Wetlands are vital for our water needs and food production. Apart from rivers, wetlands are major water-based ecosystem. Natural wetlands occur where surface water collects or where groundwater discharges to the surface. In addition to hosting a wide variety of plant and animal life, wetlands also provide water storage, filtration and offer us protection from floods and erosion. These unique ecosystems have a variety of important functions in natural and urban areas that also include – groundwater aquifer recharge. Freshwater wetlands are a repository of biodiversity.
In India, the total area under wetlands was estimated to be 11.69 m ha. This accounts for 3.66 per cent of the geographical area of the country. In Assam, the total wetland area estimated is 764372 ha, that is around 9.74 per cent of the geographical area.
Assam Remote Sensing Application Centre identified some 3513 wetlands scattered all over the state. These wetlands provide water and habitat for a diverse range of plants and animals and large number of avifaunal diversity.
Since the 1970s, the benefits and value of the world’s wetlands are increasingly receiving due attention. However, in Assam, there is an appalling lack of awareness among the masses about the functions and significance of these crucial components of the ecosystem.
“Conservation of wetlands plays a vital role in ecosystem and vegetation development. The wetlands of Kaziranga support spectacular concentration of wildlife like the Great One-horned Rhino, Water Buffalo, Eastern Swamp Deer and various species of migratory and resident birds, fishes and reptiles. Grave consequences for wildlife have been associated with shrinking of wetlands.” said Prasanna Baruah, senior scientific officer of Assam Remote Sensing Application Centre while speaking on the “status of wetlands in Kaziranga National Park: a geospatial analysis” during a conclave held in the Convention Centre of Kaziranga National Park recently. “Erosion, siltation, shallowing of wetlands, invasion of tall grassland and reduction of wet short grass area have become major threats for Kaziranga,” he warned.
The conclave brought together scientists, environmentalists and wildlife experts to brainstorm on the crucial topic of “Climate Change threats on Wetland Ecosystem of Protected Areas & their Management”. The objective of such a conclave, organized jointly by Kaziranga Wildlife Society and Assam Science Technology and Environment Council (ASTEC) in the Convention Centre of Kaziranga National Park, was to exchange scientific ideas on status of wetlands and threats of climate change on wetland ecosystem in protected areas and create a policy discourse between CSOs and government departments/agencies for effective management.
Waterfowl surveys show gradual changes in wetland ecosystems
On December 19-20, 2018, Kaziranga National Park authorities conducted a baseline survey of the waterfowl that are crucial to the wetland-dominated ecosystem of the world’s best-known habitat of the Great One-horned Rhino. The survey was conducted by 8 teams, comprising 19 bird watchers around 19 places nourished by eight major water bodies of Kaziranga National Park, said Kaziranga’s Divisional Forest Officer, Rohini Ballav Saikia. The teams covered the eastern, central and western ranges of the park where there are a number of wetlands and swampy areas. Waterfowls are found in 92 permanent and more than 250 seasonal water bodies in the Park. The bulk of the waterfowl population was counted in the vast expanse of Sohola – a wetland formed by six shallow water bodies in the eastern range.
A total of 10, 412 birds were counted in the survey, covering a total of 80 species, belonging to 21 families. Out of the total of 10,412 counted birds, 8,074 were ducks and geese belonging to the Anatidae family. Bar-headed Geese accounted for more than 3,000 of the total count, followed by Gadwalls, Lesser Whistling Ducks, Common Teals, Northern Pintails, Indian Spot-billed Ducks, Greylag Geese, Eurasian Wigeons, Mallards, Ruddy Shelducks, Common Pochards, Northern Shovelers, Ferruginous Ducks, and Chinese Spot-billed ducks. The lowest in the count in the geese and ducks category were Garganeys, the Critically Endangered Baer’s Pochards, Tufted Ducks, Common Pygmy Geese, and Falcated ducks.
Other rare birds sighted at the water bodies included the Critically Endangered Red-headed Vulture, the Endangered Pallas’s Fish eagle and the Greater Adjutant Stork, and the Vulnerable Greater Spotted Eagle, Great Hornbill, Lesser Adjutant Stork, Woolly-necked Stork, and Swamp Francolin.
The recent survey was important because a good avifauna reflects on the health of the ecosystem. Not much data on the wetland ecosystem of the 113-year-old Kaziranga National Park was available which is crucial to the survival of the Rhinoceros unicornis. “Although the Rhino prefers grasslands, wetlands are also crucial for the animal’s survival because it depends on submerged vegetation in shallow water bodies. The animal also needs to wallow,” said Anowarduddin Choudhury, author and wildlife expert and a top bureaucrat of the Assam government.
When compared with a compilation of bird records (Birds of Kaziranga National Park, India) gathered from 1993 to 1999 by M Barua and P Sharma covering all seasons and most areas with information on habitat, abundance and migration status, the recent survey showed a declining trend in many waterfowl species. The compilation by Barua and Sharma included the sightings of birds like the Nordmann’s Greenshank, the Terek Sandpiper, Red-necked Phalarope and Black-bellied Tern—not reported in the recent count. Of the Black-bellied Tern, the compilation by Barua and Sharma recounts—“seen regularly in all major wetlands in the park but numbers appear to have declined during 1997-99. The global population of this species is believed to be below 10,000 individuals (Rose and Scott 1994). It is threatened by the destruction of its breeding habitat.”
Reporting on the Pallas’s Fish Eagle, the compilation says – “Seen commonly in the well-watered areas of the Park. A total of nine nests were found in 1995-1996. Although it is locally common in parts of north-east India, it is vulnerable to wetland destruction.”
Barua and Sharma also counted four Black-headed Ibis at the Sohola wetland from 1-10 December 1998 and one in the same area on 24 March 1999 and commented that the species has become very rare in Assam.
The most declining trend was perhaps shown by the Spot-billed pelican. Seen in moderate numbers in most water bodies throughout the year, the number of nests decreased from 600 in 1984 to 155 in 1991, increasing to 219 in 1993 (Talukdar 1995b), and finally dropping to 180 in the eastern range in 1998. It has suffered considerable decline in the past few decades, probably owing to the combination of human disturbance in nesting and roosting areas, and decline in fish availability. Many Asian water fowls are now on the brink of danger due to degradation of wetlands.
Numerous small rivers and channels flow through the Kaziranga National Park from east to west and some, which originate from the Karbi Anglong hills to the south, run northwards and ultimately drain into the Brahmaputra River. Relicts of older channels remain as shallow ox-bow lakes, locally known as beels. There are at least nine such beels of 50-150 ha in area inside the Park. Some beels have silted up. Consequently, there has been an increase in areas of tall grass and a reduction in areas of short grass. This gradual change will have important ecological implications in the future.
Many of the wetlands are fast disappearing due to siltation. The destruction of habitats and loss of nesting sites have left many of the migratory birds to change route or destination altogether.
The major factors for the decline in the population of migratory species include – loss, modification, fragmentation and degradation of habitat, environmental contaminants, poaching and land use patterns, particularly conversion of large areas for cultivation, pesticide usage, high levels of disturbance and developmental activities like mining, stone crushing, hydel projects etc. Climate change is now adding to the loss of habitat for many swampy birds.
Haobam Suchitra Devi, Senior Scientist, North Eastern Space Applications Centre, Shillong giving an analysis of land cover dynamics in Kaziranga National Park using geospatial technology, said that Bank erosion is the main cause for the loss in area in KNP and the Eastern range of the Park is the most affected one. The result also showed a gradual reduction in woodland till 1988 and again in increasing trend. Land cover in the Park is also very dynamic in nature. Wetlands have changed to grassland and woodland, grasslands to woodlands. Short grassland although occupy less area, is showing an increasing trend. Therefore, monitoring land cover is utmost priority for management of the park, the scientist warned.
“Wetland mapping is the first step to monitoring this important part of the ecosystem. Mapping of wetlands using geospatial tool, can be done accurately at minimal costs and manpower use. Monitoring at multiple spatial and temporal scales, support better understanding of the ecosystem for continuous assessment and analysis of future trends,” said Prasanna Baruah.
Climate change and degradation of wetlands
Climate change poses a threat to all ecosystems. The wetland ecosystem is the most vulnerable because wetlands are the least protected ecosystems and climate change is now adding to the loss of these crucial components of the ecosystem. The New Wildlife Action Plan 2017-2031 (NWAP) of India sets out the framework for governmental intervention and management plans to be developed in the protected areas (PAs) in the coming 15 years prioritising development and conservation goals. On the other hand, the thematic focus on climate change—an entirely a new approach in conservation discussions, would set the tone for research specific to climate change, including long-term monitoring and assessment of change in the distribution of vegetation types and ecosystems.”
Scientists assessed that vanishing wetlands mean not only loss of water bodies and their economic benefits but the loss could directly contribute to climate change by releasing a large amount of trapped greenhouse gases.
Talking on climate change implications on wetlands, Dr Pradip Sharma, Associate Professor (Retd) Cotton University said, “With increase in temperature evaporation also increases that leads to depletion of surface water level resulting in depletion of aquatic life and vegetation cover.
Dr Sharma also blamed poor governance for loss of important wetlands in the state.
Dilution of wetlands
Wetlands are at the moment going through policy transition in the country. A new legal framework for wetlands was passed — the Wetland (Conservation and Management) Rules, 2017, replacing the earlier Rules of 2010. The 2010 and 2017 Rules for wetlands both emphasize that the ecological character of wetlands ought to be maintained for their conservation. In the 2010 Rules, some related criteria for wetlands such as natural beauty, ecological sensitivity, genetic diversity, historical value, etc were made explicit. However, these have been omitted in the 2017 Rules. The 2017 Rules came under severe criticism for doing away with strong wetland monitoring systems and omitting important wetland types.
The Supreme Court also passed an order directing States to identify wetlands in the country within a stipulated time-frame. There are challenges ahead in identifying wetlands – multiple and competing use is just one of them. Deepor Beel has become a classic example how wetlands are abused due to clashes of multiple interest. In an inspection made to this Ramsar site by the judicial member of the National Green Tribunal (NGT), it was noted that waste was being dumped “not beyond the site but within it,” and “demarcations are made by drying out areas or cutting off water sources”. These are classic ways of killing a wetland and turning it from a wet to a dry ecosystem; or from a lake to a cesspool. The Tribunal has now asked for the “traditional” spread of the wetland as understanding the traditional spread and ecological character is an important bulwark for the conservation of these unique ecosystems.
Mubina Akhtar is an environmental journalist and wildlife activist. She can be reached at: [email protected]