Bleaching in the Ryukyu Islands in 2016 and associated Degree Heating Week threshold

摘要

In the summer of 2016, coral reefs in the Ryukyu Islands, Japansuffered from extensive bleaching. The most severe bleachingoccurred in Ishigaki Island, with 90% and 40-55% corals bleachedin Sekisei Lagoon and Shiraho Reef, respectively (Fig. 1a). InOkinawa, 50-80% of corals were bleached (Fig. 1b). This eventwas part of a global bleaching event starting in the Mariana Islandsin June 2014 and expanding to the South Pacific and Indian Oceanin 2015 and the northern Great Barrier Reef in March 2016(Hughes et al., 2017) followed by the Ryukyu Islands. The progressof the event was similar to that of 1997-1998 associated with astrong El Ni?o and finished in the Ryukyu Islands.