Red Sea Corals: Resilient to Increasing Sea Temperatures, Potential Coral Reservior of the World

The Coral Reefs in the Gulf of Aqaba, the Northern Tip of the Red Sea, has shown resilience in increasing sea temperatures. The reefs are now considered "to play the role of the coral reservoir of the world", Fuad Al-Horani, a professor of coral biology and ecology at the University of Jordan, said.

In 2005, Moaz Fine, professor at Bar-Ilan University, leads a laboratory study on the reefs; he noticed that there was something different about the Red Sea reefs after researching reefs in Australia. He expected to see degrading one like that in Australia, but interestingly, the corals of the Gulf of Aqaba were unaffected by increasing sea temperatures and ocean acidification.

This finding led Fine to design a prototype Red Sea Simulator (RSS), a large scale, multiple aquarium system that can simulate future ocean conditions and perform experiments that might provide an understanding of the distinctiveness of the corals in the Red Sea. 

The RSS allowed Fine's team to study corals and water from the Gulf, and adjust the acidity and temperature in the tanks simultaneously to be able to understand the physiology and genetics of the reef ecosystems.

Coral reefs are biodiversity reservoirs and are vital sources of food, income, and medicines. With this development, Karine Kleinhaus, a professor in the School of Marine and Atmospheric Sciences at Stony Brook University, said that there is now a window of opportunity to apply science to be able to rescue the world's degrading reefs. However, unless they can understand the biology and physiology of the Gulf of Aqaba corals that are tolerant to warming sea temperatures, this knowledge could not be used elsewhere, Kleinhaus added. She is particularly interested in any essential ecological factors in the reef that "amplify any innate coral resilience or potential to recover from bleaching."

A coral normally dispels their algae as temperature increases at 1-2 degrees celsius beyond the maximum summer temperature. The Red Sea corals, according to their unpublished research, suggests that while resilience varied between the corals that they tested, the corals were able to tolerate 4-5 degrees celsius above the current summer maximum. Some have even withstood as much as 7C above the summer maximum. 

The corals are notably resilient, and appear to do better in increased temperature. In some cases, the oxygen produced by the symbiotic algae doubled and revealed a 51 percent increase in primary productivity. 

Scientists believe that this is because of the product of their past. This population of corals migrated over thousands of years ago from the south, where there is a higher temperature to the north where the temperature is lower. The corals seemed to have retained their capacity to thrive at higher temperatures, says Anders Meibom, a geochemist running the Laboratory for Biological Geochemistry at the Ecole Polytechnique Fédérale de Lausanne (EPFL).  

Andréa Grottoli, a professor in the School of Earth Sciences at Ohio State University, said Red Sea Coral "could serve as a model for restoration once climate change stress is mitigated". He adds that "we start being able to actually reintroduce coral... it could serve as a model for what a normal reef might look like."

Fine, Meibon, Kleinhaus, and several scientists and diplomats are calling on UNESCO to declare the Red Sea Reef as a Marine World Heritage Site to ensure the protection of the reefs from local threats that would endanger the coral's resilience.