1. Introduction

A system is a group of parts that interact through one or more processes (Odum 1983). The term ecosystem was introduced and defined by Tansley (1935), who as “a fundamental organizational unit of the natural world that includes both organisms and their spatial environment.” Ecosystems have since been defined in various ways, and at different spatial and temporal scales (Golley 1993; O’Neill et al. 1986; Evans 1956). Some ecologists define ecosystems on the basis of biotic organisms, populations, or communities. For example, Hutchinson (1978) considered the ecosystem to be the environmental context in which population or community dynamics occur. Others define ecosystems in terms of their abiotic characteristics and processes (Rowe and Barnes 1994). For example, Lindeman (1942) defined ecosystems as “…the system composed of physical, chemical, and biological processes active within a space/time unit.” Regardless of whether the emphasis is on biotic components or abiotic characteristics and processes of ecosystems, both remain integral to the concept of ecosystem. Rowe (1961) emphasized this when he defined ecosystems as “…a three dimensional segment of the earth where life forms and the environment interact.”

Wetland ecosystems have been defined in a variety of ways by researchers, resource managers, and regulatory authorities, depending on their specific needs and objectives (Mitsch and Gosselink 1993). In the applied world of regulation, planning, and management, wetlands are usually defined in terms of their physical, chemical, and biological characteristics such as hydrologic regime, soil type, and plant species composition. For example, in classifying wetlands for mapping, inventory, and other purposes, Cowardin et al. (1979) defined wetlands as “…lands transitional between terrestrial and aquatic systems where the water table is usually at or near the surface or the land is covered by shallow water…” that are characterized by the presence of hydrophytic vegetation, hydric soils, and surface water during the growing season.

Wetlands are often biodiversity ‘hotspots’ (Reid et al., 2005), as well as functioning as filters for pollutants from both point and non-point sources, and being important for carbon sequestration and emissions (Finlayson et al., 2005). The value of the world’s wetlands are increasingly receiving due attention as they contribute to a healthy environment in many ways. Wetland functions are defined as the normal or characteristic activities that take place in wetland ecosystems or simply the things that wetlands do. Wetlands perform a wide variety of functions in a hierarchy from simple to complex as a result of their physical, chemical, and biological attributes. For example, the reduction of nitrate to gaseous nitrogen is a relatively simple function performed by wetlands when aerobic and anaerobic conditions exist in the presence of denitrifying bacteria. Nitrogen cycling and nutrient cycling represent increasingly more complex wetland functions that involve a greater number of structural components and processes. At the highest level of this hierarchy is the maintenance of ecological integrity, the function that encompasses all of the structural components and processes in a wetland ecosystem. Wetlands are one of the most productive of all ecosystems, and carry out critical regulatory functions of hydrological processes within watersheds (Banner et al. 1988). Regulating water quality, water levels, flooding regimes, and nutrient and sedimentation levels are a few of these processes (Gregory et al. 1991). As with any natural habitat, wetlands are important in supporting species diversity and have a complex of wetland values. Moreover, the pattern of seasonal variation of the wetland affects the bird population fluctuation (Imran. A. D and Mithas. A. D 2009). Even small wetlands are extremely important to the conservation of biodiversity because they provide critical breeding habitat where dispersed populations can exchange genetic material, reducing the risks of extinction (Semlitsch and Brodie 1998).

The present review is aimed at providing in a nutshell, the distribution of wetlands, the value of Wetlands, the causes and consequences of the loss of wetlands and their conservation status with special reference to India.

 

2. Distribution of wetlands in India

 

In India a total area of 40494 km2  is classified as wetlands. This consists only 1.21 per cent of the total land surface. Most of the wetlands in India are directly or indirectly linked with major river systems such as the Ganga, the Cauvery, the Krishan, the Godavari and the Tapti. A Directory of Wetlands in India (1988) gives information on the location, area and ecological categorization of wetlands of our country. Wetlands in India are distributed in different geographical regions ranging from Himalayas to Deccan plateau. The variability in climatic conditions and changing topography is responsible for significant diversity. They are classified into different types based on their origin, vegetation, nutrient status, thermal characteristics, like 1. Glaciatic Wetlands (e.g., Tsomoriri in Jammu and Kashmir, Chandertal in Himachal Pradesh).

2. Tectonic Wetlands (e.g., Nilnag in Jammu and Kashmir, Khajjiar in Himachal Pradesh, and Nainital and Bhimtal in Uttaranchal).

3. Oxbow Wetlands (e.g., Dal Lake, Wular Lake in Jammu and Kashmir and Loktak Lake in Manipur and some of the wetlands in the river plains of Brahmaputra and Indo-Gangetic region. Deepor Beel in Assam, Kabar in Bihar, Surahtal in Uttar Pradesh).

4. Lagoons (e.g., Chilika in Orissa).

5. Crater Wetlands (Lonar lake in Maharashtra).

6. Salt water Wetlands (e.g., Pangong Tso in Jammu and Kashmir and Sambhar in Rajasthan)

7. Urban Wetlands (e.g., Dal Lake in Jammu and Kashmir, Nainital in Uttaranchal and Bhoj in Madhya Pradesh).

8. Ponds/Tanks, man-made Wetlands (e.g., Harike in Punjab and Pong Dam in Himachal Pradesh).

9. Reservoirs (e.g., Idukki, Hirakud dam, Bhakra-Nangal dam).

10. Mangroves (e.g., Bhitarkanika in Orissa).

11. Coral reefs (e.g., Lakshadweep).

12. Creeks (Thane Creek in Maharashtra), seagrasses, estuaries, thermal springs are some kinds of wetlands in the country.

The Indo-Gangetic flood plain is the largest wetland system in India, extending from the river Indus in the west to Brahmaputra in the east. This includes the wetlands of the Himalayan terai and the Indo-Gangetic plains. The vast intertidal areas, mangroves and lagoons along the 7500 kilometer long coastline in West Bengal, Orissa, Andhra Pradesh, Tamil Nadu, Kerala, Karnataka, Goa, Maharashtra and Gujarat. Mangrove forests of the Sunderbans of West Bengal and the Andaman and Nicobar Islands. Offshore coral reefs of the Gulf of Kutch, Gulf of Mannar, Lakshadweep and Andaman and Nicobar Islands.

Ninety-four wetlands have been identified for conservation and management under the National Programme for Conservation and Management of Wetlands.

These wetlands are eligible for financial assistance on 100% grant basis to the concerned State Governments for undertaking activities like survey and demarcation, weed control, catchment area treatment, desiltation, conservation of biodiversity, pollution abatement, livelihood support creation of minor infrastructure, educational awareness, capacity building of various stakeholders, and community development. So far 24 States have been covered; the remaining States are expected to the covered in the Eleventh Five-Year Plan.

Wetlands play a vital role in maintaining the overall cultural, economic and ecological health of the ecosystem, their fast pace of disappearance from the landscape is of great concern. The Wildlife Protection Act protects few of the ecologically sensitive regions whereas several wetlands are becoming an easy target for anthropogenic exploitation. Survey of 147 major sites across various agro climatic zones identified the anthropogenic interference as the main cause of wetland degradation (The Directory of Indian Wetlands 1993). Current spatial spread of wetlands under various categories is shown.

 

3. Wetland losses – a threat to ecological balance

 

Threats to wetland ecosystems comprise the increasing biotic and abiotic pressures and perils.

Biotic

(1) Uncontrolled siltation and weed infestation.

(2) Uncontrolled discharge of waste water, industrial effluents, surface run-off, etc. resulting

in proliferation of aquatic weeds, which adversely affect the flora and fauna.

(3) Tree felling for fuel wood and wood products causes soil loss affecting rainfall pattern,

loss of various aquatic species due to water-level fluctuation.

(4) Habitat destruction leading to loss of fish and decrease in number of migratory birds.

Abiotic

(1) Encroachment resulting in shrinkage of area.

(2) Anthropogenic pressures resulting in habitat destruction and loss of biodiversity.

(3) Uncontrolled dredging resulting in successional changes.

(4) Hydrological intervention resulting in loss of aquifers.

(5) Pollution from point and non-point sources resulting in deterioration of water quality.

(6) Ill-effects of fertilizers and insecticides used in adjoining agricultural fields.

Coastal ecosystems are among the most productive yet highly threatened systems in the world. These ecosystems produce disproportionately more services relating to human well-being than most other systems, even those covering larger total areas, but are experiencing some of the most rapid degradation and loss:

(1). About 35% of mangroves have been lost over the last two decades, driven primarily by aquaculture development, deforestation, and freshwater diversion.

(2). Some 20% of coral reefs were lost and more than a further 20% degraded in the last several decades of the twentieth century through overexploitation, destructive fishing practices, pollution and siltation and changes in storm frequency and intensity.

(3). There is established but incomplete evidence that the changes being made are increasing the likelihood of nonlinear and potentially abrupt changes in ecosystems, with important consequences for human well-being. These nonlinear changes can be large in magnitude and difficult, expensive, or impossible to reverse. For example, once a threshold of nutrient loading is crossed, changes in freshwater and coastal ecosystems can be abrupt and extensive, creating harmful algal blooms (including blooms of toxic species) and sometimes leading to the formation of oxygen-depleted zones, killing all animal life. Capabilities for predicting some nonlinear changes are improving, but on the whole scientists cannot predict the thresholds at which change will be encountered. The increased likelihood of these nonlinear changes stems from the loss of biodiversity and growing pressures from multiple direct drivers of ecosystem change. The loss of species and genetic diversity decreases the resilience of ecosystems —their ability to maintain particular ecosystem services as conditions change. In addition, growing pressures from drivers such as overharvesting, climate change, invasive species, and nutrient loading push ecosystems toward thresholds that they might otherwise not encounter.

(4). Many wetland-dependent species in many parts of the world are in decline; the status of species dependent on inland waters and of waterbirds dependent on coastal wetlands is of particular concern. Although the evidence has geographical limitations and is chiefly from species already globally threatened with extinction.

The primary indirect drivers of degradation and loss of rivers, lakes, freshwater marshes, and other inland wetlands (including loss of species or reductions of populations in these systems) have been population growth and increasing economic development. The primary direct drivers of degradation and loss include infrastructure development, land conversion, water withdrawal, pollution, overharvesting and overexploitation, and the introduction of invasive alien species.

The current loss rates in India can lead to serious consequences, where 74% of the human population is rural (Anon. 1994) and many of these people are resource dependent. Healthy wetlands are essential in India for sustainable food production and potable water availability for humans and livestock. They are also necessary for the continued existence of India’s diverse populations of wildlife and plant species; a large number of endemic species are wetland dependent. Most problems pertaining to India’s wetlands are related to human population. India contains 16% of the world’s population, and yet constitutes only 2.42% of the earth’s surface. Indian landscape has contained fewer and fewer natural wetlands over time. Restoration of these converted wetlands is quite difficult once these sites are occupied for non-wetland uses. Hence, the demand for wetland products (e.g., water, fish, wood, fiber, medicinal plants etc.) will increase with increase in population. Wetland loss refers to physical loss in the spatial extent or loss in the wetland function. The loss of one km2 of wetlands in India will have much greater impacts than the loss of one km2 of wetlands in low population areas of abundant wetlands (Foote Lee et al. 1996). The wetland loss in India can be divided into two broad groups namely acute and chronic losses. The filling up of wet areas with soil constitutes acute loss whereas the gradual elimination of forest cover with subsequent erosion and sedimentation of the wetlands over many decades is termed as chronic loss.

 

Acute wetland losses

 

(1). Direct deforestation in wetlands: Mangrove vegetation are flood and salt tolerant and grow along the coasts and are valued for fish and shellfish, livestock fodder, fuel wood, building materials, local medicine, honey, bees wax and for extracting chemicals for tanning leather (Ahmad 1980). Alternative farming methods and fisheries production has replaced many mangrove areas and continues to pose threats. Eighty percent of India’s 4240 km2 of mangrove forests occur in the Sunderbans and the Andaman and Nicobar Islands (Anon. 1991). But most of the coastal mangroves are under severe pressure due to the economic demand on shrimps. Important ecosystem functions such as buffer zones against storm surges, nursery grounds and escape cover for commercially important fishery are lost. The shrimp farms also caused excessive withdrawal of freshwater and increased pollution load on water like increased lime, organic wastes, pesticides, chemicals and disease causing organisms. The greatest impacts were on the people directly dependent on the mangroves for natural materials, fish proteins and revenue. The ability of wetlands to trap sediments and slow water is reduced.

(2). Hydrologic alteration: Alteration in the hydrology can change the character, functions, values and the appearance of wetlands. The changes in hydrology include either the removal of water from wetlands or raising the land-surface elevation, such that it no longer floods. Canal dredging operations have been conducted in India from 1800s due to which 3044 km2 of irrigated land has increased to 4550 km2 in 1990 (Anon. 1994). Initial increase in the crop productivity has given way for reduced fertility and salt accumulations in soil due to irrigated farming of arid soils. India has 32,000 ha of peat-land remaining and drainage of these lands will lead to rapid subsidence of soil surface.

(3). Agricultural conversion: The primary direct driver of the loss and degradation of coastal wetlands, including saltwater marshes, mangroves, seagrass meadows, and coral reefs, has been conversion to other land uses.  In the Indian subcontinent due to rice culture, there has been a loss in the spatial extent of wetlands. Rice farming is a wetland dependent activity and is developed in riparian zones, river deltas and savannah areas. Due to captured precipitation for fishpond aquaculture in the catchment areas and rice-farms occupying areas that are not wetlands, water is deprived to the downstream natural wetlands. Around 1.6 million hectares of freshwater are covered by freshwater fishponds in India. Rice-fields and fishponds come under wetlands, but they rarely function like natural wetlands. Of the estimated 58.2 million hectares of wetlands in India, 40.9 million hectares are under rice cultivation (Anon. 1993).

 

Chronic wetland losses

 

(1). Degradation of water quality:  Water quality is directly proportional to human population and its various activities. More than 50,000 small and large lakes are polluted to the point of being considered ‘dead’ (Chopra 1985). The major polluting factors are sewage, industrial pollution and agricultural runoff, which may contain pesticides, fertilizers and herbicides.

(2). Introduced species and extinction of native biota:  Wetlands in India support around 2400 species and subspecies of birds. But losses in habitat have threatened the diversity of these ecosystems (Mitchell & Gopal 1990). Introduction of exotic species like water hyacinth (Eichornia crassipes) and salvinia (Salvinia molesta) have threatened the wetlands and clogged the waterways competing with the native vegetation.  In a recent attempt at prioritization of wetlands for conservation, Samant (1999) noted that as many as 700 potential wetlands do not have any data to prioritize. Many of these wetlands are threatened.

(3). Ground water depletion:  Draining of wetlands has depleted the ground water recharge. Recent estimate indicates that in rural India, about 6000 villages are without a source for drinking water due to the rapid depletion of ground water.

 

4. Condition and Trends in Wetland-dependent Species

 

There is increasing evidence of a rapid and continuing widespread decline in many populations of wetland-dependent species. Data on the status and population trends of species in some inland wetland-dependent groups, including mollusks, amphibians, fish, waterbirds, and some water-dependent mammals, have been compiled and show clear declines. An overall index of the trend in vertebrate species populations has also been developed and shows a continuous and rapid decline in freshwater vertebrate populations since 1970—a markedly more drastic decline than for terrestrial or marine species.

Even in the case of more poorly known wetland fauna, such as invertebrates, existing assessments show that species in these groups are significantly threatened with extinction. For example, the IUCN Red List reports that some 275 species of freshwater crustacea and 420 freshwater mollusks are globally threatened, although no comprehensive global assessment has been made of all the species in these groups. In the United States, one of the few countries to comprehensively assess freshwater mollusks and crustaceans, 50% of known crayfish species and two thirds of freshwater mollusks are at risk of extinction, and at least one in 10 freshwater mollusks are likely to have already gone extinct. Nearly one third (1,856 species) of the world’s amphibian species are threatened with extinction, a large portion of which (964 species) are freshwater-dependent. (By comparison, just 12% of all bird species and 23% of all mammal species are threatened.) In addition, at least 43% of all amphibian species are declining in population, indicating that the number of threatened species can be expected to rise in the future. In contrast, less than 1% of species show population increases. Species dependent on flowing water have a much higher likelihood of being threatened than those in still water. (Figure 5) Basins with the highest number of threatened freshwater species— between 13 and 98 species—include the Amazon, Yangtze, Niger, Paraná, Mekong, Red and Pearl (China), Krishna (India), and Balsas and Usumacinta (Central America). The rate of decline in the conservation status of freshwater amphibians is far greater than that of terrestrial species. As amphibians are excellent indicators of the quality of the overall environment, this underpins the notion of the current declining condition of freshwater habitats around the world.

 

Key vulnerabilities

 

Gitay et al. (2001) have described some inland aquatic ecosystems (Arctic, sub-Arctic ombrotrophic bog communities on permafrost, depressional wetlands with small catchments, drained or otherwise converted peatlands) as most vulnerable to climate change, and have indicated the limits to adaptations due to the dependence on water availability controlled by outside factors. More recent results show vulnerability varying by geographical region (Stern, 2007). This includes significant negative impacts across 25% of Africa by 2100 (SRES B1 emissions scenario, de Wit and Stankiewicz, 2006) with both water quality and ecosystem goods and services deteriorating. Since it is generally difficult and costly to control hydrological regimes, the interdependence between catchments across national borders often leaves little scope for adaptation.

 

Impacts

 

Climate change impacts on inland aquatic ecosystems will range from the direct effects of the rise in temperature and CO2 concentration to indirect effects through alterations in the hydrology resulting from the changes in the regional or global precipitation regimes and the melting of glaciers and ice cover (e.g., Chapters 1 and 3; Cubasch et al., 2001; Lemke et al., 2007; Meehl et al., 2007). Studies since the TAR (Third assessment report of IPCC) have confirmed and strengthened the earlier conclusions that rising temperature will lower water quality in lakes through a fall in hypolimnetic oxygen concentrations, release of phosphorus (P) from sediments, increased thermal stability, and altered mixing patterns (Jankowski et al., 2006). In northern latitudes, ice cover on lakes and rivers will continue to break up earlier and the ice-free periods to increase (Duguay et al., 2006). Higher temperatures will negatively affect micro-organisms and benthic invertebrates (Kling et al., 2003) and the distribution of many species of fish (Kling et al., 2003); invertebrates, waterfowl and tropical invasive biota are likely to shift polewards (Zalakevicius and Svazas, 2005) with some potential extinctions. Major changes will be likely to occur in the species composition, seasonality and production of planktonic communities (e.g., increases in toxic blue-green algal blooms) and their food web interactions (Winder and Schindler, 2004) with consequent changes in water quality. Enhanced UV-B radiation and increased summer precipitation will significantly increase dissolved organic carbon concentrations, altering major biogeochemical cycles (Frey and Smith, 2005). Studies along an altitudinal gradient in Sweden show that NPP can increase by an order of magnitude for a 6°C air temperature increase (Karlsson et al., 2005). However, tropical lakes may respond with a decrease in NPP and a decline in fish yields (e.g., 20% NPP and 30% fish yield reduction in Lake Tanganyika due to warming over the last century ­ O’Reilly et al., 2003). Higher CO2 levels will generally increase NPP in many wetlands, although in bogs and paddy fields it may also stimulate methane flux, thereby negating positive effects (Zheng et al., 2006). Boreal peatlands will be affected most by warming and increased winter precipitation as the species composition of both plant and animal communities will change significantly (Weltzin et al., 2000, 2001, 2003; Berendse et al., 2001; Keller et al., 2004;). Numerous arctic lakes will dry out with a 2-3°C temperature rise (Smith et al., 2005 . The seasonal migration patterns and routes of many wetland species will need to change and some may be threatened with extinction. Small increases in the variability of precipitation regimes will significantly impact wetland plants and animals at different stages of their life cycle. In monsoonal regions, increased variability risks diminishing wetland biodiversity and prolonged dry periods promote terrestrialisation of wetlands as witnessed in Keoladeo National Park, India (Chauhan and Gopal, 2001).

 

5. Wetland management – current status

Wetlands are not delineated under any specific administrative jurisdiction. The primary responsibility for the management of these ecosystems is in the hands of the Ministry of Environment and Forests. Although some wetlands are protected after the formulation of the Wildlife Protection Act, the others are in grave danger of extinction. Effective coordination between the different ministries, energy, industry, fisheries revenue, agriculture, transport and water resources, is essential for the protection of these ecosystems.

 

Cardinal Constituents of Comprehensive Strategy for Wetland Conservation:

 

The conservation and management of wetlands calls for a comprehensive strategy, ranging from legal framework and policy support to inventorization, institutional mechanism, capacity building, and community participation. The position with regard to these aspects is as follows:

 

Legal framework

 

Though there is no separate provision for specific legal instrument for wetland conservation, the legal framework for conservation and management is provided by the following legal instruments:

1. Several legislations have been enacted which have relevance to wetland conservation. These include Forest Act, 1927, Forest (Conservation) Act, 1980, the Wildlife (Protection) Act, 1972, the Air (Prevention and Control of Pollution) Act, 1974, the Water Cess Act, 1977 and the umbrella provision of Environment (Protection) Act, 1986.

2.  India has set up 505 Wildlife Sanctuaries and 100 National Parks, 14 Biosphere Reserves, 6 Heritage Sites, Projects on Tiger conservation and Elephant conservation and Marine Turtles conservation with the objective of effective conservation of wetlands, and floral and faunal wealth in forest areas.

3. Notification declaring the coastal stretches of seas, bays, estuaries, creeks, rivers and backwaters, which are influenced by tidal action (in the landward side) up to 500 metres from the high tide line, and the land between the low tide line and the high tide line as the Coastal Regulation Zone Notification, 1991 under the provision of Environment (Protection) Act, 1986. This proposes graded restriction on setting up and expansion of industries, including pressures from human activities.

4. Portions of the listed sites have been declared as Wildlife Sanctuaries and National Parks.

5. Guidelines for sustainable development and management of brackish water aquaculture have  been drawn up. State Governments like Andhra Pradesh and Tamil Nadu have aquaculture guidelines also at the local level.

6. The Biodiversity Act, 2002, and the Biodiversity Rules, 2004, are aimed at safeguarding the floral and faunal biodiversity, and regulating their flow from the country to other countries for research and commercial use. Thus, their provisions also contribute towards conserving, maintaining, and augmenting the floral, faunal and avifaunal biodiversity of the country’s aquatic bodies.

 

Policy Support: National Environment Policy (NEP), 2006

 

Our National Environment Policy (NEP), approved by the Cabinet on 19 May 2006, recognizes the numerous ecological services rendered by wetlands. The NEP states:

  ‘Wetlands are under threat from drainage and conversion for agriculture and human settlements, besides pollution. This happens because public authorities or individuals having jurisdiction over wetlands derive little revenues from them, while the alternative use may result in windfall financial gains to them. However, in many cases, the economic values of wetlands’ environmental services may significantly exceed the value from alternative use. On the otherhand, the reduction in economic value of their environmental services due to pollution, as well as the health costs of the pollution itself are not taken into account while using them as a waste dump. There also does not yet exist a formal system of wetland regulation outside the international commitments made in respect of Ramsar sites. A holistic view of wetlands is necessary, which looks at each identified wetland in terms of its causal linkages with other natural entities, human needs, and its own attributes.’

 

The Environmental Policy identifies the following six-fold Action Plan:

1. Set up a legally enforceable regulatory mechanism for identified valuable wetlands to prevent their degradation and enhance their conservation. Develop a national inventory of such wetlands.

2. Formulate conservation and prudent use strategies for each significant catalogued wetland, with participation of local communities, and other relevant stakeholders.

3. Formulate and implement eco-tourism strategies for identified wetlands through multi stakeholder partnerships involving public agencies, local communities and investors.

4. Take explicit amount of impacts on wetlands of significant development projects during the environmental appraisal of such projects; in particular, the reduction in economic value of wetland environmental services should be explicitly factored into cost-benefit analysis.

5. Consider particular unique wetlands as entities with ‘Incomparable Values’, in developing strategies for their protection.

6. Integrate wetland conservation, including conservation of village ponds and tanks, into sectoral development plans for poverty alleviation and livelihood improvement, and the link efforts for conservation and sustainable use of wetlands with the ongoing rural infrastructure development and employment generation programmes. Promote traditional techniques and practices for conserving village ponds.

 

Inventorization

 

Survey and inventorization should take into consideration identification of different human activities, effect of both industrial and domestic effluents, and information obtained through remote sensing to be verified with the ground truth data for getting proper results. This component includes mapping of catchment areas through revenue records, survey and assessment, and land-use pattern using GIS techniques, with emphasis on drainage pattern, vegetation cover, siltation cover, encroachment, conversion of wetlands, human settlements, total area encroached, human activities at the primary, secondary, and tertiary levels, and their impact on catchment and water body. The following surveys of wetlands have been undertaken so far:

1. Asian Wetland Directory, 1989 – identified 93 Wetlands of International Importance.

2. Wetland Directory published in 1990 by the Ministry of Environment and Forests using questionnaire survey.

3. Identification of 2167 natural freshwater wetlands covering 1.5 million ha area.

4. Identification of 65,253 man-made freshwater wetlands covering 2.6 million ha area.

5. WWF-India and the Ministry of Environment and Forests in 1993 identified 54 additional wetlands of international importance with more details.

6. Space Application Centre using remote sensing techniques identified 27,403 inland and coastal wetlands covering 7.6 million ha

7. Salim Ali Centre for Ornithology under UNDP project has undertaken survey of 72 districts.

8. A project on ‘National Wetland Information System and Updation of Wetland Inventory’ has been sanctioned by the Ministry of Environment and Forests. The objectives of this project are (1) to map and inventorize wetlands on 1:50,000 scale by on-screen interpretation of digital IRS LISS III data of post and pre-monsoon seasons, (2) to prepare State-wise wetland Atlases, and (3) to create a digital database in GIS environment in respect of all wetlands in the country.

9. The Centre for Advanced Studies in Marine Biology at Annamalai University, Parangipettai, has been assisted in project mode for updating all wetlands in the country.

 

Institutional mechanism

 

(a) It is imperative to have multi-disciplinary, holistic and integrated approach for achieving long-term sustainable wetland conservation and management measures. At present, various models exist in States and different nodal agencies are responsible for implementing the Wetland Conservation Programme. In some States, the programme is executed by the Department of Forests and/or Environment or Urban Development; in some others, it is the Department of Irrigation or Science and Technology or Fisheries. However, the Wetland Conservation and Management is a specialized technical and scientific field where multi-disciplinary approach is needed, involving a number of components like water management, sustainable fisheries development, hydrological aspects, socio-economic issues, community participation, weed control, biodiversity conservation and use of aquatic macrophytes for nutrient recycling process, hydrological aspects providing information about inflow/outflow pattern in the system, nutrient fluxes and nutritional dynamics. These aspects need to be dealt with in a coordinated manner by managers having expertise in the relevant fields.

(b) Taking into consideration the complexity of the issue, the State Steering Committees have been constituted under the chairmanship of Chief Secretaries of the States having members from all Departments concerned. The Committee is also expected to have representatives from communities, NGOs and academicians. The officer from the nodal department acts as a member-secretary of the Committee. The success of the programme depends upon its strong institutional mechanism where conservation efforts are undertaken through integrated and multi-disciplinary approach. However, due to inadequacy of infrastructure and staff, conservation activities are yet to acquire comprehensiveness and sustainability in some States.

State Governments have been advised to consider constitution of Wetland Conservation Authorities so that experts from various Departments undertake conservation activities in a more scientific, cohesive and sustainable manner.

(c) Some States have already constituted Authorities for execution of wetland conservation programmes in their respective States. Notable among them are Chilika Development Authority in Orissa (mandated to manage all identified lakes in the State); Loktak Development Authority in Manipur; Shore Area Development Authority in Andhra Pradesh; Lakes and Waterways Development Authority in Jammu and Kashmir; Lake Development Authority in Karnataka and Lake Conservation Authority in Madhya Pradesh.

 

Capacity building

 

Capacity building is a major tool without which no conservation activity is possible. We need to have good infrastructure, trained people, and case studies to teach values and functions of wetlands in an integrated and multi-disciplinary manner. The Ministry has taken several initiatives in this regard as per details given below.

(a) It has published several reports/documents on conservation and wise use of wetlands which include six monographs on Ramsar sites in collaboration with WWF India and eco-tourism guidelines for Chilika Lake.

(b) During the Tenth Five Year Plan, several training programmes have been conducted in collaboration with different academic organizations/research institutes/State Governments/international NGOs to impart training on various components of wetland conservation which include wise use, catchment area treatment, weed control, hydrological aspects, research methodology, preparation of management action plans and community participation. Training is imparted to policy makers, senior/ middle level managers, organizations, stakeholders and others. A National Training Programme for Integrated Water Resource Management and Wetland Conservation was organized during 7-11 August 2006 by Chilika Development Authority with the financial support from Ministry of Environment and Forests. More training programmes are proposed to be organized at different regions of the

Country.

A series of regional workshops were organized in various parts of the country to make people aware of the importance of wetlands and integrate their traditional knowledge in the planning process. The following regional and international workshops were organized during the Tenth Plan:

1 Western Region, Gujarat

2 Southern Region, Kerala

3 Eastern Region, Orissa

4 North-Eastern Region, Manipur

5 Central Region, Madhya Pradesh

6 Northern region, Uttar Pradesh

7 Northern region, Jammu and Kashmir

8 Southern region, Lakshadweep

9 International Workshop on High Altitude Wetlands, Sikkim

10 Meeting of Board of Directors of Wetland International, Rajasthan

Holding regional workshops along with research organizations and wetland managers is an ongoing feature.

 

Community Participation

 

(a) No decision-making is complete without participation of local people whose livelihoods depend on wetland resources. People have been using wetlands since time immemorial. We have to blend both traditional and latest scientific technologies to achieve long-term conservation goals. Participatory Rural Appraisal exercise involving local communities should be the main ingredient of community participation. It should also take into consideration issues of women and gender sensitization and involve women in the management process.

(b) The component of community participation comprises the following constituents.

1. Assessment of resource availability by surveys and participatory rural appraisal of the site.

2. Stakeholder analysis

3. Contact with external institutions for resource and technical advice

4. Utilization of wastes and aquatic weeds for energy regeneration, for example through installation of community- based biogas plants.

5. Additional alternate income generation programmes like handloom, handicrafts, integrated farm management techniques and other measures to reduce pressure on wetlands.

6. Highlighting of gender-related cross-cultural, governance-related practices and other special concerns for assessment by community.

(c) The Joint Forest Management Committees (JFMCs), also referred to as Village Protection Committees (VPCs) or Eco-Development Committees (EDCs), are expected to play an active role in conservation and management of wetlands located in forest fringe areas, i.e. normally within a radius of 5 km of forest boundary. The JFMC/ VPC/EDC shall be instrumental in mobilization of communities and for implementing equitable access to information rights.

 

Use of Geo-spatial technology in wetland management

 

Remote sensing data in combination with Geographic Information System (GIS) are effective tools for wetland conservation and management. The application encompasses water resource assessment, hydrologic modeling, flood management, reservoir capacity surveys, assessment and monitoring of the environmental impacts of water resources project and water quality mapping and monitoring (Jonna 1999).

 

 

 

Flood zonation mapping

 

Satellite data are used for interpretation and delineation of  flood-inundated regions, flood-risk zones. Temporal data helps us to obtain correct ground information about the status of ongoing conservation projects. IRS 1C/D WIFS data having 180 km spatial resolution and high temporal repetitiveness has helped in delineating the zonation of flooding areas of large river bodies, thus helping in the preparation of state-wise and basin wise flood inventories.

 

Water quality analysis and modeling

 

Remote sensing data is used for the analysis of water quality parameters and modeling. Water quality studies have been done carried out using the relationship between reflectance, suspended solid concentration, and chlorophyll-a concentration. In the near infrared wavelength range, the amount of suspended solids content is directly proportional to the reflectance. Due to spatial and temporal resolution of satellite data information of the source of pollution and the point of discharge, inflow of sewage can be regularly monitored. Using IRS LISS II data (Sasmal & Raju 1996) monitored the suspended load in estuarine waters of Hoogly, West Bengal in a GIS environment. In this study band 4 of the data set was found to show a wider range of digital classes indicating a better response with depth than rest of the bands. Landsat TM and IRS –1A data were used to estimate sediment load in Upper lake, Bhopal (Raju et al. 1993). This study showed high relationship between the satellite as well as ground truth radiometric data and total suspended solids. Different image processing algorithms are also used on Landsat MSS dataset to delineate sediment concentration in reservoirs (Jonna et al. 1989). Qualitative remote sensing methods have been used for real time monitoring of Inland Water quality (Gitelson et al. 1993) Airborne sensor has also been used to study the primary productivity and related parameters of coastal waters and large water bodies (Seshmani et al. 1994).

 

Water resource management

 

With the development of highly precise remote sensing techniques in spatial resolution and GIS, the modeling of watershed has become more physically based and distributed to enumerate interactive hydrological processes considering spatial heterogeneity. A distributed model with SCS curve number method called as Land Use Change (LUC) model was developed (Mohan & Shresta 2000) to assess the hydrological changes due to land use modification. The model developed was applied to Bagmati river catchment in Kathmandu valley basin, Nepal. The study clearly demonstrated that integration of remote sensing, GIS and spatially distributed model provides a powerful tool for assessment of the hydrological changes due to landuse modifications.

 

Mapping of Wetland

 

The Space Application Center (SAC) has mapped the wetlands at 1:250000 scale in the mainland as well the islands using the visual interpretation of coarse resolution satellite data. The states of Sikkim, West Bengal, Goa Punjab, Haryana, Himachal Pradesh, Chandigarh, Delhi, Andaman, Nicobar, Lakshwadeep, Dadra and Nagerhaveli were mapped at 1:50000 scale. However, in the rest of the country, only wetlands of 56.25 ha and above in size could be mapped. It is known that a vast majority of wetlands-often in number, extent and conservation importance is below 50 ha in size (For example, those in the Indo-gangetic plains and in the Deccan peninsula). Thus, the inventory covered only a small number of wetlands: more over, the conservation values are not known for those wetlands even whose inventory has now been obtained. The data merely indicates location of wetlands, the classification of wetlands on 1:250,000 scale is moreover, only geomorphologic in nature (such as Oxbow lakes, Playas, Lakes and Ponds etc.) and has no other factual biological conservation value. By itself, the information will only be partly useful for conservation of wetlands. This estimate is likely to be twice if we include wetlands of size 50 ha or less (Das et al. 1994 for Etwah and Mainpuri districts of U.P.).

 

6. Conclusion

Threats to wetland ecosystems comprise the increasing biotic and abiotic pressures and perils. About 35% of mangroves have been lost over the last two decades, driven primarily by aquaculture development, deforestation, and freshwater diversion. Some 20% of coral reefs were lost and more than a further 20% degraded in the last several decades of the twentieth century through overexploitation, destructive fishing practices, pollution and siltation and changes in storm frequency and intensity. The primary direct driver of the loss and degradation of coastal wetlands, including saltwater marshes, mangroves, seagrass meadows, and coral reefs, has been conversion to other land uses.  In the Indian subcontinent due to rice culture, there has been a loss in the spatial extent of wetlands.  Wetlands in India support around 2400 species and subspecies of birds. But losses in habitat have threatened the diversity of these ecosystems Introduction of exotic species like water hyacinth (Eichornia crassipes) and salvinia (Salvinia molesta) have threatened the wetlands and clogged the waterways competing with the native vegetation.  As many as 700 potential wetlands do not have any data to prioritize. Many of these wetlands are threatened. In monsoonal regions, increased variability risks diminishing wetland biodiversity and prolonged dry periods promote terrestrialisation of wetlands as witnessed in Keoladeo National Park, India. So far as current status of wetland management in India is concerned, Wetlands are not delineated under any specific administrative jurisdiction. The primary responsibility for the management of these ecosystems is in the hands of the Ministry of Environment and Forests. Although some wetlands are protected after the formulation of the Wildlife Protection Act, the others are in grave danger of extinction. Effective coordination between the different ministries, energy, industry, fisheries revenue, agriculture, transport and water resources, is essential for the protection of these ecosystems. The dynamic nature of wetlands necessitates the widespread and consistent use of satellite based remote sensors and low cost, affordable GIS tools for effective management and monitoring.

 

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