Conservation and Wise Use of Aquatic and Wetland Plant Resources:Introducing West Bengal

Wetlands and different types of waterbodies of West Bengal are of diverse origin and types with a different blend of water quality parameters. These wetlands support aquatic and wetland plants of different growth forms. Wetlands of West Bengal represent nearly 60% diversity of aquatic and wetland plants of India covering only about 8.5% of the wetland areas of the country. Diversity of aquatic and wetland plants of West Bengal is represented by more than 380 species belonging to 170 genera and 81 families. More than 44 species are important as food and vegetables. Eight species of emergent hydrophytes are widely exploited for rural economy. In addition, about 21 species are medicinally important and 12 species are significant for their biological filtering capacity. A recent survey elucidates that more than 45 species became rare, 5 species are already endangered and 6 species are under threat. Increase in salinity (27-30 ppt) in the fresh water interface (which was previously 0-1 ppt.) of Sundarban biosphere reserve due to Tsunami results in large scale destruction of fresh water habitat in coastal West Bengal and thus decline in fresh water plant diversity in the region. Immediate measures should be taken to ensure the conservation of these wetland macrophyte populations to safeguard biodiversity of the Indian subcontinent.

Survey done in the 18 districts of West Bengal, reveals that traditional practices based on wetland plants provide subsistence to approximately 3 million people with a rich traditional cultural heritage. Euryale ferox, Aeschynomene aspera, Cyperus pangorei, Typha elephantina, Colocasia esculenta, Ipomoea aquatica and several others aquatic and wetland plants grow abundantly in waterlogged soils. Marketable surplus obtained from these crops provides sustenance to the rural community.

After an intensive studies in the wetlands of West Bengal for over two and half decades, it is observed that there has been a sharp decline in the richness and diversity of species in freshwater wetlands. Hypereutrophication in water bodies from the catchments and nonpoint pollution sources has led to increase in resilient competitors' species like Eichhornea crassipes, Alternanthera philoxeroides and others. Interdependence of plants and animals in the aquatic habitat is a topic of future research, which will definitely correlate the changing of freshwater faunal diversity with the change in the population density of hydrophytes in the wetlands of West Bengal. Proper and practicable state level wetland policy and a directory of traditional commercial practices in wetlands are an immediate credential. In-situ conservation of man and wetland plants and their habitats will definitely promote conservation of cultural and species diversity of the country.