Swamps, marshes, backwaters, mangroves, estuaries, vernal pools, and inter tidal zones are some wetland formations. Wetlands vary widely because of regional and local differences in soils, topography, climate, hydrology, water chemistry, vegetation, and other factors, including human disturbance. Wetlands are found from the tundra to the tropics and on every continent except Antarctica. These natural formations are in danger today. They are endangered by human activities, water pollution, and fragmentation.
Wetlands support many species of fishes, plants, birds, and other creatures that are unique to the area. Some wetlands are seasonal and people depend on them for their livelihood. All over the world the loss of wetlands is causing alarm to the environmental scientists.