What is wetland?
Wetlands are area of marsh, fen, peatland or water, whether natural or artificial, permanent or temporary, with water that is static or flowing, fresh, brackish or salt, including areas of marine water, the depth of which at low tide does not exceed six metres.
Examples: Wetlands include mangroves, peatlands and marshes, rivers and lakes, deltas, floodplains and flooded forests, rice-fields, and even coral reefs.
Categories of wetlands: The wetlands are usually split into four distinct categories with further distinctions depending on location and other factors.
- Marshes: Marshes are wetlands that are always inundated, rather than being submerged under water.Marshes can be freshwater or saltwater and amount of water in the marsh can change with the seasons.
- Swamps: Swamps differ from marshes in that, typically, they are dominated by woody plants (rather than soft-stemmed plants). There are two main types of swamps: forested swamps and shrub swamps.
- Bogs: Bogs are characterized by more acidic waters and spongy peat deposits as well as a covering of sphagnum moss. Unlike marshes and swamps, bogs tend to get their wetness from precipitation rather than waterways such as streams or runoffs from rivers. There are two types of bogs: northern bogs and pocosins.
- Fens: Fens are, like bogs, peat-forming wetlands, although they usually get their wetness from ground water rather than precipitation, which means that they are slightly less acidic.
- Peatlands include moors, bogs, mires, peat swamp forests and permafrost tundra. Peatlands represent half of the Earth’s wetlands and cover 3% of the global total land area.
- Mangrove forests are found in tropical and subtropical regions in tidal areas, which are frequently inundated with salt water.
- Dry region wetlands: These wetlands include rivers, swamps, and lakes and spring that dry up for portions of the year. Dry regions are found in Asia, Australia, Africa, the Middle East and North and South America.
- High altitude wetlands store water from rain and glacial melt, feed groundwater stores, trap sediments and recycle nutrients, enhancing both the quantity and quality of water.
- Arctic wetlands store enormous amounts of greenhouse gases and are critical for global biodiversity. These are dependent on frozen permafrost for their ability to store carbon.
- Glaciatic Wetlands: These are found at altitudes higher than 3,000 metres above mean sea level, often fed by glaciers or snow from the surrounding mountains. e.g. Tsomoriri in Jammu and Kashmir, Chandertal in Himachal Pradesh.
- Tectonic Wetlands: These wetlands are shaped by tectonic activity (uplift, subsidence), and the weathering, erosion, transportation and deposition of surface materials by surface water, groundwater, gravity, ice and wind. Such as Nilnag in Jammu and Kashmir, Khajjiar in Himachal Pradesh.
- Oxbow Wetlands: An oxbow is an arc or crescent shaped body of water located in an abandoned river channel. Like 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.
- Lagoons: It is a shallow body of water separated from a larger body of water by barrier islands or reefs. E.g. Chilika in Orissa
- Crater Wetlands: It is a fresh-water lake formed by the accumulation of rain and groundwater in a caldera or crater after lava eruption. Like Lonar lake in Maharashtra.
- Salt water Wetlands: These are coastal ecosystem in the upper coastal intertidal zone between land and open saltwater or brackish water that is regularly flooded by the tides. Such as Pangong Tso in Jammu and Kashmir and Sambhar in Rajasthan.
- Urban Wetlands: These wetlands are located within the urban suburbs. E.g. Dal Lake in Jammu and Kashmir, Nainital in Uttaranchal and Bhoj in Madhya Pradesh.
- Ponds/Tanks/Reservoirs: These are man-made and thus artificial wetlands. Like Harike in Punjab, Pong Dam in Himachal Pradesh, Idukki, Hirakud dam, Bhakra-Nangal dam.
- Mangroves: A mangrove swamp is a distinct saline woodland or shrubland habitat formed by mangrove trees. These are characterized by depositional coastal environments, where fine sediments (often with high organic content) collect in areas protected from high-energy wave action. E.g. Bhitarkanika in Orissa.
- Coral reefs: Coral reefs are well known marine wetlands. Coral reefs are underwater structures made from calcium carbonate produced by corals. For example Lakshadweep.
- Creeks: A creek is a narrow place where the sea comes a long way into the land. E.g Thane Creek in Maharashtra, seagrasses, estuaries, thermal springs are some kinds of wetlands in the country.
Regional extent of wetlands in India
- As per the National Wetland Atlas 2011, In terms of the proportion of the geographical area, Gujarat has the highest proportion (17.5%) and Mizoram has the lowest proportion
(0.66%) of the area under wetlands.
- Among Union Territories in India, Lakshadweep has the highest proportion (around 96%) and Chandigarh has the least proportion (3%) of geographical area under wetlands.
Significance of Wetlands:
- Productive ecosystems: Wetlands are among the most productive ecosystems in the world, comparable to rain forests and coral reefs.
- Carbon sequestration: All types of wetlands are carbon sequestering systems (carbon sinks), from temperate freshwater wetlands to boreal peatlands. Terrestrial wetland soils also function as carbon sinks and can store carbon produced by upland agriculture, forestry and other land uses.
|Blue carbon is the type of carbon that is stored by coastal wetland vegetation such as mangroves, seagrasses and salt marsh grasses.|
- Habitat: An immense variety of species of microbes, plants, insects, amphibians, reptiles, birds, fish and mammals can be part of a wetland ecosystem. Tropical peat swamp forests are home to many rare and critically endangered species such as the Orangutan and Sumatran tiger.
- Migratory birds: Wetlands are also important to millions of waterbirds that breed in Europe and Asia, such as waders and herons.
- Tsunami prevention: Mangroves absorb and disperse tidal surges associated with these events: a mangrove can reduce the destructive force of a tsunami by up to 90%.
- Flood prevention: Peatlands absorb heavy rainfall, providing protection against floods, and release water slowly, ensuring a supply of clean water throughout the year.
- Natural water filters: Wetlands are the world’s water filters which trap pollutants such as phosphorus and heavy metals in their soils, transform dissolved nitrogen into nitrogen gas, and break down suspended solids to neutralize harmful bacteria.
- Regulation of stream flow: Wetlands are often compared to sponges, in their ability to absorb water in wet periods, and release it during dry periods.
- Sediment trapping: Wetlands reduce runoff velocity, and wetland vegetation is effective in trapping and retaining sediment.
- Phosphate and nitrate assimilation: Wetland removes the phosphates and nitrates carried by runoff water through its vegetation and the action of anaerobic bacteria (which would otherwise not exist in fast-flowing, energised streams or rivers.
- Erosion control: Wetlands can limit the extent of erosion, predominantly through the protection provided by vegetation, and through their ability to reduce stream flow velocity.
- Industry benefits: Wetlands also provide important benefits for industry. For example, they form nurseries for fish and other freshwater and marine life and are critical to commercial and recreational fishing industries.
Threats to wetland ecosystems: Threats to wetland ecosystems comprise the increasing biotic and abiotic pressures and perils.
- Climate change: Increase in temperature is causing polar ice to melt and sea level to rise. This in turn is leading into shallow wetlands being submerged and some species of mangrove trees being submerged and drowned.
- Pollution: Drainage and runoff from fertilized crops and pesticides used in agriculture introduce nitrogen and phosphorus nutrients and other toxins like mercury to water sources. These chemicals can affect the health and reproduction of species posing a serious threats to biological diversity.
- Over exploitation of wetland resources: Increasing human population and change from subsistence to commercial exploitation of wetlands resources continue to exert pressure on limited wetland resources resulting into its decline.
- Industrial activities: This threat comes from draining wetlands for establishing industrial sites also industrial activities are threats to wetlands because of dumping of industrial wastes to wetlands.
- Agricultural activities: These are big threats to wetland since farmers convert the wetland into cultivable land due to its fertility and availability of water. Hundreds of thousands of hectares of wetlands have been drained for agriculture.
- Tourism: Many tourist activities taking place in wetlands have lead to draining of these wetlands so as to establish tourist facilities like hotels or camping sites.
- Introduction of invasive alien species: Bringing Illegally or otherwise of nontraditional or alien species into wetlands such as water hyacinths, Nile perch and clay fish can disturb the natural ecosystem of wetlands, leading to their degradation.
- River regulation and water diversion: These refer to altering the natural flow of rivers, streams, floodplains and wetlands by building dams, and other structures on rivers and waterways which leads to wetland degradation by the disturbance of natural catchment of river.
|Bihar’s shrinking wetlands: |
● Kanwar lake in Begusarai, Bihar which has the distinction of being Asia’s largest oxbow lake has shrunk rapidly post 2000.
● An extensive study by Bihar State Pollution Control Board has found that the permanently waterlogged area was a mere 2.80 percent of the total net area sown.
East Calcutta Wetlands: Bhagabanpur Mouza, which in 2002 was 88 percent water body, became 80 per cent land by 2016, according to a study by the Society for Creative Opportunities and Participatory Ecosystems.
● The settlement area for habitation increased from 0.18 per cent in 2002 to 13.2 per cent in 2016.
Legal framework: Though there is no separate legal provision for wetland conservation in India, it is indirectly influenced by number of other legal instruments. These include:
- Wildlife (Protection) Act 1972
- Water (Prevention and Control of Pollution) Act 1974
- Environmental (Protection) Act 1986
- Biodiversity Act 2002
- Scheduled Tribes and Other Traditional Forest Dwellers (Recognition of Forest Rights) Act 2006.
- The National Environment Policy (NEP) 2006 seeks to set up a legally enforceable regulatory mechanism for identified wetlands to prevent their degradation, enhance their conservation and wise-use by all the stakeholders.
- The National Action Plan on Climate Change 2008 recognises the important role of wetlands in the context of climate change.
Wetlands (Conservation and Management) Rules,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.
- It also indirectly widens the ambit of permitted activities in wetlands by inserting the `wise use’ principle, giving powers to state-level wetland authorities to decide what can be allowed in larger interest.
- The Centre’s role will be restricted to monitoring its implementation by states UTs, recommending transboundary wetlands for notification and reviewing integrated management of selected wetlands under the Ramsar Convention.
- A comprehensive digital inventory of all wetlands is to be prepared within a year.
- Central Wetlands Regulatory Authority (CWRA) has been replaced by the National Wetland Committee, which has a merely advisory role. E.g. recommending transboundary wetlands for notification, reviewing the progress of integrated management of Ramsar Convention sites etc.
- Restrictions – As per the new rules, encroachments on wetlands have been banned.
- It also prohibits solid waste dumping, discharge of untreated waste and effluents from industries and human settlements.
- In Mutlupur in Muzaffarpur district of Bihar, a group of farmers have turned the wetlands into a productive area and source of livelihood. Here farmers consulted veterinary, agricultural, fishery and horticultural experts to apply on the ground the latest technologies and developments in integrated farming.
Ramsar Convention on Wetland: It is an intergovernmental treaty, signed in 1971, which provides the framework for national action and international cooperation for the conservation and wise use of wetlands and their resources.
Major obligations of countries which are party to the Convention are:
- Designate wetlands for inclusion in the List of Wetlands of International Importance.
- Promote, as far as possible, the wise use of wetlands in their territory.
- Promote international cooperation especially with regard to transboundary wetlands, shared water systems, and shared species.
- Create wetland reserves.
- Montreux Record under the Convention is a register of wetland sites on the List of Wetlands of International Importance where changes in ecological character have occurred, are occurring, or are likely to occur as a result of technological developments, pollution or other human interference.
- It is maintained as part of the Ramsar List. Two sites in India namely, Loktak lake ( Manipur) and Keoladeo National Park (Rajasthan), are part of this list.
- Identifying and refining strategies for wise use, and reviewing best practices of participatory wetland management from around the world
- Provision incentives for local and indigenous people’s involvement and wise use: everyone must benefit in the long term.
- The active commitment and collaboration of stakeholders are essential for the management of a wetland (e.g., when the wetland is inhabited or privately owned)
- Participatory monitoring: partnerships between management and local people to monitor the ecological character of wetlands, and progress towards the community’s own objectives
- Construction should be allowed in the most eco-friendly manner and remedial measures must be adopted in the vicinity of the area.