The sea around India is warming, bleaching the treasure of corals spread underneath. Should the seas continue to warm at the current rate, corals spread between the Andaman and the Lakshadweep will only be a step away from extinction within 70 years, a new study has predicted.
The study focuses the vulnerability of corals in the Indian seas in the next 100 years due to rising sea temperature.
It was conducted by four scientists – E Vivekanandan, M Hussain Ali, B Jasper and M Rajagopalan – of the Central Marine Fisheries Research Institute (CMFRI) in Cochin and has been published in an Indian scientific journal, Current Science in December 2009.
By 2099 the annual average sea surface temperature is predicted to rise by 3 degrees Celsius to 3.5 degrees Celsius from a current 29 degree sCelsius.
It will endanger not only coral, but also several marine species that take shelter in the reefs. Coral reefs are among the most sensitive and diverse marine habitats supporting nearly 0.5 million species globally.
Corals get its their colour from microscopic algae known as zooxanthellae, which live in their tissues. Under stressful conditions such as high temperature – summer temperature exceeding 31 degrees Celsius for more than a month – the corals expel these algae and in turn lose color.
This phenomenon is known as bleaching of corals.
Indian coral reefs in the Andamans, Nicobar, Lakshadweep, Gulf of Kachh and Gulf of Mannar had already experienced at least 29 widespread bleaching events since 1989. But intense bleaching occurred in 1998 and 2002.
“Corals usually recover from bleaching but die in extreme cases. In the next 30-50 years, rising sea temperature would trigger severe and frequent bleaching. Reef building corals might lose their dominance between 2030-2040 in the Lakshadweep region and between 2050-2070 in the other four regions. They might get extinct in the future,” principal scientist of CMFRI, Vivekanandan said.
The study has only taken into consideration the effect of rising temperature and not other factors such as speed of water flow, acidity of seawater which would also add to the collapse of the coral kingdom.