Lake & Pond Zones

Lakes and ponds are made up of zones, each with its own challenges. The littoral zone is the area closest to the shore where light reaches all the way to the bottom. Plants rooted to the bottom and algae live here. Animals may include tiny crustaceans, flatworms, insect larvae, snails, frogs, fish, and turtles. The limnetic zone is the layer of open water where photosynthesis can occur. The light decreases the deeper you go until a depth is reached where the rate of photosynthesis becomes equal to the rate of respiration. This zone is not as clear and is a more prominent feature of lakes than of ponds. Aquatic life is dominated by planktonic algae, zooplankton, swimming insects and fish. Very deep lakes have an area known as the profundal zone where light does not reach. This zone is inhabited by organisms that are either attached to or crawl along the sediments at the bottom of the lake. The sediments support a large population of bacteria and fungi. The decomposers break down the organic matter and release inorganic nutrients.