This week, the National Oceanic and Atmospheric Administration told the media that the mass bleaching of reefs has been occurring around the globe since February 2023. It is the largest amount ever recorded.

Satellite data shows that 77% of coral reefs around the world - in the Atlantic, Pacific and Indian oceans – have been exposed to heat stress levels equivalent to bleaching. Climate change is fueling record ocean temperatures all over the world.

Derek Manzello, coordinator of NOAA Coral Reef Watch, said: "This event continues to grow in size and we have broken the previous record in less than half the time." This could have serious implications for the final response of these coral reefs to bleaching events.

NOAA Coral Reef Authority declared the global event of bleaching in April 2024. This will be the fourth such event since 1998. The 2014-2017 mass bleaching was the previous record, affecting just under 66 percent.

Coral bleaching is a result of corals releasing the colorful algae that live in their tissues. This occurs in warm oceans. Corals that lack these beneficial algae become pale, and more susceptible to disease and starvation. The coral may not be dead, but the ocean temperature must cool down for it to recover.

The previous global bleaching events have killed at least 14% estimated of the remaining corals in the world.

NOAA has not yet called this mass bleaching the "worst ever" despite the fact that it is the most widespread and affects reefs in 74 different countries. Scientists will assess dead corals underwater in the coming months and years to determine the extent of the damage.

Manzello stated that "it seems likely it will be record-breaking for impacts." "We have never seen a coral-bleaching event of this magnitude before."

In the past six weeks, there has been a confirmed bleaching in the water of Israel, Guam, and Palau. The Caribbean and South China Sea are also experiencing high heat stress.

Scientists have responded to the record-breaking bleaching by calling a special session on coral reefs that will be held in Colombia, at the United Nations Convention on Biological Diversity Summit (COP16), at the end this month. Leaders from around the world will discuss strategies that can be used to prevent corals from going extinct, such as further protection and funding.

The meeting will bring the global funding community together to say that we are still in the fourth event of bleaching, and these are happening back-to-back .... Emily Darling is the leader of Wildlife Conservation Society’s global coral reef program.

Scientists predicted that coral reefs will reach a tipping-point at 1.5 degrees Celsius (2,7 F) of warming. Up to 90% of the reefs could be lost. The new record bleaching is further evidence that coral reefs are already past the point of no-return at only 1.3 C (2.3 F).

It would have grave implications for ocean health and subsistence fishing, as well as tourism. According to the Global Coral Reef Monitoring Network, coral reefs produce $2.7 trillion worth of goods and services every year.

El Nino - a natural climate phenomenon that can temporarily heat some oceans - which ended in may, has made the ongoing bleaching worse.

Forecasters predict that the world may move into a La Nina pattern in the coming months. This climate pattern is known to bring cooler ocean temperatures, giving coral scientists hope for a chance of recovery.

There is still concern that this might not occur, even with La Nina. 2024 looks set to be the warmest year in history. Manzello says that if current ocean temperatures become the new norm, we may soon be in a "state of chronic global bleaching".

(source: Reuters)