Coral bleaching worsens in Japan

Asahi Shimbun: Conservationists are warning that if sea temperatures continue to be high, coral reefs off Ishigakijima island, Okinawa Prefecture, may develop more cases of large-scale bleaching.

Coral bleaching is caused by higher ocean temperatures that cause symbiotic algae to abandon the host coral. When too many of the algae detach from the coral tissue, the white coral skeleton underneath starts to show through. If the bleaching continues, the coral eventually dies. Since late July many cases of coral bleaching have been sighted in waters off Ishigakijima island.

According to the Environment Ministry's International Coral Reef Research and Monitoring Center, similar cases of bleaching have been reported this year in waters off the main island of Okinawa, Miyakojima island, Taiwan, the Philippines and Florida.

Water temperatures around Miyakojima have continuously been above 30 degrees. Bleaching has been observed in waters off 16 districts of Ishigakijima. In the Yonehara zone, for instance, coral reefs have now taken on the appearance of snow-covered forests. Although some healthy coral could be spotted on the seabed, a lot appeared dead and were covered in seaweed.

Earlier this year, the United Nations Intergovernmental Panel on Climate Change predicted that most coral around the world would be bleached if average temperatures rose by even 1 or 2 degrees.