- Freshwater fish populations in the Kavango and Zambezi (KAZA) river systems of southern Africa are in decline, so many stakeholders met last month in Namibia to share knowledge and suggest ways to address the situation.
- Of the many things shared during the conference, one message was clear: most fish stocks in KAZA are in trouble. Fewer fish means that the people and fish-dependent wildlife are also in trouble.
- “The challenges of fish conservation in KAZA are insurmountable if any of these stakeholders face them alone, but if they work together, it is possible to turn back the tide to restore fish populations and save the lives and livelihoods of our people,” a new op-ed contends.
- This post is a commentary. The views expressed are those of the author, not necessarily Mongabay.
Scientists, communities and government officials from five African countries agree that the freshwater fish stocks in the Kavango and Zambezi River systems are in severe trouble. Delegates representing all three of these stakeholder groups came together in Windhoek, Namibia in July 2024 to share their knowledge and find ways to address this urgent situation.
The Kavango-Zambezi Trans-frontier Conservation Area (KAZA TFCA) derives its name from two mighty rivers that flow through the five countries that are part of KAZA: Angola, Botswana, Namibia, Zambia and Zimbabwe. While this massive conservation area – spanning over half a million square kilometers – is best known for its huge elephant population and other charismatic wildlife on land, the rivers are its lifeblood.
The Kavango River starts in the upper highlands of Angola (where it is known as the Cubango) and flows into the world-famous Okavango Delta in Botswana. Along the way, it forms part of the Namibia-Angola border and crosses Namibia at one of its narrowest points. The Zambezi River starts in Zambia, flows through Angola before re-entering Zambia, touches Namibia’s eastern tip and plunges over Victoria Falls (Mosi-oa-Tunya), forming the border between Zambia and Zimbabwe until it enters Mozambique.
The Okavango Delta and Victoria Falls are two of the top tourist attractions in the region, and “Rivers of Life” is the aptly chosen brand for tourism in KAZA. Nonetheless, tourism wasn’t the main reason why community representatives, scientists and government officials from the KAZA countries met at a conference in Namibia during July 2024. The discussion focused on the fish in these rivers that provide a source of food and income to thousands of people that live near them in all five countries.
Where science, traditional knowledge and policy meet
The Namibian conference provided a rare opportunity for state counterparts to meet and discuss policies regarding their shared fish resources, and for scientists and communities to share their knowledge with each other and their respective governments.
The conference was ably hosted by the Namibia Nature Foundation with funding from the grant “Strengthening Community Fisheries in KAZA” that has supported work on fisheries in the KAZA TFCA since December 2020. The grant is part of the E€OFISH Programme that is promoted and funded by the European Union and implemented through the EU Delegation to Mauritius & the Seychelles with the support of eight implementing partners, including countries in the Southern African Development Community (SADC).
Of the many things we learned during the conference, one message was clear: most fish stocks in KAZA are in trouble. Fewer fish means that the people and fish-dependent wildlife are also in trouble.
The key driver for this situation is overfishing driven by the commercialization of fishing in KAZA, whereby most of the fish that are caught are sold to feed people living far from the rivers – either in towns within the KAZA countries or in other African countries. Just like commercial poaching operations, fish traders are often wealthy middlemen who may employ locals or send people from outside a local river community to fish – often using illegal types of nets.
The laws regarding fishing differ slightly between KAZA countries, which was a key takeaway from the sessions on policy delivered by government officials. In all countries except Botswana, fishing nets made of monofilament are banned. These nets are made from thousands of single nylon strands (like fishing line) that are cheap and more effective at catching fish than other types of nets or fishing methods. When these nets are used across rivers for long periods, few fish are left behind to grow or breed. Nets that are discarded or lost in the river will continue to catch and kill fish – a phenomenon known as ghost fishing.
The KAZA countries allow the use of other types of nets, and most have regulations on the size of the mesh used to ensure that larger fish are caught (nets with very fine mesh, like mosquito nets, are illegal). Despite these regulations, illegal monofilament nets are still commonly used across the region and local authorities face an uphill battle to remove the nets and apprehend illegal fishers.
Several countries have closed fishing seasons, but these are not synchronized, which means that people in one country may be prevented from fishing, while those living across the same river in a different country continue to fish. The capacity and resources available for law enforcement on the rivers are generally insufficient and highly variable from one country to another, presenting yet another challenge for cross-border cooperation.
See related: Fish kills leave Kenya’s Lake Victoria farmers at a loss, seeking answers
Community fisheries reserves: Hope for fish and people
Amidst these many challenges is a small but growing ray of hope: community fisheries reserves. In countries where policies allow for community-based fisheries management, communities may establish reserves along the rivers where they live. Relying heavily on their traditional knowledge and using scientific information when available, communities set aside parts of the river as no-fishing or controlled-fishing zones.
The community representatives at the conference hailed from the northeastern parts of Namibia where community fisheries reserves have been formally gazetted. During the conference they explained how their reserves function and some of the challenges they face. In their reserves, communities have made rules regarding the use of nets, fishing gear and methods. They employ fish guards or scouts to enforce their rules and remove illegal nets while on patrol, while encouraging the use of traditional fishing gear and methods.
People living along African rivers have fished using traditional fishing gear for millennia, some of which were exhibited during the conference. These traps are used in specific parts of the river in a targeted way. Most traditional traps targeting larger fish species will have gaps that allow juvenile fish to escape. Traps aimed at small fish species are usually used in shallow waters where larger fish species are rare.
Traditional knowledge about fish behavior, species composition in different parts of the river and seasonal fish movements are combined with traditional traps to ensure that fishing is sustainable. When communities decide to reduce the fishing pressure by reverting to traditional fishing practices and removing nets, fish stocks recover and catch rates will slowly start to increase. Unlike fish traders coming in from elsewhere, local fishers are more likely to value long-term sustainability over short-term profit that leaves their rivers devoid of fish.
Women are heavily involved in the fishing sector: they fish for themselves, make fish traps, prepare fish to eat and sell fish at markets, with many relying entirely on fish to feed their families. The commercialization of fisheries in KAZA along with declining fish stocks have left women in the fishery sector highly vulnerable, with some being forced to exchange sexual favors for fish just to survive. This was one of the many sobering lessons of the fish conference that spurred delegates into greater action to save fish and the human communities that depend on them.
Growing threats and challenges
Researchers working in the KAZA landscape reinforced the overall message that fish stocks are in decline, and added other issues of concern: pollution, changes in water flows due to dams and irrigation schemes, and climate change.
With more mines, dams and large-scale agricultural projects either operating or being planned along these rivers, river pollution is highly likely to increase. Some of the fish caught by scientists revealed that toxic chemicals like DDT are still being released into the system, where they will persist for many years to come. Fish accumulate heavy metals and other toxins that are present in the freshwater ecosystem, which makes them ideal indicators of the overall health of the ecosystem. However, continued pollution of these waters may result in fish becoming unsafe for human consumption.
The key impacts of climate change are on the amount of water that comes down the rivers each year and the dependence that people have on the river. The river systems in the KAZA region experience large seasonal changes in water levels, as rainwater makes its way down from mountainous areas through to the Okavango Delta or the into the Indian Ocean. Floodplains along the river’s route will fill with water and teem with fish for a short period of time, providing a boon for local people. If less water comes down, the extent of the floodplains will diminish, with negative implications for fish (which use these areas to spawn) and people.
At the same time, more frequent and severe droughts are increasing human dependence on river systems. When crops fail, many families turn to fish to survive. These desperate times may lead to increased conflict within communities over fish, while further exacerbating the conflict with outsiders. Furthermore, the community fish guards and their state counterparts will be under increasing pressure to turn a blind eye to illegal fishing, or engage in armed conflict akin to the anti-poaching battles on land.
Scientists and communities also noted a worrying increase in crocodile attacks on people, which is closely linked to declining fish stocks. Since 98% of a crocodile’s diet consists of fish, fish declines force them to seek different sources of food. As people and crocodiles follow the few remaining fish, deadly interactions between them become more likely. Saving fish is thus directly linked to saving human lives.
One of the clear take home messages of this conference is the need for governments, communities and scientists to talk to each other more frequently, coordinate their actions and share their knowledge. The challenges of fish conservation in KAZA are insurmountable if any of these stakeholders face them alone, but if they work together, it is possible to turn back the tide to restore fish populations and save the lives and livelihoods of our people.
Gail C. Thomson (née Potgieter) is a conservation consultant supporting community-based natural resource management and conservation organizations in southern Africa through her communications work. This op-ed was written for Resource Africa Southern Africa, with thanks to Britta Hackenberg of Namibia Nature Foundation for ensuring the accuracy of the text.
Read more about KAZA conservation issues:
Analysis of largest elephant surveys ever shows stable population, but disturbing trends
Breaking down barriers: Cattle and wildlife compete in Southern Africa
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