Wetlands are areas where water covers the soil, or is present either at or near the surface of the soil all year or for varying periods of time during the year, including during the growing season.
Article 1.1: "...wetlands are areas of marsh, fen, peatland or water, whether natural or artificial, permanent or temporary, with water that is static or flowing, fresh, brackish or salt, including areas of marine water the depth of which at low tide does not exceed six meters."
Wetlands are highly productive and biologically diverse systems that enhance water quality, control erosion, maintain stream flows, sequester carbon, and provide a home to at least one third of all threatened and endangered species.
There are many different kinds of wetlands and many ways to categorize them. NOAA classifies wetlands into five general types: marine (ocean), estuarine (estuary), riverine (river), lacustrine (lake), and palustrine (marsh).
Wetlands occur wherever water meets land and ensure the sustainability of both. These unique habitats include mangroves, peatlands, rivers, lakes, deltas, seagrass meadows, and even coral reefs.
Between 300 million and 400 million people live close to and depend on wetlands. They support the cultivation of rice, a staple in the diet of half the world’s population. They also provide flood control, clean water, shoreline and storm protection, materials, medicines, and vital habitat.
More specifically, wetlands are areas where the presence of water determines or influences most, if not all, of an area's biogeochemistry—that is, the biological, physical, and chemical characteristics of a particular site.
Despite their small footprint, wetlands have important jobs, providing fresh water and habitats, and fighting climate change. Wetlands were historically considered wastelands.