DPI Strategy Leader Aquatic Biosecurity Melissa Walker said community assistance is urgently needed to control the spread these pest fish, which were recently found in Bogangar Canal and Cudgen Lake, south of Kingscliff.
"The highest risk for transporting tilapia is via humans carrying live fish or eggs," Ms Walker said.
"If people catch or find a tilapia, it is vital that the fish is not returned to the water.
"Our advice to anyone who catches or finds tilapia is to humanely destroy and dispose of it appropriately.
"In any case of uncertainty about identification, we recommend taking a good quality photo then calling the Aquatic Pest Hotline immediately for confirmation."
Ms Walker said tilapia have pale olive to silver-grey bodies, with a long continuous dorsal fin, and can grow to more than 36 centimetres and live up to 13 years.
"The fish are particularly threatening because they are such successful breeders," Ms Walker said.
"Mothers produce up to 1200 eggs a year and protect their young fry in their mouths for up to 14 days before releasing them.
"This technique, known as 'mouth brooding', ensures that even if the mother is not living, any eggs in the mouth have the potential to survive.
"Once established in a flowing river or creek, these fish are almost impossible to eradicate so it is important to stop the spread of tilapia now before it's too late."
Tilapia impact on native fish numbers by competing for habitat and food, behaving aggressively, disturbing aquatic vegetation and could potentially introduce disease and parasites.
DPI Fisheries and Biosecurity staff are working with local council to coordinate surveys of the surrounding areas to help inform potential management options for this invasive pest fish.
Sightings of Tilapia can be reported to DPI by:
* Phone: 02 4916 3877 (24 hour hotline)
* Online or via