UNKNOWN: Fishing charter business owner Bruce Stobo said it was confusing trying to work out what had caused the outbreak.
UNKNOWN: Fishing charter business owner Bruce Stobo said it was confusing trying to work out what had caused the outbreak. Mike Richards GLA050118STAR

Crown of thorns starfish hits reef close to home

"LIKE a bushfire going through."

That's how Bruce Stobo described the impact of an infestation of crown of thorns starfish, discovered at sections of Swain Reefs, about 200 kilometres north-east of Gladstone.

"You end up with ... lots of white sections, which looks like coral bleaching, once the coral are dead, you get algae over the coral," he said.

Mr Stobo owner/ operator of Kanimbla Charters said it was his skipper Steve Bell who discovered the infestation of invasive echinoderms while out swimming on the reef.

Mr Bell said he was snorkelling at the bottom section of Swain Reefs late last year when he spotted something disturbing.

"I came across a whole bunch of crown of thorns. Over maybe an area of 100sqm there were about 1000 starfish," he said.

"I was surprised because I've swum there a lot of times and never seen them."

Mr Bell said he'd been back since the initial discovery and the affected reefs were "just covered in slime".

The Swain Reefs are made up of more than 200 individual reefs and Mr Stobo said it was important to recognise that only a small portion of the reefs had been affected by the starfish.

"There's huge sections that are absolutely beautiful and in pristine condition," he said, adding that so far he had not noticed any impact on fishing stock.

The Kanimbla team notified the Great Barrier Reef Marine Park Authority upon discovery of the infestation.

GBRMPA has since labelled the Swain Reefs infestation "severe".

The Swain Reefs has become the southern most location at which the crown of thorns starfish has been found during the current outbreak.

Fred Nucifora, GBRMRA director of education, stewardship and partnerships, said it was concerning to see an outbreak of the starfish this far south.

"Until now, the current crown of thorns starfish outbreak was largely limited to the northern and central part of the Reef," he said.

Dr Hugh Sweatman, Australian Institute of Marine Science senior research scientist, said it wasn't the first time a crown of thorns outbreak had occurred in the region.

"Our long-term monitoring has shown that Swain Reefs suffered from similar severe outbreaks of crown of thorn starfish from the late 1980s to 2005 ... but have recovered well," he said.

Mr Stobo has volunteered the Kanimbla's services to help GBRMPA cull starfish at Swain Reefs in less than two weeks time.

The team will go out for a 10-day trip where the Kanimbla crew will receive training on how to inject poison into the starfish.

AIMS research has found coral cover on surveyed reefs has declined by about 50 per cent over the past 30 years and that the crown of thorns starfish was responsible for almost half of that decline.