Second bleaching event in 10 years

Four global coral bleaching events have now occurred on record, and the second in just 10 years is currently happening, thanks to above-average sea temperatures.

The Atlantic, Pacific, and Indian oceans show extensive coral bleaching due to heat stress, which impacts environments both above and below the water surface. "From February 2023 to April 2024, significant coral bleaching has been documented in both the Northern and Southern Hemispheres of each major ocean basin," said Derek Manzello, Ph.D., NOAA Coral Reef Watch coordinator.

We have seen record-warm sea surface temperatures since all of last year, and this has continued through early 2024.

During the 2023 heatwave that impacted Florida, we saw extensive coral bleaching. NOAA sprang to action quickly, moving coral nurseries to deeper waters as well as installing sunshades.

Read more about what happened last August.

Should the coral be heat-stressed for too long, it causes complete mortality. However, coral reefs can recover should temperatures lower or mitigation practices are put in place. This helps revamp the ecosystem around the reefs, which has an impact on the economy and food above the ocean’s surface.

NOAA research continues to be done to help these environments thrive in a changing world.