Wetlands

Description

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Context

In two Ramsar areas in West Bengal, East Kolkata Wetlands (EKW) and Sunderbans, a recent audit report by the Comptroller and Auditor General (CAG) revealed unlawful structures and breaches of environmental rules.

Wetlands

Wetlands are locations where water plays a major role in regulating the environment and the plant and animal life that exists there.
They happen where the water table is at or near the earth's surface, or where the land is flooded.
"Lands transitioning between terrestrial and aquatic eco-systems where the water table is generally at or near the surface or the land is covered by shallow water," according to the definition of wetlands.

Types of wetlands

Coastal Wetlands:
Coastal wetlands include shorelines, beaches, mangroves, and coral reefs, which are situated between land and open sea and are not impacted by rivers.
Mangrove wetlands, which may be found in protected tropical coastal locations, are an excellent example.
Shallow Lakes and Ponds:
Shallow lakes and ponds are wetlands with limited flow and are made up of permanent or semi-permanent bodies of water.
Vernal ponds, spring pools, salt lakes, and volcanic crater lakes are among them.
Marshes:
These are characterised by herbaceous (non-woody) flora suited to wet soil conditions and are occasionally saturated, flooded, or ponded with water.
Tidal marshes and non-tidal marshes are the two types of wetlands.
Swamps:
These are dominated by trees and shrubs and are predominantly nourished by surface water supplies.
Swamps can be found in floodplains that are either freshwater or saltwater.
Bogs:
Bogs are wet peatlands found in historic lake basins or landscape depressions. Rainfall provides almost all of the water in bogs.
Estuaries:
The area where rivers meet the sea and the water transforms from fresh to salt may be home to a diverse range of wildlife.
Deltas, tidal mudflats, and salt marshes are among the wetlands.

What is the importance of wetlands?

Wetlands are extremely productive ecosystems that account for about two-thirds of the world's fish catch.
Wetlands play a crucial part in the watershed's ecosystem. The combination of shallow water and high nutrient levels is perfect for the growth of creatures that serve as the foundation of the food web, feeding a variety of fish, amphibians, shellfish, and insects. Wetlands are extremely productive ecosystems that account for about two-thirds of the world's fish catch.
Microbes, plants, and wildlife in wetlands play a role in world water, nitrogen, and sulphur cycles. Instead of releasing carbon dioxide into the sky, wetlands retain it in their plant communities and soil.
Wetlands serve as natural barriers that capture and release surface water, rain, snowmelt, groundwater, and flood waters throughout time. Wetland vegetation also lowers soil erosion and slows the pace of flood flows, decreasing flood heights.
Wetlands are essential for human and environmental survival. More than one billion people rely on them for a living, and wetlands are home to 40% of the world's biodiversity.
Food, raw materials, genetic resources for pharmaceuticals, and electricity are all dependent on wetlands.
They are vital in transportation, tourism, and people's cultural and spiritual well-being.
They offer habitat for animals and plants, and many of them sustain a diverse range of life, including species and animals found nowhere else.
Many wetlands are natural wonders that attract tourists, and many are significant to Aboriginal people.
Wetlands also have a lot of advantages for industry. They are important to the commercial and recreational fishing sectors because they serve as nurseries for fish and other freshwater and marine species.

What are the threats to wetlands?

Wetlands near metropolitan areas are increasingly being developed for residential, industrial, and commercial purposes. Urban wetlands are critical for the long-term sustainability of public water sources.
Paddy fields have been planted across vast swaths of marshes. The hydrology of the adjoining wetlands was considerably affected by the construction of a vast number of reservoirs, canals, and dams to supply irrigation.
Natural water filters are found in wetlands. They can only clean up fertilisers and pesticides from agricultural runoff; they can't clear up mercury from industrial sources or other forms of contamination.
Increased air temperature, precipitation changes, higher storm, drought, and flood frequency, increased atmospheric carbon dioxide concentration, and sea level rise might all have an impact on wetlands.
Material is removed from a marsh or riverbed. Dredging of streams lowers the water table in the area and dries off nearby wetlands.
Wetlands are drained by digging canals into the earth that collect and convey water away from the area. The water table is lowered, and the wetland is dried off.
Exotic imported plant species such as water hyacinth and salvinia pose a threat to Indian wetlands. They block up rivers and crowd out native plants.