Climate Changed has Damaged Reefs for Decades

Coral bleaching is now happening worldwide, according to NOAA scientists. This is the fourth global event on record and the second in the last 10 years. The world's oceans have reached a record temperature. The 2023 heatwave in Florida started earlier, lasted longer, and was more severe than any previous event in that region.

New satellite data shows the global average sea surface temperature in February was 69.91°F, higher than the previous record of 69.76°F set in August last year. The U.S. National Oceanic and Atmospheric Administration (NOAA) has warned sea temperatures are now so high that the world's coral reefs face another mass bleaching event.

It is the ninth time in a row that monthly records have been broken. Human-made climate change has been supercharged by a strong El Niño, with high water temperatures in the Pacific Ocean heating the atmosphere. Scientists believe the world's climate will become increasingly unstable if temperatures remain more than 1.5°C above pre-industrial levels in the long term.

Australia's Great Barrier Reef has been hit by a significant coral bleaching event this year, with the results consistent with patterns of heat stress that built up over summer at the biologically diverse site. The bleaching follows from similar reports on reefs worldwide due to elevated sea surface temperatures primarily driven by climate change but amplified by the impacts of the El Niño phenomenon, which usually results in warmer ocean waters. From 2014 to 2017, the Great Barrier Reef lost one-third of its corals.

This global event requires global action. The International Coral Reef Initiative (ICRI), which NOAA co-chairs, and its international members are applying resilience-based management actions and lessons learned from the 2023 marine heatwaves in Florida and the Caribbean.

NOAA and the ICRI data suggest all three ocean basins that host coral reefs - the Pacific, Indian, and Atlantic - will experience bleaching within the year, and at least 12 percent of the reefs in each basin will be subjected to temperatures that cause bleaching.

Substantial coral death has now been confirmed around Florida and the Caribbean, particularly among staghorn and elkhorn species, but scientists say it's too soon to estimate the extent of global mortality. More than 54 percent of the world's coral area has experienced bleaching-level heat stress in the past year, and that number is increasing by about one percent per week. There's been recent confirmation of widespread bleaching off the western coast of Indonesia.

For an up-to-date commentary on the condition of the coral reefs at your intended diving destination, check the most current independent reader's reports on the Undercurrent website.

(NYTimes, NOAA, and other sources)