Researchers have discovered a new species of algae that imparts heat-protecting capabilities to corals in reefs in the Arabian Gulf. Protecting corals from heat allows them to withstand water temperatures of up to 96.8 degrees Fahrenheit. Under those conditions, corals would normally die.

In a study published in the journal Scientific Reports, researchers from the New York University Abu Dhabi and the University of Southampton were able to identify the protective algae found in coral reefs in Abu Dhabi in the United Arab Emirates, the warmest reef habitat in the world. Using common molecular methods was not able to properly distinguish the algae in corals in the Arabian Gulf but by opting to use alternative approaches to molecular biology, researchers were able to isolate the algae from others, identifying it as new. It was called Symbiodinium thermophilum for its ability to withstand unusually high levels of temperature.

"Understanding how corals survive under the extreme temperatures in the Gulf will give us important insights into the ability of reef corals to handle the heat stress, which is threatening their survival in the oceans that are warming up in response to climate change," explained Jörg Wiedenmann, Coral Reef Laboratory head and biological oceanography professor from the University of Southampton.

Various coral species make up reefs and most of these species are home to microscopic algae. Corals and algae have a symbiotic relationship where the algae creates sugars that corals consume while the coral provides nutrients and shelter necessary for algal growth. When water temperature rises, the corals lose their algae partners, resulting in what is called coral bleaching.

Researchers monitored symbiotic relationships between corals and algae over the course of several reasons, ensuring the association they found would apply through various thermal conditions. They were able to confirm that the new algae they discovered was present throughout the year and was detected across several species of coral dominating the coast of Abu Dhabi.

The discovery of heat-tolerant algae gives the researchers hope that corals have more means to adapt to stressful conditions in the environment than previously assumed. However, rising water temperatures is just one of the problems corals face. Coastal development, overfishing, nutrient enrichment and pollution are also some of the severe threats corals face every day. Only in reducing all threats will stress levels for corals completely drop, allowing them to effectively adjust to the effects of climate change.

The study received funding support from NERC and the European Research Council.

Photo: Hamed Saber | Flickr

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