Ecologists' anguish

Published : Jan 14, 2005 00:00 IST

NOT since the Silent Valley Project in Kerala has a project generated such spirited protests from environmentalists as the proposed Sethusamudram ship canal. If the canal is excavated, it will slice through the Gulf of Mannar and the Palk Bay, both of which are closed marine systems, and cause irreversible damage to a variety of marine life there. The Gulf of Mannar and the Palk Bay are akin to large lagoons, undisturbed by ship traffic because of their shallow waters. They are home to a wide variety of marine ecosystems.

The Gulf of Mannar alone boasts 3,268 species of flora and fauna, including 377 species that are endemic to the region. The region provides livelihood to the families of several lakhs of fishermen in 140 coastal villages in Ramanathapuram and Tuticorin districts of Tamil Nadu.

"The coral reefs are the seat of biological diversity. By destroying them we are killing hundreds of species of marine animals. The marine sanctuary, which was protected by the efforts of scientists like Dr. M.S. Swaminathan, will be lost for ever," says Dr. R.S. Lal Mohan, who has worked for 32 years in the Indian Council of Agricultural Research (ICAR), 14 years of the period at the Central Marine Fisheries Research Institute at Mandapam, near Rameswaram in Tamil Nadu.

T. Lajapathi Roy of the Society for Community Organisation Trust says, "Sea grass meadows and seaweeds form an ecosystem which supports a variety of commercially important fish. Seagrass forms the exclusive diet of dugongs, an endangered species. Seagrass also controls coastal erosion."

The Environmental Impact Assessment (EIA) report of the National Environmental Engineering Research Institute (NEERI), Nagpur, acknowledges that the Gulf of Mannar and the Palk Bay, covering 10,500 sq km, "are biologically rich and rated among the most highly productive seas of the world". Their biodiversity is considered globally significant. The Gulf of Mannar has been categorised as a Biosphere Reserve and its 21 islands have been declared National Marine Parks.

There are 87 fish landing stations between Point Calimere and Pamban in the Palk Bay, and another 40 stations in the Gulf of Mannar. The region is home to about 600 varieties of fish, including 200 that are commercially important.

The Gulf of Mannar and the Palk Bay are sensitive regions, very different from the open sea. "If their physical environment is disturbed in a big way, it will reflect on their biological environment, biodiversity and fishery production. Fishery production depends on the physical environment," says a marine biologist. The entire fish chain will be affected.

What has alarmed environmentalists is the EIA report's observation that "there is apprehension that hard strata will be encountered in the Palk Bay/Palk Strait area" and "if the bottom strata turn out to be rock... blasting might be required". If the hard rock is blasted, the shock waves will kill the entire fish population in the area. The fish eggs/seedlings too will be killed, says Lajapathi Roy.

"I see a couple of applications for bail almost every day at the Madurai Bench of the Madras High Court because fishermen explode gelatine sticks in the rivers or the sea to catch fish," says Lajapathi Roy, who is an advocate. Lal Mohan points out that dolphins, whales and dugongs are sensitive to sound and they depend on echolocation for capturing food and for navigation. The sound produced by the blasting will drive them away.

Coastal Action Network, an organisation fighting for the protection of coastal ecology and the livelihood of coastal communities, in a critique of the EIA report, says that the Gulf of Mannar Biosphere Reserve is a unique marine reserve. "The report does not give details of the ecological destruction likely to be caused by the project. Apparently, no major studies have been carried out with special focus on the fauna of the Bay," maintains Ossie Fernandes, co-convenor, Coastal Action Network.

According to Lal Mohan, there are many coral beds in the region. The coral beds, which are sensitive biological entities, contribute to the fishery wealth. Destruction of the coral reefs will have an impact on fishery. If the canal were to be excavated, it will throw up 62 million tonnes of silt and sand, he says. "The argument that we are not destroying coral reefs because we are not dredging in the area is wrong," says Lal Mohan. It takes thousands of years for coral reefs to form. Corals trap algae and manufacture oxygen in the algae. This helps small fish to thrive. The coral fish will not be able to withstand even a minor change in the temperature of the water.

There are more than 120 varieties of sea grass in the region. If sunlight is blocked because of dredging, sea grass beds will die. Dugongs feed on sea grass meadows. If these meadows wilt, they will not survive. According to Dr. V. Sudarsen, Head of the Department of Anthropology, Madras University, dugongs migrate between the Palk Bay and the Gulf of Mannar through Adam's Bridge during the two monsoons. They migrate from the Gulf of Mannar to the Palk Bay during the southwest monsoon when the sea in the Gulf becomes rough, and it would be difficult for the dugongs to feed on sea grass. During the northeast monsoon, the water in the Palk Bay becomes turbid. "Hence, dredging of Adam's Bridge and the movement of ships through the area would prevent the movement of dugongs between the Gulf of Mannar and the Palk Bay. This would lead to the fragmentation of their habitat and the population of dugongs would further decline," says Sudarsen.

The NEERI report claims that "the canal may facilitate the movement of fishes and other biota from the Bay of Bengal to the Indian Ocean and vice versa. By this way, the entry of oceanic and alien species into the Palk Bay and the Gulf of Mannar, as also the dispersal of endemic species outside the Palk Bay and the Gulf of Mannar could occur." About this, Lal Mohan says, "This is a preposterous claim, not supported by any scientific data. From one ecological niche to another ecological niche, fish cannot and will not migrate. Hence changes in their habitat will kill them."

Environmentalists find it odd that T.R. Baalu, Union Minister for Shipping, who is enthusiastically backing the project, should compare the proposed Sethusamudram canal with the Suez Canal or the Panama Canal. They point out that the Suez Canal was cut in a desert. Neither biodiversity nor coral reefs nor fisheries were affected. It is a different ball game here, they say.

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