WETLANDS - FUNCTIONS, THREATS AND MANAGEMENT

The Ramsar Convention defines wetlands as areas of marsh, fen, peat land or water, whether natural or artificial, permanent or temporary, with water that is static or flowing, fresh, brackish, or salt. The definition includes marine water less than six meters deep and all rivers and coastal areas, as well as most coral reefs. Wetlands are among the world's most productive environments. These wetlands have vital physical, chemical, biological and socio-economic functions. They are important because of:

Another important function of the wetlands is as habitats for wildlife and migratory birds. Terrestrial wild animals are linked with wetlands. Migratory birds select routes via wetlands where they take rest for few days.

India with a varied climate supports a rich diversity of inland and coastal wetland habitats. It has about 4.1 million ha. of wetlands of which 1.5 million ha. are natural and 2.6 million ha. are man made. It has important wetland types like:

Tanks, reservoirs and other water bodies of Deccan peninsula;

Backwaters and estuaries of West Coast of the peninsula;

Saline expanses of Rajasthan and Gujarat;

Fresh water lakes and reservoirs of Gujarat, Rajasthan and Madhya Pradesh;

Deltas, lagoons and salt swamps of East Coast;

Marshes, jheels, terrai swamps and chaur lands of the Gangetic plains;

Flood plains of Brahmaputra;

Marshes and swamps in the hills of North-Eastern India;

Lakes and rivers of the montane regions in Jammu & Kashmir, Uttar Pradesh and Himachal Pradesh;

Wetlands in Islands of Bay of Bengal and Arabian Sea; and

Coastal brackish water wetlands in West Bengal, Andhra Pradesh, Tamil Nadu, Kerala and Karnataka. Wetlands in India harbour diverse flora and fauna, many of which are endangered. Many of the wetland areas have been drained and reclaimed for agriculture and urban sprawl. Sedimentation is a problem particularly in shallow lakes (such as Chilka in Orissa and Kolleru in Andhra Pradesh) and most wetlands are eutrophic (such as Srinagar's Dal Lake, etc.). Other threats are the agricultural runoff with pesticides, construction of dams and barrages and dumping of garbage and domestic effluents (Singh R.V., 2000).

An important aspect of these wetlands is that they provide livelihood to the local community living in and around them. A majority of the low-income group population of artisan fishermen depends on the bioresources available from these ecosystems for their daily food, health care and energy needs. Traditional fishermen are solely dependent on the natural resources like fish and shellfish, for their sustainable livelihood. Thus these wetlands influence the socio-economic status of the local communities. On the other hand the local communities also influence the wetlands to a great extent in controlling the ecosystem health. Coastal wetlands support diverse and growing economic activities including aquaculture, recreation and tourism.

LOCAL WETLANDS:

The important function of the coastal wetlands is that they support the mangroves with special adaptations. The people of Coastal Karnataka depend on these wetlands for food, fuel, fodder, and low cost construction material for housing as the timber is quite strong. The backwaters are also used as sites for recreation and leisure. Ecotourism is well developed on the Kerala coast and contributes to the economy of the state. Similarly, ecotourism in coastal Karnataka should be developed. The recreation centre along coastal Karnataka near Kundapur is in a developing stage. However, no effective attempts are being made even though there are many potential sites.

THREATS TO WETLANDS:

The major threats include the urbanisation and anthropogenic pressure; land based industrial outfalls, and community pressure for fuel, food and fodder. The other major threats include:

dumping of tile factory wastes

coconut husk curing

sand and shell removal

weed choking

waste disposal by intensive aquaculture and its wastes

industries and agricultural practices along the catchment area

A major threat to the inland wetland is the aquatic weeds, which multiply very quickly and cover the waterbodies (species of Salvinia, Pits, Eichhornia, Hydrilla, etc.). Subsequently, the human use system fails, productivity drops, aesthetic values diminish and detritus organic matter accumulates, filling up the wetland basin. Inspite of concentrated efforts by the people nearby, clearing the weeds is a major problem. In fact at Karkala, the Thavarkere and Ramasamudra wetlands were cleared of weeds a year back but are now covered with salvinia and pistia, which are creating a big menace. Throughout the world controlling the growth of aquatic weeds is a major challenge and billions of dollars are spent to overcome this problem (Madhyastha et.al., 1990).

The most important threat to the coastal backwaters is the upstream anthropogenic activities, which exert stress on the downstream area. These disturbances can be minimized with strong co-operation between the downstream and upstream population in restoring the valuable wetlands. People in the head region of the river/stream should be vigilant about dumping of contaminants. The concept of ecosystem health and function needs to be highlighted to the communities along the river basin (Elseworth, 1990).

The resource conservation and management of environment needs a holistic approach involving strong cooperation of the people in the participatory programmes. The developmental activities should also consider the immediate stress on the biota and the local community who are the stakeholders. Many a time, economic and legal instruments and suitable interventions are essential to protect these resources. The residing community on the banks of these wetlands are the stake holders of these resources: unless the minimum requirements of the marginal population or low income groups who are solely dependent on these ecosystems for their daily needs are met. Effective management of the ecosystem is not possible and the protection and conservation practices may fail. The management programmes should adopt economically sound measures that act as incentives for conservation and sustainable use of resources and components of biodiversity of these habitats. Promoting scientific, technical and socio-economic co-operation with the stakeholders, and implementing measures that avoid and minimize adverse impacts on biodiversity should be encouraged (Govt. of India, 1999).

Integrated management with a collaborative approach, which brings together interested parties to incorporate social, cultural, environmental and economic values, needs to be looked into. Socio-economic assessment for conservation, social, cultural, and economic activities is an essential component in the development of integrated management plans.

1.) Department of Biosciences,
Mangalore University,
Mangalagangothri 574 199,
India