Japan Sees Sharp Decrease in Coral around Iriomote Island

May 18, 2018

Tokyo- Japan has seen a sharp decrease in areas covered with live coral off the southwestern islands of Iriomote and Ishigaki since 2008, according to the Environment Ministry.

Around Iriomote, the total size of areas covered at least 50 pct by live coral slumped to 2 hectares from 97 hectares in 2008, representing a drop of 98 pct, the ministry said Thursday.

"A likely cause is effects of massive coral bleaching in summer 2016," a ministry official said.

The ministry conducted research into coral around the two islands through field surveys and analysis of satellite images between October 2016 and January this year.

Around Ishigaki, areas with a coral density of 50 pct or more totaled 64 hectares, up from 57 hectares in 2008. But areas with a density between 5 pct and less than 50 pct nearly halved to 452 hectares from 879 hectares.

Coral bleaching happens when seawater temperatures rise sharply and other rapid change occurs in the environment. Coral dies if bleaching continues.

"Bleaching has definitely had an impact on the ecology," the official said. Jiji Press