A recent study taken up by a team of researchers from the Zoological Survey of India (ZSI), Chennai, brought to light the serious threat of extinction the coral reef colonies and mangrove forests in the Palk Bay are facing. At present, only two per cent of the coral reefs survive in the area.

Global warming, siltation, release of untreated raw sewage into the water bodies and overgrowth of algae were stated to be the three important reasons for the possible disappearance of coral colonies and its associated organisms from the Palk Bay area.

Giving details to TheHindu, K. Venkataraman, Director of ZSI said, a decade ago, the Palk Bay area used to be rich in biodiversity. The uniqueness of the place is that no where in the Gulf of Mannar Biosphere Reserve one could see coral colonies, sea weed and grass, besides mangrove forests.

Dr. Venkataraman said this area, so rich in biodiversity, slowly started dying due to large amount of silt coming from developmental projects, as well as due to east-flowing rivers. Silt deposits will not allow the new colonies to be formed and, similarly, they will also not allow the corals to re-colonise in the Palk Bay region.

The study showed that release of untreated raw sewage from the nearby areas into the water bodies, which ultimately drained into the sea, led to diseases in coral colonies, due to which they died. The mix of sewage water into the sea water had a cascading effect, resulting in coral colonies being covered with an increased growth of algae. This also led to the disappearance of corals, Dr. Venkataraman added.

At present, a small colony of bolder corals, a resilient species, is only found in the Palk Bay region.

“A decade ago, the entire region used to be filled with a lot of life forms and it was a paradise for researchers. But, today, the place is totally deserted,” Dr. Venkataraman said. Apart from these problems, the conflicts of interest between the traditional fishermen and the trawler operators also took a toll on the biodiversity of the Palk region.

In an attempt to restore the dying coral colonies, the ZSI researchers are attempting to transplant live coral colonies from other parts of the Gulf of Mannar Biosphere Reserve and plant them at Palk Bay. This work is done with support and assistance from various funding agencies, Dr Venkataraman said.

More than transplanting the corals from other areas into the Palk Bay, conservation efforts have to be taken up by various agencies to preserve the species, he added.

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