The world’s oceans have gone ‘crazy’, authorities warn, with most coral reefs in danger

The world’s oceans have gone “crazy,” according to an official at the National Oceanic and Atmospheric Administration, with record-high temperatures coral reefs in danger.

Derek Manzello, coordinator of NOAA’s Coral Reef Observation Program, said at a news conference Thursday that about 60.5%, or nearly two-thirds, of the world’s coral reefs have experienced high-level heat stress. enough to cause bleaching, a major health threat.

Coral bleaching occurs as a result of abnormal ocean conditions, such as when water temperatures are unusually hot or cold, or when the oceans are more acidic than normal. The corals respond by expelling tiny photosynthetic algae that live in their tissues, causing the normally colorful marine invertebrates to turn ghostly white.

Current threats comes on the heels of record-breaking marine heatwaves which hit most of the world’s ocean basins last year.

Manzello said conditions last year were so unusually warm in parts of the Atlantic Ocean, Caribbean Sea and Gulf of Mexico that heat stress levels were literally off the charts in NOAA’s existing warning system.

“We had to add additional bleaching alert levels to properly categorize how hot it was,” Manzello said.

The agency’s updated bleaching alert system, introduced in December, categorizes heat stress on a severity scale of 1 to 5.

“For an alert level 5, we estimate that approximately 80% or more of the corals on a given reef could die,” he said. “This is analogous to a Category 5 hurricane or cyclone.”

Daily monitoring of ocean conditions around the world, released by NOAA’s Coral Reef Watchshows Bleaching Alert Level 4 zones in the central Pacific Ocean and off the Atlantic coast of South America, with some Alert Level 5 bands in the South Atlantic.

The impacts were widespread, Manzello said: Bleaching “has occurred in at least 62 countries and territories since February 2023, spanning the northern and southern hemispheres of all ocean basins.”

Manzello added that water temperatures in the Atlantic, in particular, have been “the most extreme and unprecedented” and said that 99.7% of Atlantic reef areas experienced bleaching-level heat stress last year.

Bleaching doesn’t necessarily kill corals, but the process causes reefs to become more susceptible to disease.

Last month, NOAA confirmed that the planet is experiencing a global coral bleaching event due to record ocean temperatures, worsened by climate change and a natural climate cycle known as El Niño.

El Niño events are characterized by warmer-than-normal sea surface temperatures and tend to exacerbate background warming due to climate change.

The last global coral bleaching event lasted from 2014 to 2017 and affected 56.1% of the world’s reefs, according to NOAA.

This article was originally published in NBCNews. with