Scientists on an expedition to Jarvis Island in the Pacific Remote Island Marine National Monument have found devastating loss of corals due to record warm ocean temperatures from April 2015 to May 2016, the National Oceanic and Atmospheric Administration (NOAA) said Wednesday.

Jarvis is an unpopulated island about 1,500 miles south of Honolulu, and it is typically a treasure trove of biological diversity.

According to NOAA, the area has the highest fish biomass, which measures the total amount of fish species in a given area, yet it is studied as part of the agency’s Pacific coral reef monitoring program.

Image: Seascape of bleached plating Montipora corals on Jarvis Island’s forereef | Photo Credit: Cohen Lab, WHOI.