Three main life zones exist in freshwater: the epilimnion, the hypolimnion and the thermocline. The epilimnion is a shallow area where small fish, marine animals and plants, and amphibians live. The hypolimnion is deep water where fish live. Plants do not live well here. Thermocline is an in-between area where transitions occur between the shore and the deep water.
Shallow water hosts many creatures. Vegetation also grows here providing hiding places for amphibians like frogs and salamanders. Young trees sometimes grow in this area especially willows. Crabs, crayfish and other invertebrates also make their homes in the sand. Birds will stop to drink water if the water is not too murky or stagnant. Ducks like to swim along the shoreline looking for bugs and small fish to eat. Many grasses grow in freshwater ponds and lakes. The epilimnion hosts lily pads, moss, and reeds or rushes, as well as small creatures. Deer will frequent the shallow zone.
The hypolimnion hosts the fish. Life here consists of fishes: trout, salmon, bass, and wall-eyes. Beavers and otters live in this part of the lake or river. Snakes and alligator even venture out to the deeper part of the river in search of bigger prey. Ducks and birds also use this zone for a supermarket. This zone has the coldest water in the region. Bugs do not live here. They have no place to roost and when they tire, they fall in the water where fish quickly consume them.
The thermocline is the area where the water is tepid. It is not as warm as the shallow yet not as cold as the deep zone. Some of the same animals that live in the shallow zone will also live in thermocline. This also holds true for the deep zone. Some animals in the deep zone can also live in the thermocline; however, most do not live in both the shallow and deep zones.
Freshwater draws all kinds of animals. Animals that do not live in the water, but make their homes nearby, frequently use the water. Freshwater consists of many different things from lakes and rivers, to backyard ponds, wetlands, marshes and swamps, and even reservoirs which hold water for future use.
Freshwater has no shortage of life. Unfortunately, dangerous things like viruses and bacteria live in it in the form of alga and molds, which can cause sickness and death if inhaled.
All the zones support some life form. Visit a freshwater zone and discover the life there.