Little Cayman deep reefs help in adaption study

(CNS): Researchers at the Central Caribbean Marine Institute are involved in an important study about how coral can adapt to climate change. A team of scientists is seeking answers by studying the corals living down to 50m on the reef walls of Little Cayman. CCMI is partnering with the University of Haifa, Israel, where researchers have developed specialised equipment and new methods to help them fathom out how certain corals survive across broad environmental gradients and their capacity to change to conditions in the deeper ocean.

This information may give insight into their overall adaptative potential and ability to survive in the face of future climate change. “We know that some species of corals are capable of living under very different environmental conditions,” said CCMI’s Dr Gretchen Goodbody-Gringley, who is leading the team along with Dr Tali Mass, Senior Lecturer at Haifa University.

“You can see examples of this all along the reef walls of the Cayman Islands. The same species of coral can look very different when they grow 10 meters underwater versus 50 meters because those individuals have had to adapt to survive given different conditions like light availability, temperature variability, and nutrient flow.”

But little is known about how they do that. “If we understand the mechanisms of coral adaptation, maybe we can help more corals survive in the face of rapid, human-caused climate change,” Dr Goodbody-Gringley said.

This project began earlier this year with scientists photographing and collecting samples from corals at various depths to get baseline information on genetic composition, physiology, and skeletal structure. They will next cross-transplant selected individual corals between deep and shallow reefs, documenting changes in these corals over the course of a year, including genetic alterations, skeletal differences and variations in the number of symbiotic algae present in the corals, which they depend upon for food, the scientists explained in a press release.

Supported by the US National Science Foundation-Binational Science Foundation of Israel (NSF-BSF), researchers are comparing the data gathered from this experiment in Little Cayman with corals subjected to the same experiments in the Red Sea and the Mediterranean Sea for a wider basis of understanding.

Researchers also want to understand if these changes are then passed on genetically to future generations. To do this, researchers will monitor larval release from these corals, collect the larvae from different depths and then settle them under various conditions (from deep to shallow and vice versa). The larva and newly settled juveniles will subsequently be assessed for growth, survival, and variations in physiology, morphology and gene expression.

“Human-caused climate change is subjecting corals to conditions beyond their normal limits, thus we’re in a period of rapidly declining reef health worldwide. However, some species and some individuals display the capacity to survive,” Dr Goodbody-Gringley said. “Dr Mass and I are interested in understanding the ability of some corals to persist in our changing climate.”