The document discusses widespread coral bleaching in the Andaman Sea and Gulf of Thailand due to increased water temperatures and sunlight from global warming. The National Parks Office has been monitoring this and convened a meeting with marine experts, deciding to close two dive sites in Mu Ko Similan National Park where bleaching affected over 80% of coral. The closures aim to help the coral regenerate without human disturbance. Violators face legal punishment under the National Parks Act. The announcement orders tourism operators to comply and notes the parks will reopen the sites once conditions return to normal.