Pulicat Lake is considered to be the second largest brackish lake in the Indian Subcontinent. It covers the land of around 720 sq.kms. Out of the total land covered by the Pulicat Lake 84% of the land is found in the region of Andhra Pradesh and the 16 % is covered by the land of Tamil Nadu. The lake is very shallow and measures the depth of 1-2 meters. The lagoon of the Pulicat Lake is around 0.2 kilometers to 17.5 kilometers.
Especially during the period of monsoon which starts from the month of August or September, the lake of Pulicat is covered with the nutritious water and huge number of zooplankton and phytoplankton are found in the Pulicat Lake.
These infinitesimal organisms have the necessary food for the invertebrates and the fishes that helps them to survive happily in the lake. Hence, there are thousands of the birds especially the wet lands attracted to the food on the grounds of Pulikat Lakes. Nowadays, the forest department of Andhra Pradesh protects the lake and the living creature of it.
There are 3 most important points where the Pulikat Lakes begins and they are Bay of Bengal, being the largest end of the southern part of Shri Harikota Islands and the next one is the northern top of Shriharikota and the other one is to the acute edge of the northern part and the Moolthangal and Arani in the southern region that pour its water in the lake during the season of monsoon, that helps to increase the level of water and also the decrease the level of salt from the lake.
Pulicat is considered to be the 20th islands being one of the largest one from the islands from Shriharikota.
There are in all three most important rivers that feed the lagoon from the Arani River at the southern tip. The river Kalangi arises from the northwest and the river Swarnamukhi River in the northern end. Apart from this, it also arises in some part of the small rivers. The Buckingham Canal, a channel for navigation is amongst the part of the lagoon situated in the western part. The water of lagoon gets exchanges with the Bay of Bengal is from one of its inlet that lies in the end of north region that belongs to Shriharikota and out flow channel of about 200 mts. Width in the southern part of the lagoon that has the flow of water only during the rainy season.
The salt level of the water changes from zero in the period of monsoon that goes beyond the 52 ppm which is considered to be the range of hyper saline at the time of pre and post monsoon seasons. It is very difficult to adjust with the wide range of variation that is found in the lake. Hence, the species do migrate from the lake. Even the quality of the water changes from one season to another. There is different kind of water in the period of summer, period of pre monsoon, monsoon and the post monsoon as the width and the depth of the lake mouth changes causing the dynamic circulation of the water and the situation of mixing. The left over water and the contents of the salt and the proportion of the dissolved oxygen that actually affects the living being inside the lake that includes the primary production of the bio diversity, plankton and the fisheries in the lake.
The habitat that lies in the bottom of it are distributed in major three zones. The first zone comprises of the southern zone which has the domination from sand along with some amount of word. The second part of this region totally comprises of the mud. The third part of the region is covered with sand and mud in equal proportion. The region is covered with dense weeds and it is considered to be very rich in the biodiversity.
There are numerous amount of metals found in this region that includes the lead, magnesium, nickel, zinc, aluminium, cadmium and the copper and other chemicals that includes sulphate, ammonia and the fluoride in the lake are present in certain limits.
Fauna and Flora :
The lagoon has a rich content of flora and fauna that includes the commercial fisheries and a huge variety and varied population of the birds.
There are a large number of fishes and the crustaceans, around 1200 tonnes those have harvested in a year. Out of the fishing activity, the prawns constituted of the 60% of the total fishing along with the mullets. There is a huge amount of the seafood export from this region that includes the Tiger prawns, white, finfish, jellyfish, live green crabs from the lagoons. There are in all 168 species found in the Pulikat lake. There are many rare species which are found frequently are the Mullets viz - M. cunnesius, M. dussumieri,M. jerdoni, M. cephalus, Blowfish T. nigropunctatus, Barbus dorsalis,and M. bornensis Sardines, Catfish Macrones vittatus, Sardinella fimbriata and the milk fish. Green crabs, Finfish, Prawns and Clams are the most important fishes that help to make business and to be exported.
The Green Sea turtles are amongst the one that falls under the category of the getting extinct. In this region, fishing is carried by many of the People and it is considered to be one of the most important occupations of this region. The lake is decorated with all the beautiful species with the rich variety, marine species, and brackish water marine life along with the few species from the fresh water. Cat fish and the Mullets are the brackish marine life. The lake is just like the nursery for the several species of fishes. The amount of the settlements of the fishes of the Tamil Nadu and the remaining part is found in the region of Andhra Pradesh. There are 12 370 fisherman’s who live in the region of Pulikat Lake and are totally dependent on it for their income. Fishery is their fulltime fishery done on the lake. Number of fishermans found in the region of Andhra Pradesh is around 6000 and in the region of Tamil Nadu is 6370. Apart from the sea food, salt has been produced in the Pulika Lake.
The shallow lake is well known for the variety of the aquatic birds and is one of the important stop over for the many of the birds who are on their route to migration. Pulicat Lake is denoted as the third most important wetland that is situated on the eastern coast for the migratory shore birds, especially in the autumn and the spring season. In the avifauna, there are two bird sanctuaries are recognized in the lagoon, one present in two states of Tamil Nadu and Andhra Pradesh.
The portion that is present in the region of Andhra Pradesh was established in the month of September 1976. It covers the land of around 172 kilometers that covers the lagoon too. It is located in the Tada Taluk in the district of Nellore. The wildlife division in the state is enriched with 115 species of land and water birds in the sanctuary.
The lagoon that is found in the Tamil Nadu district covers the land of around 60 square kilometers that is extending from the region of Gummiddipundi taluks and Ponneri from the district of Thiruvallur was stated as Bird Sanctuary in the month of October 1980.
The total number of flamingo’s fyinng on the lakes is around 15,000 every year. This is not only the species found here but there are many other species. The lakes also has the Kingfishers, pelicans, painted storks, herons, ducks and spoonbills. Also, the species of spoonbills are found here. The species of wintering waterfowl, Commom Teal, Gadwall, Northern Pintail, Northern Shoveler, Gargenery, Common Pochard, and Black headed Gull, Brown headed Gull, Capsican Tern and Gull Billed Tern. The huge number of the flemingoes is found here in the edge of the lagoons. The concentrations of the beautiful Flamingoes are associated with the amount of the water flowing with the high agal, benthic diversity and fishes. The other species of birds that are found in the region of Pulikat Lake is Spot-billed Pelican, egrets, seven different species of herons, Painted Stork, 20 species of shorebirds, Greater Flamingos, ducks, Little Grebe, Little Cormorant, Indian Cormorant, Asian Openbill Stork, Eurasian Spoonbill, Black-headed Ibis, Lesser Whistling Teal, Great Thick-knee, Spotbill Duck and the stone Curlew.
The prey birds includes the winter are White-bellied Sea Eagle, Harriers, Osprey and the Peregrine Falcons. The huge concentrations of the Flamingo’s are in the region of Andhra Pradesh as a part of the Sanctuary that covers the island of Irukkum and Vendadu.
Andhra Pradesh side has the point of vantage for the location of the birds those are watching from the Sullurpet and is located on the National Highway 5, takes a turn in the eastern part of the Shar Road of the lake to watch the flocks of the feeding of water birds. Specially flocks that of Flamingoes.
Aquatic Vegetaion :
There are several species found in the lake around 59 different species that includes the eight Cyanophyceae, two Rhodophyceae and Seven Chlorphyceae. There are several patches of the residual, evergreen forest, dry and the large areas of the littoral scrub in the forest in the villages that has fishing as their occupation. There are also invasive phytoplankton species of Prosopis juliflora, Rhizosolenia castracanei, Spirulina major Oscillatoria spp.Anabaena spp., Rhizosolenia castracanei, Climacodium fravenfldianum and Eucampia cornuta in the lakes is recorded.