Imphal: Winged guests migrating to Manipur as well as countless fishes who swim across from bordering Burma for breeding now have to look elsewhere.
A friendly host to them for years, Manipur`s picturesque Loktak lake is no longer a welcome home for these international visitors whose presence add to the beauty of the threatened wetlands and reflect its ecological health.
The construction of the Ithai barrage on the lake to aid NHPC`s hydro-power project has blocked the entry route of fishes from the Chindwin-Irrawady river system of Burma to the Manipur river since the last few years, say experts.
And now the dwindling ecological health of the wetland and widespread hunting by fishermen has made it inhospitable to migratory birds from the northern hemisphere which come to seek refuge here in winter, they say.
Ornithologists and environmentalists say the sprawling wetland`s most majestic birds like cranes and pelicans have not been sighted for the last two-three decades and are therefore presumed disappeared from this region.
"The pink-headed duck is extinct and the white-winged duck has also disappeared. They all were abundant in Manipur few years ago but now many of them have become rare," says environmentalist Dr Kh Shamungou, who has been conducting surveys in the region with bird watchers.
Although no comprehensive census has ever been done in the Loktak, wildlife activists say the number of migratory birds has dropped down so drastically in the last few years that merely 2000 winged guests visited the 286 sq km lake from last September till March this year.
"The lake is getting shallower due to siltation and the proliferation of large number of `phumdies` or floating islands of decaying biomass. This makes it unattractive to migratory birds as many of them need deep water levels," Dr S Balachandran, ornithologist from the Bombay Natural History Society (BNHS), said.
Another important reason for the lake being hostile to birds is poaching and encroachment.
Around 4000 fishermen live on more than 600 floating huts built inside the lake on `phumdies`, while another 1,21,000 people live in its vicinity.
Wildlife department officials complain of lack of manpower and other resources to tackle poaching.
"Poaching is rampant while the food for birds have also decreased as several fishes and macrophytes have sharply declined from the lake," says R K Ranjan from the Indian Bird Conservation Network.
The ongoing exercise of clearing `phumdies` from the lake and a stagnant water level due to blocking of water outlet at barrage has brought changes in the hydrological regimes disturbing the wetland`s eco-system, he points out.
Pollution is another critical issue in the lake, designated as a wetland of international importance under the Ramsar Convention.
According to a report by Wetlands International, water quality in the lake has deteriorated due to the inflow of organo-chlorine pesticides and chemical fertilisers, municipal wastes and domestic sewage from settlements in and around the lake.
"Besides contaminating water the toxic chemicals affect the reproductive potential of birds. It even makes hatching of thin-shelled eggs difficult," says Shamungou.
To restore the ecosystem`s health, the Loktak Development Authority (LDA) is trying to control `phumdies` and harmful fishing practices in the lake.
"We are clearing the excess `phumdies` and stopping detrimental fishing practices like `atha phum` which is fragmenting the lake and harming the ecosystem," says LDA`s project co-ordinator Sanajaoba Meitei.