Edward Smith

Deep Sea DNA

Arabian Gulf corals could hold the key to climate change survival for threatened reefs around the world

The Arabian Gulf region contains some of the most unique but understudied coral reef ecosystems on Earth. Corals in the Arabian Gulf survive extreme sea temperatures and are more heat tolerant than any other corals on the planet.

Few studies, however, have explored the molecular mechanisms that allow them to persist in such harsh conditions. NYU Abu Dhabi’s Marine Biology Lab is turning to genetics for answers. What they find out in Abu Dhabi could provide important insights for corals elsewhere in the world threatened by rising sea temperatures, a primary cause of coral reef bleaching.

A comparative study in the Arabian Gulf and the neighboring Gulf of Oman is one of few that has examined genetics of both corals and their natural symbionts — an alga that lives inside coral tissue. The alga is hugely important, the scientists said, because corals get more than 90 percent of their energy from it.

“By looking at both corals and algae partners, we can get a better idea of whether one or both are involved in Gulf coral thermal tolerance,” said Edward Smith, NYUAD postdoctoral associate researcher, and also determine if there’s any exchange of genes between reefs around the region.

DNA analysis was performed on corals collected from the Arabian Gulf near Abu Dhabi and from sites in the Gulf of Oman around Fujairah and Muscat — where average sea temperature is nearly five degrees cooler. The scientists used sequences of DNA to examine both individual corals and groups of corals, and discovered key differences, Smith said, namely that Arabian Gulf corals and their algae partners are genetically distinct from those in the Gulf of Oman.

Limited gene flow exchange between regions indicates that Arabian Gulf corals have adapted to cope with their extreme conditions, Smith said. Genetically adapted populations of corals are an important scientific resource “that 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,” he concluded.

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