Original story at ABC Tropical North
A north Queensland community is trialing the use of barramundi to eradicate a pest fish from public waterways.
The South African tilapia has been introduced into the Mackay Gooseponds and experts fear they could take over and threaten native species.
Reef Catchments aquatic habitats coordinator Tim Marsden says the species was first identified in far north Queensland in the 1970s.
"There's no natural predators to tilapia here in Australia, they can survive in hot water, cold water, low dissolved oxygen, really poor water... and so that means whenever we've got any conditions, for example an urban waterway where you might have less than ideal conditions, tilapia will end up dominating that waterway," he said.
He says while tilapia are very difficult to eradicate, he hopes the use of 1,000 barramundi will help reduce the number of fish in the pond.
"We're putting up a biological control option as a trial to see if we can do something," said Mr Marsden.
"We've got a fairly unique set of circumstances where we have a very small population, because I discovered them accidentally, we actually got in ahead of the game, normally we don't find out until they've been in there for two or three years.
"It does look like they've only been in here for months."
Mackay Area Fish Stocking Association's Keith Day says he's concerned that if the tilapia are allowed to breed in the Gooseponds, they will have a detrimental impact on other waterways in the region.
"We have a very invested interest in stocking our three dams, which is Eungella, Kinchant, and Teemburra, we've stocked over five million fish in those dams," he said.
"If these tilapia get into those dams, they will have a huge impact on our created fisheries."
About 80 volunteers took part in the event to release barramundi into the Gooseponds on the weekend.
Mr Day says he was overwhelmed by the amount of people who turned out for the event.
"I really think that the government agencies should be taking a really mainstream role in this," he said.
"We've now got the army of tilapia fighters, it just blows me away that our community actually care enough to come and assist with this."