From WIRED · Eli Siegel-Bernstein · · 2m
Egypt's super corals begin to crack under heat
Red Sea corals long thought resilient to warming are bleaching as heat waves strain their defenses.
In brief
Red Sea corals long thought resilient to warming are bleaching as heat waves strain their defenses. Egypt's Red Sea corals, unusually heat-tolerant and predicted to be the world's last-remaining reefs, suffered significant bleaching in 2023 and 2024, raising questions about what has protected them and whether that…
Hope fading for super corals
Egypt's Red Sea corals have been unusually resilient to rising water temperatures, with some scientists predicting they could become the world's last-remaining corals if oceans continue warming.
Heat waves strain the reefs
In summers 2023 and 2024, heat waves strained Red Sea coral ecosystems. A survey led by Mahmoud Hanafy found bleaching throughout the Red Sea corals in 2024, affecting less than a tenth of colonies in…
How coral bleaching works
In overly warm waters, algae nestled among corals' polyps produce toxic substances. Corals eject the algae as a defense mechanism, but because these organisms are their primary food source, bleaching leaves corals to starve.
Why reefs matter globally
According to the United Nations Environment Program, reefs cover less than one percent of the seafloor yet support at least twenty-five percent of marine species, some only just now being discovered.
Two theories on resilience
Eslam Osman at King Abdullah University of Science and Technology points to evolutionary history: heat-tolerant corals survived crossing the warm Bab al-Mandab Straight and spread northwards.
What triggered 2024 bleaching
The Red Sea remained unusually calm for about a month and a half during the 2024 heat wave, weakening circulation that normally protects reefs.
Signs of recovery emerge
HEPCA's preliminary estimates a year after the bleaching event put recovery rates at seventy-five to eighty-eight percent, depending on species and location.
Conservation alone cannot save them
The Egyptian government is designating new protected areas and partnering with the United Nations Development Program and Global Fund for Coral Reefs.
“the key is to reduce carbon dioxide and greenhouse gases. Any other solution will just buy time”
What it means
Egypt's Red Sea corals, unusually heat-tolerant and predicted to be the world's last-remaining reefs, suffered significant bleaching in 2023 and 2024, raising questions about what has protected them and whether that protection will hold.
