this proper regulation, Lake Victoria’s fisheries stand a good chance of increased production without damaging wild stocks or the environment.</p><img src="https://counter.theconversation.com/content/112641/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>James Njiru works for Kenya Marine and Fisheries Research Institute, Mombasa, Kenya. He receives funding from Kenya Marine and Fisheries Research Institute</span></em></p><p class="fine-print"><em><span>Christopher Aura receives funding from Kenya Marine and Fisheries Research Institute</span></em></p>With proper regulation, Lake Victoria’s fisheries could increase production without damaging wild stocks or the environment.James Njiru, Professor and Director of Kenya Marine and Fisheries Research Institute, Kenya Marine and Fisheries Research InstituteLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1111232019-02-27T13:53:19Z2019-02-27T13:53:19ZEarth observation data offers hope for Africa’s wetlands<figure><img src="https://images.theconversation.com/files/257194/original/file-20190205-86213-1nuraon.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Botswana's Okavango Delta.</span> <span class="attribution"><span class="source">Shutterstock/Gaston Piccinetti</span></span></figcaption></figure><p>Wetlands <a href="https://africa.wetlands.org/en/wetlands/what-are-wetlands/">support</a> millions of people around Africa. They include all areas that are permanently or frequently covered by water, and could be at the edge of a lake or the mouth of a river. </p>
<p>Wetlands <a href="http://www.iwmi.cgiar.org/Publications/IWMI_Research_Reports/PDF/PUB137/RR137.pdf">offer a</a> source of freshwater, fisheries, moist soil for farming and wild plants for food, construction and medicinal uses. They also help to control floods, maintain rivers in dry seasons, recharge groundwater and purify water.</p>
<p>But despite their importance, they remain among the most <a href="https://www.ramsar.org/sites/default/files/flipbooks/ramsar_gwo_english_web.pdf">threatened</a> ecosystems in the world. Between 1970 and 2015, inland and coastal wetlands both declined <a href="https://www.ramsar.org/sites/default/files/flipbooks/ramsar_gwo_english_web.pdf">by about</a> 35% globally. That’s three times the rate of global forest loss. This is a huge loss to important flora and fauna and a critical loss to the many people who relied on them for their livelihoods. </p>
<p>In Africa, <a href="https://www.ramsar.org/sites/default/files/documents/library/bn7e_0.pdf">three things</a> contribute to the decline of wetlands: growing populations, economic development and climate change. </p>
<p>For example, Lake Chad and Lake Victoria have both undergone significant change in recent years because of human activity. Lake Chad has shrunk by 90% partly <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5055484/">because</a> its water is being used for irrigation. Lake Victoria has experienced dramatic changes <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1690894/pdf/11839198.pdf">because of</a> the introduction of Nile perch, sewage inflows and more sedimentation and nutrients from increased agriculture in the basin. </p>
<p>Part of the solution to protecting wetlands is through the creation of accurate inventories. Inventories provide essential information – like the type of wetland, exact geographic location and area – needed for effective wetland management. But despite their importance, <a href="https://www.ramsar.org/sites/default/files/flipbooks/ramsar_gwo_english_web.pdf">less than</a> 35% of African nations have a national wetland inventory. </p>
<p>Gathering data from satellite based sensors, called Earth observation data, could offer a solution. These could feed into national inventories by providing valuable information on the status and physical characteristics of the Earth’s wetlands.</p>
<h2>Wetland inventories</h2>
<p>Wetlands cover <a href="https://www.ramsar.org/sites/default/files/flipbooks/ramsar_gwo_english_web.pdf">about 4.7%</a> (1.15million km²) of Africa’s continental area – about the same size as Ethiopia. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/260373/original/file-20190222-195853-1gep49f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/260373/original/file-20190222-195853-1gep49f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=397&fit=crop&dpr=1 600w, https://images.theconversation.com/files/260373/original/file-20190222-195853-1gep49f.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=397&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/260373/original/file-20190222-195853-1gep49f.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=397&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/260373/original/file-20190222-195853-1gep49f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=499&fit=crop&dpr=1 754w, https://images.theconversation.com/files/260373/original/file-20190222-195853-1gep49f.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=499&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/260373/original/file-20190222-195853-1gep49f.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=499&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Women plant rice in a paddy field in Madagascar.</span>
<span class="attribution"><span class="source">Hajakely/Shutterstock</span></span>
</figcaption>
</figure>
<p>Covering 692,631km2, <a href="https://www.ramsar.org/sites/default/files/flipbooks/ramsar_gwo_english_web.pdf">freshwater marshes</a> are the most extensive wetland type within the region. And <a href="https://www.ramsar.org/sites/default/files/flipbooks/ramsar_gwo_english_web.pdf">about 65%</a> of wetland area is located within the four largest river basins on the continent –- the Chad, Congo, Niger and Nile river basins. </p>
<p>But there is considerable uncertainty in these figures. This is because countries either don’t have them, or because they classify and create wetland inventories in <a href="https://www.ramsar.org/sites/default/files/documents/pdf/lib/hbk4-15.pdf">different</a> ways. </p>
<p>Comprehensive and up-to-date national wetland inventories are vital. A <a href="https://medwet.org/aboutwetlands/wetland-terminology/">wetland inventory</a> typically involves the collection and presentation of data on wetlands within a certain area. It covers attributes like; location, type, area, uses, ownership, physical characteristics, the organisms that live in it and the challenges it faces. </p>
<p>This information is essential for policy-making and management. It can also be used to establish baselines against which the effectiveness of policies can be <a href="https://www.ramsar.org/sites/default/files/documents/library/rtr10_earth_observation_e.pdf">assessed</a>.</p>
<p>Developing a comprehensive inventory has its challenges, but increasingly available <a href="https://www.asf.alaska.edu/wetlands/">Earth observation data</a> can help. By collecting data from satellites, we can describe many types of wetland over huge areas. The data are also more efficient and reliable as consistent methodologies can be applied nationally for a particular wetland type. They are also more
affordable as many wetland areas are difficult to access on the ground. </p>
<p>Aside from flagging challenges to wetlands, this sophisticated data can be used to identify where things can be improved. </p>
<p>For example, the <a href="https://www.mdpi.com/2072-4292/10/10/1669">first</a> global study to map mangroves consistently across time using Earth Observation data showed that 20% of the world’s mangroves are found along African coastlines. Further assessment showed that over the past 20 years, about 6% in East and Southern Africa have become degraded, and about 2% in West and Central Africa. However, the majority of these – over 90% – have the potential to <a href="http://maps.oceanwealth.org/mangrove-restoration/">be restored</a>. </p>
<p>Based on the global mangrove maps and associated tool, decision-makers are given the information they needed to determine where restoration can be attempted by identifying locations where mangroves once thrived, and where conditions are still suitable for restoration.</p>
<p>With this information policymakers can support communities so that they can then use <a href="http://theconversation.com/how-farmers-in-africa-are-finding-ways-to-sustainably-use-wetlands-72104">local knowledge</a> to manage the wetlands themselves.</p><img src="https://counter.theconversation.com/content/111123/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Lisa Rebelo receives funding from the CGIAR program Water Land and Ecosystems, supported by CGIAR Trust Fund Contributors, including: ACIAR, DFID, DGIS, SDC, and others</span></em></p><p class="fine-print"><em><span>Matthew McCartney receives funding from the CGIAR program Water Land and Ecosystems, supported by CGIAR Trust Fund Contributors, including: ACIAR, DFID, DGIS, SDC, and others</span></em></p>Wetlands are disappearing rapidly - but new data and technologies are revolutionising our knowledge.Lisa Rebelo, Senior Researcher – Remote Sensing & GIS, International Water Management InstituteMatthew McCartney, Principal Researcher, CGIAR System OrganizationLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1033532018-11-04T08:49:30Z2018-11-04T08:49:30ZAgreements that favour Egypt’s rights to Nile waters are an anachronism<figure><img src="https://images.theconversation.com/files/243213/original/file-20181031-76390-ln4mz2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The Nile River during sunset in Luxor, Egypt.</span> <span class="attribution"><span class="source">EPA-EFE/Khaled Elfiqi</span></span></figcaption></figure><p>Egypt has historically adopted an aggressive approach to the flow of the River Nile. Cairo considers the Nile a national security matter and statements continue to include <a href="https://www.alaraby.co.uk/english/news/2017/11/19/egypts-sisi-warns-ethiopia-over-dam-construction-project">threats of military action</a> against Ethiopia should it interfere with the flow as set out in agreements signed in <a href="http://treaties.fco.gov.uk/docs/pdf/1929/TS0017.pdf">1929</a> and another in <a href="https://www.internationalwaterlaw.org/documents/regionaldocs/UAR_Sudan1959_and_Protocol1960.pdf">1959</a>. </p>
<p>The first agreement was made between Great Britain, as the colonial power in eastern African, and Egypt. Cairo was favoured over other riparian countries as an important agricultural asset. In addition, the Egyptian-run Suez Canal was vital for British imperial ambitions.</p>
<p>The British riparian colonies – Sudan, Uganda, Kenya and Tanganyika (now Tanzania) – as well as Ethiopia had no say. </p>
<p>Under the terms, Egypt would receive 48 billion cubic metres water annually and Sudan 4 billion cubic metres. Egypt would not need the consent of upstream states to undertake water projects in its own territories but could veto projects on any tributaries of the Nile in the upstream countries, including the 43,130 square kilometre Lake Victoria. The world’s second largest fresh water lake is fed by direct precipitation and by thousands of streams from Tanzania, Burundi, Uganda and Kenya, all located in the central east of Africa. </p>
<p>To this day Egypt argues that the 1929 Anglo-Egyptian Treaty and its modified version, the 1959 Agreement, are still <a href="https://www.npr.org/templates/story/story.php?storyId=130266337">valid</a>. The 1959 agreement, signed by Egypt and an independent Sudan, increased Egypt’s share to 55.5 billion cubic metres and Sudan’s to 18.5 billion. </p>
<p>These bilateral agreements totally ignored the needs of other riparian countries including Ethiopia which <a href="https://www.jpost.com/Opinion/Egypt-Ethiopia-and-the-Nile-447910">supplies 70% to 80% of the Nile waters</a>. Consequently, none of the other Nile basin countries has ever approved the <a href="https://doi.org/10.5539/jms.v4n3p108">agreements</a>. </p>
<p>On the other hand, the <a href="http://www.nilebasin.org/index.php/nbi/cooperative-framework-agreement">Cooperative Framework Agreement</a> signed by four Nile basin countries in 2010 was strongly <a href="http://news.bbc.co.uk/2/hi/africa/8682387.stm">rejected by both Egypt and Sudan</a>. </p>
<p>It’s <a href="https://doi.org/10.1080/00207233.2018.1509564">my argument</a> that the strength of past agreements in modern times and Egypt’s threats to use military force are questionable for two reasons. First, the former colonies are now independent nations and should be part of negotiating a new deal. Secondly, environmental circumstances have changed: precipitation is becoming more intermittent and periods of drought are getting longer. </p>
<h2>Egypt’s security approach</h2>
<p>The threat to use force to defend Egypt’s right to water from the Nile has been a common theme through successive governments.</p>
<p>The current president of Egypt Abdel Fattah al-Sisi has described the flow of Nile to Egypt as <a href="http://english.ahram.org.eg/NewsContent/1/64/281712/Egypt/Politics-/Egypts-Nile-water-share-a-matter-of-life-or-death,.aspx">a matter of life and death</a>. Badr Abdelatty, Egypt’s ambassador to Germany and former spokesman of the Foreign Ministry, has described the Nile as <a href="https://www.bbc.com/news/world-africa-26679225">“a national security issue that can never be compromised on</a>”.</p>
<p>Even Anwar el-Sadat, the president of Egypt in the 1980s, threatened the use of force. He <a href="https://www.ibtimes.co.uk/grand-ethiopian-renaissance-dam-nile-water-dispute-1597589">stated that</a> </p>
<blockquote>
<p>if Ethiopia takes any action to block our right to the Nile waters, there will be no alternative for us but to use force. Tampering with the rights of a nation to water is tampering with its life, and a decision to go to war on this score is indisputable in the international community. </p>
</blockquote>
<p>He believed that after signing the Camp David Peace Accords with Israel in 1979, no other problem could again take Egypt to war except water. </p>
<p>The threat of using force has continued. But a security mindset is not going to guarantee Egypt its past share of the waters.</p>
<h2>Ethiopia’s Grand Renaissance Dam</h2>
<p>Ethiopia’s <a href="https://www.bbc.com/news/world-africa-26679225">Grand Renaissance Dam</a> constitutes a recent but probably the biggest challenge to Egypt’s militaristic approach to the Nile flow. The dam is a huge project on the headwaters of the Blue Nile in Ethiopia in Benishangul-Gumuz region, 500 km North West of the capital Addis Ababa and about 32 km east of the border of Sudan. </p>
<p>The dam is considered to be the largest hydropower project in Africa and 8th-largest in the world. It’s designed to generate 6,000 megawatts of electricity. The reservoir can hold <a href="https://www.hydroworld.com/articles/2016/09/contract-awarded-for-studies-of-6-000-mw-grand-renaissance-dam-in-ethiopia.html">more than 70 billion cu metres of water</a> which is <a href="http://www.fao.org/docrep/015/an530e/an530e.pdf">nearly equal to the flow of the Nile in one year</a>.</p>
<p>The Ethiopian government intends to fill the dam’s immense reservoir in five years. This will have considerable impact on the downstream countries. Even after the reservoir is filled there will not be too much hope for the normalisation of the flow of the Nile because Ethiopia will hold the key to the dam. Normalisation is also not expected because of <a href="https://doi.org/10.5539/jms.v4n3p108">evaporation in the reservoir</a>. </p>
<p>Another challenge to the Nile is the fact that the river is shrinking due to less and more <a href="https://www.independent.co.uk/news/world/africa/ethiopia-drought-floods-starvation-malnourished-crisis-catastrophe-east-africa-a7901156.html">intermittent precipitation in Ethiopia</a> and in other upstream countries. In addition, Lake Victoria, the source of 20%-30% of the Nile waters, is <a href="https://www.nation.co.ke/lifestyle/1190-126958-gjok4nz/index.html">shrinking at an alarming rate</a>. </p>
<p>What these developments mean is that Egypt’s insistence that the old agreements should remain untouched is no longer practical. </p>
<h2>Normal bargaining process</h2>
<p>Egypt needs to stop issuing threats and turn its attention to normal bargaining processes as the first step towards equitable and reasonable sharing for all the riparian states. </p>
<p>Egypt’s threatening stance doesn’t allow compromise because security is directly connected to people’s lives and their survival. But the growing challenges are unlikely to be met with force.</p>
<p>In addition, Ethiopia needs to recognise Egypt’s need for water too and use its large dam for the regulation of the Nile – not its blockage. And all the Nile basin states must cooperate for the peace and prosperity of Africa.</p><img src="https://counter.theconversation.com/content/103353/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Salam Abdulqadir Abdulrahman 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 threat to use force to defend Egypt’s right to water from the Nile has been a common theme through successive governments.Salam Abdulqadir Abdulrahman, Head of Political Science Department, College of Law and Politics, University of Human Development, IraqLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/978122018-09-11T14:40:38Z2018-09-11T14:40:38ZHow corruption encourages illegal fishing on Lake Victoria<figure><img src="https://images.theconversation.com/files/235740/original/file-20180911-144476-5swxqg.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Lake Victoria sees high levels of illegal fishing carried out by local fisherman and traders.</span> <span class="attribution"><span class="source">Shutterstock </span></span></figcaption></figure><p>Illegal fishing is a global challenge. By ignoring legislation, using illegal gear or selling undersized fish, 26 million tons of seafood, estimated at USD$23 billion, is <a href="http://www.fao.org/fao-stories/article/en/c/1136937/">extracted from</a> the oceans each year. While huge international attention is given to illegal fishing in the <a href="https://worldoceanreview.com/en/wor-2/fisheries/illegal-fishing/">marine sector</a>, illegal fishing inland, by small-scale fisheries, is often forgotten. </p>
<p>Lake Victoria is <a href="https://thisisafrica.me/world-water-day-focus-lake-victoria-second-largest-fresh-water-lake-world/">the second</a> largest freshwater body in the world, bordered by Kenya, Tanzania and Uganda. Around <a href="http://www.globalgreatlakes.org/agl/victoria/">one million tons of fish</a> are caught from the lake each year, by around <a href="http://www.lvfo.org/sites/default/files/Final%20FMP%20III%202016%20to%202020_0.pdf">200,000 fishers</a> working from locally-made boats. </p>
<p>It’s widely believed that there are high levels of illegal fishing activity on and around the lake. <a href="https://www.eac.int/press-releases/488-768-190-fisheries-management-plan-iii-fmp-iii-for-lake-victoria-fisheries-launched-in-arusha">This includes</a> the use of nets with small mesh and illegal fishing gear to catch immature fish. Such fishing gear include monofilament nets, which are highly destructive if lost as they continue “fishing”, and beach seines, which are small mesh size nets and therefore are indiscriminate in what they catch. In addition, illegal methods, like tycoon fishing to beat fish into the net, may be carried out near breeding areas. </p>
<p>These methods threaten the sustainability of Lake Victoria’s fisheries. Of particular concern is the Nile perch industry, the most valuable of the three commercial fisheries in the lake. The majority of the catch is exported, contributing greatly to government revenue and local economies. Stocks and catches of perch have <a href="http://www.theeastafrican.co.ke/scienceandhealth/Scientists-alarm-over-decline-Nile-perch-stock-in-Lake-Victoria/3073694-3488878-a92u0a/index.html">reduced</a>, from 340,000 tons in 1990 to about 251,000 in 2014. </p>
<p>To address illegal fishing, a <a href="http://toobigtoignore.net/wp-content/uploads/2016/08/final-Nunan-and-Onyango.pdf">comanagement approach was introduced</a> in the late 1990s. Many inland fisheries <a href="http://www.fao.org/fishery/topic/16625/en">use this</a> arrangement whereby local resource users, including fishers, traders and processors, work with government, and other actors, like NGOs, to manage fisheries. It’s implemented in the hope that by involving the users of the resource, it will encourage more sustainable practices. It is also used when the state doesn’t have the capacity to manage fisheries, including enforcing regulations, on its own. </p>
<p>However, there’s little evidence that the introduction of comanagement has led to a reduction in illegalities – and one of the reasons for this is corruption. </p>
<p>We did <a href="https://www.thecommonsjournal.org/articles/10.18352/ijc.827/">research</a> to find out how corruption affects the comanagement system of Lake Victoria fisheries. We were concerned that comanagement was said to be failing, as illegalities were still widespread, yet there was no link made between corruption and illegal fishing in lake management plans. We believed corruption to be systemic and strongly linked to illegal fishing practices. </p>
<p>Our fears were confirmed. We found that it is a major enabler of illegalities; <a href="https://www.u4.no/publications/illegal-unreported-and-unregulated-fishing-and-corruption/">from</a> paying a bribe to prevent gear from being seized, to receiving advance information on patrols from government officers to avoid arrest. By encouraging illegal fishing to continue, corruption is undermining the comanagement system. </p>
<h2>Corruption and Lake Victoria fisheries</h2>
<p>The lake’s comanagement system is centred around 1,000 community-based beach management units, made up of all those that work in fisheries at a landing site – where fish is brought to shore. There are almost 1,500 landing sites, some are villages, others more temporary settlements. Beach management unit committees of between nine and 15 people are elected to work with government officers in registering fishers, gear, keeping landing sites clean and participating in patrols.</p>
<p>For our research, we conducted 133 interviews with leaders from the beach management units, boat owners, boat crew, fish processors and traders and fisheries officers. These were done at six landing sites in each country bordering the lake – Kenya, Tanzania and Uganda. Respondents were not asked directly about corruption. Instead they were asked about their knowledge, and experience, of illegal fishing and many volunteered information about corruption. </p>
<p>Our research confirmed that corruption exists and perpetuates illegal activity. It’s part of the system and involves all stakeholder groups: fishers, fisheries officers, police and the judiciary. About half the boat owners and boat crew, though fewer fish processors and traders, referred to bribery and corruption when talking about their knowledge and experience of illegal fishing. They explained how enforcement officers demand bribes, rather than take offenders to court, or may arrange for regular payments in exchange for allowing the continued use of illegal gear.</p>
<p>Given the <a href="https://tikenya.org/east-african-bribery-index/">prevalence</a> of corruption within Kenya, Tanzania and Uganda, it would be ambitious to expect the fisheries sector to be immune from corruption. But recognising that corruption exists, that it encourages illegal behaviour and affects the management of the lake is imperative to putting an end to illegal fishing. </p>
<h2>How corruption affects co-management</h2>
<p>Corruption affects co-management in at least three ways. </p>
<ul>
<li><p>Committee members become discouraged from enforcing regulations when enforcement officers, such as government fisheries staff and police officers, actively seek bribes and return seized gear. </p></li>
<li><p>Cases were reported of government fisheries staff interfering in the election of committee members. </p></li>
<li><p>Corruption among committee members made enforcement impossible and discouraged compliance amongst other fishers.</p></li>
</ul>
<p>There are also other incidents. For instance, politicians will intervene to stop enforcement during election periods. An <a href="https://www.newvision.co.ug/new_vision/news/1411741/museveni-probe-illegal-fishing">example</a> of this is when the Ugandan President, Yoweri Museveni, suspended the work of fisheries officers and beach management units during the last presidential election campaign. He claimed that corruption was rife. But no action was taken against anyone or measures adopted to prevent corruption linked to illegal activity and enforcement.</p>
<h2>Way forward</h2>
<p>Multiple measures would be needed to stop corruption within fisheries. </p>
<p>These could be relatively simple, for instance ensuring fisheries departments do their job in a timely way –- licensing boats can take years whereas it should be done quickly and regularly. The issue of how fisheries staff are monitored and supervised could also be discussed. For example, staff shouldn’t necessarily be in post at one location for a long time. </p>
<p>Ultimately, the use of land and water patrols, fines and arrests to enforce regulations are futile unless corruption is recognised, openly discussed and measures taken to address it.</p><img src="https://counter.theconversation.com/content/97812/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Fiona Nunan receives funding from the Leverhulme Trust and the Ecosystem Services for Poverty Alleviation programme, funded by the UK Natural Environment Research Council, Economic and Social Research Council and the Department for International Development.. </span></em></p>Urgent measures need to be adopted to prevent corruption linked to illegal fishing activity in and around Lake Victoria.Fiona Nunan, Professor of Environment and Development, University of BirminghamLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/902342018-02-05T14:21:17Z2018-02-05T14:21:17ZHow a radio series about Lake Victoria’s troubles missed the mark<figure><img src="https://images.theconversation.com/files/202843/original/file-20180122-46226-xt83te.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Participation is needed from all role players to save Lake Victoria from further degradation</span> <span class="attribution"><span class="source">Reuters/Stringer</span></span></figcaption></figure><p>Lake Victoria is one of the African Great Lakes. It’s <a href="https://www.utdallas.edu/geosciences/nile/victoria.html">the source</a> of the River Nile and forms a natural boundary between Kenya, Tanzania and Uganda. Unfortunately today, it’s in a critical state due to <a href="https://www.scidev.net/global/pollution/feature/modern-strains-put-lake-victoria-in-critical-condition.html">severe</a> pollution and over fishing. </p>
<p>Various developments have led to the lake’s terrible condition. These include industrial waste, the discharge of effluents, fertilisers and sewerage into the lake. And increases in the water’s nutrient salts have led to <a href="http://www.eniscuola.net/en/2016/11/03/what-is-eutrophication-causes-effects-and-control/">eutrophication</a> – changes that affect the lake’s ecosystem, like increases in aquatic plants. </p>
<p>The lake’s perilous condition is disastrous for the region. Its fisheries support <a href="http://www.worldbank.org/en/news/feature/2016/02/29/reviving-lake-victoria-by-restoring-livelihoods">more than</a> 3 million livelihoods, bringing in USD$ 500 million every year. Its catchment provides water to major urban centres like Kampala and Kigali and it’s also a huge source of hydropower, providing energy to Uganda, Burundi and Rwanda. </p>
<p>The type of information people are given about the threats facing the lake, and how they perceive them, are crucial if the current state of affairs is ever going to be reversed. My <a href="http://www.tandfonline.com/doi/abs/10.1080/23743670.2015.1084588">research</a> examines this. I looked at how a radio programme in Uganda portrayed Lake Victoria’s environmental crisis and how the lakeside communities interpreted the information. Even though the programmes were broadcast in 2005, my analysis about their content and how local people felt about them still resonate today.</p>
<p>I found that the programme missed the mark. The biggest flaw was that it didn’t give a voice to people most affected by the crisis. Those I spoke to said that their views were excluded and that the programmes didn’t focus on the major causes of pollution.</p>
<p>Ignoring the voices of people affected by the changes, as well as the major drivers of the lake’s problems, is bound to hamper efforts to manage the threats to the lake. And radio could play a key role because broadcasts are a key source of information, as is the case across Africa where <a href="http://www.un.org/africarenewal/magazine/july-2005/community-radio-voice-poor">radio is</a> the dominant mass medium.</p>
<h2>People’s voice excluded</h2>
<p>Concerns about the lake have been voiced for almost 20 years at varying levels of intensity. In 2005 governmental, as well as non-governmental organisations, <a href="https://reliefweb.int/report/kenya/usda-low-water-levels-observed-lake-victoria">called</a> for urgent action to be taken. A lot of media coverage about the challenges facing the lake followed. </p>
<p>The interest led to a private radio station in Uganda making a series called <a href="http://www.ingentaconnect.com/content/intellect/jams/2014/00000006/00000002/art00007?crawler=true">Victoria Voice</a>. Sponsored by the Swedish International Development Agency, the series was broadcast on Central Broadcasting Radio between January and June 2005. Its main objective was to create awareness on the lake’s environmental crises. </p>
<p>The radio station has a large reach, covering many parts of Uganda and some parts of neighbouring Rwanda and Kenya. Its total audience is <a href="https://cbsfmbuganda.co.ug/index.php/organisation/sponsors">about</a> ten million people. </p>
<p>My research focused on the Victoria Voice series and the three lakeside communities at the Gaba, Mulungu-Munyonyo and Kasenyi landing sites. These communities make a living from the lake. </p>
<p>I analysed the 12 episodes of the Victoria Voice series and had in-depth conversations with community members who had listened to them. </p>
<p>My analysis revealed three dominant themes in the documentaries: </p>
<ul>
<li><p>Basic economic survival. This was mostly voiced by individuals who earn a living from the lake’s resources – like fishermen – and are now struggling. For example, one interviewee who earns a living through smoking and selling fish blamed corporate practices (fish processing factories) for affecting her business by taking all the fish stock. </p></li>
<li><p>Sustainability of the lake. This was mostly commented on by scientists, specialists and local leaders at the landing sites. Scientists focused on the lake’s environmental crisis. They said pollution, from industry, contributed to a lack of oxygen in the water – a fundamental necessity for aquatic life. They also criticised the government’s unsustainable investment and modernisation plans which exploit its natural resources. Local leaders blamed this on agricultural industries, beer-processing factories and fish factories. </p></li>
<li><p>Modern development. This was related to corporate investment, profit and growth. It was brought up by politicians and industrialists. For example, when commenting on the impact of industries along the shores of the lake, the Minister of Tourism, Trade and Industry said that the pollution was “not necessarily due” to the mushrooming industries. With so many activities around the lake “all people are responsible”. He also stated that when giving a company a license, the government insists on proper waste disposal and treatment.</p></li>
</ul>
<p>I found that the Victoria Voice reinforced the status quo in decision-making conversations when it came to the lake. These consist of a wealthy elite including scientists, industrialists, government officials and politicians, and a poor excluded majority, like the fisher folk and farmers. In addition to the frequency of the elites interviews and the time they were given to speak, the production team often failed to question the views presented. </p>
<p>The community members I spoke to said the programmes were relevant for the information they provided, but they interpreted them as not being in their best interests. </p>
<h2>Biggest problems ignored</h2>
<p>The problem with this is that huge challenges facing the lake, and the people that depend on it, were avoided and weren’t given enough prominence. </p>
<p>For example, the radio series didn’t address the <a href="http://aquaticcommons.org/20738/1/livelihoods%20paper%203.pdf">commercialisation</a> of Lake Victoria’s fishing industry. This has had a <a href="http://www.theeastafrican.co.ke/news/Bans-fishing-Lake-Victoria-fish-stocks/2558-3847516-10astq1/index.html">negative impact</a> on those that rely on fisheries. Fishermen are particularly affected as they work harder now and catch less. The populations of <a href="https://www.nation.co.ke/counties/kisumu/The-small-fish-that-sustains-life-of-Nile-Perch/1954182-4164256-sylc5r/index.html">smaller fish</a>, traditionally their source of livelihood, have been <a href="http://ruby.fgcu.edu/courses/twimberley/EnviroPhilo/LakeVictoriaCrisis.pdf">ruined</a> both by bigger predators and over-fishing. </p>
<p>It also didn’t address the fact that large factories have displaced entire businesses. For instance, women at landing sites have lost the income they made from smoking, drying and frying fish to sell. </p>
<p>And the series didn’t look at concerns that wetlands are disappearing as buildings are constructed. Wetlands play an important role as a watershed area and breeding ground for fish. They are also important for filtering the city’s waste before it flows into Lake Victoria. </p>
<p>By not giving communities a proper voice, the programme ignores the reality on the ground and the change won’t be enough for the communities. Efforts to save the lake from further degradation will also be futile without equal participation of all concerned parties.</p><img src="https://counter.theconversation.com/content/90234/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Margaret Jjuuko, Ph. D. 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>Information about the threats facing Lake Victoria and how they’re perceived are crucial to reverse the damage that’s been done.Margaret Jjuuko, Ph. D., Senior Lecturer, University of RwandaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/885362017-12-06T13:35:26Z2017-12-06T13:35:26ZWhat Migingo, the world’s tiniest disputed island, tells us about international law<figure><img src="https://images.theconversation.com/files/197548/original/file-20171204-4055-cltd56.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Ugandan fishermen pull in their nets at dawn in Lake Victoria, which is shared between Uganda, Kenya and Tanzania.</span> <span class="attribution"><span class="source">Reuters/Euan Denholm</span></span></figcaption></figure><p>For as far back as anyone could remember, Migingo was nothing more than an uninhabited pinprick on Lake Victoria. One of three small islands in the eastern waters that make up an island chain, Migingo is barely the size of half a football pitch. It measures about one-half acre or about two thousand square metres.</p>
<p>In 2001 resourceful fishermen began using Migingo as an offshore weigh station. The islet just happened to be more habitable than the steeply sloped adjoining islets. And because the fishermen earned three to four times in a day what shore-based fishermen could earn in a month, word soon spread that Migingo’s geographic location made it ideally suitable to hunt the Nile perch.</p>
<p>The Nile perch, locally known as mbuta, is one of the most invasive and best studied species in history. This devastating piscavore, probably <a href="https://www.researchgate.net/publication/232694102_The_Origins_of_the_Nile_Perch_in_Lake_Victoria">introduced by Uganda</a> in the 1950s, is rapidly turning Lake Victoria into an Anthropogenic problem. But there is no doubting the economic value it generates as a <a href="http://www.sciencedirect.com/science/article/pii/S030691920700036X">much sought-after</a> dinner item in European restaurants and in expanding worldwide markets.</p>
<p>The islet quickly became a micro slum, housing hundreds of people, including pirates and smugglers. It also sparked for the first time competing claims by Uganda and Kenya over who owns Migingo. Both countries claim it is theirs.</p>
<p>The debate about Migingo’s fate has been fuelled by the perceived imbalance in the Nile perch trade – Kenya owns 6% of Lake Victoria but dominates the perch trade while Uganda owns 43% but harvests less than half of Kenya’s catch. An added complication was the 2006 discovery of commercially viable oil deposits across the East African Rift System. An oil find could potentially straddle the disputed demarcation line. </p>
<p>The dispute has become intractable, despite bilateral and multilateral discussions. A series of <a href="https://books.google.com/books?id=z7MBCgAAQBAJ&pg=PA159&lpg=PA159&dq=uganda+kenya+migingo+police+marines&source=bl&ots=JdcEPjdwwQ&sig=xLKtdQWbtz3GXKIM3Uy0PFN_SDc&hl=en&sa=X&ved=0ahUKEwitrt7Ij_PXAhVq4IMKHRnYDTYQ6AEIYjAN#v=onepage&q=uganda%20kenya%20migingo%20police%20marines&f=false">aggressive encounters</a> between Ugandan marines and Kenyan police have brought the parties to the brink of violence while eight years ago Kenyan <a href="http://www.panapress.com/Kenyan-protesters-uproot-rail-link-to-Uganda--13-524454-18-lang1-index.html">rioters uprooted</a> landlocked Uganda’s rail link to the Kenyan port of Mombasa. This disruption in turn affected the commercial interests of, among others, Rwanda, Burundi and eastern Democratic Republic of Congo.</p>
<p>Characterisations of the dispute as <a href="http://www.businessinsider.com/migingo-island-shanty-fishing-island-africa-2016-10?r=UK&IR=T">small</a> do no justice to the importance of the international legal issues at play. Migingo intertwines issues of ethnicity, nationality, and politics around the competing temptations of a resource. But it also serves as an example of the lingering effects of <em>uti possidetis</em>, </p>
<blockquote>
<p>a principle of international law, which provides that newly formed sovereign states should have the same borders that their preceding dependent area had before their independence. </p>
</blockquote>
<p>This principle reinforced the work of British imperial line drawers who reshaped the landscape of this region through cartographic shortcuts and a 1926 British Order in Council.</p>
<h2>A brutal principle</h2>
<p><em>Uti possidetis</em> has been described as an important building block of the state system. This is because it emphasises stability, finality, and respect for territorial borders. The World Court places it among the <a href="https://books.google.com/books?id=dVycAQAAQBAJ&pg=PA224&lpg=PA224&dq=uti+possidetis+most+important+legal+principle&source=bl&ots=_FjNt3CCPr&sig=7GpFxbQ_xVmZ9iZmw9P2BZtMzl0&hl=en&sa=X&ved=0ahUKEwjv9d_kkPPXAhXGqYMKHaJ7BzoQ6AEIOzAD#v=onepage&q=uti%20possidetis%20most%20important%20legal%20principle&f=false">most important legal principles</a>.</p>
<p>But it is a brutal principle. It requires that states emerging from decolonisation essentially inherit the borders they received at the time of independence. The presumption is that territorial title freezes, like a photographic snapshot, at the moment of independence, regardless of how arbitrary the borders may be. </p>
<p>Migingo’s problem boils down to a difference of opinion between Uganda and Kenya about the ‘snap shot’ used to draw the line demarcating the border. Add to this the fact that the British took the photo a long time ago, and its camera may have been out of focus.</p>
<p>Out of focus or not, the international doctrine aided the project of African statecraft by settling, or at least forestalling, disputes over porous borders. It allowed African elites to consolidate power. Indeed it has informed the <a href="http://hrlibrary.umn.edu/africa/OAU_Charter_1993.html">Charter</a> of the Organisation of African Unity, the African Union’s Constitutive Act, and the 1964 OAU Cairo Declaration. </p>
<p>But the costs associated with this blunt instrument of international law remain substantial. It leaves Africa with a forced coincidence of borders among many states. Africa’s tiniest border dispute of Migingo is a metaphor for the pressures now associated with areas of conflict affecting Africa’s great hydrographic catchments.</p>
<p>Colonial cartography, like the entire nineteenth century Scramble for Africa begun at the <a href="http://www.sahistory.org.za/article/berlin-conference">Berlin Conference</a>, was done with little regard for human geographies or the <a href="http://www.dw.com/en/130-years-ago-carving-up-africa-in-berlin/a-18278894">overlapping realities</a>. </p>
<p>Even more problematic was the <a href="http://www.monitor.co.ug/Magazines/PeoplePower/689844-3457736-7ccq3k/index.html">decision</a> taken later by the British to remove the Eastern Province of the Ugandan Protectorate to the East African Protectorate. This placed a huge portion of the Rift Valley in what would become Kenya. The rationale for this line drawing was to keep within one administrative jurisdiction the 960km railway connecting Mombasa on the Indian Ocean to the northeast corner of Lake Victoria. But inserting a geographic line of convenience to accommodate railroad administration created a human geographic chaos of its own.</p>
<h2>Where the line falls</h2>
<p>Some <a href="http://www.nation.co.ke/news/1056-636292-jn4sccz/index.html">evidence suggests</a> that Migingo was the generic name of the undifferentiated island chain which only later differentiated the two other islets. These are Ugingo, which lies 660 feet east of Migingo, and Pyramid Island, 2km south of Migingo. Ugandan surveyors claim that Ugingo is actually Pyramid Island, because it is shaped like a pyramid. This finding would put Migingo inside Uganda by a matter of meters. </p>
<p>Uganda’s President Yoweri Museveni was said to have suggested that Migingo was located in Kenya’s water but he claims he was misquoted. Even if this were indisputably so, much of the Kenyan catch of Nile perch may derive from illegal fishing activity in Ugandan waters. </p>
<p>Evidence suggests the perch breed off Kenya’s shallow littoral and migrate into deeper waters around Migingo. Where the line falls between Uganda and Kenya in Lake Victoria will have little effect on the need for a managed solution. This would necessarily also involve Tanzania, and require cooperation, which is lacking.</p>
<p>Problems facing the Lake Victoria catchment directly affect the livelihood of 30 million people. Efforts to promote the sustainable development of the lake now involve an array of international organisations, specialised institutions of the East African Community, and Rwanda and Burundi as part of a more sensitive environmental understanding of the lake catchment region. </p>
<p>The small geographic size of the Migingo dispute belies the grave political consequences of inaction, making Migingo a metaphor for African resolve in the Anthropocene.</p>
<p><em>The author’s in depth analysis of the Migingo dispute has just been <a href="http://ssrn.com/abstract=2819216">published</a> in the Brooklyn Journal of International Law</em></p><img src="https://counter.theconversation.com/content/88536/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Christopher R. Rossi 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 dispute between Uganda and Kenya over an islet half the size of a football pitch has been fuelled by the perceived imbalance in fish harvests and the prospects of oil reserves beneath.Christopher R. Rossi, Lecturer in international law, University of IowaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/880432017-11-27T08:05:43Z2017-11-27T08:05:43ZA close up look at the social networks of Lake Victoria’s fisherfolk<figure><img src="https://images.theconversation.com/files/196264/original/file-20171124-21811-1h0decm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Lake Victoria sustains about 200,000 fishers.</span> <span class="attribution"><span class="source">Jen Watson/Shutterstock</span></span></figcaption></figure><p>The fisheries of Lake Victoria, the second largest freshwater body in the world, support the livelihoods of <a href="http://www.firstmagazine.com/Publishing/SpecialistPublishingDetail.aspx?SpecialistPublicationId=24">around</a> three million people in the countries that border the lake – Kenya, Tanzania and Uganda. But there have been widespread concerns, since the early 2000s, that fish stocks and catches of the key commercial fishery of <a href="http://www.theeastafrican.co.ke/scienceandhealth/Scientists-alarm-over-decline-Nile-perch-stock-in-Lake-Victoria/3073694-3488878-a92u0a/index.html">Nile perch</a> are declining. This is largely attributed to <a href="http://www.businessdailyafrica.com/news/counties/Lake-Victoria-Nile-Perch-stocks-drop-over-pollution/4003142-4141910-qex4b6z/index.html">pollution</a>, <a href="http://www.news.com.au/travel/world-travel/africa/africas-biggest-lake-is-on-the-verge-of-dying/news-story/364bdb4e810ab33aa6434f3b71a473dc">overfishing</a> and the widespread use of <a href="http://www.nation.co.ke/business/seedsofgold/Destroy-illegal-fishing-nets-on-Lake-Victoria/2301238-3234536-102ftot/index.html">illegal gear</a> that catch undersized fish. </p>
<p>With <a href="http://www.fao.org/fishery/nems/37841/zh">around</a> 1,500 landing sites, Lake Victoria sustains <a href="http://www.firstmagazine.com/Publishing/SpecialistPublishingDetail.aspx?SpecialistPublicationId=24">about</a> 200,000 fishers, referring both to the owners of boats and the crew who undertake the manual work of fishing. There are then the small-scale fish processors (usually women), agents who buy fish for fish processing factories and local traders who buy for local and further markets.</p>
<p>These fisherfolk live and work at the fish landing sites where they develop close social and economic ties over time. These ties form social networks that are critical for gaining access to employment, labour for the boat and fish to process and trade. Efforts to address the challenges facing Lake Victoria, particularly of illegal fishing, should therefore take into consideration these close community ties as they demonstrate that there is close cooperation and dependence among the fisherfolk. This could be built on to strengthen their involvement in fisheries management.</p>
<p>We did <a href="http://www.tandfonline.com/doi/abs/10.1080/08941920.2017.1383547">research</a> in the three countries bordering the lake to understand the personal networks of the three main occupational groups better; boat crew, boat owners as well as fish processors and traders. We also tried to understand how they benefited from having strong social ties.</p>
<p>We found that people rely heavily on others working in the same occupation and living at the same landing site, despite significant migration between landing sites, and that the provision of credit, employment, labour and social support brought people together and secured livelihoods. </p>
<p>Our findings are important because social ties influence people’s attitudes to management and their willingness to get involved in managing the fisheries with government. Understanding the basis of social cohesion can therefore inform the design and implementation of fisheries development and management approaches so that they build on connections people already have, and that are critical to their well-being.</p>
<h2>Understanding social ties</h2>
<p>The research involved both a quantitative questionnaire and a qualitative interview. Interviews were conducted with a sample of boat owners, boat crew and fish processors/traders at 18 landing sites – six in each country. We interviewed 85 men and 19 women. Most of the women were in the fish traders and processors category while the men were mostly boat crew and boat owners.</p>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/196261/original/file-20171124-21805-vohayp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/196261/original/file-20171124-21805-vohayp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=468&fit=crop&dpr=1 600w, https://images.theconversation.com/files/196261/original/file-20171124-21805-vohayp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=468&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/196261/original/file-20171124-21805-vohayp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=468&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/196261/original/file-20171124-21805-vohayp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=588&fit=crop&dpr=1 754w, https://images.theconversation.com/files/196261/original/file-20171124-21805-vohayp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=588&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/196261/original/file-20171124-21805-vohayp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=588&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Fish buyer and fishermen.</span>
<span class="attribution"><span class="source">Jen Watson/Shutterstock</span></span>
</figcaption>
</figure>
<p>To find out who mattered most in people’s personal networks related to fisheries, respondents were asked to name up to seven people with whom they had discussed their fishing activity within the previous two weeks. What we found was that the largest group within each personal network came from the same occupation, though this was even more the case for fish traders and processors than for boat crew and boat owners. </p>
<p>This was surprising. We’d expected that the networks of fish traders and processors would be more diverse given that they frequently interacted with crew and boat owners to buy fish. Their close relations within the occupational group reflected the high degree of dependence they have on each other. Dependencies included needing to trade onwards, to get access to credit and to get business advice. Around half of their network members lived outside of the landing site, reflecting their wide trading networks.</p>
<p>But we found that most of the network members of boat crew and boat owners stayed at the same landing site. The mobility of fishers might suggest that their networks would be more geographically diverse, but boat crew rely on their local friends when they migrate in search of better fish catches and prices, using their networks to help them move.</p>
<h2>Benefiting from ties</h2>
<p>So, how do people benefit from these social ties? </p>
<p>For boat crew, financial help and provision of advice were the most common benefits stated. Most advice related to fishing grounds, but also included advice on running businesses and how to get into fisheries. Boat crew frequently rely on each other, for example they may replace a friend who can’t go out to fish or share their portion of the catch with crew members who were not able to go out or caught a poor catch. These reciprocal arrangements provide an important safety net.</p>
<p>Boat owners reported that they benefit from boat crew through the skill, hard work and knowledge the crew members have. They also benefit from ties with other boat owners through providing financial assistance and advice. In terms of their relationships with fish traders and processors, boat owners gain access to credit and secure a market for their catch. Fellow fish traders/processors also benefit significantly from receiving advice and assistance from each other, such as helping secure access to markets and transport fish.</p>
<p>The networks are therefore critical for gaining access to credit and employment, maintaining reliable and skilled labour, and sustaining access to markets. People turn to each other when in need of resources and advice, whether in relation to fisheries, running their business or for personal matters. These networks ensure that fish, income, employment and information flow, at and from the landing sites. They also confirm that there is constant economic and social interaction, with personal and work lives strongly intertwined.</p>
<p>These networks, associated with the provision of advice and credit, could be harnessed to use peer communication in tackling illegal fishing. They could also be harnessed to strengthen the <a href="https://www.newvision.co.ug/new_vision/news/1411741/museveni-probe-illegal-fishing">case for</a>, and implementation of, co-management of the lake’s threatened fisheries. The findings confirm that the cohesive nature of fishing communities is encouraging for community-based and collaborative management as community members have shown themselves to be able to work together effectively.</p><img src="https://counter.theconversation.com/content/88043/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Fiona Nunan receives funding from the Leverhulme Trust and the Ecosystem Services for Poverty Alleviation programme, funded by the UK Natural Environment Research Council, Economic and Social Research Council and the Department for International Development. </span></em></p>Social ties between Lake Victoria’s fisherfolk are critical for gaining access to credit, employment, maintaining reliable and skilled labour and access to markets.Fiona Nunan, Professor of Environment and Development, University of BirminghamLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/829472017-09-04T15:41:39Z2017-09-04T15:41:39ZEthiopia’s Lake Tana is losing the fight to water hyacinth<figure><img src="https://images.theconversation.com/files/184000/original/file-20170830-23702-17vlg7u.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The aquatic weed water hyacinth is causing major problems in Ethiopia's Lake Tana.</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>Lake Tana is the largest lake in Ethiopia. It holds 50% of <a href="https://cgspace.cgiar.org/handle/10568/21499">the country’s fresh water</a>. It is also the source of the Blue Nile, which contributes up to 60% of the <a href="https://link.springer.com/chapter/10.1007/978-1-4020-9726-3_9">Nile’s water</a>. Not only is the lake important as a water source for over <a href="http://mandalaprojects.com/ice/ice-cases/bluenile.htm">123 million people</a> in the Nile Basin, it is also a source of food in the form of fish. But weeds are threatening this life-giving resource.</p>
<p>The lake has been listed in the top 250 lake regions of <a href="https://cgspace.cgiar.org/handle/10568/21499">Global Importance for Biodiversity</a>. It has 28 species of fish, of which <a href="https://link.springer.com/chapter/10.1007/978-3-319-45755-0_12">21 are endemic</a>. Commercially, the lake’s most important fishes include the large African barbs, Nile tilapia and African catfish. The annual commercial value of fish production at Lake Tana is about USD$<a href="http://www.fao.org/docrep/v6718e/v6718E01.htm#12">1.1 million</a>. </p>
<p>The potential fish production of the lake is estimated to be <a href="http://www.fao.org/fi/oldsite/FCP/en/ETH/body.htm">13 000 tons yearly</a>. But its current fish production is less than 1000 tons a year. <a href="http://onlinelibrary.wiley.com/doi/10.1002/ldr.2730/abstract">Recent studies</a> show a serious decline in fish stocks due to the spread of the aquatic weed water hyacinth around fish spawning grounds.</p>
<p>Water hyacinth, <em>Eichhornia crassipes</em>, is an exotic free-floating invasive plant that is native to South America. People who tend aquariums and gardens are believed to have spread the plant inadvertently across the Atlantic to <a href="https://link.springer.com/content/pdf/10.1007%2F978-3-319-55396-2_9.pdf">Africa and Asia</a>. </p>
<p>It restricts water flow, blocks sunlight from reaching native water plants and depletes the oxygen in the water - often choking aquatic animals like <a href="http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2427.2009.02294.x/abstract">fish</a>. It also has an economic impact by interfering with navigation, irrigation, power generation and fishery.</p>
<h2>The infestation</h2>
<p>The weed forms thick mats that cover the open water. <a href="http://www.netjournals.org/pdf/NJAS/2017/1/16-039.pdf">Recent data</a> show that Lake Tana is critically infested with water hyacinth and it’s putting the aquatic biodiversity at extreme risk.</p>
<p>In 2011, the <a href="http://www.ethiopia.gov.et/amhara-regional-state">Regional Environmental Bureau</a> named water hyacinth as <a href="http://allafrica.com/stories/201708080175.html">the most dangerous weed</a> affecting Lake Tana. By then, about <a href="https://www.peertechz.com/Allergy/Allergy-1-103.php">20 000 hectares</a> of the north-eastern shore of the lake was infested. In 2014, researchers from Ethiopia <a href="http://www.bdu.edu.et/sites/default/files/Water_Hyacinth_Lake%20Tana_Report%20Series%201.pdf">found out</a> that about one-third of the lake’s shoreline, around 128km, was invaded by water hyacinth.</p>
<p>In just two years, the estimated coverage of the weed doubled from <a href="http://www.bdu.edu.et/sites/default/files/Water_Hyacinth_Lake%20Tana_Report%20Series%201.pdf">20 000 to 40 000 hectares</a>. The weed is now estimated to cover <a href="http://www.netjournals.org/pdf/NJAS/2017/1/16-039.pdf">50 000 hectares</a> of the lake. To make matters worse, inflowing rivers carry heavy loads of soil <a href="https://link.springer.com/chapter/10.1007/978-1-4020-9726-3_9">and suspended sediment</a> into the lake, which affects the water quality and creates favourable conditions for the spread of the weed.</p>
<p>The release of <a href="https://link.springer.com/chapter/10.1007%2F978-3-319-45755-0_10">untreated waste water</a> from industries around the lake adds to the deterioration of the lake ecosystem. As a consequence, the lake has lost 75% of its fish stock <a href="http://www.sciencedirect.com/science/article/pii/S0006320703001988">in recent years</a>. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/183197/original/file-20170823-6585-1a8cdw7.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/183197/original/file-20170823-6585-1a8cdw7.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/183197/original/file-20170823-6585-1a8cdw7.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=443&fit=crop&dpr=1 600w, https://images.theconversation.com/files/183197/original/file-20170823-6585-1a8cdw7.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=443&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/183197/original/file-20170823-6585-1a8cdw7.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=443&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/183197/original/file-20170823-6585-1a8cdw7.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=557&fit=crop&dpr=1 754w, https://images.theconversation.com/files/183197/original/file-20170823-6585-1a8cdw7.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=557&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/183197/original/file-20170823-6585-1a8cdw7.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=557&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Farmers trying to remove water hyacinth from Lake Tana.</span>
<span class="attribution"><a class="source" href="https://www.youtube.com/watch?v=6OW4DMuolYk">CGTN Africa</a></span>
</figcaption>
</figure>
<h2>Control measures</h2>
<p>A water hyacinth infestation is hard to get rid of. But there are three ways to do this: removal, chemical spraying (using herbicides) and biological control. </p>
<p>Removing the weed, either manually or using machines, could reduce coverage and slow its spread. But it’s expensive and takes time. Local authorities are mobilising an estimated <a href="http://www.bdu.edu.et/sites/default/files/Water_Hyacinth_Lake%20Tana_Report%20Series%201.pdf">162 000 people</a> to remove the weed by hand. This happens only when the lake shores are accessible and when farmers have time.</p>
<p><a href="https://www.britannica.com/place/Lake-Victoria">Lake Victoria</a>, lying in Tanzania, Uganda and Kenya, offers lessons for dealing with the water hyacinth problem. An estimated 60 000 hectares is covered by the weed in Kenya alone. A weed harvesting machine can clear only 10 hectares a day, so it would take 6 000 days (more than 16 years) to <a href="http://www.nation.co.ke/counties/kisumu/removal-of-water-hyacinth-lake-victoria-could-take-longer/1954182-3804090-mw2c6z/index.html">remove the weed</a> entirely. Methods like biological control have been shown to be more <a href="http://www.abc.net.au/science/slab/hyacinth/">effective</a>. </p>
<p>Herbicides have been widely used to reduce the spread of the weed, but they may harm the environment. They can kill native plants that are necessary for a healthy functioning of <a href="http://www.spc.ichemejournals.com/article/S2352-5509(15)00010-X/pdf">the lake’s ecosystem</a>.</p>
<p>This control method is expensive for developing countries and requires highly skilled people. In Sudan, the costs of chemical treatment for water hyacinth control were estimated to be <a href="https://www.invasive.org/proceedings/pdfs/6_491-496.pdf">£1 million each year</a>.</p>
<h2>The best approach</h2>
<p>Biological control has been widely used. It appears to be the most economical and effective approach to manage water hyacinth in the long term. It uses natural enemies, with little cost and usually no negative environmental impact. Two weevil – or beetle – species, Neochetina eichhorniae and Neochetina bruchi, have been widely used with success. They have shrunk the coverage of the weed and controlled its spread <a href="http://ageconsearch.umn.edu/bitstream/135372/2/PR102.pdf#page=8">in 33 countries</a>, including the United States, Uganda, Nigeria, Ghana, India and Australia. But this method takes years of work by the insect to clear the weed. For instance, the weevils took two years to control the weed at Lake Victoria <a href="http://www.abc.net.au/science/slab/hyacinth/">in Uganda</a>. </p>
<p>Neochetina weevils eat only water hyacinth. <a href="http://www.fao.org/docrep/006/y5031e/y5031e0c.htm">Studies</a> show that these weevils rely on the water hyacinth’s root system for crucial stages of growing. They feed heavily on the plant tissue: larvae eat the inside of the plant and adults eat the outside. Feeding damage by both life stages inhibits the growth of the plant by slowing the flowering process. </p>
<p>Biological control using weevils has been <a href="http://www.abc.net.au/science/slab/hyacinth/">successful in Lake Victoria</a>. A recent study on the adaptability and efficacy of weevils for water hyacinth control in the Ethiopian Rift Valley showed <a href="http://www.sciencedirect.com/science/article/pii/S0261219415300557">promising results</a>. Potential negative effects, however, should to be studied before realising the weevils to new environment. Once the weevils are released, there is no operational cost as they naturally reproduce and continue feeding until all the weed is cleared. </p>
<p>Researchers are also looking at the potential of <a href="http://www.apms.org/japm/vol51/japm-51-02-109-121.pdf">using weevils</a> for water hyacinth control around Lake Tana. At least <a href="https://en.nabu.de/projects/ethiopia/tana/area/population.html">2-3 million</a> people living around the lake will be relying on the success of all these efforts.</p><img src="https://counter.theconversation.com/content/82947/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Dr Solomon Kibret is a member of the Global Coalition for Lake Tana Restoration, a not-for-profit group supporting environmental and watershed management activities to restore Lake Tana's ecosystem in Ethiopia. </span></em></p>Lake Tana in Ethiopia has been massively affected by the invasive weed, water hyacinth. Control methods are available but there are challenges.Solomon Kibret, Postdoctoral researcher, University of California, IrvineLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/754672017-04-27T16:09:44Z2017-04-27T16:09:44ZThe fate of Africa’s Lake Tanganyika lies in the balance<figure><img src="https://images.theconversation.com/files/164925/original/image-20170411-26715-ch8yu7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The declining fishing yield in the Lake Tanganyika region is being exacerbated by an influx of refugees.</span> <span class="attribution"><span class="source">Reuters/Sala Lewis</span></span></figcaption></figure><p>Standing on the steep rocky shores of Lake Tanganyika at sunset, looking out at fishermen heading out for their nightly lamp-boat fishing trips, it’s easy to imagine this immense <a href="http://www.fao.org/fi/oldsite/ltr/gen.htm">32,900km2</a> body of water as serene and unchanging. </p>
<p>Located in the western branch of the great African Rift Valley it’s divided among four countries; Tanzania, the Democratic Republic of the Congo, Burundi, and Zambia. It’s one of the <a href="http://www.sial-online.org/lakes/tanganyika">oldest</a> lakes in the world, probably dating back about 10 million years.</p>
<p>That expanse of geological time has permitted literally <a href="http://www.geo.arizona.edu/sites/www.geo.arizona.edu/files/files/113%20Salzburger%20et%20al%202014%20Ann%20Rev%20Ecol%20Evol%20Syst.pdf">hundreds</a>
of unusual species of fish and invertebrates to evolve in isolation - organisms that are unique among the world’s lakes. Every day <a href="http://www.irinnews.org/report/92318/zambia-lake-tanganyika-fishing-industry-adrift">millions</a> of people rely on the lake’s riches. </p>
<p>But despite being a world class reservoir of biodiversity, food and economic activity, the lake is changing rapidly and may be facing a turbulent future. </p>
<p>Lake Tanganyika was <a href="http://www.dw.com/en/lake-tanganyika-threatened/g-37427846">recently declared</a> the “Threatened Lake of 2017” – adversely affected by human activity in the form of climate change, deforestation, overfishing and hydrocarbon exploitation.</p>
<h2>The threats</h2>
<p>Beginning in the late 1980s <a href="http://www.hydrosciences.fr/sierem/produits/biblio/Management%20and%20conservation%20of%20the%20African%20Great%20Lakes%20Lakes%20Victoria%20Tanganyika%20and%20Malawi%20comparative%20and%20comprehensive%20study%20of%20Great%20Lakes.pdf">scientists studying</a> the lake began to notice significant and concerning changes caused by human activity. </p>
<p>But at the time worldwide attention was focused <a href="http://www.hydrosciences.fr/sierem/produits/biblio/Management%20and%20conservation%20of%20the%20African%20Great%20Lakes%20Lakes%20Victoria%20Tanganyika%20and%20Malawi%20comparative%20and%20comprehensive%20study%20of%20Great%20Lakes.pdf">on other</a> African Great Lakes, particularly Lake Victoria where evidence was beginning to emerge of the enormous impact the <a href="http://www.fao.org/docrep/005/t0037e/t0037e09.htm">Nile Perch</a> – an introduced species – was having. </p>
<p>The problems in Tanganyika were somewhat different. </p>
<p>Fortunately, no major exotic species introductions have occurred up to now. Instead, evidence <a href="http://www.geo.arizona.edu/sites/www.geo.arizona.edu/files/web/Cohen/pdf/25%20Cohen%20et%20al%201993%20Conservation%09Biology.pdf">shows</a> that underwater habitat degradation is taking place adjacent to hill slopes. They are being rapidly deforested – converted to agricultural lands or for urban expansion –in the fast growing population centres around the lake. This activity has led to a rapid increase in the amount of loose sand and mud being washed into the lake which is smothering the lake floor.</p>
<h2>Danger of sediment</h2>
<p>The biodiversity of Lake Tanganyika can be imagined like a thin bathtub ring. It hugs the <a href="https://www.youtube.com/watch?v=eNPigqSyFw8">shallow zones</a> around a deep and steep bottomed lake, up to 1470m in its deepest parts. The hundreds of species that inhabit the sunlit shallows give way to a dark expanse of water lacking oxygen and, so, animal life. </p>
<p>This narrow strip of extraordinary biodiversity is on the front line. Eroded sediments are being carried into the lake, affecting this strip.</p>
<p><a href="http://www.ltbp.org/SSS.HTM">Researchers</a> have begun to document where the impact is being felt. They are also <a href="http://www.geo.arizona.edu/sites/www.geo.arizona.edu/files/web/Cohen/pdf/71%20Cohen%20et%20al%202005%20JOPL%09Summary.pdf">looking back</a> in time by collecting sediment cores with fossils of the many endemic animals to see when the impact was first felt. </p>
<p>They <a href="http://www.geo.arizona.edu/sites/www.geo.arizona.edu/files/web/Cohen/pdf/71%20Cohen%20et%20al%202005%20JOPL%09Summary.pdf">have found</a> that some heavily populated regions lost much of their diversity more than 150 years ago. Other regions, particularly in the more southerly past of the lake, are seeing these effects unfold only in recent decades.</p>
<h2>Other pressures</h2>
<p>Excess sedimentation is just one problem. <a href="http://lta.iwlearn.org/the-fishing-pressure-is-an-increasing-threat-to-the-sustainability-of-fishery-resources-in-lake-tanganyika">Fishing pressure</a> and <a href="http://www.voanews.com/a/lake-tanganyika-climate-change/3458543.html">climate change</a> are also affecting the lake.</p>
<p>Large scale fisheries for the lake’s small sardines started in the 1950s, quickly mushrooming into a major industry. They export <a href="https://global.arizona.edu/lake-tanganyika-fisheries-declining-global-warming">up to</a> 200,000 tons of fish per year and make up a very large portion of the average person’s animal <a href="http://www.pnas.org/content/113/34/9563.full.pdf">protein intake</a> in the surrounding regions. </p>
<p>In recent years this fishing yield has <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5003268/">declined dramatically</a>. This has been partially caused by the unsustainable growth in fisheries, and exacerbated by large numbers of <a href="http://tracks.unhcr.org/2015/05/rescue-on-lake-tanganyika/">refugees</a> flooding into the region because of conflicts in Rwanda, Burundi and the DRC during the 1990s.</p>
<p>It’s now increasingly clear that another factor has also been at play. </p>
<p>Starting in the early 2000s, scientists began to <a href="http://www.nature.com/nature/journal/v424/n6950/abs/nature01833.html">document</a>
that the surface waters of Lake Tanganyika were warming rapidly. This is most likely because of global climate change <a href="http://example.com/">related to</a> an increase in greenhouse gas emissions. This warming has had serious consequences for the lake’s fragile ecosystems. </p>
<h2>Warming lake</h2>
<p>Warm water is relatively light and struggles to mix with the deeper layers of the lake. This in turn keeps the vast pools of nutrients from being churned back to the surface by waves. It cuts down on the growth of floating plankton, which is what the lake’s many fish populations eat.</p>
<p>Scientists have been able <a href="http://www.pnas.org/content/113/34/9563.full.pdf">to show</a> that the decline in fish populations began well before the onset of commercial fishery in the 1950s. This implicates climate change and lake warming as the probable cause for much of the fishery’s long-term decline. </p>
<p>Unfortunately, this trend is unlikely to be reversed as long as the climate in the <a href="http://www.pnas.org/content/113/34/9563.full.pdf">region</a> continues to warm. </p>
<p>A related consequence of the reduction of mixing in the lake, is a continuous shallowing of the transition from the oxygenated to deoxygenated waters on the lake floor. This means there’s less of an oxygenated ring, reducing the habitat area within the bathtub ring of biodiversity from below.</p>
<p>As if scientists and lake managers at Lake Tanganyika didn’t have enough on their plates, a new problem has emerged: <a href="http://af.reuters.com/article/drcNews/idAFL5N1CA40M">the search</a> for oil and gas deposits.</p>
<p>Rift lake sediments of the type found in Lake Tanganyika are <a href="http://www.geology.wisc.edu/%7Ecarroll/publications/pdf/Bohacs%20et%20al.,%202000.pdf">well known</a> among geologists as reservoirs of hydrocarbons, as over millions of years vast quantities of plankton have died and settled on the lake floor. </p>
<p>The consequences of actual production are still unknown. But the recent record of catastrophic oil spills, for example along the <a href="http://pakacademicsearch.com/pdf-files/eng/453/38-51%20Vol%202,%20No%203%20(2012).pdf">Niger River Delta</a>, highlight the critical need for very careful study and environmental planning before production proceeds in fragile Lake Tanganyika. </p>
<p>The biological and economic riches produced by 10 million years of evolution could lie in the balance.</p><img src="https://counter.theconversation.com/content/75467/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Andrew Cohen receives funding from the U.S. National Science Foundation and the International Continental Scientific Drilling Program. He is affiliated with the Department of Geosciences, University of Arizona. </span></em></p>Climate change, deforestation, overfishing and hydrocarbon exploitation threatens one of Africa’s oldest lake’s, Lake Tanganyika.Andrew Cohen, University Distinguished Professor Joint Professor, Geosciences and Ecology and Evolutionary Biology, University of ArizonaLicensed as Creative Commons – attribution, no derivatives.