Wetlands
Wetlands

Wetlands

What are wetlands ?

Wetlands are the lands that remain saturated or inundated with water permanently or seasonally (yet recurrently). Frequent or permanent saturation or inundation of land with water leads to anaerobic/anoxic environment of its undrained soil. Such soils are called ‘hydric soils’. Moreover, the domination of water (that is usually shallow) and anaerobic soil environment also lead to development of special types of plants. Such plants that are adapted to survive and grow in watery areas with wet soils having anaerobic soil environment are called "hydrophytes”. Thus, distinct kind of abiotic elements, i.e., hydric soil frequently or permanently covered by waters of varying depth and distinct kind of hydrophytic vegetation and all other water-dependent biota collectively form distinct ecosystems, called wetland Ecosystems.

There are large number of definitions of the term wetland. Most well-known among them are one by Ramsar Convention, 1971 and another by U.S. Fish and Wildlife Service 1979. Of the two, the Ramsar Convenetion definition is widely used in India. The two definitions are as follows:

Ramsar Convention Definition

"Wetlands are areas 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.” (Article 1.1.)

The U.S. Fish and Wildlife Service Definition

"Wetlands are lands transitional between terrestrial and aquatic systems. It defines wetlands as follows: "Wetlands are the lands transitional between terrestrial and aquatic systems where the water table is usually at or near the surface or the land is covered by shallow water…Wetlands must have one or more of the following three attributes (1) at least periodically, the land supports predominantly hydrophytes, (2) the substrate is predominantly undrained hydric soil, and (3) the substrate is non-soil and is saturated with water or covered by shallow water at some time during the growing season of each year.”

Of the two definitions, the definition promoted by the Ramsar Convenetion is all encompassing and as per this definition, all inland waters such as natural lakes, natural or man-made ponds or tanks, irrigation reservoirs, urban reservoirs (often called man-made lakes), marshes, paddy-fields, rivers and streams are wetlands. Similarly, a variety of coastal waters such as inter-tidal mudflats, mangroves, lagoons, creeks, estuaries, backwaters, saltpans are wetlands too. A wetland classification system developed by Ramsar Convention include 42 types of inland and coastal wetlands determined by the authority but does not include main river channels, paddy fields and the coastal wetland.

Importance of Wetlands: Their Role in Nature and in Human Life

Any wetland does not exist in isolation. Rather, it functions as an element in its entire landscape. Thus, each wetland might be linked with other wetlands in its environs from the viewpoint of movement of waterbirds, spread of aquatic vegetation and flow of energy and water and cycling of nutrients. If a larger wetland(e.g., Nalsarovar) is surrounded by several smaller wetlands(e.g., e.g., several village ponds and small dams in environs of Nalsarovar), the latter are referred to as ‘satellite wetlands’ of the former. From waterbird point of view, such a complex of a larger wetland and its satellite wetlands is very important as waterbirds can move opportunistically among all these wetlands to fulfill their life requisites. A wetland in its landscape is also linked to several landscape element (other than satellite wetlands) like croplands (e.g., for feeding by geese and cranes), woodland (e.g., for formation of nesting colonies by heronry birds).

Wetland ecosystems provide many services which are beneficial to people’s socio-economic needs and economy at large and these services are known as ecosystem services. They provide water for domestic and irrigation purposes; they often contribute to groundwater replenishment. Thus, wetlands contribute to addressing objectives of water security and water for food security. Other ecosystem services provided by wetlands include nutrient trapping and cycling, climate climate mitigation and adaptation, provision of crops and nurseries for fisheries and a variety of cultural benefits, including knowledge (scientific and traditional), recreation and tourism, and formation of cultural values, including identity and spiritual values. Wetlands’ important contribution to many societies is towards flood absorption. Wetlands, especially larger wetlands act as buffers or sponges against otherwise devastating floods and reduce their magnitude.

Objectives of Wetland Management

Wetlands are distinct ecosystems and therefore, like any other types of ecosystems, wetland ecosystems too have structure and functions. Wetland structure refers to the assemblage of biotic (living) and abiotic (non-living) components whose elements keep on interacting among each other while sun’s energy keeps flowing through the ecosystem. Important elements of abiotic component are water, hydric soil and air (with all its gases) that envelopes the wetland. Water is so important an abiotic element that wetland hydrology is considered to be the base of wetland ecology. Variability of wetland hydrology in terms of presence and absence, timing, duration, frequency, extent and depth of water makes each wetland unique. In biotic component, hydrophytic plants and waterbirds (often referred to as ‘waterfowl’) are the most important and conspicuous elements. However, there are many other elements in water or soil that are microscopic (e.g., phytoplanktons and zoo-planktons) or macroscopic yet inconspicuous (e.g., macro-algae, aquatic invertebrates like insects and their larvae, molluscs, crustraceans and worms). Hydrophytic plants are of different habits. Some like Hydrilla and Vallisnaria are the rooted submerged hydrophytes, whereas others like Typha, Phragmites and a variety of sedges (i.e., plants of Cyperaceae family) are the emergent hydrophytes. There are also plants like water hyacinth (Eichhornia) and duckweed (Lemna) which keep on freely floating on water surface. Others like waterlily (Nymphaea), lotus (Nelumbo) and water chestnut (Trapa) are floating-leaved rooted submerged plants. There are also a few free-floating submerged hydrophytes like Ceratophylum. There are two main zones in lake-like wetlands, namely, Littoral or near-shore zone which is typically predominated by marshy vegetation, and Limnetic or off-shore open water zone that is typically predominated by open water area with/without submerged hydrophytic vegetation.

Waterbirds form an important biotic element in many wetlands. In India (including Gujarat), species richness and abundance of waterbirds drastically increase between late October and March owing to influx of wintering migratory or resident-migratory waterbirds. They need micro-habitats like open water area, islands/islets, marshy vegetation and muddy, sandy or rocky shorelines of wetlands for fulfilling their feeding, resting and roosting life requisites. Waterbirds like migratory cranes, geese, several waders (like Ruff and Godwits) as also some ducks need cropland in the environs of the wetlands for fulfilling their food requirement. Resident and resident-migratory waterbirds like Little Grebe, Coot, Spot-billed Duck and Great Crested Grebe need wetlands even for nesting purpose. From foraging view point, waterbirds can be grouped as swimmers (including surface feeders like Northern Shoveler, Northern Pintail, Common Teal, Grey lag Goose, Pelicans etc. and divers like darter, cormorants, grebes and ducks like pochers), large waders (like egrets, herons, storks etc.), small waders or shorebirds (like sandpipers, stints, plovers etc..), marsh dwellers (like moorhen, swamphen, waterhen, rails and crakes, jacanas etc.) and aerial hunters (like terns, gulls, kingfishers and wetland-dependent raptors) As per an estimate, around 150 species of water birds can occur in Gujarat state.

Wetland ecosystem function refers to the flow of solar energy through a , food-chains/web, and material/biogeochemical cycling (e.g., hydrological cycle, carbon cycle, nitrogen cycle etc.) play vital role.

"Ramsar Site” Declaration Idea Behind

"Ramsar Convention” is the oldest of the modern global intergovernmental environmental agreements or treaties on conservation and wise use of wetlands. It is the nickname of the "Convention of Wetlands of International Importance”. The treaty was negotiated through the 1960s by countries and non-governmental organizations concerned about the increasing loss and degradation of wetland habitat for migratory waterbirds. It was adopted in the Iranian city of Ramsar in 1971 and came into force in 1975.

The Convention’s mission is "the conservation and wise use of all wetlands through local and national actions and international cooperation, as a contribution towards achieving sustainable development throughout the world”.

The countries that adopt this international treaty by signing it are called Contracting Parties. The Contracting Parties commit to work towards the wise use of all their wetlands; to cooperate internationally on trans-boundary wetlands, and to designate suitable wetlands for the list of Wetlands of International Importance (the "Ramsar List”) and ensure their effective management. There are total 168 Contracting Parties in the world. Each of these Contracting Parties (i.e., countries) proposes its one or more significant wetland sites as internationally important wetland sites. On fulfilling certain criteria of Ramsar Convention, such sites are declared as Wetlands of International Importance or Ramsar Sites. There are total 2186 Ramsar Sites in the world that cover 20, 84, 493 sq. km. In India there are 26 Ramsar Sites, the oldest being Chilika Lake (Odisha) and Keoladeo Ghana (Rajasthan) that were declared in 1981 and the newest (i.e., 26th) being the Nalsarovar Bird Sanctuary (Gujarat) that was declared in September 2012.

Wetlands of Gujarat

In India, Gujarat is considered as wetland rich state. In fact, from the view-point of extent of the wetlands, Gujarat is number one state as its wetland area contributes unmatchable 23% of wetland area of the country. Space Applications Center (SAC-ISRO) has estimated total wetland area of 34,749.50 sq. km in Gujarat state in its "National Wetland Atlas-Gujarat” (2010). It accounts for about 17.56% of geographical area of the state. The coastal wetlands dominate in the state, of which the major wetland types include intertidal mud flat (22,603.65 sq. km.), creek (1,498.98 sq. km) and salt marsh (1,442.68sq.km). Among inland wetlands river/stream (2,758.77 sq.km), and reservoir/barrage (2,489.79 sq.km) are the major wetlands in the state. Some of the unique wetlands like corals and mangrove are found in Gujarat state.

As per SAC’s "National Wetland Atlas-Gujarat” are total 14,183 wetlands with minimum 2.25 ha each in Gujarat. Out of these 14,183 wetlands 1,358 wetlands (i.e., 9.57%) are inland natural wetlads covering 3200 sq.km, whereas 10,075 wetlands (71.035%) are inland man-made covering 3400 sq. km. As far as coastal wetlands are concerned, 2,448 wetlands (i.e., 17.26%) are natural wetlands covering 27100 sq. km area, whereas 302 (2.12%) wetlands are man-made wetlands covering 1000 sq.km of the State.

There are eight wetlands in Gujarat that are declared as Nationally Important Wetlands by Government of India. These wetlands are as follows

About Nalsarovar Wetland And It’s Importance

The word ''Nalsarovar'' originated from the word "Naal” meaning a narrow sea creek. Till late Quaternary period there existed a narrow linkage of sea between Gulf of Kutch & Khambhat. Due to the gradual process upheaval over a very long Geological times scale, this sea got regressed and land mass having a closed basin of Nalsarovar came into existence. Nalsarovar is a shallow fresh water lake spread over an area of 120 sq.km in in Ahmedabad & Surendranagar districts of Gujarat State. It is situated at a distance of 62 km from Ahmedabad. The 115 sq. km of area was declared as Bird Sanctuary on dated 8-4-1969 under the provisions of the Gujarat Wild animals & Wild birds, Protection Act, 1963. Later on additional 5.82 sq. km of area was declared as Bird Sanctuary on dated 27-12-1982 under the provisions the Wildlife Protection Act, 1972. The people claimed no individual rights & privileges.

The area lies between 710 58’E to 720 06’E longitudes and 220 41’N to 220 52’N latitudes. It falls under 4B Gujarat Rajwara biotic province of semi-arid bio-geographical Zone. There are more then 300 islets (bets) out of which 36 have sizable area and traditional names. The area receives rainwater from North, East and West directions. Excess of water drains out from Southern end. In north, water enters though Brahmani River. In East its comes by Ghoda Feeder Canal & in West through Surandranagar Bhogavo river & many small streams. The maximum depth time of flooding in 2.0 – 2.5 mts., which reduces to 1.0 – 1.5 mts., during the winter season. The water storage capacity of lake is about 66 MCM of water.

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