The majority of Japan's largest coral reef is dead. A survey conducted by the country's Environment Ministry revealed that 70 percent of the coral in the Sekisei lagoon area has already fallen victim to coral bleaching, according to a report from Japan Times.

The area, which is nestled between Ishigaki and Iriomote islands in the Okinawa Prefecture, was surveyed at 35 different points last November and December. It found that much of Sekisei, the biggest coral reef in the country, is already gone, while 91.4 percent of the surveyed area is already at least partly bleached.

The Environment Ministry report also observed that coral bleaching became worse in the time between June and September in 2016. Like much of bleaching, this is due to a jump in temperature specifically ocean temperatures that increased by 1 to 2 degrees Celsius than normal.

Bleaching happens when the rising temperature of the sea makes the corals removes the algae in their tissues, according to a report from The Guardian. This makes them turn white, and eventually die because they need the algae to survive.

The death of Japan's largest coral reef is only one of the casualties of bleaching; this event has been destroying coral reefs all over the world. EcoWatch reported that a study from the Scientific Reports journal observed that the longest global coral bleaching event is currently underway. This event began in 2014, but the problem could extend into 2017. Just last year, 90 percent of the famous Great Barrier Reef were affected by bleaching and an alarming 20 percent of the coral died.

"Bleaching that takes place every year will invariably cause major changes in the ecological function of coral reef ecosystems," Ruben van Hooidonk of the U.S. National Oceanic and Atmospheric Administration and the University of Miami said. "Further, annual bleaching will greatly reduce the capacity of coral reefs to provide goods and services, such as fisheries and coastal protection, to human communities."