The Department of Marine and Coastal Resources (DMCR) said it was able to save more than 60% of the coral bleached since last year.
Since April last year, around 60% to 80% of coral in Thailand's seas were found to have suffered bleaching, 60% of which has been saved, while the rest died, said Pinsak Suraswadi, director-general of the department.
Rising sea temperatures caused the coral to become highly stressed, leading to them expelling zooxanthellae algae. When this algae is lost, coral weakens and turns white, said Mr Pinsak.
However, after a survey in the Andaman Sea, where about 55% of coral was found bleached last year, 60-70% has so far been saved.
Coral bleaching in the Gulf of Thailand, meanwhile, reached its peak in May last year when about 90% of the coral was bleached, while only 40% to 60% has recovered so far, he said.
Coral in shallow water was affected the most, said Mr Pinsak, but no coral bleaching has been found currently in either location — a better-than-expected result. The DMCR has this year regrown coral in seven provinces: Trat, Rayong, Chon Buri, Prachuap Khiri Khan, Surat Thani, Phangnga and Phuket, totalling 24 rai of reefs, he said.
About 60,000 reproduced colonies were also being nursed as part of the department's bid to conserve Thai coral reefs and make them thrive again, he said.
Natural Resources and Environment Minister Chalermchai Sri-on has ordered steps taken to help curb coral bleaching, including temporarily closing certain marine tourist attractions to allow the coral to recover.
As well, officials are discouraging tourists feeding fish in the sea, collecting trash from the coral, encouraging the use of sunscreens that are environmentally friendly, and temporarily relocating coral to help save them.