Research reveals unique adaptations help Arabian Gulf corals survive sea temperatures of 36 degrees or higher

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Press Release

Research undertaken by scientists at NYU Abu Dhabi (NYUAD) will help provide new insight into how coral reefs around the world will be able to cope with climate change.

Rising sea temperatures are a primary cause of global coral reef bleaching, when water is too warm, corals expel the algae living in their tissues, causing the coral to turn white (known as coral bleaching). Major coral bleaching events have occurred around the world, including significant events in Australia on the Great Barrier Reef, and experts expect to see continued damage in the coming years.

NYU Abu Dhabi researchers may have found new insight into this global challenge, using corals found in the Arabian Gulf. A team of researchers examined the genetics of a widespread coral to understand how corals survive extreme sea temperatures of 36 degrees Celsius or higher in the Arabian Gulf, making them more heat tolerant than any other corals on the planet.

The study, which was published in the scientific journal PLOS One, sought answers to whether these corals have genetically adapted to these extreme conditions or have physiologically acclimated to the heat. To this end, the genetic structure of the coral Platygyra daedalea and its symbiotic algae in the Arabian Gulf and the nearby Gulf of Oman were investigated.

“By looking at both corals and algae, we can get a better idea of whether one or both are involved in Gulf coral thermal tolerance,” said Edward Smith, postdoctoral associate researcher at NYU Abu Dhabi.

DNA analysis was performed on corals collected from reefs in the Arabian Gulf near Abu Dhabi and from sites in the slightly cooler Gulf of Oman around Fujairah and Muscat. This analysis found some key differences, revealing that the Arabian Gulf corals and their algae are genetically distinct from their counterparts in Gulf of Oman.

According to Smith, limited gene flow exchange between regions indicates that Arabian Gulf corals have adapted to cope with their extreme conditions. “This is interesting because the results suggest that both the coral and their algae together contribute to the superior thermal tolerance traits of Arabian Gulf corals,” Smith said.

“Genetically adapted populations of corals and their symbionts in the Arabian Gulf are an important scientific resource”, he added. “This study will help us understand the mechanisms involved in coral thermal adaptation, and provide new insight into whether corals elsewhere in the world will be able to cope with climate change.”

Regional adaptation has also lead the researchers to conclude that reefs threatened by climate change in the Gulf of Oman or Indian Ocean are unlikely to acquire the so-called “super genes” of Arabian Gulf corals.

Reefs in the Arabian Gulf are the most diverse ecosystems in the region and support major economic industries such as fisheries. “Unfortunately, the conditions that have made Arabian Gulf corals among the hardiest known to science, also makes them vulnerable: they are living in very stressful conditions, and any further stress can push them over the edge”, said John Burt, NYUAD associate professor of biology.

“In the past three decades we’ve witnessed widespread degradation of reefs around the region, with sedimentation from coastal development and nearshore reclamation being the prime culprits,” he explained. “If we are to conserve these scientifically and economically important natural assets, management efforts to limit human stressors are critical.”

Link to the paper: http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0180169