Lake Ossa: Where wildlife and humans live side by side

The Lake Ossa Wildlife Reserve in Cameroon is part of the Douala-Edea Landscape - a swathe of jungle, marshland, mangroves, and rubber and palm oil plantations bisected by rivers and lakes. The area is home to a wide variety of aquatic species, including dwarf crocodiles, West African manatees, softshell turtles, freshwater and marine fish that swim upriver from the ocean. Around 2000 people live in the area, and most rely on the lake and the forests that surround it for their livelihood. However, human population growth, invasive species, and the encroachment of industrial agriculture is exerting pressure on the lake ecosystem.

Much of the area around Lake Ossa is rainforest, although it has been significantly degraded by illegal logging and pressures from growing local populations, including poaching and extraction of wood for fuel. With the support of the Zoological Society of London (ZSL), those who used to fish the lake have established a social enterprise around the collection of abandoned nylon fishing nets - a project that combines community-led conservation with micro-enterprise, since the nets are purchased by Italian company Aquafil, which turns them into ECONYL regenerated nylon thread.

Palm oil and rubber plantations established in the 1950s occupy land to the west of the lake. Whilst the plantations provide some employment opportunities, they have affected the lake ecosystem by impacting the drainage basin downstream, causing erosion and an increased incidence of landslides. Fertilizer run off may also be affecting the lake, as parts of the palm oil plantations grow right up to the shore, despite set back rules.

Many of the communities living around Lake Ossa rely on fish from its waters as their main source of protein and income. Fishers use simple hand carved wooden canoes and paddles, heading out in the early hours of the morning and usually returning with their catch between 8am and 10am. Though traditional bamboo fish traps are still used, most fishers now use nylon nets that are inexpensive to buy, and enable them to catch more fish. Over the years, thousands of these nets have been abandoned in the lake, littering the shore and encouraging the growth of invasive plants that damage the lake ecosystem. This alongside overfishing, poaching, and agricultural encroachment have impacted fish stocks, which are no longer a reliable source of subsistence for the local population.

A member of ZSL’s Net-Works initiative extracts a discarded nylon fishing net from Lake Ossa. It is hard work, as the nets are tens, sometimes hundreds of metres long and often need to be disentangled from underwater obstructions. Being nylon, these fishing nets will take hundreds of years to degrade. That makes them an environmental menace, but also an economic resource. So far, the communities around Lake Ossa have collected more than six tons of discarded net - though there is still a great deal left across the lake’s 4000 Ha area.

Moukoko Daniel collects salvinia from Lake Ossa. Salvinia is an invasive floating fern that clusters around the lake’s shores, adhering to abandoned fishing nets and robbing the lake of oxygen and sunlight. The nets also prevent the salvinia from being dispersed by the tides, hemming them in. ZSL is researching a pilot project to turn the salvinia into compost that can be used to grow commercially valuable crops such as peppers.

Moukoko Daniel is currently the Net Manager for ZSL project Net-Works. A former fisherman, he now oversees the retrieval, cleaning, weighing and storing of nylon fishing nets abandoned in Lake Ossa. During his time as a fisherman, Daniel saw his catch steadily dwindling - a fact he attributes to the growing population in the area and the proliferation of salvinia. Daniel is now a custodian of the lake ecosystem, and his income means he can provide an education to his children so that they won’t be forced to fish.

Christian Kongte is the Impact Management Officer for ZSL’s Net-Works initiative. Originally from Cameroon’s capital Yaounde, Kongte is a trained fisheries engineer. He now works closely with Daniel and the other members of the net retrieval group to ensure the fishing nets are properly processed and stored. The nets are first cleaned and put into a hand-driven net bailing machine, which compresses them into a compact bail that is easy to store and transport. The net warehouse is located in a former hospital, which also houses a number of families who have enterprisingly taken over some of its wings. Net-Works sent their first shipment containing four tonnes of netting to Europe in late 2017. The nets are processed, together with other nylon waste, into ECONYL regenerated nylon.

Basic infrastructure and services are severely lacking around Lake Ossa - including financial services that many of us take for granted. With no access to conventional banks, local people have set up community banks with the help of ZSL. A president, secretary, and treasurer each have one key to a cash box with three locks. Nine of these banks handle income from the collection of abandoned nets, with money split between the net manager and collectors, and a community conservation fund. Run by women from the communities, the banks meet once a month to go over the books - and to celebrate with singing and dancing. Deposits are often made using a stamp that represents a given amount of money, since illiteracy and innumeracy levels are high.

Dizangue is the biggest settlement in the Lake Ossa area. The town facilities and services are severely limited - there are no formal financial institutions such as banks, for example, and the local health clinic is severely under resourced. Forty per cent of the lakeside community lives in poverty, while 80 per cent rely on its resources to survive. ZSL works closely with local people to help establish community-level support systems, including community banks, alternative livelihood initiatives, and conservation projects.