India is bestowed with a rich diversity of wetlands, ranging from high altitude lakes of the Himalayas, floodplains and marshes of the Gangetic – Bramhaputra alluvial plains, saline flats of Green Indian Desert to extensive mangroves marshes bordering the country’s East and West coastline. India has total of 757,060 wetlands covering a total area of ca. 15.26 million ha, roughly equal to 4.6% of its land area.
Of this, inlands wetland constitutes 69.22% (10.56 million ha). India is a signatory to Ramsar Convention and 26 sites have been designated as Wetlands of International importance under the Convention.
Distribution of Wetlands (Where wetlands occur today?)
Wetlands occur in all climatic zones – from tropical deserts to cold tundra, and at all altitudes – from below the sea level to about 6000 m elevation in the Himalaya. Wetlands occur wherever water accumulates for enough long periods that allow the establishment of plants and animals adapted to the aquatic environment. Water need not be present permanently and the depth may generally fluctuate.
Thus, wetlands occur in or along all water bodies – from temporary ponds to shallow or deep lakes, springs, streams and rivers. Typically, wetlands are recognised by the presence of aquatic plants (called macrophytes) other than microscopic algae (phytoplankton or filamentous algae) (see types of macrophytes in the figure). The macrophytes play the most significant and predominant role in determining the functions of all wetlands.
The growth and distribution of the macrophytes is determined among various factors by the water depth and is usually restricted to a depth of two metres. Submerged plants may occur under clear water conditions to a depth of about 4 metres. Therefore, only the shallow and usually the periodically flooded marginal areas of large rivers (called the floodplains) and lakes and reservoirs (called the littoral zones) are considered to be proper wetlands.
A similar situation exists in case of another kind of wetlands – the mangroves- which also lie between higher land and the deep open waters of the sea. Many wetlands have been modified and are managed by humans for specific purposes. For example, majority of the paddy fields and fish ponds have been created out of the natural wetlands by manipulating their vegetation and fauna.
Hundreds of thousands of human-made wetlands owe their existence to a wide range of human activities such as excavation of soil for making bricks or roads, stone quarrying, or due to waterlogging of low-lying lands along the canals.
Wetland Functions (What wetlands do and how?)
Wetlands perform the transfer of energy within their bio zones but differ among themselves in the magnitude and efficiency according to their hydrological regimes and climate which govern the biodiversity.
All macrophytes and various algae produce organic matter which is consumed directly or indirectly by the animals. Besides food, the macrophytes also provide habitats and support many other plants and animals. Submerged macrophytes oxygenate the water column whereas the emergent and rooted floating leaved plants help exchange of gases between the soils and the atmosphere. They transport oxygen to their root zones and carry methane and nitrous oxide to the atmosphere.
All macrophytes sequester carbon in their biomass which remains undecomposed under certain conditions for very long periods, and sometimes turns into peat. Macrophytes transform nutrients through uptake, assimilation and storage but also immobilise some heavy metals on their root surfaces.
Many macrophytes have the ability to take up and accumulate more nutrients than their requirements if the nutrient availability increases. Macrophytes function both as a source (from soils to water) and sink (from water to soils) of nutrients. Macrophytes influence also the hydrological cycle as they enhance or lower the loss of water to the atmosphere through evapotranspiration. Emergent macrophytes facilitate also the movement of water into the ground.
Ecosystem Services of Wetlands (How do we benefit from them?)
Humans use wetlands in several ways but also benefit from them indirectly. Various kinds of benefits derived from an ecosystem by the people and the society have recently been termed as ecosystem services.
These benefits are often categorised into Provisioning (food, fiber, fodder, fuel, water, and other materials), Regulating (regulation of biogeochemical cycles including climate), Supporting (e.g., soil formation, supporting biodiversity) and Cultural (aesthetics, recreational and spiritual activities) services.
Among the direct and most important benefits from wetlands to humans are the production of rice and fish which are the staple food for more than half of the world’s human population.
Macrophytes are also used for extracting several vitamins and essential oils (e.g., Vetiveria zizanioides). Wetlands are known to be among the most productive systems and some macrophytes may produce up to 20 tonnes per ha of biomass annually.
High organic production in wetlands causes a reduction in the atmospheric carbon dioxide which is sequestered in the plant or animal biomass or as organic matter in the soil. Thus, wetlands contribute to regulating climate change.
All wetlands, through their nutrient cycling strategies, regulate water quality. Submerged macrophytes oxygenate the water column, lower the nutrient content and keep the water clean and transparent unless the systems are heavily human impacted. Perennial macrophytes often accumulate large amounts of nutrients in their belowground organs.
These processes in the littoral zones and floodplains help maintain the water quality in open water areas by intercepting and transforming the nutrients and a wide range of pollutants, particularly from nonpoint sources. Wetland have indeed been called as ‘Kidneys of the Earth’. The water quality improvement function of macrophytes has been utilised in developing the constructed wetland technology which is widely used in many countries.
The flowing water systems also regulate water quality through their waste-assimilation capacity that is limited by the characteristics of their flow regimes, and is aided by the riparian and floodplain wetlands. Further, wetlands with perennial macrophytes and woody plants control soil erosion and stabilise shore lines. This is also helps improve water quality as sediments are trapped by the vegetation.
The fine sediments bring with them also the nutrients. In wetlands such as the floodplains humans benefit from this sediment trapping by way of renewed soil fertility and better crop yields. The most important benefit from the wetlands (and all inland aquatic ecosystems) lies in their regulation of water regimes.
All wetlands receive their water from the catchments, retain it for varying periods of time, transport it downstream and allow some of it to infiltrate into the ground. Some water also evaporates back into the atmosphere. This regulation of water movement, according to their water holding or flow carrying capacity, benefits the humans by making it available over longer time and greater space (distance) as well as by protecting them from the hazards of floods and droughts caused by events of extreme precipitation.
The macrophytes influence this function by reducing the water storing potential and obstructing the flow, but the emergent macrophytes also improve the hydraulic conductivity and help greater infiltration into the ground. Humans benefit from the wetlands which are in general the most preferred sites for a variety of recreational and socio-cultural activities.
Macrophyte dominated wetlands are highly valued for recreation involving bird watching, boating, angling, and resting or similar leisurely activities. Rivers, lakes and reservoirs are valued for recreational activities such as river rafting, diving, swimming, which require avoiding shallow areas with abundant submerged or floating macrophytes. Emergent macrophytes together with other wildlife (birds, mammals, and insects) invariably enhance the aesthetic appeal of the landscape. Many rivers and lakes, especially the high-altitude glacial lakes, in the Himalaya have very high spiritual and religious value; they are held sacred and attract numerous visitors. The benefits of such non-consumptive uses are difficult to quantify, and their value depends on individual and cultural assessments.
Threats to wetlands:
Dense human population in catchments, urbanisation, and various anthropogenic activities has resulted in over exploitation of wetland resources, leading to degradation in their quality and quantity. Now, there is increasing concern to conserve and restore perishing wetlands and endangered habitats to achieve ecological sustainability.
As per one of the studies, wetlands in our country are disappearing at a rate of 2% to 3% every year. Some of the major threats to wetlands are as given below:
• Urbanization- increasing developmental pressure for residential, industrial and commercial facilities.
• Anthropogenic activities-unplanned urban and agricultural development, industries, road construction, impoundment, resource extraction and dredge disposal.
• Agricultural Activities- conversion of wetlands for paddy fields; construction of a large number of reservoirs, canals and dams; diversion of streams and rivers to provide for irrigation.
• Deforestation-removal of vegetation in the catchment leading to soil erosion and siltation.
• Pollution-unrestricted dumping of sewage, solid wastes and toxic chemicals from industries and households.
• Salinization-over withdrawal of groundwater has led to salinization.
• Aquaculture-pisciculture and aquaculture ponds.
• Introduced Species-exotic introduced plant species such as Water Hyacinth and Salvinia clog waterways and compete with native vegetation.
• Climate change- increased air temperature; shifts in precipitation; increased frequency of storms, droughts, and floods; increased atmospheric carbon dioxide concentration; and sea level rise.
Wetlands Conservation – Indian Scenario:
The National Wetland Management Committee was formed in 1987. The functions of this committee are as follows:
• To create a policy related to Wetland, to guide the conservation, management, and research of Wetland.
• Selecting a Wetland for Conservation.
• Reviewing the implementation of programs.
• To advise the preparation of disinvestment inventory over Indian Wetland.
Other Legislative measures:
1. In 2008, the Ministry of Environment and Forests issued a Draft Regulatory Framework for Wetlands Conservation, under the provisions of the Environment (Protection) Act (EPA), 1986.
2. The Draft 2008 ‘Regulatory Framework for Wetland Conservation’ was put out for comments and suggestion and many organisations made suggestions.
3. In May 2010, another draft of Regulatory Framework was put out for comments, which included the draft Rules, 2009. Again, a number of comments and suggestions were sent to MoEF.
4. Seeking to protect over 2 lakh wetlands across the country, the Centre has come out with rules to identify and manage these ecologically fragile areas which play an important role in flood control, groundwater recharge, preserving plant varieties, supporting migratory birds and protecting coastlines.
5. Finally, on the 2nd of December 2010, the Union Ministry of Environment and Forests notified the Wetlands (Conservation and Management) Rules 2010, thus these rules now become a law.
6. It calls for the constitution of a Central Wetland Regulatory Authority.
7. It seeks to regulate wetlands which include Ramsar Wetlands, and what it calls ‘Protected Wetlands’ which include ecologically sensitive wetlands, UNESCO sites or wetlands near UNESCO sites, above the elevation of 2500 meters or below the elevation of 2500 meters, but with an area more than 500 hectares or any other wetlands suggested by the Central Wetland Regulatory Authority.
8. Restricted Activities within the wetlands include reclamation, setting up industries in vicinity, solid waste dumping, manufacture or storage of hazardous substances, discharge of untreated effluents, any permanent construction, etc.
9. Regulated Activities (which will not be permitted without the consent of the state government) include hydraulic alterations, unsustainable grazing, harvesting of resources, releasing treated effluents, aquaculture, agriculture, dreading, etc.
10. The major functions of the authority include identification of new wetlands for conservation, ensuring that the Rules are followed by the local bodies, issue clearances, etc.,
11. The State Governments are to submit a ‘Brief Document’ identifying and classifying wetlands in their state. The Authority will then assess the wetland and if accepted, the Central Government shall notify it as a ‘Protected Wetland’.
12. The Brief document includes: broad geographical delineation, zone of influence size of wetland, account of pre-existing rights and privileges, consistent or not with the health of the wetland
13. Any appeals against the decision of the Authority can be made to the National Green Tribunal.
14. The new rules, notified by the environment ministry in 2017, decentralise wetlands management by giving states powers to not only identify and notify wetlands within their jurisdictions but also keep a watch on prohibited activities.
15. The new rules, notified by the environment ministry, decentralise wetlands management by giving states powers to not only identify and notify wetlands within their jurisdictions but also keep a watch on prohibited activities.
16. It also indirectly widens the ambit of permitted activities by inserting the ‘wise use’ principle, giving powers to state-level wetland authorities to decide what can be allowed in larger interest.
The notification says, “The wetlands shall be conserved and managed in accordance with the principle of ‘wise use’ as determined by the Wetlands Authority.”
The Centre’s role under the Wetlands (Conservation and Management) Rules, 2017, will be restricted to monitoring its implementation by states/UTs, recommending trans-boundary wetlands for notification and reviewing integrated management of selected wetlands under the Ramsar Convention.
The Ramsar Convention:
The Convention on Wetlands is an intergovernmental treaty adopted on 2nd February 1971 in the Iranian city of Ramsar, on the southern shore of the Caspian Sea.
Ramsar is the first of the modern global intergovernmental treaties on the conservation and sustainable use of natural resources, but, compared with more recent ones, its provisions are relatively straightforward and general.
The official name of the treaty, The Convention on Wetlands of International
Importance especially as Waterfowl Habitat, reflects the original emphasis upon the conservation and wise use of wetlands primarily as habitat for water birds.
Over the years, however, the Convention has broadened its scope of implementation to cover all aspects of wetland conservation and wise use, recognizing wetlands as ecosystems that are extremely important for biodiversity conservation and for the well-being of human communities, thus fulfilling the full scope of the Convention text.
Issues and way forward:
- Right now, there are multiple agencies involved in river and lake conservation, right from planning to implementation and monitoring. There is a need to consolidate all these functions under an umbrella agency for better coordination and accountability.
- MoEF/States need to ensure that projects for source control of all kind of pollutants entering the lakes is included in projects for conservation and restoration of lakes, especially sewage and agriculture runoff which leads to nutrient over-loading of the lake.
- MoEF should ensure that all lakes facing encroachment and resultant filling up are included in NLCP.
- Further, all State governments should declare bio-conservation zones around lakes so that encroachment of shoreline is prevented.
- States should involve citizens in proposing and monitoring programmes to control pollution of rivers and lakes.
- Both natural and human-made wetlands should be declared as specific land use category and their hydrological characteristics (sources and regimes) should be identified.
- Their conversion to any other land use or any reduction in their area or alteration in their water regime should be prohibited, except for strategic reasons after exploring other options and providing for compensatory measures.
- The total biodiversity of all wetlands should be assessed and periodically monitored. All ecosystem services of all wetlands should be assessed and valued in economic terms.
- All development projects such as those related to urban or industrial development, or those concerned with storage, diversion and abstraction of water from any source should consider all kinds of wetlands to be affected directly or indirectly, within the project area or far away from them.
- The assessment of ecosystem services and their economic valuation should particularly address the benefits to the local community and their livelihoods. A few kilograms of rhizomes of lotus or the leafy shoots of Ipomoes aquatica may not be priced significantly but may have a high value for the local community in terms of vegetable use and nourishment a no cost to them.