Sightings of the invasive fish tilapia are increasing at the Gooseponds.
Sightings of the invasive fish tilapia are increasing at the Gooseponds. Contributed

Invasive tilapia 'virtually impossible to eradicate'

IRRESPONSIBLE fish owners have sparked something of an environmental catastrophe in the Mackay region.

The invasive tilapia are breeding at a rapid rate - the result of unwanted fish being dumped into waterways, according to Mackay Regional Council.

There's been a growing number of sightings of the fish at the Gooseponds recently.

Tilapia compete with native fish for food and habitat and are known for aggressive behaviour, leading to the decimation of popular fishing spots.

The council has undertaken projects to improve conditions at the Gooseponds for native fish, such as barramundi, including building a series of log fish hotels and installing oxygenation fountains in the most upstream pond of the Gooseponds to try and eliminate low oxygen-induced fish kills.

Councillor Karen May said the council participates in regular educational and fishing events at the Gooseponds to increase awareness.

"Tilapia are well-established in the Gooseponds catchment," she said.

"When tilapia become established in a system, they are virtually impossible to eradicate.

"We have already carried out predatory trials by releasing barramundi to hunt the pest fish species as well as employing electrofishing to help control numbers.

 

One of the world's most invasive fish species, the tilapia, has been found on the North Coast. Photo contributed
One of the world's most invasive fish species, tilapia populations can rapidly increase.

"Unfortunately, this has been largely ineffective as tilapia breed at a much faster rate than can be controlled."

Signage at the Gooseponds displays key information regarding tilapia and their impacts.

Biosecurity Queensland principal biosecurity officer Michelle Smith said education was key to combat tilapia.

"Tilapia must not be distributed, kept, or fed and must be killed immediately upon capture," she said.

"If you catch a tilapia you must remove it at least three metres from the waterway and kill it humanely.

"Tilapia are mouthbrooders and could have hundreds of eggs/hatchlings in their mouth, so the fish must be buried, as soon as practicable, away from the water body."

She confirmed noxious fish, such as tilapia, have been introduced by human activities.

"Our message to residents is not to empty unwanted fish tank contents into our waterways," she said.

"If you have unwanted material, plant or fish, please return them to where you purchased them from or destroy them humanely and bury them."

For more information on tilapia visit www.biosecurity.qld.gov.au.