Sekisei lagoon in Okinawa has suffered from coral bleaching

More than 2/3rds of Japan’s biggest coral reef has died due to rising sea temperatures caused by global warming.

70% of the Okinawa’s Sekisei lagoon has been killed by coral bleaching, according to the Japanese environment ministry.

Coral bleaching occurs when warm water causes the coral to expel algae living in their tissue. The coral turns white as a result. If the water temperatures do not return to normal, the coral dies from a lack of nutrition.

A survey carried out by the ministry investigating 35 locations in Sekisei lagoon showed that 70.1% of the coral had died, with the dead coral now dark brown and covered with algae. The survey was taken in November and December 2016. A similar survey taken in September and October 2016 showed that 56% of the coral reef had died.

The ministry has described the demise of the coral reef as “extremely serious”.

Between June and August 2016 in southern Okinawa, water temperatures were reportedly 30.1°C, one to two warmer than normal, marking the highest average temperatures since records began in 1982. The rise in temperatures has been attributed to global warming.

Bleaching has reportedly spread to 90% of the Sekisei coral reef, a 400sq km diving spot.