Satellite remote sensing and field studies on a sea mouth in the northern part of Pulicat Lake

The Pulicat lagoon extending between 13 degree 20'-13 degree 40'N lat. and 80 degree 14'-80 degree 15'E long., and formed out of backwaters of the Bay of Bengal super(1)- super(2), is the second largest brackish water lagoon having an area of approximately 600 km super(2). The river waters of Kalangi, Uppativagu, Pamu-lakalva and other rainfed freshwater streams super(3)' super(4) drain into the lagoon, making it rich in biodiversity. Pulicat lagoon is the feeding ground for local and longdistance migrant bird species. Longdistance migrants like the pelican, flamingo, painted stork, spoon-billed stork, snake bird and sand piper, and a variety of bird species super(3) feed on aquatic flora and fauna of the Pulicat Lake waters. Besides, several species of crustaceans, brachiopods, edible and non-edible fishes, and mollusks are present in the Pulicat Lake, providing food for secondary and tertiary consumers of the food chain, namely migrant birds super(3,5,6),. About 50,000 fishermen are also dependent on the Pulicat Lake. The sea mouth is important as sea water flows into the lake during high tide and lake water flows into the sea during low tide. Satellite data and field work undertaken showed shrinking of one of the three sea mouths, namely that at Tupilipalem on the northern most side of the Pulicat lagoon located in Nellore District, Andhra Pradesh, which might pose a threat to the lake biodiversity. The sea-mouth width retrospective data were retrieved by satellite remote sensing, whereas direct observation data in the field were collected for 2007 and 2008. Future ecoremedial measures for conservation are discussed and presented here.