Coral bleaching has been found in 19 of the country's 26 national marine parks, the Department of National Parks, Wildlife, and Plant Conservation (DNP) has revealed.
Pol Gen Patcharawat Wongsuwan, Minister of Natural Resources and Environment, has ordered the DNP to work with the Department of Marine and Coastal Resources (DMCR) in response to rising concerns over the bleaching.
DNP chief Athapol Charoenshunsa said that from April 2 to May 8, bleaching was detected in eight national parks in the Gulf of Thailand and 11 in the Andaman Sea.
Three of them, namely Hat Wanakorn National Park in Prachuap Khiri Khan, Sirinat National Park in Phuket, and Moo Koh Chumpon National Park in Chumphon, are currently under high-risk monitoring, as bleaching was found in over half of the coral in those areas, Mr Athapol added.
To address the problem, Mr Athapol said that particular parts of some marine national parks have been closed until the situation improves.
According to DMCR chief Pinsak Surasawadi, at least 90% of coral fields in the country were reported to have been affected by bleaching over the past couple of weeks, with the majority of those found in Chumpon. Mr Pinsak's report was similar to the DNP's inspection.
He said that bleaching covered at least 50% of the Koh Kut and Koh Mak areas in the eastern province of Trat. However, the situation is expected to improve due to lower temperatures.
Despite a strong network working on marine conservation in the province, he said that the DMCR will look to improve the situation within the next 30 days.
According to Mr Pinsak, the DMCR's progressive restoration measures, including coral and seagrass propagation, would be conducted in conjunction with passive measures, such as allowing the coral and seagrass to heal naturally.
Mr Athapol explained that coral bleaching is the process by which coral becomes white due to the loss of photosynthetic pigments as a reaction to environmental conditions such as warm ocean temperatures, oil stains, and sediment deposited on coral reefs.
The conditions cause the corals to experience high stress and expel zooxanthellae algae, which lives in their tissue and gives the coral energy and colouration. Without the algae, the coral weakens, turns white and dies of starvation within three weeks, he said.