Warming Lake Tanganyika endangers fish and livelihoods

Scientists have discovered that Lake Tanganyika, the second oldest and deepest lake in the world, is at the warmest in 1,500 years. Some 10 million people in Burundi, Tanzania, Zambia and the Democratic Republic of Congo live around and depend on the lake.

Francesca Ansaloni

The surface waters of Lake Tanganyika is at 26 degrees Celsius, a temperature unprecedented since the sixth century.

The temperature change could affect fishermen's livelihoods, according to Jessica Tierney, the geologist who led the research.

“It affects the amount of algae that grow in the lake and those algae feed fish,” said Tierney. “There are about 10 million people living in the watershed of Lake Tanganyika and it’s estimated that at least 1 million of those directly benefit from the fishery and the fishing industries around the lake.

"These warm temperatures might contribute to a decline in the fish stock in the lake and that will affect millions of people.”

Tierney's study, which will be published in an upcoming issue of the journal Nature Geoscience, examined samples of the lake’s sediment cores to reconstruct lake surface temperatures for the last 1,500 years.

The largest temperature increases have occurred within the last century, which suggested that the trend is a response to the production of anthropogenic greenhouse gases.