Bleaching of corals in Lakshadweep a major concern

Will the soaring temperatures this summer be catastrophic for the coral reefs of Lakshadweep islands? This has been a major concern for researchers, who have already raised an alarm about the widespread bleaching of corals seen here. 

In fact, studies and surveys being conducted by researchers from Nature Conservation Foundation (NCF) indicate increase in sea surface temperature caused by this year's El Nino ocean current rivals that of 1998 — when the Lakshadweep coral reefs witnessed the worst bleaching effect — and concerns are being raised that the damage this year could be equal or even worse than it. However, the total extent of damage can only be figured out post monsoon. 

"The earliest signs of coral bleaching was observed in December 2015 but the worst effects were seen as temperatures began rising since April this year and continues till date. Our surveys have shown that every coral reef here is showing moderate to high level of bleaching and in some cases even severe bleaching with average temperatures rising by around two degree Celsius," informed Rohan Arthur, scientist, oceans and coasts, with the NCF who has been studying the effects of climate change on the coral reefs of Lakshadweep since 1998. He added that one reef surveyed in Kavaratti island showed that 87 per cent of coral individuals were bleached.

Coral bleaching at Lakshadweep islands. Photo courtesy: Nature Conservation Foundation

Explaining further Arthur said that corals were actually marine animals who lived in symbiosis with an algae that provided it with food and even colour and it was due to several external factors like rise in temperature or others the algae leaves the corals and it not only looses its colour but it also leads to its death and this effect is known as bleaching.

Marine biologists along with members of Lakshadweep department of science and technology have been conducting several rapid surveys of as many atolls as possible as they know that once the monsoon begins and the  aters gets choppy, the surveys will have to be stopped. "I have just returned from the islands a few days ago. We have, thus far only been able to survey coral reefs in four atolls. One of our researchers from the NCF is still on the islands trying to sample as many atolls as possible before the monsoons make it impossible. With any luck, we should be able to survey at least 7 atolls by the middle of May, while that will not be adequate, it is the best we can do with our current resources," informed Arthur, adding that surveys will be carried out again post monsoon and it will be only by the end of this year that they will be able to estimate the actual extent of the damage to the coral reefs. 

On one hand the long term solution to save the corals of Lakshadweep certainly is fighting climate change but at the local level it was becoming pertinent to manage reef fishing. "Studies are making it increasingly clear that the reefs of the Lakshadweep have a remarkable ability to recover from even the most devastating disturbances. After the coral mass mortalities of 1998, many reefs recovered very well. This capacity to recover is linked to healthy populations of reef fish — essential to maintain ecological processes on disturbed reefs," explained Arthur. 

According to him post-2010, there has been a worrying increase in the amount of commercial reef fishing taking place. "While the genuine livelihood requirements of the Lakshadweep communities cannot be denied, the reef is now poised at a delicate state and increased reef fishing can seriously compromise the natural ability of these reefs to recover," said the biologist, stating that what is needed is careful regulation of reef fishing in these reefs, which needs to be done with the complete cooperation of local fishing communities as it was obvious that if the coral reefs were destroyed the first to be hit would be local community.

Bleaching Corals of the Great Barrier Reef, Australia

In what is being cited as the worst case of coral bleaching, aerial surveys and diving expeditions have revealed that around 93 per cent of the Great Barrier Reef — known as the worlds largest reef — is damaged by coral bleaching due high water temperature for long periods.

About Lakshadweep and El Nino

The smallest of India's Union Territories, the Lakshadweep archipelago comprises 12 atolls, three reefs and five submerged banks in the Arabian Sea. Its lagoon area covers 4,200sqkm, 20,000sqkm are territorial waters and about 4,00,000sqkm comes under the economic zone. 

El Nino, literally 'little boy' in Spanish, refers to the large-scale ocean atmosphere climate interaction linked to a periodic warming in sea surface temperatures across central and east-central Equatorial Pacific.