The crown-of-thorns starfish (COTS) is the greatest threat to the Great Barrier Reef, new research suggests.
The latest health report on the Great Barrier Reef by the Australian Institute of Marine Science (AIMS) shows COTS, cyclones and to a lesser extent bleaching and disease, have been the most significant causes of damage over the last 20 years.
The AIMS team samples reefs from north of Cooktown to Gladstone covering 1,750 kilometres of coastline. They provide information on population trends in key groups of organisms – particularly COTS, corals, algae and reef fishes.
Team leader Dr Hugh Sweatman said in the two years since the last report it has been a relatively quiet period, free from bleaching and major cyclones.
He said: “In the absence of big disturbances, reefs have a chance to recover. We use underwater video to measure coral cover and in the past two years we have seen the cover increase, particularly on inshore reefs near Cairns.