e - poz 2 - Central Institute of Brackishwater Aquaculture

VEMIANAD LAKf a masswe ud vibrant costal -land eaxyrrrm, stretches m om 24000 ha rnarea and contributes m ovn 50% d the Ism1 area d backwarn (Kayalsl rn Kerala State. h4om than20,000 fishermen are didy dependent on dte aquahc rrsourres d this lake k h i owr ~ 7OOO tof fish and shellfish annually L hdmy wealth cay~lws d ovn 150 spec*, rncludrng the przedvariehu such n the pearl spot, mulko, the gunt frrshwakr prawn and the penwid prawns. Thrf~sh and shellhsh landed from Vmbad lake a valued a owr Rs 100 rnill~on annuallyCoastal wetlands are known to be an ~ndrspensable %tat m a van* of biologically andeconomically Important resident and mrgralory aquahc and avian fauna Thew are alx, mqln~zednursery grounds for several spec= d fish and shellfish Moreover, the lnterdepndence of rnanneand the adjoinrng estuarln zones in cmplaron of tk Irk cyck proceru, d lnnurnerable aquaticspecin is amply described In fihq l~terature The bmlqllcal Importam of Vernbanad arid theinterconnected backwaters are m be view4 and assessed in thls context Thl\ 1s all the moreev~&nt slnce the adlolnlng rnanne coastal zone in the Llshadwrp sea continues to be one of themost product~ve fishery zorm In lt~world contribut~ng to about 0 6 millron t of hsh and fetchlngllvelvhmd for 1 5 million fishermenOn the other s~de. 41 of the 44 riven In the State fill Into the backwater system before they emptyInto the *a Thls accounts for 5 % of India's annual freshwambudget Vembanad lake ltwlfrecewe the anflow trm SIX major rivers of the Stdle with a runoff volume of 24000 mill~o n~' peryear Several of the ftsh spec* esnhabrting the lake share bolh the river and ldke envirolimeiilr Intheor vary~ng lik stages The giant rlver prawn Macrobrach~um rerenberg~r for wtioiri theVembanad ecosystem forms a natural abode. is a classical example of this behav~ourNwenheless, over the past several derddes, (he unmtrtcted human ~nterferenct. lor theheterogeneou5 purpores had irrevocable advenc consequences on the enttly of the ldke 1tw1f Theonblaught wa5 on the lncrease during past few decades and rt still continues The mo5t si~nif~cd~iteventuality among these Mlivitles was the comm#rsroning of the Thanneerrnukkom bdtrdg~ d( IOIIthe lake In 1976 T~IS has destroyed (he contlnurly of the ecosystem proh~b~tlng the sharing of itrptiyso~al dnd b~olog~cal ~dentity between both the seclorr Thus, to quote Gopalan el dl 119831 ~neffect an area ol 69 km' of brxfr~shwater ly~ng south of Thanmcrmulrkom had been rrolog~(dllycut off from the rest of backwaters