Lakes are basically water bodies that are enclosed by land, majority of which consist of fresh water. They can be classified based on the nature of their formation process. Lakes can be formed by landslides, glacial blockages, depressions created by tectonic uplift of mountains and several other natural phenomena. The size and shape of lakes also vary to a great extent depending upon their type (Lake Access). Also, the diverse variety of aquatic life inhabiting these lakes is determined by their type and geographic location.
A subglacial lake is one which is found under the surface of ice caps and glaciers. The water in such lakes remains in liquid state, as the layer of ice above retains the heat resulting from geothermal heating and friction. A subglacial lake is usually round-shaped and does not facilitate animal life due to the extremely low temperatures. Lake Vostok located in Antarctica is a classic example of a subglacial lake; its coordinates on the earth are 77 degrees South-105 degrees East. The amount of water found in such lakes is approximately around 5400 cubic kilometers.
A reservoir is an artificial lake brought into being by human intervention. These man-made lakes are usually bigger compared to their natural counterparts. A reservoir is made by filling up an open pit mine or unused patches of land behind a dam with massive quantities of water. These lakes are commonly shaped like a bean or moon. They accommodate aquatic life such as Catfish, Guadalupe bass and many other varieties of fish. Lake Nasser, an artificial lake on River Nile is a well-known reservoir; it is geographical location extends between 22-25 degrees North and 31-45 degrees East.
An endorheic lake is a closed lake which does not experience any substantial outflow of water. The surface of such lakes is flat and dry since they are mainly located in desert regions, where inflow of water is low; they are also characterized by steep holes and their depth varies a lot. Although the outflow of water in most lakes is through underground diffusion or rivers, endorheic lakes are quite an exception since the outflow is only by water evaporation in the endorheic basin. Hence, these lakes are also known as terminal lakes. Endorheic lakes mostly consist of reptilian life forms such as snakes and lizards. Lake Eyre is a commonly known endorheic lake located in central Australia between 28-22 degrees South and 137-22 degrees East. Lake Turkana and Lake Torrens are some other examples of an endorheic lake.
A meromictic lake consists of several layers of water that do not mix with each other. The deepest layers in such lakes have a scarcity of oxygen and the sediments there remain intact. They are circular in shape; the basin of such lakes is quite steep, while the surface area of the lake is relatively less deep. Meromictic lakes are inhabited by cormorants, turtles, herons, geese, ducks and raccoons. Green Lake located between Washington D.C and Seattle is an excellent example of a meromictic lake; it is nearly 2.1 meters in depth. Lake Nyos and Lake McGinnis are some of the other popular meromictic lakes.
An Oxbow is a lake which is formed when a stream channel bend is abandoned from a river. When a river meanders slowly in a low-lying plains and river valleys, a horseshoe-shaped bend is cutoff from the main channel as a result of continuous silt deposition, giving rise to oxbows. They distinctively look like curve-shaped cracks or loops. An Oxbow does not support much of animal life and its size is about 22miles long and three-fourths of a mile wide. Lake Reelfoot in Tennessee and Lake Chicot in Arkansas are examples of an Oxbow.
Reference:
Lake Access. (n.d.). Formation of Lakes. Retrieved 2 July, 2007 from,
<http://lakeaccess.org/ecology/lakeecologyprim1.html>
