As is obvious by the name, wetlands are water bodies. Of course, a wetland is not just any water body, but that which is transitional between terrestrial and aquatic systems. In simple terms, it is land that is covered with shallow water - either still or flowing, in which the water table is close to the surface. Swamps, marshes, oases in deserts, mud flats, and paddy fields are all examples of wetlands. Stretches of marine water where the depth does not exceed 6 meters at low tide also categorizes as a wetland. It is an entire ecosystem with its associated plant and animal life. Wetlands are world's most productive environments with stunning biological diversity. Wetlands stretch from mountains to seas and include a wide variety of habitats from lagoons and mangroves to coral reefs. These habitats support a variety of species of birds, mammals, reptiles, and fish. Many of them are habitats for migratory birds like the Keoladeo Bird Sanctuary which is the winter home for Siberian cranes. Some are shrimp farms or fisheries, while others are purely for recreation purposes, valuable in ecotourism. Wetlands like mangroves provide a bulwark between the sea and land and help in stabilizing the shoreline. They help in preventing soil erosion and also in reclaiming land. They are breeding ground for marine organisms like shrimps and variety of fish. Some wetlands help in checking floods and siltation of waterways, others help in checking erosion of forests. Wetlands, which are freshwater bodies, are sources of water supply.Environmentalists, biologists, and others concerned about the health of the planet and its inhabitants recognize the key role wetlands play in life on Earth. The EPA points out that, besides containing a disproportionately high number of plant and animal species compared to other landforms, wetlands serve a variety of ecological services including feeding downstream waters, trapping floodwaters, recharging groundwater supplies, removing pollution and providing fish and wildlife habitat. Wetlands can also be key drivers of local economies, given their importance to agriculture, recreation, and fishing. According to Wetlands International, a global non-profit dedicated to the conservation and restoration of wetlands around the world, wetlands are on the ?front-line? as development pressures increase everywhere. ?Wetlands are vulnerable to over-exploitation due to their abundance of fish, fuel, and water,? reports the group, which works on the ground in 18 countries to educate the public and policymakers about the health of local wetlands and to advocate for better policies. ?When they are viewed as unproductive or marginal lands, wetlands are targeted for drainage and conversion.? ?The rate of loss and deterioration of wetlands is accelerating in all regions of the worlds.The pressure on wetlands is likely to intensify in the coming decades due to increased global demand for land and water, as well as climate change.? We can do our part by staying current on local zoning laws, keeping an eye on local wetlands and speaking up if something looks amiss. Potential problems are much easier to resolve early on than after damage is done, so speaking up soon can often lead to more successful and less contentious outcomes.   India has 19 Ramsar sites, i.e. 19 wetlands sites which are of international importance. Bhitarkanika Wildlife Sanctuary's Gahirmata beach, famous for its gigantic Olive Ridley turtles, in Orissa, is a Ramsar site. So is the Chilka Lake in Orissa which is famous for its prawn and shrimp farming. Vembanad backwaters of Kerala, Andaman and Nicobar islands and Keoladeo National Park are other examples of important wetland sites. 
Around 4 - 6 % of earth's surface is covered by wetlands. It is interesting to note that wetlands cover a tiny portion of the earth's surface, but by the nature of their unique ecosystem, it becomes all the more important to protect and conserve them.