Fishing in Lake Tanganyika
*Estimated Reading Time = 3 mins
Grace Dickins [UK]
Climate change is happening whether we like it or not, and you can already see evidence of its impact around the world. An example of how it is a threat to communities on a local scale is Lake Tanganyika.
Lake Tanganyika is one of Africa’s Great Lakes, containing 17% of the world’s freshwater. It borders the countries of Burundi, the Democratic Republic of Congo, Tanzania and Zambia, all of which are referred to as less economically developed countries. This means they are not very resilient to the impacts of climate change and lack the infrastructure to deal with it as well as we can.
Lake Tanganyika itself has 10 million people alone living within its drainage basin, a number which is still rapidly increasing due to population growth. These people rely on the lake as a source of income, food and water, and are therefore vulnerable to any changes the lake may experience. So it isn’t good news that the lake’s temperature has already risen by 1 Celsius in the last 100 years. This may not sound like a lot, but small changes can have big impacts. In fact, this rise has led to a 20% reduction in biological productivity.
A reduction in biological productivity is caused by a lack of nutrient mixing. Water warmed at the surface becomes less dense and doesn’t sink, meaning that less cold, nutrient-rich waters from deeper in the lake rise to the surface. Without these nutrients, plankton and other organisms lower down the food chain can’t survive. This leads to less food for the fish and consequently, fish stocks decline. In fact, fish stocks in Lake Tanganyika have been in decline since 1962.
It should be noted that some of the decline in fish stocks is due to over-fishing because of the increasing human population around the lake, but climate change is definitely a contributing factor. These people source 25-40% of their animal protein from the lake, which means reduced fish stocks pose a threat to their food security. In the next 50-100 years, the air temperature in Africa is expected to rise by 2-5 Celsius so these four countries need to start thinking about how they can adapt.
Perhaps you’re thinking why this concerns us. Well, it was mostly more economically developed countries such as the UK that started the ball rolling on the problem of man-made climate change in the first place. If we act to slow down climate change now, we could significantly reduce the impact on people’s welfare, such as of those living around Lake Tanganyika. It only takes a bit of effort on our part.