Wetlands

V

Recreational, Cultural, and Aesthetic Value

Hunting, birdwatching, observing nature, hiking, boating, camping, and photography bring many people to wetland areas. Wetlands are often tranquil areas away from intensive human activities. With increased tourism, the recreational value of wetlands has become more important than ever. Britain’s large number of wetland areas support sizeable populations of birds and many wetland nature reserves and wildlife sanctuaries are much visited, including the Slimbridge Wildfowl Trust on the estuary of the Severn, Rainham Marshes on the Thames estuary, and Minsmere reserve in Suffolk ; the Norfolk Broads are popular for family holidays. In some developing countries ecotourism is providing a means to attract tourists and yet protect the environment. In Botswana, for example, at the Okavango Delta, visitors can observe the wetlands wildlife, but are offered restricted access to some of the best sites. It is hoped that ecotourism will increase revenues without degrading valuable wetland resources.

VI

Threats to Wetlands from Human Activity

The greatest threat to wetlands is conversion to agricultural land. With population growth and the availability of technology to drain the land, new areas of agricultural land have been created. Extensive areas of such farmland are found in Britain, for example, in Lincolnshire and East Anglia. In Africa there has been much drainage of wetlands to provide agricultural land, in areas of Rwanda, Kenya, Malawi (the Nyika Plateau), and Burundi. In Indonesia large areas of peat swamp have been cleared of forest as part of a large rice-planting scheme. However, as wetland areas have reduced, their true value has been more fully understood. The loss of wetlands is now seen as a cause of concern. Some land drained for agriculture has a lower economic productivity than traditional uses (such as hunting or forestry).

Many wetland areas have decreased as water has been taken for irrigation from the rivers that drain into them. The most famous example is the Aral Sea in central Asia. There human activity has grown in the area and has further increased water abstraction, with the resulting loss of wetlands.

Dams have been built to flood wetland areas, even out the annual water supply, and provide hydroelectric power. Examples of this are found worldwide, and the schemes at the Akosombo Dam in Ghana and the Aswān High Dam in Egypt are well known. Such changes in wetlands threaten the wildlife and the indigenous people who derive their livelihoods from these areas. Other wetlands such as the Sudd in Sudan are now targeted for dam projects. The affected area of the Sudd region covers 80,000 sq km (30,880 sq mi) and currently supports about 1 million people, 2 million cattle, sheep, and goats, and 3 million wild herbivores. Most of the surrounding area is arid or semi-arid and not very productive. Much work is being done to calculate the alternative values of wetland areas so that a true assessment of the benefits of dam schemes can be made.

Wetland drainage can help the eradication of pests, including mosquitoes, which carry diseases such as yellow fever and malaria. However, other diseases, such as schistosomiasis in Africa, have increased because the snails, which are essential in the life cycle of the parasite, thrive in the irrigation channels created for agriculture. A further problem in hot areas under irrigation is salinization of the soil. It is estimated that as much as 25 per cent of the agricultural land of the Nile Valley in Egypt has been lost by salinization.

VII

Natural Changes in Wetlands

Wetlands are particularly dynamic ecosystems and are shaped and destroyed by extreme natural events, such as floods, storms, or drought. Plant succession and sedimentation also cause wetlands to dry out as the ecosystem changes to a more terrestrial one. Such changes take a very long time, often thousands of years. Wetlands respond to changes in global temperatures, as can be seen from the present extent of Lake Chad in central Africa, which is about 10 per cent of the size it was 7,000 years ago. In the future, changes in sea level resulting from climate change may affect wetland areas.

VIII

Protection and Regulation of Wetlands

The Convention on Wetlands of International Importance is an intergovernmental treaty adopted in 1971 in Ramsar, Iran. It is known as the Ramsar Convention or the Convention on Wetlands. It provides a framework for international cooperation for the conservation and wise use (or sustainable use) of wetlands. The convention was signed by 945 states and more than 800 wetland sites, covering more than 500,000 sq km (193,000 sq mi), have been included on the Ramsar List of Wetlands of International Importance.

The convention places a number of obligations on the contracting party states. Each has to designate one wetland for the list and promote its conservation. They have to ensure the sustainable use and conservation of all wetlands in their country whether or not on the list, and create nature reserves and promote research, management, and wardenship. The United Kingdom currently has 149 sites on the list, which is the highest of all contracting parties, and all of these are also Sites of Special Scientific Interest.

The Ramsar Convention is working with all countries around the world to identify wetlands of international significance and to promote greater conservation and better use of these ecosystems.