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  • Pulicat Lagoon is the second largest brackish water lagoon in India, after Chilika Lake.
  • The Lagoon is one of the three important wetlands to attract North-East Monsoon rain clouds during October to December season to Tamil Nadu.
  • The lagoon comprises the following regions, which adds up 759 km2 according to Andhra Pradesh Forest Department:
  1. Pulicat Lake (TN & AP)
  2. Marshy/Wetland Land Region (AP)
  3. Venadu Reserve Forest (AP)
  4. Pernadu Reserve Forest (AP)
  • The lagoon was cut across in the middle the Sriharikota Link Road, which divided the water body into lake and marshy land.
  • The lake encompasses the Pulicat Lake Bird Sanctuary.
  • The barrier island of Sriharikota separates the lake from the Bay of Bengal and is home to the Satish Dhawan Space Centre.
  • Major part of the lake comes under Nellore district of Andhra Pradesh.

Flora and fauna

  • The lagoon has rich flora and fauna diversity, which supports active commercial fisheries and a large and varied bird population.
  • Mullets and Catfish are the major brackish water fish, which have supported sustenance fishing for the lake fishermen. The lake is a nursery for several species of fish.
  • Finfish, green crabs, clams and prawns are the most commercially exploited fishes of the lagoon. Endangered green sea turtles are found on the beaches of Sriharikota beach.
  • Apart from prawns, salt is also produced from the lagoon.
  • The Andhra Pradesh portion of Pulicat Lake Bird Sanctuary, established in September 1976, has an area of 172 square kilometres (66 sq mi) within the lagoon’s total area in the state in the Tada Taluk of Nellore district.
  • The Wildlife Division of the state has listed 115 species of water and land birds in the sanctuary.
  • Nelapattu Bird Sanctuary is also located nearby in its catchment area. The Tamil Nadu part of the lagoon of 60 square kilometres (23 sq mi) area, extending over the Ponneri and Gummidipundi taluks of Thiruvallur district was declared a Bird Sanctuary in October 1980.
  • Every year approximately 15,000 greater flamingos are reported to visit the lake along with pelicans, kingfishers, herons, painted storks, spoonbills and ducks.
  • The highest concentrations of flamingo are found in the periphery of the lagoon where the water level is below40 centimeters (16 in).
  • The concentrations of flamingos are also associated with high algal, fish and benthic diversity.
  • Other water birds in the area include spot-billed pelican, seven species of herons and egrets, painted stork, greater flamingos, ducks, 20 species of shorebirds, gulls, terns, little grebe, Indian cormorant, little cormorant, Asian open bill stork, black-headed ibis, Eurasian spoonbill, lesser whistling teal, spotbill duck, great thick-knee and stone curlew.
  • Several species of wintering waterfowl have been noted including bar-headed goose, ruddy shelduck, Eurasian wigeon, common teal, northern pintail, garganey, northern shoveller, common pochard, brown-headed gull, black-headed gull, whiskered tern, gull-billed tern and Caspian tern.
  • Birds of prey which appear in winter are the: white-bellied sea eagle, harriers and peregrine falcons.
  • The largest concentrations of flamingos occur in the Andhra Pradesh part of the sanctuary, around the islands of Vendadu and Irukkam.

Threats and issues

  • In the Andhra Pradesh part of the lake several threats to the lagoon have been identified.
  • These are:
  • pollution from sewage, pesticides, agricultural chemicals and industrial effluents – from Arani and Kalangi rivers draining into the lake that bring in fertilizers and pesticides with the run off from the agricultural field in to the drainage basin, domestic sewage, effluents and wastes from numerous fish processing units;
  • oil spills from the mechanized boats;
  • release of4,780 hectares (11,800 acres) of the sanctuary for a marine chemicals and salt-manufacturing industry and shrimp farming in more than 1,000 acres (400 ha) on the eastern part of the lagoon have affected the Pulicat Bird Sanctuary;
  • Livelihood of 30,000 fishermen and 20,000 agricultural labourers (for whom fishing is an off-season economic activity) have also been disturbed.
  • Siltation and periodic closure of the bar mouth due to the dynamic process of sediment transport has caused reduction of size and seasonal closure of the mouth of the lake has reduced fresh sea-water exchange and made the lake shallow and turbid.
  • This has caused difficulties such as
  1. mouth getting silted up and getting closed during the summer season
  2. raise in flood level occurs during the rainy season;
  3. the lake acts as a large evaporating basin when the bar is closed resulting in salinity levels remaining low or high subject to the flood discharge into the lake during the north east monsoon;
  4. fluctuation of water level in the lake (above or below the sea level) is affecting flora, fauna and fisheries;
  5. The flood plains reclamation in Arani river basin for industrial and residential purposes is also increasing lake maximum water level during the floods.

Reference

https://en.wikipedia.org/wiki/Pulicat_Lake