Wetlands are any areas where water collects, not in river or lake form, but in the ground itself, forming marshes, swamps, or bogs. Wetlands are very fertile areas and full of animal and plant life; wetlands occur most frequently around the equator of the Earth, where the temperatures keep water from freezing and turning to ice or snow, and are often used for hunting, fishing, drilling, parks, and open space for redevelopment.
In recent years, the use of wetlands for purposes other than the natural has been harmful to the local ecosystems, many of which depend on the diverse nature of wildlife to spread seeds or predation to control fast-breeding species. One major problem is the fragile nature of wetlands; one minor change can spread to damage or even destroy the entire ecosystem. For example, the standing groundwater carries nutrients to a huge variety of plants, which simultaneously purifying and cleaning the water by flowing it through a constant mixture of soil, animal waste, and absorbent plant roots. If the standing groundwater is contaminated, for example by a factory pouring waste in large quantities, the natural purifying systems may not be able to keep up with the new demand, and plants that feed animals will die. Those animals might move to a different area, and a previously controlled pest might overpopulate.
To conserve wetlands, private organizations have bought up large amounts of land to keep it from being developed or flooded by business. The U.S. Government is also involved, declaring national parks or reserves to keep land from being developed, and removing pollution or human presence from damaged wetlands to allow them to renew. Although previously-developed wetlands may be too damaged to recover -- for example, a dammed and flooded area might not be able to recover even if the dam is removed -- most conservation efforts are relegated to non-involvement, allowing the natural course of the wetland to continue. When pollution is present, a certain amount of intervention is necessary to remove it, but after that the proper thing to do is leave the land alone to recover naturally.
Other methods include replanting lost species of plants and building artificial nests and habitats for animals to live in. A certain amount of landscaping for water redirection can also help an over-saturated wetland recover, as in the dam example above. Most important is keeping the area off-limits from casual contact by humans, who might not be aware of the protected status and inadvertently damage the ecosystem.