Concrete reefs help 'save' sinking Indian island

MUMBAI • Deploying artificial reefs made of concrete to protect and restore a sinking island off India's south-east coast has proved so successful that national funds will be used to pay for other similar reefs, a state environment director said yesterday.

Tamil Nadu's Mr H. Malleshappa said the reefs, installed in 2015, helped "save" Vaan Island and regenerate biodiversity in the Gulf of Mannar even as warmer temperatures prompted rising sea waters that threaten ecologies and livelihoods.

Vaan Island is one of 21 uninhabited islands in the Gulf of Mannar between India and Sri Lanka which was declared Asia's first marine biosphere reserve in 1989.

Mr Malleshappa said the project had proved so successful that more such reefs will now be placed in other degraded areas to also boost fish stocks and help fishermen.

"The primary aim was to protect Vaan Island from further erosion and submergence," he said.

"The other objectives were restoration of the island, conservation of biodiversity including the coral reefs, and enhancement of fishery production, thereby ensuring a sustained livelihood for fisherfolk," he added.

More than 150,000 fishermen depend on the marine national park and its buffer zone of 10,500 sq km for their livelihoods.

But coral mining and over-fishing led to the erosion and submergence of two of the 21 islands, Poovarasanpatti and Vilanguchalli.

Vaan Island had shrunk to a tenth of its original size, to less than 2 ha, Mr Malleshappa said.

The concrete reefs helped prevent further erosion and led to an increase in Vaan Island's surface area. Several types of coral have regenerated and more fish are now seen, he said.

"The project will have the long-term benefit of making the entire ecosystem resilient to climate change impacts," Mr Malleshappa said.


A version of this article appeared in the print edition of The Straits Times on August 31, 2017, with the headline 'Concrete reefs help 'save' sinking Indian island'. Print Edition | Subscribe