Close this search box.

Divers Kill Almost 47,000 Crown-of-thorns Starfish on Great Barrier Reef



Volunteer divers in Australia have carried out a record-breaking mission killing nearly 47,000 crown-of-thorns starfish in seven days on the southern Great Barrier Reef.

The starfish were found in their thousands months ago, eating through sections of Swains Reef which is located 250 kilometres off the central coast of Queensland.

It was Gladstone charter operator Bruce Stobo who led the team of 25 divers on the nine day mission.

Mr Stobo, told ABC Radio Australia: “They tell me, unofficially, that it's the most amount of starfish that [have] been killed in a single trip in that time.”

Stobo, who donated his catamaran to the mission, has been working on the Swain Reefs for 21 years with his boat charter and dive equipment businesses. He was compelled to act after he learned of the destructive outbreak which was in his ‘backyard’.

Queensland Parks and Wildlife identified the crown-of-thorns starfish infestation during a survey in November 2017, yet the divers were taken aback by the the number they found. The starfish were so abundant in certain areas that they were ‘piling on top of each other to get to the coral’.

Similar missions have culled up to 30,000 crown-of-thorns starfish.

Mr Stobo told the publication: “Everyone was absolutely surprised. We had professional divers on board who've been working up north, and one in particular who's been doing it for eight months full-time, and he said it was the most that he's seen in one area.”

The divers conducted the mission in groups of 12, each diving three times per day, for an hour each dive. The starfish were injected with bile salts into the shoulder, with divers competing with swells and currents while they set about the huge task at hand.

“For the first couple of days, we did training on board so we were getting our technique right and after day two, we got into the thick of it and the weather was fantastic, so it allowed us access to some huge aggregations,” Stobo told ABC.

He said the cull couldn’t kill all of the crown-of-thorns in the Swains Reef but highlighted the extent of the problem, and that with a combined effort they could ‘certainly put a dent in it.’

Queensland Parks and Wildlife were also involved in the expedition, surveying the reef and pinpointing concentrations of starfish.

Despite some sections of the reef being devastated by crown-of-thorns starfish, there are other areas which remain pristine.

The mission coincides with the Australian Government’s $60m Great Barrier Reef Protection Plan to improve the health of the reef.

Main image via

Notify of

Inline Feedbacks
View all comments


Get a weekly roundup of all Scuba Diver news and articles Scuba Mask
We don’t spam! Read our privacy policy for more info.

Picture of Scuba Diver Magazine
Scuba Diver Magazine
Scuba Diver Magazine is a global publication serving all the major English speaking markets in print and digital format.
Latest Stories
Would love your thoughts, please comment.x