Lakes are large bodies of water home to many aquatic animals and plants. The Lakes rely on wetlands to filter runoff, to help "purify" water, to exchange groundwater and to provide habitat essential for fish and wildlife populations. Because human effects on lakes are growing, concern increases that Lake Ecosystem services are in jeopardy.

LAKE SUPERIOR	LAKE BAIKAL
LAKE CHAMPLAIN	LAKE HURON SHORELINE

Importance of lakes

1. Home to many aquatic animals and plants
2. A source of minerals
3. Source of recreation and esthetic enjoyment.
4. Source of drinking water
5. Provide water for irrigation and for industries
6. Transportation
7. Help in the generation of hydroelectric power
8. Dilution of pollutants

Still water, in general much warmer than rivers and streams, can support many different kinds of plant and animal life. The silty bed of ponds and the shallower parts of lakes support rooted plants and burrowing larva, food for free-swimming animals such as fish and frogs. In deeper zones, where oxygen is less abundant, only animals adapted to the cold environment exist. Plankton develop at all levels.