|March 30, 2011
Lake Tanganyika fishing industry adrift
Fishing for a living on Lake Tanganyika has become a gamble, with the rising costs of fuel and the ever greater distances navigated to catch fewer fish stacking the odds against those working in the industry.
Lake Tanganyika is regarded as one of the world's most biologically diverse lakes and reaches depths of about 1.470 metres, making it the second deepest after Lake Baikal in Siberia. Its waters are stratified with cold bands, a feature of tropical lakes, but below about 250 metres the water is anoxic - devoid of oxygen. In May, June and July, the southeasterly "kapata" wind blows across the lake, causing "upwelling". This mixes some of the water layers and forces algae into the oxygenated water, which zooplankton then feed off and are in turn are consumed by pelagic fish. During those months the waters turn green, and some have argued that because "buka-buka are a visual predator" they were not active, and that was why the catches tailed off, but this explanation did not address why they used to be caught during this period in the past, Daniel Sinyinza, a biologist at the department of fisheries, said. He stressed that the surface water had warmed by as much as two degrees centigrade since the 1960s, and there were some suggestions that the strength of the kapata wind had also decreased, making it more difficult for the lake's colder and warmer layers to mix.
Four countries border Lake Tanganyika - Democratic Republic of Congo (DRC), Zambia, Burundi and Tanzania - and share territorial jurisdiction of the world's second largest fresh water lake by volume. Millions of people in the four countries with access to Lake Tanganyika rely on it, and it is estimated about 30.000 to 40.000 catch its fish. A baseline survey in the four countries will determine how many earn a living from the lake and the types of fishing equipment they use, so as to establish uniform regulations and practices.
Zambia and Burundi hold the smallest territorial claim to the lake, which measures 673km along its north-south axis and has an average width of 50km. DRC controls 45 percent and Tanzania 41 percent, but the focus of commercial activity on the lake is Mpulungu, land-locked Zambia's only port. One fisheries expert said three-quarters of the fish passing through Mpulungu came from waters outside of Zambia's territorial control.
The change in fishing patterns led to a different approach - fishing company trawlers were mothballed and local fishing operators became virtually the sole suppliers of commercial freezing and packaging plants in Mpulungu, which export to markets in Zambia’s Copperbelt Province, the capital, Lusaka, and other urban areas. Buka-buka have sold for between $1.60 and $1.80 a kilogramme in 2011, while "in other years it used to sell for about 2,000 [Zambian] kwacha [about $0.42] a kilogramme," Sinyinza said, "Less fish, a higher price."
Better prices do not mean greater rewards. Many expeditions end without any profit to pay the fuel costs to fund the next trip, so commercial packaging operations are providing loans to pay for fuel, with a first option on any catches. While large-scale fishing operations using trawler-type vessels all but disappeared as catches diminished and profits declined, companies had invested hundreds of thousands of dollars in infrastructure, cold rooms, and generator systems to compensate for erratic electricity supplies. Some fishing jobs have been swapped for factory jobs.
Large-scale commercial fishing began in the 1960s in Zambia, a decade after similar operations started in the northern reaches of the lake off Bujumbura, capital of Burundi. Zambian commercial fisheries caught a couple of thousand tons of pelagic fish annually, three-quarters of which were kapenta and the balance Nile perch. Commercial fishing operations exported 46.6 metric tons of dried fish from Mpulungu in 2010 and about 74 metric tons of fresh buka-buka, says the Mpulungu fisheries department. Stocks of the three large species of Nile perch - the apex predators - soon dwindled, allowing the smallest of the Nile perches, buka-buka, to flourish and become commercially viable, along with two species of kapenta. According to the biologist Sinyinza, buka-buka used to be caught throughout the year, "but this started changing in the mid-1990s and now between April and October you don't get buka-buka any more."