Facing fish decline in Lake Tanganyika, Zambia's Indigenous communities take action

After toiling a cold night away on Lake Tanganyika in search of fish, Patrick Sikasote, a local fisherman, emerges in his boat on the lake bay at 6:15am. Fish traders, both young and old, rush towards the boat in the hope of buying fresh fish for resale.

But with dissatisfied faces, they soon leave.

Sikasote, a native of Mpulungu district in the northern part of Zambia, laments in the lungu dialect while docking his boat how fish stocks have continued to decline on the lake over the years. He recounts a time when he was able to catch enough fish to sell and to feed his family.

“We are so worried with the stocks of fish. Every day the fish keeps reducing as if someone is hiding it from us,” he joked as he left the shore.

Sikasote, like many other fishermen, is worried about the rate at which fish stocks are waning on Lake Tanganyika, Africa’s natural wonder. The lake, which is the continent’s second deepest and world’s second oldest freshwater lake, is an important natural resource which is bordered by Zambia, Burundi, Tanzania and the Democratic Republic of Congo (DRC). The lake is an important diverse water body which produces between 160,000 to 200,000 metric tonnes of fish yearly for both home and commercial purposes.

In Zambia, the lake is shared between Mpulungu and Nsama districts in the Northern Province, and is also home to 400 identified fish species, of which three are harvested for commercial purposes. The most common harvested fish species are Lates stapersii, popularly known as buka-buka; Stolothrissa tanganicae; and Limonothrissa miodon, also known as kapenta, which is enjoyed among the natives of the two districts whose main way of life is fishing.

Thousands of people in Zambia rely on Lake Tanganyika for survival, just like Sikasote, but the lake is in crisis. Its fish stocks are declining year by year, forcing researchers to be on their toes looking for answers.

Recently, a group supported by Internews' Earth Journalism Network visited Mpulungu and Nsama districts to look for those answers. During the visit, it was discovered that a lot of research is being conducted to ascertain the reason behind the massive decline of fish stocks on the lake.

The Department of Fisheries in Mpulungu district attributes the decline of fish stocks to the use of unconventional fishing methods, the increase in the number of fishers on the lake and the negative effects of climate change. Mabo Lwabanya, the Mpulungu acting fisheries and livestock coordinator, noted that the demand for fish has increased.

Lwabanya said the trend has prompted more people from various communities to engage in fishing, thereby reducing the fish stocks.

“It is also noted that fishermen are not using the recommended fishing net of 10 millimeters, resulting in overfishing," he said. "You find the fishermen catching even baby fish which they sell on the market and customers are buying without questioning the size of the fish."

While overfishing and use of unconventional fishing methods have been categorized as some of the factors leading to the decline of fish on Lake Tanganyika, researchers are alarmed about the future of the lake. Marine conservationists recognize the threat that overfishing poses to the county’s marine biodiversity.

However, researchers have argued that overfishing is not the real cause of fish decline. Instead, they point to climate change.

“The rise in temperatures on the lake forces nutrients to get locked on the bottom of the lake thus depriving fish of the much-required nutrients meant for its growth,” said Lloyd Haambiya, the technical advisor for Nsumbu Tanganyika Conservation Project under Frankfurt Zoologist Society.

Haambiya observed that the shrinking and dying of the lake’s natural habitats due to heavy rains, coupled with other factors, also poses a threat to the growth of fish.

“If we do not combat climate change and find sustainable management methods for our natural resources, we expect a lot of our people to go into abject poverty as the majority of them depend on the lake, which is running out of fish stocks,” he said.

Biologists believe that the continuous warming of the lake diminishes the mixing capabilities of the lake’s top and bottom layers. Other research findings reveal that bad agricultural practices around the lake basin could cause land degradation.

“Soil erosion, if not well monitored, can lead to pollution of the lake and eventually suffocate the fish,” observes Willem Colenbrander, a natural resources management specialist at the Lake Tanganyika Development Project.

It has also been established that running water from the mountain pushes tonnes of soil into the lake, posing a danger to fish and other marine organisms. The non-biodegradable waste that is littered along the lake shore always finds its way into the lake, resulting in pollution.

As experts continue to look for further answers and solutions to this challenge, the Indigenous community of Mpulungu is concerned how it will survive once the fish is depleted. Ackim Mwelwa, a fisherman, said not only will the depletion of fish make the community vulnerable to hunger but it will also lead to unemployment among Mpulungu residents.

“We do not have industries here in Mpulungu for people to work in. If we do not get white-collar jobs in government, we come here to fish for our survival,” he said. Mwelwa is also the secretary of the Lake Tanganyika Fisheries Multi-Purpose Fishing Association.

Mwelwa said a few years ago, he could afford to travel to Kasama and Lusaka to buy basic necessities for his family out of his earnings from selling fish, but today, he fails because he cannot sell the same amount of fish he did five years ago.

He also said he believes that people’s over-dependence on the lake could lead to the depletion of fish, but was quick to mention that fishermen are working towards changing the current situation. He is confident that the depletion of fish could be addressed if there are concerted efforts from the fishermen.

Experts are also working tirelessly to ensure that they combat the adverse effects of climate change on the lake by developing sustainable management strategies.

The Lake Tanganyika Development Project, a government intervention implemented by the Ministry of Water Development, Sanitation and Environmental Protection, and funded through a loan facility from the African Development Bank (AfDB) and a grant from Global Environmental Facility (GEF), is supporting 15 villages in Mpulungu and five villages in Nsama in a pilot project aimed at safeguarding the ecological system through tree planting.

Farmers are also advised to practice conservation farming to avoid clogging up the lake with impurities from the plateau. The Lake Tanganyika Development Project is also supporting village conservation and development committees that monitor and control the use of natural resources in the lake basin.

“We are not refusing communities from using these natural resources but we want people to use them in a sustainable way so that they are not depleted but replenished,” Colenbrander said.

The villages have also developed by-laws that stop people from indiscriminate felling of trees and also the use of unconventional fishing gear on the lake. The traditional leadership in the area is also encouraging communities not to over-depend on fishing but to venture into other lucrative businesses such as agriculture.

Chief Chitimbwa of the Lungu people noted that over-dependence on fishing, if not addressed, could lead to hunger among his people once the fish is depleted.

“We are already farming in my chiefdom. We have cassava and maize which are being grown on a small scale but I would love to encourage people to grow these produce for commercial purposes,” he said.

Haambiya further observed that regulation on the number of fishers found on the lake would also save the fish from extinction. Predicting the depletion of fish on the lake has prompted the Department of Fisheries to introduce fish breeding areas which are closely monitored and protected.

The Lake Tanganyika Development Project is also working with other cooperating partners to not only protect biodiversity but also support the sustainable use of natural resources in the lake basin. Colenbrander said he believes that the promotion of sustainable and equitable management of the lake’s natural resources could also save the lake from diminishing.

“We do not also want to see the lake become a white elephant or a dead lake once the fish depletes. We still want to see its marvel,” said Colenbrander, the project’s Natural Resources Management Specialist. He said the project also plans to create employment opportunities during its years of implementation so as to avoid over-dependence on fish.

While men tell the fishing tales of Lake Tanganyika, the impact of climate change on the lake is felt by everyone, including cross-border traders who travel long distances to buy the famous buka buka fish from Mpulungu. The district’s economic status will soon fall apart if commitment and passion are not shown towards programs put in place by the government aimed at bettering the lives of Mpulungu residents.

The onus is now on the inhabitants to take ownership of Lake Tanganyika by using recommended fishing methods as well as taking measures to conserve the water body by engaging in activities that are sustainable.

This story was produced with the support of Internews' Earth Journalism Network and was originally published in The Times of Zambia on 19 July 2021. It has been lightly edited for length and clarity. 

Banner image: Artisanal fishers' boats on Lake Tanganyika / Credit: Hannah Jane on Flickr.