Limnetic zone

The limnetic zone is the well-lit, open surface waters in a lake, away from the shore. The vegetation of the littoral zone surrounds this expanse of open water and it is above the profundal zone. This is the main photosynthetic body of the lake. This zone produces the oxygen and food that support the lake's consumers.

It can be defined as the lighted surface waters in the area where the lake bottom is too deep and unlit to support rooted aquatic plants. This area is occupied by a variety of phytoplankton, consisting of algae and cyanobacteria, as well as zooplankton, small crustaceans, and fish. Most photosynthesis takes place in this part of the lake.