Wetlands are sources of extreme biodiversity and ecological benefit. They contain a multitude of species of plants and animals, including 79 species classified as rare, threatened, or endangered. An estimate by the U.S. Fish and Wildlife Service indicates that wetlands provide for, directly and indirectly, up to 43% of federally threatened or endangered species. Wetlands are the leading producer of oysters, 50% of the shrimp crop, 75% of the alligator harvest, 27% of the oil and gas, and the largest port complex in the United States. The world’s wetlands have an estimated worth of $14.9 trillion.
Wetlands also provide for disaster protection, including surge protection from hurricanes, as they and barrier islands help to break down the power of a storm before it reaches mainland. They also provide flood relief, as they are able to hold about three-acre feet (one million gallons) of water. This holding of water allows for rejuvenation of ecosystems, as new sediment is able to settle. Flooding also affects factors such as root penetration, soil temperature, conductivity, and bulk density.
Wetlands are highly effective at removing pollutants and excess nutrients due to the slow water flow and absorption by the plant systems. This has been shown to be effective in the removal of nitrogen and phosphorus, the major nutrients involved in “dead zones”. They are also major sinks for heavy metals and sulfur.