However, resilience varies across the region, which is part of why Hanafy is unconvinced that evolutionary history is the primary explanation for the resilience of Egypt’s reefs. He places greater emphasis on water circulation.
The northern Red Sea experiences changes in current direction. This can create vertical mixing, which brings cooler water from far below toward the surface, he explains. These conditions could be buffering the corals against the heat even when the surrounding air temperatures remain high.
The distinction matters. The survival of these reefs may not have much to do with the biology of the corals or their symbiotic algae, and this might explain why the Red Sea corals began bleaching in 2024.
The sea remained unusually calm for about a month and a half during the 2024 heat wave, weakening the circulation he believes normally helps protect the reefs. HEPCA’s report identifies weak water circulation as a contributing factor in the bleaching. Exceptionally low tides in July 2024 may also have intensified stress on shallow coral communities.
Osman accepts that calm seas could have made bleaching more severe but says the circulation explanation needs further research. “I’m not denying the possibility of that,” he says. “But what I’m saying is, the temperature was the main issue.”
The two explanations are not necessarily mutually exclusive. But understanding their relative importance could help scientists assess how vulnerable these reefs are to future heat waves.
There are signs of recovery. HEPCA’s preliminary estimates a year after the bleaching event put recovery rates at 75 to 88 percent, depending on species and location. That is a far stronger rebound than seen elsewhere across the globe, where many reefs are only beginning to recover—if they show any progress at all.
Work to protect the Red Sea reefs ahead of the next heat wave is also under way, with the Egyptian government designating new protected areas as well as partnering with the United Nations Development Program and the Global Fund for Coral Reefs on conservation and sustainable management.
Osman sees such initiatives as a positive step but stresses that conservation requires sustained support. “We definitely need more stable financial resources, because conservation is not a single-year act.”
For Hanafy, the future of Egypt’s reefs also depends on whether climate change alters the circulation that has perhaps been keeping the corals alive.
Whatever explains their unusual resilience, local conservation cannot halt ocean warming. “Therefore, the key is to reduce carbon dioxide and greenhouse gases. Any other solution will just buy time,” Hanafy adds.
This story originally appeared in WIRED Middle East.