Level in lakes

profundal zone:Aka aphotic zone. Deep open water too dark for photosynthesis. Oxygen levels low without sunlight and plants.

littoral:top layer, near the shore, most productive zone (due to sunlight and nutrients from surrounding land), high biodiversity, shallow sunlit waters

limnetic zone:main photosynthetic body of the lake, produces the food and oxygen that support most of the lake's consumers, sunlit surface (away from shore)-extends the depth of sunlight penetration

benthic zone:"floor" or bottom layer. Inhabited by decomposers, detritus feeders, and some fish. Dead matter falls here.