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Vol. 11 No. 2 - April 2005

Biodiversity Conservation of Freshwater Ecosystem in India

By: S.K. Kulshrestha

Introduction

Biodiversity includes assemblage of plants, animals and micro-organisms; their genetic variability expressed in varieties and populations; their habitats, ecosystems and natural areas, the mosaic of which gives richness to the natural environment. Biodiversity or biological resources provide food, clothing, housing, medicine and spiritual nourishment to human beings. Apart from the rich flora, having 7% of the 89,500 animal species, found in the world. The loss to Indian biodiversity is mainly from habitat destruction, over-harvesting, pollution and inappropriate introduction of exotic plants and animals.

As stated in ‘Global Biodiversity Assessment’, published by the UNEP, "unless action is taken to protect biodiversity, we will lose forever the opportunity and the most precious assets of natural resources, available to the mankind." Biodiversity conservation is of critical importance as it may be of direct or indirect benefit to mankind.

Among major biodiversity countries, the number of species of higher plants in Brazil is 55,000 followed by Columbia  35,000, China South Africa 23,000, former Soviet Union 22,000, 20,000, United States of America 18,000, Australia 15,000 and 15,000.

Freshwater Resources

Over 99% of biosphere water occurs in oceans and polar ice deposits, out of which 97.61% occurs in oceans. The freshwater is mainly in the form of ice, snow and ground water, 0.009% in freshwater lakes, 0.0009% in atmospheric water vapour and 0.00009% in rivers. Only 0.01% of the global freshwater is available in rivers, lakes and reservoirs. The dam reservoirs contain five times as much water as in rivers. The surface waters sustain freshwater biodiversity, perform ecological functions and support human needs such as agriculture, hydro-electricity, industry, sewage and sanitation, aquaculture, fisheries, drinking water, transportation, recreation and spiritual needs, etc. About 54% of accessible surface run off is used. About 45,000 species of freshwater organisms are known while about one million are yet to be discovered. Major organisms include viruses, bacteria, diatoms, plants and animals from protozoa to mammals. Freshwater organisms constitute about 25% of the total number of organisms.

Aquatic bacterial diversity knowledge is increasing rapidly. Almost 20% of the fishes, found globally, are extinct, vulnerable or endangered. The rich endemic ichthyofauna of African Lake , Victoria , has been reduced by exotic predatory eutrophication. Groundwaters, as deep as 2.8 Km, may have rich bacterial flora. According to World Bank, 80 countries with 40% of the world’s population have water shortage that could cripple agriculture and industry. Fish diversity is threatened by construction of dams, hydro-electric facilities, channelization projects and invasion of non-native biota. The Ganges and Brahmaputra rivers carry more than 3 billion metric tons of soil to the Bay of Bengal each year, spreading it over 3 million sq. km of sea bed.

Benefits from Freshwater Biodiversity

Freshwater biodiversity provides benefits to humans. This includes inland water fishing for food, aquaculture production, ornamental fish trade, recreational fishing, rice farming, harvest of a variety of other living resources, medicinal plants, fuel resources and ecological functions including primary production, provision of three dimensional habitat, biogeochemical recycling, pollutant remediation, moderation of nutrient pulses and population . Terrestrial and aquatic ecological functions have been estimated to be worth US $ 33 trillion per year globally. Freshwaters and their varied biodiversity form part of the Earth’s ecosphere which restores us spiritually, inspires us aesthetically and must be passed on to future generations. The Biodiversity Convention and the World’s Charter of Nature have emphasized that like all other life forms, freshwater organisms have an intrinsic right to survival and warrant respect.

Wetlands

Wetlands are transitional areas between dry terrestrial and permanent aquatic ecosystems. These are recognized as highly productive ecosystems. Wetlands include 22 habitat types (IUCN, 1989). The Indian wetland area is about 7.6 million ha, excluding paddy fields, rivers and canals, out of which 3.6 million ha is inland and 4 million ha coastal. There are 2,175 natural wetlands having 1.46 million ha area and 65,254 man-made lakes having 2.85 million ha area in India . The total number of animal species, reported from , is 89,461; out of which 17,853 belong to wetlands comprising 19.9% of the total number. About 50,000 ha area of wetlands is degraded every year in Asia . It results in soil acidification, soil erosion, loss of soil nutrients, change in hydrology, loss of flora and fauna and disruption of delicate ecosystem. The wetlands perform enormous variety of functions including regulatory, carrier, production and information functions. The regulatory functions include storage and cycling of nutrients, human wastes and organic wastes; groundwater recharge and discharge; control of natural floods, erosion and salinity; water treatment, climatic stabilization; and maintenance of ecosystem stability; integrity of other ecosystems and biological diversity. The carrier functions include agriculture, irrigation, transport, energy production, tourism, recreations, human habitat and settlements and as nursery for plant and animal species. The production functions include water, food, wood fuel, medicine resources, genetic resources and raw materials for building, construction and industrial use. The information functions include research, education, monitoring and their role in cultural heritage. The natural functions of the wetlands include climatic, biodiversity, habitat, hydrological and hydraulic and water quantity functions. Among biodiversity functions are centers of endemism, ecosystem diversity, habitat diversity, species and population diversity. Besides this, they provide diverse species assemblages, highly diverse microbiological activity, large genetic pool and link between terrestrial and aquatic ecosystems, Wetlands are being modified or reclaimed through out the world, their resources over exploited, and their lands converted to other uses. Since 1900, more than half of the world wetlands have disappeared. Water management in wetlands has been oriented towards the needs of people, such as transportation, flood control, agriculture and settlement. There are many stakeholders whose diverse interest lay claim on the wetland function. These include direct extensive and intensive users, exploiters who dredge sediments or exploit mineral resources, agricultural producers who drain and convert wetlands to agricultural land, water abstractors who use wetland as source of drinking or irrigation water, human settlements expansion and indirect users who benefit from flood control use of the wetland . Our primary objective should be to build capacity for wetland management. Compilation of national wetlands database is the first stage of a conservation strategy. All products from the natural environment should be valued and costed according to their real costs, including the cost of sustainable production and environmental protection. In , efforts have been made to restore Chilka Lagoon, a coastal wetland and along Gandak sub basin, Bhoj Wetland and other such water bodies. However, baseline data on the biodiversity of freshwater ecosystem, in , is meagre. In our studies on the Lowe Lake and Mansarovar Lake, which for a part of Bhoj Wetland, we found 93 species of phytoplankton, 53 taxa of zooplankton, 130 of periphyton, 38 of macrozoobenthos and 26 species of fish. We found rich aquatic flora and fauna in Chambal, Kshipra and Khan  rivers . Scattered studies are available on the biodiversity of waterbodies in India . However, a continuous and comprehensive database is not available. Compilation of a national database is the need of the time.

Conservation Action Plan

The conservation of aquatic biodiversity should be done at ecosystem level. Appropriate management of wetlands and rivers may be a proper step in this direction. Restoration of acidified, eutrophied or weed infested lakes need different treatments, The main problem in Indian lakes, are: siltation, eutrophication, weed infestation, pollution and human encroachment for habitation, agriculture, aquaculture and land use. The lake management includes passive and active actions. In passive action, minimum human interference maintains the ecosystem in a natural way; such system is possible in unpolluted lake. In active management, manipulation of environmental conditions is undertaken to affect the desired change. The active management includes soft strategies, covering water control and weed eradication, while hard strategies include altering of the vegetation, construction of dikes, canals, etc. for changing the environmental conditions. An effective lake management would include both soft and hard strategies. The restorative measures would include afforestation of lake basin or catchment area; shoreline stabilization and demarcation; maintenance of water level; restoration of eutrophied lakes by prevention of sewage or nutrients from point and non-point sources, biological control, chemical control, mechanical control, aeration and sediment removal; restoration of lakes having aquatic weed infestation by manual, mechanical and biological methods; pollution control; monitoring the water quality for various physico-chemical and biological parameters; development of fisheries, tourism, etc.; environmental awareness and evaluation of restorative measures.

All rivers, lakes, reservoirs, wetlands, etc. should be treated as integrated component of a river basin and a mechanism for coordination between all programmes for conservation and management should be developed. Necessary steps are required to ensure adequate flow in rivers for maintaining their ecological integrity, water quality and biodiversity. The abstraction of river and surface waters for various uses, such as, for agriculture, domestic and industrial use should be regulated in relation to the total flow. The return flow of adequate quality by recycling and reuse of wastewater should be endured. Certain rivers may be given status of “National Heritage Rivers”. Conservation and restoration of floodplains and protection of upper watersheds of rives, throughout the country, should be given priority. A network of “Protected Areas of River Systems” may be established to conserve riverine biodiversity. A holistic integrated approach for conservation of rivers and other inland surface waters should be adopted.

Conclusions:

Wetlands, lakes and rivers are daughters of the land. Ecologically sound and economic practices on land as well as in the water realm, will maintain and restore aquatic ecosystems and faltering species can be reinvigorated with them. We need suitable practices in watersheds and waterbodies, and willingness to share the planet’s surface with other species.

Prof. S.K. Kulshrestha, President Academy of Environmental Biology is a former Professor of Zoology at M.V.M. Bhopal. His current address is: 27/3 Geetanjali Complex, Bhopal-462003, India E-mail: drskulshrestha@yahoo.co.in


This article has been reproduced from the archives of EnviroNews - Newsletter of ISEB India.


 

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