Reef show regrowth after COTS management

Thousands of reefs have bounced back following a mass purge of Crown of Thorn Starfish.

The COTS management program uses six boats and specialist divers to inject starfish with vinegar Photo: Dr Rick Abom

Entire reefs have bounced back following management of the coral-eating starfish on the Great Barrier Reef.

University of Queensland research has found Crown of Thorn Starfish eradication efforts have increased coral cover by 85 per cent in some reefs, with one third of sites showing at least 10 per cent improvement.

The starfish can consume 10 square metres of coral and produce 200 million eggs per year, making it a significant threat to a struggling system.

Lead researcher Dr Tina Skinner said the results offered hope.

“By going to these reefs and controlling, not only are they stopping those COT larvae from spreading to other reefs and causing outbreaks, but they’re also protecting coral populations,” Dr Skinner said.

“It shows that if you’re timely about your management and going to these reefs … semi-frequently, you can keep populations low enough that coral can still rebound.

“Even when we do increases in a lot of disturbances from climate change, you can still get good benefits from COT control.”

Capable of eating 10 metres squared of coral and producing 200 million eggs per years, COTS are one of the largest threats to the Great Barrier Reef. Picture: Professor Peter Mumby

The research used a comprehensive simulation of 3806 reefs across the GBR to model how management would impact reefs when stressors such as heat, cyclone and water quality stressors increased.

The $51.7m management strategy has copped criticism in recent years, due to the relatively small number of reefs managed.

Great Barrier Reef Marine Park Authority COTS Control Program assistant director David Williamson said targeting specific reefs was vital to stop millions of eggs taking hold down current.

“The COTS Control Program has demonstrated that early detection, timely and sustained control effort delivers coral protection benefits across entire reefs and regions,” Mr Williamson said.

“These reefs span the full spatial extent of the GBR Marine Park and are targeted because they are both at risk from COTS and provide valuable sources of coral larvae that replenish downstream reefs.”

Originally published as Reef show regrowth after COTS management