Help stop the spread of spotted tilapia

News release | 23-Jan-2018

Fishers and residents in Far North Queensland are being asked to be on the lookout for spotted tilapia to help stop the spread of this invasive fish.

In late 2017, spotted tilapia (Tilapia mariae) were found in two locations in a remote stretch of the Walsh River, around 30 km from Chillagoe.

Biosecurity Queensland Invasive Plants and Animals General Manager Graeme Dudgeon said follow up surveillance also found a small number of spotted tilapia near the Bruce Weir, which was close to Dimbulah.

“Further field surveillance to date has focused on the Mitchell and Walsh Rivers, Emu Creek, Mareeba Wetlands and the Mareeba-Dimbulah Irrigation Scheme,” Mr Dudgeon said.

“While no further spotted tilapia were found as result of our surveillance activities, we need more information to determine the current spread of spotted tilapia in the area.

“With the onset of the wet season hampering our surveillance efforts, we’re asking residents and recreational fishers to keep an eye out for spotted tilapia and report any sightings.”

Mr Dudgeon said reports of spotted tilapia would help determine future efforts in the area.

“Once established in a flowing river or creek, tilapia are almost impossible to eradicate, so we’re keen to build a better understanding of the current distribution of spotted tilapia in the area as quickly as possible,” he said.

“The first detection of spotted tilapia in the Walsh River in late 2017 was the result of a public report.

“The general public are our additional eyes and ears out in the field, so it’s important that residents and fishers nearby know how to identify spotted tilapia and report sightings.”

Spotted tilapia grow up to around 30 cm long, range in colour from dark olive-green to light yellow, have five or six bars or blotches on their sides and adults can have red margins on their fins and red blushing on their bodies.

If fishers catch a spotted tilapia in the area, they should photograph it, record their location and report it online at

Tilapia should never be used as bait (dead or alive). If caught tilapia should be humanely killed and buried or placed in a bin as returning them to the water can spread tilapia.

Tilapia are one of the greatest threats to Queensland’s native aquatic biodiversity.

If large populations of spotted tilapia become established in the Mitchell River catchment or its tributaries, they would pose a significant threat to the ecosystem, and the commercial and recreational fisheries in the Gulf of Carpentaria that rely on healthy rivers.

For more information, or to report spotted tilapia visit or call 13 25 23.

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Media contact: Andrew Clark, 3087 8605