Thanks to the proliferating shrimp farms on the banks of the Korayar river and the indiscriminate felling of mangrove trees by bootleggers on the lookout for the firewood required to run their illegal `distillation units', the entire ecology of the region is at risk. Incidentally, this felling has long been banned by the government, but it still carries on.

The last 50 years have witnessed a string of state governments, under various political banners. Not one of them has taken any steps to preserve this unique forest which not only cleanses the water but also purifies the air and maintains the eco-balance of this swampy region.

What's more there is just no popular awareness of the enormity of this tragedy. The mangrove ecosystem in the Muthupet lagoon once served as the breeding and feeding ground for most of the valuable fin and shellfish of the region. Now it only serves as a haven for anti-social elements.

The local fishing community is left to bear the consequences of this indifference. Says Peryanakam, a local fisherman, ``Now we are not getting a good catch because the fish stock has declined sharply thanks to the effluents from the nearby shrimp farms and the felling of the plants by the agents of the bootleggers.''

The Muthupet mangrove forest, a part of the Great Vedarnayam Swamp which extends from Adirampattinam in the west to Point Calimer in the east, is bordered in the south by the Palk Straits. The mud flats on its northern flank are prone to flood during the monsoon season.

It is into the Muthupet wetlands that the various arteries of the Cauvery -- namely the namely Paminiyar, Korayar, Kilathangiyar, Marakakorayar and Valavanar -- empty their waters. The mangrove area of the wetlands is spread over 68.03 sq km. Of this, some 10 per cent is thick forest, while 20 per cent of the area is submerged under water.

Mangroves contribute a great deal, directly or indirectly, in maintaining the local ecosystem. At one point of time, the forests were quite luxuriant with huge trees extending over lakhs of hectares. Now this has shrunk to around 10,000 hectares.

One of the immediate causes for this drastic decline is the presence of some 14 salt pans and 27 prawn farms which are located close to the mangrove forest. The total area of these farms is about 580 acres. Of this, 376 acres are located on the western side of the Muthupet mangrove forest and 204 acres on the eastern side.

Most of the organic matter produced in these shrimp ponds settles at the bottom and forms a thick layer. After the harvest the mud, which turns black in colour, is either scraped off or dried and ploughed back into the soil so that it decomposes during the fallow period. But this method does not work in the Muthupet area because the ponds do not dry since water from the adjacent river continuously seeps in.

Therefore, the only way to remove the organic residue from the farms is to flush it out by using suction pumps or high pressure hoses to drain out the waste. The waste water containing the effluents flow through man-made canals into the Korayar. The siltation caused as a result of these operations choke the mangrove vegetation. What's more, these effluents also contain pesticides like tea seed powder, which also destroys the local ecology.

On account of the abundance of basic food they provide, mangrove ecosystems are crucial for fish. It follows then that the shrinking of mangroves leads in turn to dwindling fish stock. Says Deiva Oswin, a research scholar working here, ``A few species, like the Acanthus ilicifoilus, that were once plentiful in this region, have disappeared.'' Old-timers say that at one time phytophagous fish such as milk fish, mullet and pearlspot, in addition to valuable crustaceans like Penaeus Spp, Metapeanaeus Spp, Scylla serrata and sesarmid crabs, used to proliferate in the Muthupet lagoon. Adds Govindan, a fisherman from a nearby fishing hamlet, ``We also used to get many migratory fishes which entered the lagoon to feed and having fed move out to sea again.''

It is found that at least 85 per cent of species caught here regularly are of commercial value. In fact, nearly two-third of all fish caught throughout the Cauvery basin are hatched in the mangroves and tidal water. This water system acts as a habitat for over 73 species of fish, 17 species of molluscs and 14 species of crustaceans.

G Ramamurthy, wildlife warden of Nagapattinam district, is upset about the general apathy to the problem. ``It is the bounden duty of the government to preserve the ecosystem of mangrove forest in Muthupet,'' he says.Ramamurthy is also the president of the Environmental Conservation Society at Muthupet.

The local people have always lived in harmony with nature and harvested fish in an extremely sustainable manner. The ancestors of the fisherfolk here had made canals some 150 years ago at the Thamarankottai and Maravakkadu reserve forests for fish cultivation. A single family or group of families may own a canal from which they harvest fish. They also maintain these canals scrupulously by regularly desilting them.

Perhaps the only way to regenerate the mangrove forest would be for the government to make artificial canals and hand them over to those who commit themselves to planting mangroves on their banks. There are, moreover, some 48,000 acres of barren land in the possession of the revenue department in and around the Muthupet area. This could also be handed over to those who want to raise mangroves.

The forest department here has already made creeks in the mangrove forests to help regenerate them. But they still do not allow voluntary organisations to make creeks and develop mangroves within the reserve forest area although, clearly, the task of regenerating mangrove forests is a massive one and cannot be done just by government agencies. A concerted afforestation drive must be launched in the area with as much community and NGO support as possible, otherwise it may just be too late.

The mangroves are the lifeline of this region. If they thrive, and the fish they harbour thrive, the local communities prosper. Not only do they provide people here with food and livelihoods, they also provide an important barrier to nature's fury when floods and cyclones ravage the region.