Bid to stop Tilapia invading the Gulf and threatening fisheries

Drastic steps are being taken to remove the introduced fish species Tilapia from Eureka Creek , 90 km North West of Cairns, to stop this damaging pest invading the Gulf.

Primary Industries and Fisheries Tim Mulherin said DPI&F officers will be damming 5kms of Eureka Creek, which flows into the Gulf, and then applying fish poison to the waterway to kill the tilapia.

Mr Mulherin said: “This exercise of removing pest fish from a flowing waterway, by using fish poison, had never been done before in Queensland.

“Pest fish have been removed from closed water bodies such as dams in the past but never a river system.

“This is an environmentally approved control method. The fish poison, Rotenone, will only kill species which breathe through their gills and will dissipate within 12 hours.

“Before the fish poison is applied, large native species will be fished out and re-located to other parts of the waterway.”

“This operation will greatly reduce the risk of these exotic pest fish from spreading into the Gulf region.

“Eureka Creek is a tributary of the Walsh River, which flows into the Mitchell River and then the Gulf of Carpentaria and the Endeavour River near Cooktown.

“This is the first time tilapia have been found in a western flowing waterway, and they would pose a major threat to commercial and recreational fisheries in the Gulf if large populations were to become established,” Mr Mulherin said.

Member for Cook Jason O’Brien said: “Tilapia are an aggressive, fast breeding fish and if left to populate a waterway, they will destroy the native fish population and the aquatic environment.

“There has been extensive consultation in the lead up to this exercise. Those consulted include Traditional Owners, Landcare, the Mitchell River Catchment Group, the Pest Fish Working Group, landholders, and irrigators,” Mr O’Brien said.

DPI&F senior fisheries biologist Malcolm Pearce said: “The poison is not harmful to humans but precautions have been taken with Sunwater to limit human and animal contact during the treatment.

“We have contained the treatment area by SunWater stopping the water flows from Solanum Weir and installing temporary sand dams immediately upstream and downstream of the Chillagoe Road Crossing,” Mr Pearce said.

“Rotenone is a plant-derived poison that rapidly degrades when exposed to light and moisture and has short-term environmental impacts.”

Tipalia are considered one of the world’s top worst 100 introduced species.

“After discovering Tilapia in Eureka Creek earlier in the year DPI&F used electro-fishing to reduce tilapia numbers in these catchments, however this is a short-term solution,” he said

“For a pest as invasive as Tilapia in a river system such as this, an equally invasive control method is necessary.”

Generally tilapia become established in new waterways by people moving them there. Fishers who catch tilapia must kill the fish humanely and dispose of them away from the water.

It is illegal in Queensland to possess tilapia alive or dead for any purpose. Fines of up to $150,000 may apply.

“Female tilapia may carry eggs in their mouth, and these eggs can survive long after the adult fish is dead,” Mr Pearce said.

“These fish reproduce rapidly and can quickly dominate waterways, forcing out native fish as well as introducing diseases and parasites.”

To report anyone suspected of moving tilapia, or report any sightings of tilapia, contact the Fishwatch Hotline on 1800 017 116.

Fore more information visit www.dpi.qld.gov.au

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