Anyone who visits the Great Barrier Reef in Australia, Southeast Asia’s coral triangle, or the reefs of Central America, will surely speak of how stunning and vibrant these environments are.
Anyone who visits the Great Barrier Reef in Australia, Southeast Asia’s coral triangle, or the reefs of Central America, will surely speak of how stunning and vibrant these environments are. Indeed, coral reefs are believed to house more biodiversity than any other ecosystem on the planet, with the coral providing protection and shelter for hundreds of species of fish and crustaceans.
But these ecosystems are under threat. Global pressures, such as rising ocean temperatures, are causing coral to turn ghostly white, a phenomenon called bleaching, and die. One family of coral – Acropora – seems to be particularly susceptible and its numbers are expected to decline in the future. This is especially concerning as these corals are fast growers and thus structurally important for the reefs. Researchers took a close look at Acropora tenuis, a species within this family, which is known to have three color morphs – brown, purple, and yellow-green. Their new study, published in G3: Genes|Genomes|Genetics, indicates that these color morphs speak of the coral’s resilience to high temperatures, and found the underlying genetic factors that seem to be responsible for this.
“Coral reefs are very beautiful and have a whole variety of different colors,” said Professor Noriyuki Satoh, who leads the Marine Genomics Unit at the Okinawa Institute of Science and Technology Graduate University (OIST). “When we started looking at the different color morphs of A. tenuis we noticed that some morphs bleach more readily and die more frequently than others. During the summer of 2017, we saw that many of the brown and purple morphs bleached, with the brown morph dying at a higher rate, but the yellow-green morph seemed to show resilience to the summer temperatures.”
Image: The three different color morphs of this coral have been grown in the private aquarium - Umino-Tane Co. LTD (Sea Seed) - located in Okinawa, for the last two decades. This aquarium was instrumental in the OIST researchers being able to conduct this study. (Credit: OIST)