The Current Global Coral Whitening Event is expanding to new countries, according to NOAA, why?

The massive episode of coral bleaching reported by US authorities last month is expanding and deepening in reefs around the world, NOAA scientists warned

bleached corals
Bleached corals acquire a ghostly white color underwater. If they can't recover quickly enough, the bleached corals die and the algae cover the surface that was once colorful. These images of Lizard Island, part of the Great Barrier Reef, capture the consequences of coral mortality. Image courtesy of The Ocean Agency / XL Catlin Seaview Survey, for illustration only.

In the midst of record ocean temperatures, coral bleaching has been recorded in 62 countries and territories since February 2023, said the U.S. National Oceanic and Atmospheric Administration. UU. (NOAA), an increase of nine since its notice in April 2024.

Coral bleaching is increasing

"This event continues to grow in size and impact," Derek Manzello, coordinator of NOAA's Coral Reef Watch program, said at a press conference, adding: "This is not something that would be happening without climate change."

Manzello said that new damage to corals has been reported since the NOAA warning of April 15 in India, Sri Lanka and the Chagos Islands in the Indian Ocean.

Severe or prolonged thermal stress causes the death of corals, although there is a possibility of recovery if temperatures drop and other stressors such as overfishing and pollution are reduced.

The consequences of coral bleaching are far-reaching and affect not only the health of the oceans but also people's livelihoods, food security and local economies.

The current massive bleaching of corals is the fourth recorded in the world, and three others occurred between 1998 and 2017.

About 60.5 percent of the world's reefs have experienced record heat in the last 12 months, according to the NOAA.

The previous widespread global whitening, which occurred between 2014 and 2017, retains the record for the largest cumulative impact, for now.

Bleaching could occur even more on the reefs of Asia and off Mexico, Belize, the Caribbean and Florida as the oceans continue to warm during the summer, Manzello said.

So far, the Great Barrier Reef in front of Australia has been affected by bleaching, which also affects corals in Thailand.

Accumulated Temperatures and Heat in Record Waters

There is a 61 percent chance that 2024 will end as the hottest year recorded on Earth and a 100 percent chance that it will be one of the five warmest years, said Karin Gleason, head of the monitoring section of the National Environmental Information Centers of the NOAA.

Meanwhile, last month, the world's oceans recorded the highest temperatures ever recorded in April, a record broken every month for the last 13 months.

"The accumulation of heat stress has been extreme and unprecedented in the Atlantic Ocean," Manzello said.

coral bleaching
Can the coral survive a bleaching event? If the bleaching caused by stress is not severe, it is known that the corals recover. If the loss of algae is prolonged and the stress continues, the coral ends up dying. NOAA infographic

Understanding the consequences of coral bleaching can take time: in the Caribbean, for example, corals could survive immediate thermal stress only to die later due to "outbreaks of diseases or aggregations of coral predators," Manzello added.

Last year, 2023, was the hottest recorded, attributed to a twisted mixture of climate change and the climate pattern of El Niño.

sea surface temperature
Image of 5 km daily global satellite bleaching alert of NOAA Coral Reef Watch (CRW) presented, maximum of 7 days, describes the areas where heat stress from coral bleaching currently reaches several levels, according to our satellite monitoring of sea surface temperature (SST) as of May 18, 2024. NOAA

This year, as the cooling pattern of La Niña comes into force from now until the fall, "my hope is that... we begin to see that the percentage of affected reef areas begin to decrease," Manzello said.