The year 1998 saw a large scale destruction of coral reefs all over the world. This was due to increased sea surface temperature.
Coral reefs are extremely sensitive to water temperature. Any change beyond 1 degree C for extended periods of time affects the corals.
Ten years ago saw a layer of warm water spreading from the south into the tropical water. The warm water conditions persisted for as long as one month in certain places.
The mean maximum summer sea surface temperature increased by 2 degree C. “About 40-50 per cent of corals were lost in most of the reefs,” said Dr. M. Wafar, Senior Scientist at the National Oceanography Institute (NIO), Goa. “80-90 per cent of corals in Lakshadeep were destroyed.” Dr. Wafar has been involved in coral research for nearly 25 years.
Scientists from NIO have recovered coral reef in Kavaratti island, Lakshadeep through coral transplantation.
“The recovery has been quite good. In some places the live coral cover has increased by nearly 50 per cent,” said Dr. Wafar. “The government now wants us to undertake similar initiative in all the islands at Lakshadeep.”
Scientists will soon start growing corals for transplantation work at Agatti and Kadmat islands.
Pieces of corals broken naturally or otherwise are tied to slabs and put in shallow water and allowed to grow. The coral are put in reefs once they have grown well.
“We started the pilot exercise in Nov-Dec 2005. We used 100 coral tips, most of them belonging to fast growing coral genera.
“In 2 years’ time the growth was up to 25 cm in the best of the cases,” Dr. Wafar said.
In all 4 fast growing coral species and 4-5 slow growing species were grown and transplanted in the coral reefs in Kavaratti in 2008.
“We grew fast and slow growing coral species to offset a bias in the natural species composition,” he said. “We will do the same now as well.” Since reefs support many fishes, increased coral coverage has a direct positive impact on fish population.
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