Of course, there has always been occasional mixing, as animals and underwater waves move through the lake. But global warming is driving a bigger wedge between Lake Tanganyika’s warm and cool water zones. As the surface warms at an accelerating rate, like oil on top of water, the temperature divide cuts off this mixing and starves the surface waters of the nutrients needed to grow enough aquatic plants to sustain fish populations.
Peter McIntyre, associate professor and Dwight Webster Sesquicentennial Faculty Fellow in the Department of Natural Resources, has been studying Lake Tanganyika for 20 years.
“This lake used to produce 200,000 tons of fish per year. Now, it’s producing half that, at best,” McIntyre said.
“Even with a very small increase in surface water temperatures, the entire ecosystem is collapsing. And this is a key food source for 20 million people,” said Peter McIntyre.
McIntyre joined Cornell last year, as part of a slew of new faculty hires intended to strengthen Cornell’s capacity to understand and address the intensifying challenges caused by climate change. He now co-leads the Adirondack Fisheries Research Program, which is assessing the many ways that New York’s lakes and fisheries are being harmed by rising temperatures and shifting precipitation.
What’s happening in lakes is just one of many examples of how climate change has already fundamentally altered the ecosystems that we rely upon for survival. Experts agree that it will get much worse.