fish left in the dark

Climate Change Could Harm Lake Fish: Light Determines Growth Of Fish In Lakes.

“In the brownest lakes sunlight can’t penetrate more than about two meters. In clear mountain lakes, the light can reach down to depths of 15-20 meters and lead to high production of algae on lake bottoms,” says Jan Karlsson, associate professor at Climate Impacts Research Center (CIRC).

The problem is that the algae that live on the lake bottom need sunlight for their photosynthesis. The algae provide food for various bottom-dwelling animals, which in turn are eaten by fish.

Limited light penetration thus has negative consequences for all living beings in a lake. Light is what determines the growth of fish in lakes. Climate change is expected to lead to browner lakes with less light penetration, which will lead to reduced growth of fish. Science Daily, 18 Aug 2009