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Coral reef cover has declined dramatically in Okinawan waters, Environment Ministry

  • July 21, 2017
  • , Nikkei , p. 38
  • JMH Translation

On July 20, the Ministry of the Environment (MOE) announced the findings of its survey of coral reefs in the seas of Okinawa Prefecture where mass bleaching occurred last year. It reported that coral reef cover in some of the seas has dramatically declined compared to last year.


The situation is serious on the west and east coasts of Ishigaki Island and the northeast coast of Miyako Island in particular. It was a tragic sight as the coralla that had died from bleaching had turned black. Sea temperatures are predicted to rise further in the area waters from summer through autumn. “We will continue to monitor the state of the coral,” says the MOE.


In June and July, the MOE conducted a snorkeling survey mainly in the waters that last year’s survey confirmed to have abundant coral reefs. Only 5% coral reef cover was found at the survey points on the west coast of Ishigaki Island, where last year it was confirmed coral covered 50% of the seafloor. Coral reef cover on the northeast coast of Miyako Island decreased from 40% to 10% while that in the Sekisei Lagoon, which is located between Ishigaki and Iriomote Islands, declined from 30% to 13%.


Coral bleaching occurs if sea temperatures are high for a prolonged period. Coral dies when it loses the photosynthetic algae that live in its tissues.



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