Large volumes of permanent water in these lakes buffers water temperatures and effects of nutrient input on water quality. The spatial extent and range of habitats support very large numbers of species in some groups such as fish, some of which are unique to a single lake, often composed of closely related species, endemic to a lake. The high primary productivity from algae and aquatic plants lake supports diverse foodwebs. High numbers of plankton support large numbers of waterbugs, fish, frogs, reptiles, waterbirds, and mammals. Bacteria play key roles in cycling organic matter.