A new study recently released found more than half the world’s coral reefs are bleached because of ocean warming.

Data from more than 15,000 reefs globally analyzed by a team of scientists over a three-year period found 51% of the world’s reefs sustained “moderate or worse bleaching” while 15% experienced “significant mortality.”

“Ocean warming is increasing the frequency, extent, and severity of tropical-coral bleaching and mortality,” researchers, including C. Mark Eakin, an oceanographer with the National Oceanic and Atmospheric Administration, wrote in the new report published Tuesday.

Dubbed the “Third Global Bleaching Event,” scientists reported that their findings from 2014 to 2017 show the impacts of ocean warming on coral reefs are increasing, with “the near certainty that ongoing warming will cause large-scale, possibly irreversible, degradation of these essential ecosystems.”

The extensive bleaching and heat stress stretches across the Atlantic, Pacific and Indian oceans, NOAA previously reported.

“With heat stress levels during this event surpassing those observed previously, (NOAA) developed more extreme Bleaching Alert levels that are now being used during the ongoing Fourth Global Coral Bleaching Event,” the report reads.

“And yet, reefs are currently experiencing an even more severe Fourth Event, which started in early 2023,” while the Pacific coastline of Panama experienced worse heat stress and coral death, corresponding author Sean R. Connolly with the Smithsonian Tropical Research Institute, said.

Coral reef bleaching history

Bleaching events began in the spring of 2023 in Florida and the Caribbean, prompting emergency rescues in experimental coral reefs, sparking a slew of research projects aimed at helping them become more resilient to rising temperatures.

In recent years, bleaching has been reported in Australia’s Great Barrier Reef, Brazil, Mexico, Costa Rica and islands in the South Pacific, NOAA previously reported. Coral reefs also are experiencing die offs in the Red Sea, Persian Gulf, Tanzania, Seychelles and Indonesia.

According to NOAA, coral reefs help prevent loss of life, property damage and erosion by acting as a natural barrier against waves, storms and flood. They also benefit communities through tourism, food security and biodiversity.

A study released in the summer of 2023 reported 1 in 3 species in the world’s oceans live among coral reefs, including nearly as many microscopic organisms as all of those previously identified on earth.