ASIA NEWS NETWORK
WE KNOW ASIA BETTER
Publication Date : 08-08-2013
Thailand's state marine-watch agency has found that some coral reefs in the oil-slick-affected Ao Phrao area of Koh Samet have been killed off by bleaching, and some marine life had been reduced by up to 20 per cent.
The team's report was released by the Marine and Coastal Resources Department director-general Noppon Srisuk.
When the oil slick hit Ao Phrao beach on the western side of the island, the agency sent a team to survey the coral reefs in 11 spots surrounding Koh Samet in Rayong province.
The team dived into the sea to depths of up to four metres to study damage at Noi Na, Laem Ya, Ao Lung Dam, Ao Kew Nha Nok, Ao Phai, Ao Look Yon, Koh Kudee, Koh Kham - Kruai, Koh Pla Teen, and the northern area of Ao Phrao.
Preliminary results showed that most of the intertidal zone had been tainted by the oil slick. The survey also revealed that about 10 to 20 per cent of marine life in Ao Phrao, especially stone crabs, snails, and oysters, had died.
The survey team collected samples of coral tissue to find the cause of death and estimate the percentage and scale of coral bleaching. The department was joined by marine experts from various educational institutes to conduct the survey and study the short, middle and long-term impact of the oil spill on the coral reefs. This team will take a year to survey the coral reef surrounding the affected island.
However, Noppon insisted no orders had been issued to close Ao Phrao for tourism activities.
Meanwhile, marine biologist Thon Thamrongnawasawat of Kasetsart University's Faculty of Fisheries, said he had also sent a team to survey changes to the coral reef in Ao Phrao last week.
The preliminary result of a parallel survey found that about 20 massive corals, located two metres undersea in the southern area of Ao Phrao, were bleached. Thon assumed this bleaching was caused by the oil slick.
However, he said his team needed to collect samples of coral tissue for in-depth analysis to confirm the real cause.
"At least we know where it should be closely monitored to determine further impacts of oil spills on coral reefs in this area," he said.
Sumet Saithong, chief of the Khao Laem Ya-Mu Koh Samet National Park, said he could not say right now whether coral reefs surrounding the island and affected area were dead. During the past few years, coral reefs surrounding the island had been bleached already before the oil slick affected the island.