Up to half of the coral reefs off Surin Islands is now bleached due to the high temperature of the seawater, the Department of Natural Parks, Wildlife and Plant Conservation said yesterday.
About 70 per cent of the corals in diving areas in Phang Nga and Phuket provinces are now bleached, directorgeneral Jatuphorn Burusphat said, adding that diving would be temporarily prohibited in affected areas pending official announcement.
About 25 per cent of the corals near Similan Islands and 30 to 50 per cent in the North and South Surin Islands are bleached.
Wannakiat Thabthimsaeng, a senior Department of Marine and Coastal Resources (DMCR) scientist, said the coral bleaching began since early April when the temperature of seawater rose by 23 degrees Celsius. Coral reefs about 20metres high have mostly died due to direct exposure to sunlight, while those growing in greater depth were being bleached.
The other areas where coral bleaching is reported are off the coasts of Trang, Krabi and Satun provinces, located on the Andaman Sea, as well as in Chumphon, which is on the Gulf of Thailand.
Coral bleaching occurred in a large scale during 1991 and 1995, effects of which have lasted to this day. Bleaching also occurred in 2004, but the coral reportedly fully recovered once temperatures returned to normal due to a southwest monsoon, Niphon Phongsuwan, another DMCR scientist, said.
"If there is no seasonal southwest monsoon this year, the coral bleaching will only expand," he added.