DPI&F fisheries biologist Malcolm Pearce said it was most likely the fish had been illegally released into the creek. Those found were all juveniles.
"There were no breeding adults, which combined with the remote location and the small population found, leads us to believe they were introduced into this area by people deliberately bringing them in," he said. The department will use electro-fishing techniques to reduce the populations it is the only viable control mechanism.
Culling the fish using rotenone (poison) is not an option as this water course is a flowing river system and such methods are likely to be ineffective and possibly harmful to other marine life. Eureka Creek is a tributary of the Walsh River which flows into the Mitchell River and then into the Gulf of Carpentaria.
"As well as undertaking control activities, we will be stepping up our surveillance both up and downstream of the detection site so that we can track the extent of the possible infestation," said Mr Pearce.
He said the area was extremely important to both the commercial and recreational sector, particularly in relation to barramundi catch, and was also a significant breeding ground for other native species.
This new detection is particularly frustrating as DPI&F has mounted a thorough 12-month campaign to educate the community about the threat posed by pest fish
"Tilapia is a declared noxious fish species in this state. These fish do not belong here and there are heavy fines of up to $150,000 for possessing them. If the spread of the fish isn't controlled, tilapia could significantly impact on our commercial and recreational fisheries," explained Mr Pearce.
These species reproduce rapidly and can quickly dominate waterways, forcing out local fish and introducing diseases and parasites.
The public is being urged to report anyone suspected of moving tilapia, or any possible sightings of the fish to Queensland's Fishwatch Hotline or to complete online Pest Report Fish Form.
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