Ecology-and-environment / Terrestrial and Aquatic Ecosystems / Wetland Ecosystem

Wetland Ecosystem

  • Wetlands are water bodies but also include land. They are freshwater, brackish or saline, inland or coastal, seasonal or permanent, natural or man-made. Ramsar is a city in Iran where the first World Convention on Wetlands was held on 2nd February 1971.
  • The Ramsar convention defined wetlands as areas of marsh, fen, peat land or water whether natural or artificial, permanent or temporary, with water that is static or flowing, fresh, brackish, salt including areas of marine water, the depth of which a low tide does not exceed six metres.
  • The definition talks about the maximum water depth in case of marine areas for these to qualify as wetlands. However, it does not indicate the same for other aquatic bodies. Therefore, it becomes difficult to classify other aquatic bodies into wetland group.
  • Wetland is a generic term for water bodies of various types, and includes various hydrological entities, namely lakes, marshes, swamps, estuaries, tidal flats, river flood plains and mangroves.
  • Wetlands may be fresh, brackish or saline, and are characterised in their natural state by plants and animals that are adapted to living in wet conditions.
  • Swamps are predominantly and permanently wet from through flowing waters. The water level may be constant, or vary from season to season. As the water derives from a land source (as opposed to rain-fed systems called bogs), nutrient levels are high (termed eutrophic), and they may accumulate organic silt, but seldom form proper peat.

Types of Wetlands

  • There are different types of wetlands, in which some important types are as follows.
  • Lagoons are one type of wetland that occur in coastal enclosures that are shallow and separated from the sea by a sand bar or strip of land. Occasionally they may receive sea water, but do not experience typical tidal fluctuations of an estuary. Waters are brackish as a result, and the water level fluctuates somewhat unpredictably.
  • Estuaries are different from Lagoons that are partially enclosed by land, but that are open to the sea and subject to regular fluctuations of the tide. The salinity regime depends on the mixing of sea and freshwater from rivers and the nature of the vegetation reflects this balance.
  • Ephemeral are wetlands that appear only at certain times of the year, especially winter. The plants occupying such situations when wet are short-lived and tolerant of the wetness, while normal dry land plants occupy the site in drier conditions. Sometimes wetlands occur at the interface between land and water bodies that may be flowing (rivers) or stationary (lakes). The characteristic of vegetation is the same as swamps, unless the fluctuations in water level are highly predictable.
  • Dune slacks are also wetlands that occur in hollows between sand dunes. The water may be above the sand surface (dune lake) or below it (dune slacks. These are typically brackish, and subject to changing water table levels.
  • Marshes are also wetlands that undergo fluctuations in water level that are considerable and seasonal.

Importance of Wetlands

  • Wetland ecosystems provide many services that contribute to human well-being of human beings. The millennium ecosystem assent 2005 provides a comprehensive understanding of various services provided by the wetlands. Two of the most important wetland ecosystem services affecting human well-being involve fish supply and water availability.
  • Wetlands are considered as the principal source of renewable fresh water for human use. It also play an important role in climate regulation, water purification, etc. It also provides cultural and aesthetic value to the human population.
  • It is regarded as one of the most productive ecosystems. Besides these the wetland helps to reduce the effects of floods, regeneration of groundwater and provides recreational opportunities.
  • The climatic function of some wetlands is also important as it affects the mesoclimate of nearby land by increasing evaporation and absorbing heat during periods of drought. It also acts as barriers against strong winds.

What is adversely affecting our Wetlands?

Human activities cause wetland degradation and loss by changing water quality, quantity, and flow rates; increasing pollutant inputs; and changing species composition as a result of disturbance and the introduction of nonnative species. Common human activities that cause degradation include the following:

  • Hydrologic Alterations: Common hydrologic alterations in wetland areas include:
    • Deposition of fill material for development.
    • Drainage for development, farming, and mosquito control.
    • Dredging and stream channelization for navigation, development, and flood control.
    • Diking and damming to form ponds and lakes.
    • Diversion of flow to or from wetlands.
    • Addition of impervious surfaces in the watershed, thereby increasing water and pollutant runoff into wetlands.
  • Pollution Inputs: Although wetlands are capable of absorbing pollutants from the surface water, there is a limit to their capacity to do so. The primary pollutants causing wet-land degradation are sediment, fertilizer, human sewage, animal waste, road salts, pesticides, heavy metals, and selenium. Pollutants can originate from many sources, including:
    • Runoff from urban, agricultural, silvicultural, and mining areas.
    • Air pollution from cars, factories, and power plants.
    • Old landfills and dumps that leak toxic substances.
    • Marinas, where boats increase turbidity and release pollutants.
  • Vegetation Damage. Wetland plants are susceptible to degradation if subjected to hydrological changes and pollution inputs. Other activities that can impair wetland vegetation include:
    • Grazing by domestic animals.
    • Introduction of non-native plants that compete with natives.
    • Removal of vegetation for peat mining.

Initiatives to protect Wetlands

  • World Wetlands Day is celebrated every year on the 2nd of February across the globe. 
  • Ramsar Convention is the first World Convention on Wetlands held on 2nd February 1971.
  • Montreux Record 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.

Indian Context

  • India became a party to the ‘Convention on Wetlands’, also known as the Ramsar Convention on 1st February 1982 and has since then designated 75 wetlands covering an area of 13,48,879 hectares under the List of Wetlands of International Importance which includes 5 sites designated during FY 2020-2021. Presently, India stands first in South Asia and third in Asia in terms of number of designated sites.

Initiatives by Government of India to Protect Wetlands:

  • The Ministry of Environment, Forest and Climate Change (MoEF&CC) has notified Wetlands (Conservation and Management) Rules, 2017 under the provisions of the Environment (Protection) Act, 1986 as regulatory framework for conservation and management of wetlands across country to conserve, manage and maintain the ecological character of the wetlands without restricting the wise use.
  • The Ministry of Environment, Forest & Climate Change (MoEF&CC) is currently implementing a centrally sponsored scheme namely, National Plan for Conservation of Aquatic Eco-systems (NPCA) for conservation and management of identified wetlands (includes lakes) in the country on cost sharing basis between Central Government and respective State Governments.
    • Four – pronged approach of preparing Brief Documents, filling Ecosystem Health Cards, instituting Wetland Mitras and formulating Integrated Management Plans based on the health and specific threats facing the wetlands, is in place for conservation and management of wetlands.
    • Under the NPCA scheme, the central assistance is based on the proposals received from the State Governments in the form of Integrated Management Plans including brief documents, in conformity with the guidelines and budget availability.
  • A dedicated Web Portal (https:// indianwetlands.in) for Wetlands has been developed, which is a publicly available information and knowledge platform in order to facilitate knowledge sharing, information dissemination, host capacity building material, and provide a single-point access data repository for processing information and making it available to the stakeholders in an efficient and accessible manner.
  • A Centre for Wetlands Conservation and Management (CWCM) under the Ministry’s National Centre for Sustainable Coastal Management (NCSCM) has been established to serve as a knowledge hub and enabling to exchange between wetland users, managers, researchers, policy-makers and practitioners and to assist the national and State/ UT Governments in the design and implementation of policy and regulatory frameworks, management planning, monitoring and targeted research specifically related to wetlands.

Ramsar Sites in India

Ramsar Site in India State
Karikili Bird Sanctuary Tamil Nadu
Pallikaranai Marsh Reserve Forest Tamil Nadu
Pichavaram Mangrove Tamil Nadu
Sakhya Sagar Madhya Pradesh
Pala Wetlands Mizoram
Khijadia Wildlife Sanctuary Gujarat
Bakhira Wildlife Sanctuary Uttar Pradesh
Haiderpur Wetland Uttar Pradesh
Sultanpur National Park Haryana
Bhindawas Wildlife Sanctuary Haryana
Thol Lake Wildlife Sanctuary  Gujarat
Wadhvana Wetland  Gujarat
Ashtamudi Wetland Kerala
Beas Conservation Reserve Punjab
Bhitarkanika Mangroves Odisha
Bhoj Wetlands Madhya Pradesh
Chandra Taal Himachal Pradesh
Chilika Lake Odisha
Deepor Beel Assam
East Kolkata Wetlands West Bengal
Harike Wetlands Punjab
Hokera Wetland Jammu & Kashmir
Kanjli Wetland Punjab
Keoladeo National Park Rajasthan
Keshopur-Miani Community Reserve Punjab
Kolleru lake Andhra Pradesh
Loktak lake Manipur
Nalsarovar Bird sanctuary Gujarat
Nandur Madhameshwar Maharashtra  
Nangal Wildlife Sanctuary Punjab
Nawabganj Bird Sanctuary Uttar Pradesh
Parvati Agra Bird Sanctuary Uttar Pradesh
Point Calimere Wildlife and Bird Sanctuary Tamil Nadu
Pong Dam lake Himachal Pradesh
Renuka lake Himachal Pradesh
Ropar Wetland Punjab
Rudrasagar Lake Tripura
Saman Bird Sanctuary Uttar Pradesh
Samaspur Bird Sanctuary Uttar Pradesh
Sambhar lake Rajasthan
Sandi Bird Sanctuary Uttar Pradesh
Sarsai Nawar Jheel Uttar Pradesh
Sasthamkotta lake Kerala
Surinsar- Mansar lakes Jammu & Kashmir
Tsomoriri Ladakh
Upper Ganga river Uttar Pradesh
Vembanad Kol Wetland Kerala
Wular lake Jammu & Kashmir
Sunderban Wetland West Bengal
Asan Barrage Uttarakhand
Kanwar Lake or Kabal Taal Bihar
Lonar Lake Maharashtra
Sur Sarovar Uttar Pradesh
Tso Kar Wetland Complex Ladakh

 

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