Coral reef scientists have discovered four new tropical coral species not previously reported growing in southern locations. Published in the journal Coral Reefs, researchers say the discovery is part of a larger trend in reef-building corals moving southward along the New South Wales coastline.
Dr Andrew Baird, James Cook University, recently discovered the newly arrived species when he led an underwater survey in the Solitary Islands. “All four of these coral species are easy to identify, so we’re confident that if they had been around in the 1990s, they would have been picked up in the extensive surveys published at the time,” said Baird.
This discovery was part of a larger three-year project supported by the NSW Environmental Trust, to understand and monitor the southward expansion of reef corals in NSW. Led by Dr Joshua Madin of Macquarie University, the project brings together researchers from the University of Technology Sydney, James Cook University (JCU) and the University of Queensland. “Over the last ten years researchers have observed clear increases in the number of tropical reef fish species appearing along the NSW coastline. We’re motivated by a growing number of corals and other tropical organisms being spotted, some as far south as the Sydney area,” explains Madin.
Along the NSW coast the average water temperatures have increased by almost half a degree over the last 50 years. Researchers say the expansion of coral habitats into south-eastern Australia is critical to understand, as it will pave the way for arrival of a range of small organisms, such as tropical fishes. “Half a degree might seem insignificant to some but not to the fish and coral species of the southern Great Barrier Reef, many of whom already live on the edge of their comfort zone. Some of these species have survived through winter, thereby increasing their chance of establishing year-round local populations,” says project collaborator Professor David Booth, University of Technology Sydney. The team behind this latest discovery now have plans to enlist the public to help track the continued expansion of corals along the NSW coastline.
People who swim and snorkel along the coast are encouraged to report any subtle changes in the plants and animals they see to local scientists. The project will help provide marine resource managers with the information needed to develop strategies to cope with projected changes in coastal habitats. “Every little bit will help to understand the potential for reef species to expand their ranges southward,” says Madin.