FISHOS at the barrage on the Mary River have contacted the Chronicle saying pest fish tilapia has recently been caught there.
Fisheries Queensland said they were aware of the sighting and had been providing advice to the local catchment group about monitoring, to gain an understanding of how widespread the problem may be.
A Fisheries Queensland spokesman said it was currently not possible to eradicate pest fish species such as tilapia once they were established in large, open bodies of water.
The spokesman said in Queensland it was illegal to be in possession of noxious fish such as tilapia or carp.
"This includes eating them," he said.
"If you capture a noxious fish, you are required to humanely kill it and place it in a bin or bury it on site."