A vibrant city of colorful corals can be found beneath the warm and clear waters of Gulf of Aqaba, located at the northern tip of Red Sea. At sunrise, fish emerge out of their coral shelters to join turtles, eels and octopuses in swimming through these teeming waterways.
This vibrant scene is unaffected by the mass bleaching that has affected reefs elsewhere. Corals can only survive within a limited temperature range. As the oceans heat up, stressed corals become less energy-producing and lose their color. Whole ecosystems can be destroyed when corals die or bleach.
Corals such as those found on the Great Barrier Reef have already succumbed in warm waters, leaving behind a ghostly underwater landscape that has lost its once-vibrant life.
A recent study found that 14% of the world’s coral reefs were lost in less than a decade. Global coral reef cover has shrunk by global warming, pollution, habitat destruction, and global warming since the 1950s. Experts predictIn the next decade, up to 90% of corals may die.
Some hope is emerging from northern shores of Red Sea as Aqaba’s corals are unaffected despite the steady warming waters.
“We found that corals at Aqaba could withstand temperatures well above the summer maximum of 27°F.” [Celsius]Maoz Fine, a marine biologist who conducted research on coral heat-resilience at The Interuniversity Institute for Marine Sciences (Eilat), Israel, said, “Yes.”
Hope from the Red Sea
Fine and his team devised an aquarium system to simulate future Red Sea conditions and conducted experiments on the resilience of corals in Aqaba.
The majority of corals will eventually bleach. Within a degree or soExperiments revealed that Aqaba’s corals can withstand temperatures up six degrees Celsius higher than their normal range.
Fine stated that he tested 20 species of corals and found that all of them were highly resistant to thermal stress. “Despite rising temperatures, the corals never became bleached.”
This resistance to heat is thought to result from corals migrating into the Red Sea from India during the last Ice Age, approximately 20,000 years ago.
Corals had first to cross the Gulf of Aden and southern part of Red Sea in order reach the Gulf of Aqaba. Here, water temperatures are much higher. Over time, the larvae of surviving corals moved north to more populated areas with lower water temperatures. However, they kept their heat resilience.
Scientists can study Aqaba’s corals that are extremely resistant to heat with the ‘Red Sea Simulator.
Fine stated that although these corals were chosen for their high temperature, they actually live at temperatures six degrees below their bleaching threshold.
Fine stated that although corals can adapt to warmer waters in other areas, there is no comparable gap between the maximum temperatures and bleaching thresholds of corals. “This is one the few places that corals will be able survive global warming,” Fine stated.
Researchers and conservationists hope that the Gulf of Aqaba will be a refuge for the remaining corals as coral reefs are threatened by rising temperatures.
Could Aqaba’s corals be helping other reefs?
Manuel Aranda, a marine biologist from the King Abdullah University of Science and Technology (Saudi Arabia), said that “Aqaba’s corals might be a source for repopulating reefs if corals are dying everywhere else.”
Aranda said that scale is the problem.
“The Great Barrier Reef has a size comparable to Italy. We can’t plant reefs like we spread seeds on the land,” he stated. Coral plantation requires divers to enter the water and manually fix the coral fragments that have been grown in nurseries.
Coral plantations can be too expensive and time-consuming. Also, species introductions can be very difficult. Aranda is part a research team at KAUST that aims to identify heat-resilient corals, and cross-breed them to increase their heat tolerance.
Corals are a home to a rich variety marine life that is highly vulnerable to climate change.
Aranda said that corals can adapt in many generations. The planet is warming faster that this process of adaptation. He hopes to speed up genetic interactions to give corals a chance to keep up with rising temperature: “We hope with cross-breeding that we don’t need to plant corals. They will reproduce by themselves.”
Fine isn’t convinced this method will work on large scales. Fine believes the main focus should be on identifying and conserving resilient reefs, not trying to grow corals elsewhere.
Fine stated, “What we can offer are knowledge, understanding which genes have been selected down south when entering Red Sea and what that means in thermal resilience.”
Future generations owe us this.
Coral reefs are home for 25% of all marine species. This makes them one of the most diverse habitats around the globe.
Ehab Eid, a Jordanian conservationist, said that the Gulf of Aqaba is home to a diverse ecosystem. “We have identified 157 species in Jordan of hard corals, and over 500 species fish. More than half depend on corals.”
Coral reefs not only provide vital habitats for marine life but also provide food and medicine, protect coastlines, and ensure the livelihoods and security of over a million people.500 million people worldwide.
Despite their resistance to high temperatures, Aqaba corals are susceptible to pollution and unsustainable urban coast development. This puts at risk the livelihoods of many people in Jordan and Israel who depend on tourism and fishing in the Gulf of Aqaba.
Ibrahim Riady, a fisherman in Aqaba, Jordan for more than two decades, said that corals are vital for fish here. “Our livelihoods are dependent on them.” He said that their catch had declined over the past decade, as did other local fishermen.
Scientists call for protection of the reef to ensure corals can survive local threats and revive reefs elsewhere. Eid said that the Gulf of Aqaba could be one of the last remaining reefs at the end of this century. It is a treasure. Future generations owe it a debt of preservation.”
Edited By: Ruby Russell