It is not easy to give a clear definition of what a wetland actually is. They are neither just land, nor just water. They can actually be both at the same time, or seasonally aquatic, or terrestrial. Every institute, government or organisation dealing with wetlands will have its own definition. Just to give you a rough idea of what wetlands are:
“Wetlands are areas on which water covers the soil or if water is present either at or near the surface of that soil. Water can also be present within the root zone, all year or just during various periods of time of the year.”
There are several ways in which to categorise wetlands. A wetland may be found in:
Coasts: areas between land and open sea that are not influenced by rivers (e.g. shorelines, beaches, mangroves and coral reefs)
Estuaries: where rivers meet the sea and water changes from fresh to salt as it meets the sea (e.g. deltas, mudflats and salt marches)
Floodplains: areas next to the permanent course of a river that extends to the edge of the valley (e.g. ox-bow lakes and river-islands)
Marshes/swamps: areas where water is more or less permanently at the surface and/or causing saturation of the soil (e.g. papyrus swamp, fen, peatlands)
Shallow lakes: areas of permanent or semi-permanent water with little flow (e.g. ponds, salt lakes, volcanic crater lakes).
All wetlands have two characteristics in common: Water or ice and earth. For Wetlands International the most important common feature is their importance for nature and mankind. No other type of ecosystem is so important to millions of migratory birds, fish, amphibians, insects, plants and trees. And no other type of area is so important to mankind. It is Wetlands International’s mission to preserve the 6% of the planet’s surface we call wetlands.