The heat-resistant reefs of the Red Sea offer last resort protection for corals

The heat-resistant reefs of the Red Sea offer last resort protection for corals


Beneath the waters off Egypt’s Red Sea coast, life teems in a kaleidoscopic ecosystem that could become the world’s “last coral haven” as global warming obliterates reefs elsewhere, researchers say.

Most of the shallow-water corals battered and bleached white by repeated ocean heat waves are “unlikely to survive the century,” the Intergovernmental Panel on Climate Change said this year.

This threatens to be a devastating loss for the hundreds of millions of people around the world who depend on the fish stocks that live and breed in these fragile ecosystems.

Even if global warming is limited within the Paris climate targets of 1.5 degrees Celsius above pre-industrial levels, 99 percent of the world’s corals may not recover, experts say.

But the Red Sea’s coral reefs, unlike those elsewhere, have proven to be “very tolerant of rising sea temperatures,” said Mahmoud Hanafy, a professor of marine biology at Egypt’s Suez Canal University.

Scientists hope at least some of the Red Sea’s corals — five percent of all the world’s remaining coral — could hold on amid an otherwise looming global collapse.

“There is very strong evidence that this reef is humanity’s hope for a coral reef ecosystem in the future,” Hanafy said.

Eslam Osman of the King Abdullah University of Science and Technology in Saudi Arabia said: “It is vital that we conserve the northern Red Sea as one of the last coral reserves as it could be a seed bank for future recovery efforts.”

– livelihood for millions –

The impact of coral loss is devastating: it covers just 0.2 percent of the sea floor, but is home to at least a quarter of all marine life and plants, and helps sustain the livelihoods of half a billion people worldwide.

Global warming, along with dynamite fishing and pollution, wiped out a staggering 14 percent of the world’s coral reefs between 2009 and 2018, according to the Global Coral Reef Monitoring Network.

Where once vibrant and biodiverse ecosystems thrived, now cemeteries of bleached coral skeletons remain.

Recent studies have shown that northern Red Sea corals are better able to withstand the ravages of hot water.

“We have a buffer temperature before the coral bleaches,” Osman said. “One, two, even three degrees (Celsius) warming, we’re still on the safe side.”

Osman said one theory explaining coral’s apparent resilience to heat stems from “evolutionary memory” developed many thousands of years ago when coral larvae migrated north from the Indian Ocean.

“In the southern Red Sea, coral larvae had to pass through very warm water, which acted as a filter and only let through species that could survive up to 32 degrees Celsius (89 degrees Fahrenheit),” Osman said.

But scientists warn that even if Red Sea corals survive rising water temperatures, they are at risk of damage from non-climatic threats — pollution, overfishing and habitat destruction, including from coastal development and mass tourism.

“As non-climate threats increase, so does vulnerability to climate change,” Osman said.

– “Global Responsibility” –

Reefs off Egypt are very popular with divers, and some Red Sea dive sites operate at up to 40 times their recommended capacity, Hanafy said.

Fisheries, another major pressure, must drop to one-sixth of current rates to become sustainable, he said.

For Hanafy, protecting the reef is a “global responsibility” and one that Red Sea tourism companies – which make up 65 percent of Egypt’s vital tourism industry – must share.

Local experts say they have already observed damage to parts of the delicate ecosystem.

One solution, Hanafy said, is for the environment ministry to step up protection of a 400-square-kilometer area of ??coral known as Egypt’s Great Fringing Reef.

More than half already lies in protected areas or ecologically managed areas, but creating a continuous protected area would support the corals by “regulating activities and fisheries, implementing carrying capacity plans, and banning pollution,” Hanafy said.

Further south, off Sudan, a near-lack of tourism has protected pristine coral from polluting boats and the wandering fins of divers.

But despite their greater resilience, the corals are far from immune to climate change, and the reefs there have experienced multiple bleaching events over the past three decades.

For Sudan, a country mired in severe economic and political crises including a military coup last year, monitoring the coral without funding is “difficult,” Sudan’s Supreme Council on Environment and Natural Resources said.

Corals off both the Egyptian and Saudi coasts face coastal development threats, including sewage and sediment from construction runoff, Osman warned.

The great irony, he said, is that while the natural wonders of Red Sea coral have attracted tourists and developers, increased man-made pressure is in turn accelerating their destruction.

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