Wetland conservation is aimed at protecting and preserving areas where water exists at or near the Earth's surface, such as swamps, marshes and bogs. Wetlands cover at least six per cent of the Earth and have become a focal issue for conservation due to the ecosystem services they provide. More than three billion people, around half the world’s population, obtain their basic water needs from inland freshwater wetlands. The same number of people rely on rice as their staple food, a crop grown largely in natural and artificial wetlands. In some parts of the world, such as the Kilombero wetland in Tanzania, almost the entire local population relies on wetland cultivation for their livelihoods.
Fisheries are also an extremely important source of protein and income in many wetlands. According to the United Nations Food and Agriculture Organization, the total catch from inland waters (rivers and wetlands) was 8.7 million metric tonnes in 2002. In addition to food, wetlands supply fibre, fuel and medicinal plants. They also provide valuable ecosystems for birds and other aquatic creatures, help reduce the damaging impact of floods, control pollution and regulate the climate. From economic importance, to aesthetics, the reasons for conserving wetlands have become numerous over the past few decades.
Various definitions of wetlands exist. The Convention on Wetlands of International Importance, also known as the Ramsar Convention, defines wetlands as including: lakes and rivers, swamps and marshes, wet grasslands and peatlands, oases, estuaries, deltas and tidal flats, near-shore marine areas, mangroves and coral reefs, and human-made sites such as fish ponds, rice paddies, reservoirs, and salt pans. Meanwhile, the United States Environmental Protection Agency (EPA) or Wetlands Reserve Program, describes wetlands as "those areas that are inundated or saturated by surface or groundwater at a frequency and duration sufficient to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions. Wetlands generally include swamps, marshes, bogs and similar areas." Wetlands vary widely in their salinity levels, climatic zones, supported flora, surrounding geography, whether they are coastal or inland and so on.