CHENNAI: Tamil Nadu is continuing its efforts to protect the wetlands, which play a pivotal role as habitats for diverse avian species besides offering unique hydrological and ecological characteristics.
The State-run Advanced Institute of Wildlife Conservation (AIWC) has conducted a detailed assessment and identified 207 wetlands across the State, which are located outside the protected areas, and have potential to be declared as bird sanctuaries.
These wetlands were classified based on bird abundance, area size, and presence of vulnerable species, adhering to wetland assessment protocols. Prominent wetland-rich districts include Chengalpattu, Coimbatore, Kancheepuram, Thiruvallur, Madurai, Villupuram, Salem, and Kanyakumari.
A project report titled “Assessment and identification of potential wetlands as bird sanctuaries and conservation strategies for them in Tamil Nadu” was presented during the recently held annual conference at AIWC. The research team, including project scientist TT Shameer, project assistant D Divinia Juanita and junior research fellow M Riaz Sheriff have used the data from secondary sources like eBird to identify the potential wetlands. Government officials said the project compliments the ambitious Tamil Nadu Wetland Mission, which was launched by Chief Minister MK Stalin with a mandate to notify at least 100 wetlands.
“Our report stands as a fundamental reference for initiating an assessment of the potential to designate these wetlands as protected areas or community reserves. The focus of this assessment is to ensure the safeguarding of both the avian fauna and their associated habitats,” the team said.
However, wetlands are under threat from various human activities such as urbanisation, agriculture, and resource extraction, as well as from natural events such as climate change and sea-level rise. Conservation efforts are therefore needed to protect and restore wetlands, to ensure that these valuable ecosystems can continue to provide their essential services to society, the report said.
According to the Tamil Nadu Biodiversity Conservation and Greening Project report, Tamil Nadu has about 8,312 wetlands covering an area of 4.63 lakh hectares (46,300 sqkm). These wetlands include tanks, ponds, lakes, reservoirs, estuaries, mangroves, and other types of water bodies.
10 priority wetlands
Among the 207 potential wetlands identified, the AIWC research team has zeroed-in on 10 top priority wetlands that needed immediate recognition. Adyar Estuary in Chennai, Achankulam in Coimbatore, Nayapakkam lake in Thiruvallur, Nochimedu Lake in Thiruvallur, Kiliyur tank in Trichy, Mamandur lake in Tiruvannamalai, Kolarampathy Lake in Coimbatore, Thaiyur Lake in Chengalpattu, Sengulam Kanmaai in Madurai and Kelambakkam backwaters in Chengalpettu are the priority wetlands.
For priotising the conservation efforts, a scoring system was developed, integrating critical factors like bird population and wetland area. Employing advanced Geographic Information System (GIS) technology, meticulous mapping of these prioritized sites, integrating data on boundaries, elevation, and zones of influence was done.
A total of 364 bird species were identified from these wetlands and categorised according to their IUCN conservation status. The analysis revealed 2 ‘Endangered’, 336 ‘Least Concern’, 16 ‘Near Threatened’, 2 ‘Not Recognized’, and 8 ‘Vulnerable Species’.
For instance, Adyar Estuary in Chennai, which measures 1.049 sq.km, it is home to a number of fishes, crustaceans, and marine species. It is also a crucial breeding ground for migratory birds that visit the coast during the winter. Apart from this, the Adyar eco-park is a protected area near the estuary. A total of 201 bird species have been recorded until September.
Among the wetland bird species, the Black-winged Stilt, Pacific Golden-Plover, and Little Stint stand out with substantial numbers, indicating their significant presence in wetland habitats. Among the near-threatened birds recorded in the wetland are Bar-tailed Godwit, Black-headed Ibis, Black-tailed Godwit, Curlew Sandpiper, Eurasian, Curlew, Eurasian Oystercatcher, Lesser Flamingo, Oriental Darter, Red-necked Falcon and Spot-billed Pelican. Additionally, vulnerable birds like the Black-capped Kingfisher and endangered birds like the Great Knot were recorded in this wetland.
AIWC officials said the information provided in this report serves as a valuable resource for decision-makers and environmental authorities looking to protect and preserve vital bird habitats and biodiversity. “By designating identified wetlands as bird sanctuaries, we can promote the conservation of avian species and their natural habitats, ensuring a sustainable and harmonious environment for wildlife and human communities,” the report said.
Objectives
Identification of hotspots with bird congregations outside protected areas
Wetland bird species composition, relative abundance, and distribution in different wetlands of TN
Formulating conservation and management initiatives to protect suitable wetlands and their avian diversity
Top 10 priority wetlands
1 | Adyar Estuary (Chennai)
2 | Achankulam (Coimbatore)
3 | Nayapakkam lake (Thiruvallur)
4 | Nochimedu Lake (Thiruvallur)
5 | Kiliyur tank (Trichy)
6 | Mamandur lake (Tiruvannamalai)
7 | Kolarampathy Lake (Coimbatore)
8 | Thaiyur Lake (Chengalpattu)
9 | Sengulam Kanmaai (Madurai)
10 | Kelambakkam backwaters (Chengalpettu)
Importance of wetlands
The wetlands of Tamil Nadu serve as breeding, nesting, and foraging sites for several bird species, including migratory birds that travel long distances every year
Wetlands act as natural water filters, purifying water and improving its quality. They also help regulate the water cycle, preventing flooding during heavy rains and maintaining water availability during droughts
Additionally, wetlands provide important ecological services, such as carbon sequestration and nutrient cycling
Several studies have reported a high diversity of bird species in the state’s wetlands, with some wetlands serving as important sites for migratory birds
For instance, a study conducted in the wetlands of Kanyakumari district reported the presence of 91 bird species, including 31 migratory species
A study in the Vellode Birds Sanctuary wetland reported the presence of 127 bird species, including several endangered species such as the painted stork and the black-necked stork