Wetlands are transitional land between aquatic and terrestrial ecosystems. IUCN defines Wetland as a Submerged or water-saturated land, both natural and man-made, 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 6 meters. Mangroves, lake littorals (areas adjacent to river channels beyond natural levees and periodically flooded during high river discharge), floodplains (areas lying adjacent to river channels beyond natural levees and periodically flooded during high river discharge), and other marshy or swampy areas are examples. This article will explain to you the Wetland Ecosystem which will be helpful in Environment preparation for the UPSC Civil service exam.

Wetland Ecosystem

• Wetland ecosystems are transitional zones between territorial and aquatic ecosystems (Ecotone).

The Ramsar convention on wetlands defines wetlands as:

• as an area of marsh, fen, peatland,
• which is temporary or permanent, formed naturally or artificially,
• This includes fresh, brackish, or salt water,
• Where depth of marine water at low tide will not exceed six meters of height .

Classification of Wetlands

Wetland are classified under 2 main categories:

1. Inland wetland
2. Coastal wetland

Types of Wetland

Marsh

• The marsh type of wetland is flooded with water and has vegetation from saturated soil conditions.
• They are found both in inland and coastal ecosystems.
• Marshes are also found underground and beneath the surface.

Swamp

• Woody plants are the main characteristics of Swamps.
• Swamps are classified as forest and shrub swaps.
• They are present in freshwater and saltwater.

Fen

• They are high nutrient wetlands which are formed from precipitation.
• The main source is rainfall i.e. precipitations.

Bogs

• Bogs are peatlands which are waterlogged.
• Rainfall is the main source of water in Bogs.
• They are basically found in depressions which prevent downstream flooding.
• Bogs support very less plan growth when compared to Fen.

Lakes and Ponds

• Lakes and ponds are a diverse group of inland freshwater ecosystems found all over the world.
• They provide vital supplies and habitats for both terrestrial and aquatic creatures.

River Floodplains

• These are regions that are near a river or stream .
• They are periodically inundated by water overflowing the channel.
• The Yamuna floodplains are Delhi's principal supply of water.

Oxbow Lakes

• Oxbow Lakes arise when a river's meander is cut off by silt deposition or a river's channel changes, isolating a crescent-shaped waterbody.
• Oxbows Lakes abound in the Ganga and Brahmaputra river basins.
• Example : Ansupa is an oxbow in the peak of the Mahanadi Delta.

Estuaries

• An estuary is a brackish water feature that is partially contained along the coast, with one or more rivers or streams flowing into it and a free access to the open sea.
• Estuaries serve as a transition zone between the river and the sea.
• Example :Chilika is an Odisha lagoon divided from the Bay of Bengal by a lengthy sand barrier.

CLASSIFICATION OF WETLANDS

Inland Wetlands

Inland wetlands are classified into two major categories based on their formations

1. Natural Wetlands
2. Man Made wetlands

Natural Wetlands

Wetlands which are formed naturally without any man made interference.

Classification of Inland Wetlands includes,

Lake and ponds

• Lakes and ponds are inland water bodies which are generally surrounded by the land and inlet or outlet river steam.
• These streams act as a source of water and outlet drains of water.
• The lakes and ponds are differentiated by the length and depth of the water surface.
• Example: Loktak Lake Manipur, Thol lake Gujarat, Nal sarovar Gujarat, Udhwa Lake Jharkhand.

High Altitude Wetland

• High altitude wetlands are wetlands whose water bodies are present in higher altitudes above 3000 m.
• Example: Tso moriri and Tso kar of Jammu and Kashmir, Gurudongmar Lake Sikkim.

Riverine Wetland

• Riverine wetlands are present in river floodplains.
• They provide various ecosystem services like flood control, water purification, water storage, carbon storage etc.
• They act as a food reservoir during flooding seasons.
• Examples: Bachamari bil West Bengal

Waterlogged

• In waterlogged wetland the soil profile is temporarily or permanently saturated in water.
• Examples: Nal sarovar catchment area Gujarat , Ghana bird sanctuary Gujarat.

Rivers and Stream

• Rivers are inland drainage basins (endocrine).
• Rivers and streams form an important aspect of the inland ecosystem.
• Examples: Kaveri river Tamilnadu , Dhansiri river Nagaland.

Man-made wetlands

Reservoirs / Barraige

• The reservoirs stop the flow of water and create a water source, whereas barrages are more temporary in nature which are built to divert the course of the river.
• The reservoirs and barrages both are man-made results in creation of wetland which support biodiversity.
• Example: Tenughat reservoir Jharkhand, Tawa reservoir Madhya pradesh

Salt pan

• Salt pan is a surface which is covered with salt and other minerals.
• They are commonly found in deserts.
• The minerals present in salt pan acts as a reflector in sun rays .
• Salt pan holds rich species like birds and insects which survive there.
• The significance of salt pan here is that it has high water holding capacity which assists in flood control.
• Examples: Sambhar lake Rajasthan, Gulf of Kachchh Gujarat

Tanks and ponds

• Tanks and ponds are parts of traditional water conservation systems.
• They have high cultural and social benefits.
• These act as a reservoir which enables water storage and distributions.
• Example:Kottakulam tank tamilnadu

Coastal Wetlands

• Coastal wetlands are found in the transition area (ecotone) between the land and open sea.
• Coastal wetlands are not much influenced by rivers.
• Examples of coastal wetlands include beaches, mangrove and coral reefs.

Coastal wetlands are classified into two main categories as,

1. Natural Coastal Wetland
2. Man made Coastal Wetland

Natural Coastal wetland

Lagoon

• Lagoons are shallow water bodies which are separated from large water bodies.
• They are separated from the ocean by coral reefs , barriers and sandbars.
• Lagoons also form a part of estuaries.
• They are classified in fresh water lagoons or salt water lagoons
• Example: Chilika lake Orissa and Ashtamudi wetland Kerala

Creek

• Creek is defined as a narrow piece of water in the land.
• This usually acts as an inlet of sea water into the Land.
• They are smaller channels of water when compared to rivers which are voluminous.
• Creek forms an important part of coastal wetlands as they support high flora and fauna and are rich in biodiversity.
• Example: Kori creek Gujarat

Sand/beaches

• The sand and beaches are formed along the coast due to the actions of waves.
• They are coastal landforms which contain the loose particles.
• Sands and beaches act as a transition between the continental shelf and the slope.
• Beeches provide ecosystem services like sediment storage and transport.
• Sand beaches are rich in biodiversity and they mainly act as hatching grounds for coastal ecosystems.
• Coast of Tamilnadu , Orissa and Gujarat are major examples.

Mangrove

• Mangroves are permanently and semi permanently submerged in water, which are mainly found in tropical and subtropical areas.
• They support extreme weather conditions and high biodiversity.
• Mangrove forests are important nesting grounds for shorebirds and migratory birds.
• Mangrove helps in coastal protection by reducing the impacts of strong waves from the open seas.
• Example: Bhitarkanika Orissa, Sunderbans Westbengal , Gulf of khambhat gujarat

Salt Marsh

• Salt marshes have non woody vegetation (herbaceous) which are formed in wet soil conditions.
• They are characterized as tidal marshes and non-tidal marshes.
• They are seasonally filled with water.
• Salt marshes are found along the coastline of Tamilnadu, Orissa, gujarat, maharashtra etc

Coral Reef

• Coral reefs are the most vulnerable ecosystems, consisting of underground reef building corals.
• Coral reefs facilitate the highest biodiversity of any ecosystem in the world.
• They provide ecosystem services like flood protection, sustaining fishing grounds, social and health benefits.
• Global warming poses a major threat to the coral reef.
• Examples: Gulf of mannar, North reef island of Andaman and nicobar islands.

Man Made Coastal Wetlands

Aquaculture Ponds

• They are manmade ponds which serve the purpose of nurturing aquatic species.
• They are also called as fish ponds which support marine and freshwater diversity of species.
• They are artificial and provide commercial services.
• Examples: Kolleru Lake Andhra pradesh.

Significance Of Wetlands

Sources of water :

• A variety of wetlands provide our primary source of freshwater. Aquifer-stored groundwater makes for over 95 percent of all available freshwater and is the most important source of drinking water and irrigation. Several wetlands aid in the absorption of rainwater and the recharge of groundwater.
• Several wetlands serve as habitat for a variety of endemic and near-endangered species. Chilika is home to a robust population of and is one of only two lagoons in the world where endangered Irrawaddy Dolphins can be found.

Wetland Products :

• Wetlands that are well-managed can supply a diverse assortment of plants, animals, and minerals. Coastal wetlands provide over two-thirds of fish, one of the most important sources of animal protein.
• Wetlands produce more than three-quarters of Asia's rice. Many mangrove swamps, like the Sundarbans, produce honey.

Medicinal characteristics of wetland:

• Medicinal characteristics can be found in a variety of wetland plants. Wetlands also provide a source of income for a huge number of people, particularly those who live along their shorelines.

Wetlands and Climate change:

• These ecosystems, on the other hand, can help moderate and adapt to climate change.
• Some wetlands, such as mangroves and salt marshes, operate as carbon sinks, preventing hazardous greenhouse gas emissions from entering the atmosphere.

Threats to Wetland Ecosystem

• Changes in natural hydrological regimes Water regimes influence wetlands' biodiversity and ecosystem functions.
• Reduced water availability, changing hydro-period, loss of linkage with biodiversity areas, restricted nitrogen exchange, and other factors all contribute to the degradation of natural hydrological regimes.
• Catchment degradation depletes the water holding capacity in wetlands thus affecting wetland ecosystem.
• The majority of India's inland wetlands have been overrun by exotic species, which have grown to be a nuisance and have had a significant impact on the local biota and ecological conditions.
• Example: Hyacinth (water hyacinth) is an invasive species introduced in india.
• Other factors like Unsustainable harvest of wetland resources, Over grazing, Unsustainable water abstraction, Mining (e.g. salt, sand or laterite) also affects the wetland Ecosystem in India.

India's Wetlands of International Importance

• India has a diverse range of wetlands, as well as a large number of them.
• This vast diversity has been supported by a wide range of precipitation patterns, physiography, geomorphology, and climate.
• Each of these wetlands is a unique ecosystem with enormous potential.
• On February 1, 1982, India became a party to the 'Convention on Wetlands,' generally known as the Ramsar Convention, and has subsequently identified 49 wetlands totaling 10,93,636 hectares under the List of Wetlands of International Importance, including 5 sites in FY 2020-2021.
• In terms of the number of authorized sites, India currently ranks first in South Asia and third in Asia.

The Montreux Record

• The Montreux Record is a database of wetland sites on the List of Wetlands of International Importance that have experienced, are experiencing, or are projected to experience changes in ecological character as a result of technological advancements, pollution, or other human involvement.
• As part of the Ramsar List, it is kept up to date.
• At Present , two Indian wetlands are on the Montreux list: Keoladeo National Park (Rajasthan) and Loktak Lake (Manipur).

National Wetlands Conservation Program (NWCP)

• The National Wetlands Conservation Program aims to protect wetlands around the country (NWCP)
• In 1985-86, the NWCP was implemented.
• Wetland management is the responsibility of state governments/UT administrations because the land resources belong to them.
• The MoEF has selected 115 wetlands that require immediate conservation and management measures as part of the initiative.
• It also provides state governments with guidelines, financial and technical aid.
• The criteria for identifying wetlands of national significance under the NWCP are the same as under the Ramsar Convention on Wetlands.
• The overall coordination of wetland conservation programs is the responsibility of the federal government.

Conclusion

Global climate change has emerged as a major driver of wetlands loss and degradation, particularly at high altitudes and along coastlines. According to studies, a one-meter rise in sea level would put 84 percent of India's coastal wetlands at risk. Changing hydrological regimes, eutrophication, and algal blooms are all threats to inland wetlands as a result of rising temperatures. Hence it is important to conserve the Wetland ecosystem.