28 Wet Lands – II

Dr Sunil Mittal

1.      Introduction

2.      Major threats to wetlands

3.      Wetland restoration

4.      Wetlands – Indian Prospective

5.      Wetlands of International Importance in India

1. Introduction

In the past the wetlands were regarded as wasted lands since these were viewed as polluted, muddy, swampy, bug infested waters. These were regarded as the habitat of many diseases causing mosquito’s and source of foul smell. These were also blamed for causing diseases like Malaria. Hence most of the times these were drained off or filled with soil or build over. Fortunately, scientists in the last few decades have realized the importance of wetlands. The wetlands are now considered as distinct ecosystems with specific ecological characteristics, functions and values. They have recognized wetlands as one of the most productive ecosystems of earth. These serve many functions ranging from the food and wood for local communities to many ecosystems and environmental services. Wetlands are commonly referred to as nature’s kidneys as these remove harmful materials from water such as excess nutrients, pollutants and contaminants. Despite many services provided by wetlands, these are under threat due to unsustainable use, lack of conservation and management of these biodiversity rich areas. In the previous module we have defined wetlands, discussed their types and classification and their functions or benefits. This module will discuss in detail about threats to wetlands, why to conserve and manage them, what can be done. The latter part of the module will discuss about the Wetlands in Indian Prospective.

2. Threats to wetlands

According to World Wildlife Fund report wetlands are the one of the most endangered ecosystems of the world. Though they are endowed with a rich biodiversity yet of late they are being greatly exploited. As per some reports half of the wetlands have disappeared since starting of 19th century. Conversion of wetlands for commercial development, water diversion, excessive hunting and overfishing, excessive tourism, commercial exploitation, extraction of nutrients, pesticide discharges from intensive agriculture, toxic pollutants from industrial waste, and the construction of dams and dikes, etc. are major threats to wetlands. These are discussed in detail as follow.

i)   Human Population and Development: One of the major threats to wetlands comes from the ever increasing population which puts pressure on land usage directly and indirectly. The need for more land for housing, urbanization, industrial development, agriculture leads to destruction of these wetlands. The usage of these sites for other purposes not only destroys the wetlands but also leads to habitat destruction of flora and fauna present in these wetlands. The developmental activities can cause changes in river flows, more sedimentation, increase in nutrients, changes in salt levels in water etc. The activities may also lead to outbreaks of pests & weeds and toxic blue-green algae. These toxic algae may kill the flora and fauna of the wetland and make water unsuitable for urban, agricultural and recreational uses.

ii)   River regulation and water diversion: The alteration of natural flow of rivers, streams, flood plains and their regulation are the biggest threats to wetlands. The most common reasons for the alteration are constructing dams and other structures on rivers. River regulation and water diversion are carried out to make water available for hydro power plants, urban, industrial and agricultural uses.

The changes in the water course leads to drying of the wetlands. The river regulation and water diversion can result in dying of plants & animals, decline in fishes and consequently water birds dependent on fishes for their food etc.

iii)   Weeds and Pest Animals: Weeds compete with native wetland species for resources and habitats and displace them in the process. The common wetland weeds found are flowering plant lantana, floating fern salvinia, seaweed caulerpa etc. Similarly, pest animals also lead to destruction of habitat of native animals.

iv)   Climate change: The climate change is another big threat to wetlands. The climate change has led to changes in rainfall pattern, temperature fluctuations, evaporation rate etc. These changes not only affect water availability but also adaptability of the native biodiversity.

v)     Pollution: The discharge of industrial effluents and agriculture runoff into wetland reservoirs alternate its water quality. This also affects the population of several sensitive species. Agriculture runoff water rich in nitrates and phosphates often leads to accelerated eutrophication of natural wetlands. The uncontrolled growth of weeds and consequent decay also cause dying of wetlands.

vi)   Siltation: Uncontrolled siltation reduces the shallowness and water holding capacity of wetlands. This reduces the amount of available water during dry period.

vii)   Vegetation Damage: The activities that can damage wetland vegetation are over grazing, removal of vegetation for peat mining etc.

viii)     Political and Socioeconomic Issues: Although rules and regulations exist for the protection of wetlands but non implementation of legislation properly leads to interruption in their management process. Political will and interference is also a hurdle in many countries for effective measures for their management. The lack or shortage of funding to tackle threats is also a reason.

ix)   Limited awareness and public participation: Another key issue that impairs wetland conservation and restoration is the lack of awareness and limited participation of local communities and stakeholders. Further, the conflicting interests between the locals/stake holders make this task even more difficult to achieve.

The quantity of water present and the timing of its presence in part determine the functions of a wetland and its role in the environment. Even wetlands that appear dry at times for significant parts of the year — such as vernal pools– often provide critical habitat for wildlife adapted to breeding exclusively in these areas.

3.Wetland restoration: What can be done?

Wetland restoration involves renewing a degraded wetland to its pre-existing, naturally functioning conditions or a condition as close to that as possible. All restoration projects require planning, implementation, monitoring, management and team with expertise in ecology, hydrology, engineering and environmental planning.

• Reduce pollution
• Minimize anthropogenic activity
• Prevent overgrazing
• Protection laws and government initiatives
• Proper planning and monitoring
• Building awareness

4.        Wetlands – Indian Prospective

India is very rich in wetland habitats and almost all states have wetlands. These exhibit different ecological diversities, climatic conditions and changing topography. These are located in different geographical regions of India ranging from Himalayas to Deccan plateau. As per the estimates of Space Applications Centre report 2011, the area of wetlands in India varies from 1% to 5% of total geographical area. The wetlands in India support nearly 20% of the known biodiversity. According to WWF-India, wetlands are one of the most threatened of all ecosystems in India. Out of several wetlands in India, Chilka lake in the state of Orissa, is the largest one. It was designated as Ramsar site in 1991 and has magnificent unique biological diversity of its own type, ecological complexity and sustainability. Twenty six (26) sites have been designated as Ramsar Sites (wetlands) in India.

Indian Wetlands, on the basis of topographical variation can be divided into 4 major types:

1)  Himalayan Wetlands

2) Wetlands in the Gangetic plain

3)  Wetlands in the desert

4)  Coastal Wetlands.

5. Wetlands of International importance in India

Source: Map is created using QGIS

Indian Wetlands under Ramsar List:

1. Chilika Lake: On 1st January 1981, one of the largest brackish water body, Chilika Lake was selected under Ramsar list of wetlands. Chilika Lake is spread over 1165 sq. km during monsoon and 906 sq. km during summer. From the east coast of Odisha state, Chilika Lake is connected with Bay of Bengal through a 35 km narrow channel. Fresh water in Chilika Lake is supplied by the Daya and Bhargavi rivers from the Indian mainland. The large water filler area of Chilika Lake hosts many migratory birds and provide habitat to local fauna like Dolphin, ducks, flamingoes, pelicans, plovers, gulls etc. Various flora varieties like halopyta ovata, cladocera, potamogeton, etc, are also found in Chilika Lake.
2. Keoladeo National Park: It is located on the confluence of two rivers namely, Gambhir and Banganga in Bharatpur district of Rajasthan. In the year 1981, this park has been selected under Ramsar list. An amazing diversity of flora and fauna have been found here due to availability of unique habitats including wetlands, woodlands, scrubs, forests and grasslands. Keoladeo National Park’s flora consists of about 375 species of angiosperms out of which 90 species are found in wetland areas. The fauna includes more than 350 species of birds, 27 species of mammals, 42 species of raptors and 9 species of owls, 7 species of amphibians, 13 species of reptiles, 71 species of butterflies, 58 species of fishes, more than 30 species of dragonflies and more than 30 species of spiders. Keoladeo National Park has got the title of ‘Birders Paradise’ due to abundance of birds.
3. Wular Lake: It is a large fresh water lake of Jammu and Kashmir state approx.18,900 hectares in area . It absorbs high flood water of the river Jhelum and acts as a huge reservoir. Wular Lake has been selected under the Ramsar List in 1990. The lake is characterized with extensive marshes of emergent and floating vegetation. Water chestnut Trapa Natans of the lake is also the source of revenue for the government. The lake supports fishing industry and considered as a valuable source of water for irrigation and domestic use. The lake is also important for wintering, staging and breeding of many bird species. Loss of biodiversity due to human interference is quite apparent in the Lake. Degrading water quality due to effluents brought by the river Jhelum is also a major threat to Lake.
4.  Harike Lake: Harike wetland is one of largest manmade wetland of northern India, situated at the confluence of Beas and Sutlej River. It has been selected under the Ramsar Site in 1990. In the year 1992, it was selected as a wildlife sanctuary. It provides an important space for staging and breeding of birds. Approximately, one lakh winged guests like Bills, Sybarian Gills, Shellduck Spoon, common koot, Shawler vision, Rudi, Pantel, etc. come from the Russia, Siberia, Kazakhstan and other cold regions during the winter to the Wetland. Harike wetland has a rich diversity of fish fauna, where 61 fish species of 17 families and 35 genera are found. The Harike wetland has faced the problem of extensive pollution leading to the problem of excessive growth of hyacinth and encroachment of areas for agricultural activities.
5. Loktak Lake: Loktak Lake of Manipur having an area of 26,600 ha, has been added to the Ramsar list in 1990. Thick floating weeds covered with soil (phumids’) are a major characteristic feature of this lake. Except, being used for irrigational and domestic purposes, it is an important place for wintering and staging of water birds, particularly ducks. The lake has also been included on the Montreux Record in 1993 due to threats to its ecology such as infestation of water hyacinth, degrading water quality along with deforestation in the catchment area. Even the construction of a multipurpose dam has caused the extinction of several native fish species.
6. Sambhar Lake: A large saline lake of Rajasthan state, situated within the municipality of Jaipur District. It has been designated a Ramsar site in 1990. This shallow wetland is fed by four streams named Mendha, Runpangarh, Khandeland, Karianwhich. The wetland is a key wintering area for pink flamingos and other birds migrating from northern Asia, Siberia and other cold regions. The growing algae and bacteria in the lake provide striking water colours. Some human activities like salt production and livestock grazing are performed near the Lake.
7. Kanjli: Kanjli is manmade wetland that came into existence after making a small barrage over Kali Bein for irrigation purposes in 1870. It spreads over 183 hectares in area in Northern Punjab. The site has been selected as Ramsar site in the year 2002 under the Criteria 3 because it supports a considerable diversity of aquatic, mesophytic, and terrestrial flora and fauna. From religious point of view, it is the most significant as it is associated with the first Sikh Guru Shri Guru Nanak Dev Ji. The site faces the problem of water pollution due to excessive use of areas for agricultural activities. In spite of this, deforestation and unwanted grazing further increase the problem.
8. Ropar Wetland: Ropar Wetland is a manmade wetland formed by the construction of a dam over Sutlej River. Ropar wetland is located in eastern parts of Punjab. Ropar wetland was selected under Ramsar list in 2002. A number of migratory as well as native birds visit the areas in winter seasons. It is also a breeding place for Indian otter, Sambar, Hog Deer and several reptiles. Due to their specific location in Shivalik foot zones, wetland is mainly affected by higher amount of siltation in the wetland.
9. Astotamudi Wetland: Ashtamudi Wetland of Kerala state has been designated as ramsar site in 2002. The wetland is an estuarine covering an area of 61400 ha. The Astotamudi wetland ecosystem supports a large number of mangrove species, (40 associated plant species and 57 species of birds including 6 migratory bird species). Availability of 100 fish species sustain the fishing industry around the wetland. Oil spills from fishing boats along with enhancing population density and urban extension pose threats to the wetland in terms of pollution and encroachment of wetland areas.
10. Bhitarkanika Mangroves: Bhitarkanika Mangroves, a 65,000 ha wide beach of Odisha, was enlisted as Ramsar site of wetlands in 2002. The conservation practices for mangroves, from last 25 years along the Indian coast, have made the site one of the best known wildlife sanctuaries. Some beaches nearby this site are nesting sites for the largest known Olive Ridley sea turtles and largest number of saltwater crocodiles in the country, with nearly 700 Crocodylus porosus. Among the 58 recorded species of mangroves in India, 55 species are found in Bhitarkanika, which made it wider mangrove diversity than in the Sundarbans. Some traditional activities like harvesting of food, fuel wood, medicines, tannins, and construction materials were done in sustainable manner, but due to population pressures and encroachment of the area may threaten the equilibrium.
11. Bhoj Wetland: Two lakes Upper and Lower, which were created during different time spans, collectively called Bhoj Wetland (area of 3201 ha) in Madhya Pradesh state, was recognized as Ramsar Site in 2002. The two man-made reservoirs “Upper Lake” created (11th century) by construction of an earthen dam over the Kolans River, and the “Lower Lake” was constructed (nearly 200 years ago) from the leakage of the Upper Lake. These lakes are rich in biodiversity, native and migratory birds, insects, natural and cultured fish species, amphibians, reptiles, macrophytes, zooplankton and phytoplankton.
12. Deeper Beel: In Assam state, 4,000 ha wide permanent freshwater lake, was recognized as Ramsar Site in 2002. It was a former channel of the Brahmaputra River, which has a great biological importance. The Beel is a staging site for migratory winged birds with the largest concentrations of aquatic birds in Assam. Some of the globally threatened species of birds like Spotbilled Pelican (Pelicanus philippensis), Baer’s Pochard (Aythyabaeri), and lesser and Greater Adjutant Stork can be found here. Availability of 50 fish species in the wetland provide livelihoods for a number of people living in surrounding villages. Nymphaea nuts and flowers, seeds of the Giant water lily Euryale, medicinal plants, ornamental fish, and ferox are major revenue sources in local markets also. Over-fishing, hunting, pollution from pesticides and fertilizers, and infestation by water hyacinth Eichhornia crassipes, are potential threats to the site.
13. East Calcutta Wetland: East Calcutta Wetland is a world-renowned model of multiple use wetlands with resource recovery systems which purely developed by local people covering an area of 12,500 ha. It was designated as Ramsar site in 2002. The wetland provides an urban facility by treating the city’s waste water which is further utilized for pisciculture and agriculture. Thus the system is described as “one of the rare examples of environmental protection and development management where a complex ecological process has been adopted by the local farmers for mastering the resource recovery activities” (RIS). Wetland is the major source of livelihoods for people; it provides about 150 tons of fresh vegetables on daily basis, and approximately 10,500 tons of table fish per year. Unauthorized use of the waste water outfall channels by industries adds metals to water and canal sludge which is a major threat to the water.
14. Kolleru Lake: Kolleru Lake is located in Andhra Pradesh covering 90,100 ha of area. It is a natural eutrophic lake, situated between the two major river basins of Godavari and Krishna. This is fed by two seasonal rivers and a number of drains and channels. The lake is a habitat for many native and migratory birds, including Grey Pelican (Pelecanus philippensis), and sustains both culture and capture fisheries along with the agriculture. The lake is facing many damages and losses due to flooding in monsoon seasons and partial drying during summers. Adequate management and conservation is seriously required in this area.
15. Point Calimere Wildlife and Bird Sanctuary: Point Calimere Wildlife and Bird Sanctuary of Tamil Nadu state, spread over 38,500 ha area was enlisted under Ramsar site in 2002. About 257 species of birds (119 are water birds), including the vulnerable species like Grey Pelican (Pelecanus philippensis), Spoonbill Sandpiper (Eurynorhynchus pygmeus) and Flamingos are found here. The site is a perfect breeding ground for many commercially important species of fish, prawns and crabs. The decreasing inflow of freshwater, increasing brackish groundwater due to historical salt works, Illegal collection of firewood and spread of Prosopis chilensis (Chilean mesquite) are major threats to the sanctuary.
16. Pong Dam Lake: Pong Dam Lake covers 15,662 ha area of Himachal Pradesh state. In the foothills of Himalayas, on the northern edge of the Indo-Gangetic plain, a reservoir was created in 1975 which was later on considered as Ramsar Site in 2002 as Pong Dam Lake. More than 220 bird species along with 54 species of waterfowl are found in this lake. In terms of hydrological values, the lake serves as groundwater recharge, monsoon-season flood prevention, silt trapping and prevention of soil erosion, both in the surroundings and downstream due to water regulation and electricity generation. A lucrative fishery with 27 fish species of the lake gives livelihood to approximately one thousand families directly or indirectly.
17. Sasthamkotta Lake: Sasthamkotta, a freshwater Lake is located in the state Kerala with 373 ha area. This spring-fed lake is the source of drinking water for half a million people in the Kollam district of Kerala state. About 27 freshwater fish species are present. Due to non-availability of common salts or other minerals, the lake could not support any water plant. A larva called Cavaborus is abundant which eliminates bacteria from the water, thus, the lake has exceptional purity of water.
18. Tsomoriri: Tsomoriri is located at 4,595m above sea level in the state of Jammu & Kashmir and is spread over 12,000 ha with wet meadows and borax-laden wetlands along the shores. This site is the only breeding ground outside China for the most endangered cranes Blacknecked Crane (Grus nigricollis), and only breeding ground for Bar-headed geese in India. While, the area is on the way of ancient trade routes and now major trekking routes, but the wetland is considered sacred by local Buddhist communities and the water is not used by them.
19. Vembanad-Kol Wetland: Vembanad-Kol wetland is the largest brackish, humid tropical wetland on the southwest coast of India. The 151,250 ha area of the state Kerala is under this wetland which is fed by 10 rivers and this estuarine area was recognized as Ramsar site in 2002. Approximately, 90 species of resident birds, 50 species of migratory birds are found in wetland area. Flood protection for densely populated coastal areas of three districts of Kerala is getting major benefits from the wetland. This also helps for groundwater recharge which further supplies water for the region.
20. Chandertal wetland: Chandertal wetland is situated in Himachal Pradesh. Chandertal is a high altitude lake near Pir Panchal ranges and Kunzam pass joining the Himalayas. It is spread over 49 hectares. It was selected under Ramsar list 2005. The wetland supports many species like Kestrel, Golden Eagle, Chough, Red Fox, Himalayan Ibex, Blue Sheep Black and Ring Stilt. It also supports endangered species.Snow leopard comes under the red list of CITES and IUCN. The area faces problems of deforestation and over grazing. The Chandertal wetland is a center of tourist attraction mainly in summer seasons, but lack of sanitation facilities leads to the problem of littering. For the conservation of area fund has been released under the ecotourism services. The State Council for Science, Technology and Environment is a coordination committee that seeks the management activities.
21. Horeka wetland: Horeka wetland is a natural permanent water body that is fed by Jhelum River situated in Jammu & Kashmir. It is situated at 1584 m above sea level in the northwest province of Kashmir. The wetland is spread over 1375 hectares. The wetland was selected under Ramsar list in 2005. A number of migratory and native waterfowl are supported by Horeka wetland. Large Egret, Common Shelduck, Little Cormorant, Great Crested Grebe, Tufted Duck and endangered White-eyed Pochard visit wetland areas in winter season.
22. Renuka wetland: Renuka wetland is a natural wetland selected as Ramsar site in 2005. The wetland is fed by a small Giri River and natural springs. It covers an areas of 20 hectares situated in Himachal Pradesh. A number of pilgrims and tourist visit the place, because of its religious values in Hindu religion, as it is named after the mother of Parshuram. It is the home of more than 443 species of fauna; crimson-breasted barbet, Pheasants, Bulbul, Egrets, Herons, Mayna, and Lapwing. The Sambhar, Ghorals and Barking deer are common in areas. The area faces the problem of siltation owing to deforestation in hilly region.
23. Rudrasagar Lake: Rudrasagar Lake (240 hectares area) is a lowland reservoirs nourished by the three streams of Gomti River situated in Tripura state. A plentiful amount of fresh water fishes mainly Chitala, Ompokpabda, Labeobata etc. are found here. It also provides a habitat space for three striped roof turtle Kachuga dhongoka that are listed under IUCN Red list. The human pressure, encroachment of areas for agricultural activities and soil erosion in the areas are major threats faced by the wetland.
24. Surinsar Mansar Lake: It is a non-permanent freshwater lake situated in semi-arid Panjab plains of Jammu and Kashmir covering about 350 hectares. Many red list species such as Lissemys punctate, Mansariella lacustris and Aspideretes gangeticus are found in Surinsar Mansar Lake. Many waterfowls like Aythya fuligula, Gallinula chloropus, Podiceps nigricollisa and Fulica atra exist in the region. The site has been worshiped by people as many temples are located around the Lake, which has a connection with Mahabharata era. Major threat is agricultural runoff, religious bathing, tourists littering and cremation ceremonies.
25. Upper Ganga River: It is located in Uttar Pradesh. The Upper Ganga River was selected under Ramsar list in 2005. It spreads over an area of 26,590 hectares. The IUCN red listed species include; Gharial, Ganges River Dolphin, Crocodile, otters, 6 species of turtles, 82 species of fish and many species of birds are supported by the area. In terms of Flora, high medicinal value tree includes; Dalbergia sissoo, Eucalyptus globulus, Saraca indica, Ficus bengalensis, Azadirachta indica and aquatic Eichhorina. The areas faced the problems of discharge of untreated waste, agricultural runoff and religious waste like cremation rituals.
26. Nalsarovar: Nalsarovar Bird Sanctuary (spread over 12000 hectares) located in Gujarat was selected as Ramsar site in 2012. The Nalsarovar is one of largest natural fresh wetland lake in Thar region. The area provides a suitable habitat for breeding and feeding of flora and fauna. More than 200 bird species visit both in summer and winter seasons. The numbers changed with respect to season, such as average 174,128 individuals recorded throughout the winter and 50,000 in the summer. The wetland is also a lifeline for endangered Indian Wild Ass that uses areas in dry season. The Nalsarovar also provides water for drinking and irrigation uses.