INVASION: New pest fish threatening barra numbers
EXCLUSIVE: AN AGGRESSIVE and carnivorous pest fish that poses an extreme risk to native species has been found in large numbers in Mackay.
The discovery of the Jaguar Cichlid in the lower Pioneer River is one of only two reported cases in the entire country.
The predatory species is native to freshwater habitats in Central America and Fisheries Queensland considers it a biosecurity risk.
Catchment Solutions fisheries ecologist Matt Moore said Jaguar Cichlid were first found in the Fursdon Creek Catchment in 2014.
Mr Moore said it was likely the decorative aquarium fish was released into the natural environment.
An eradication program using Rotenone, a naturally occurring poison that is toxic to fish, in January 2015 was thought to have curbed the problem after follow up monitoring found no evidence of the species.
But two 120mm Jaguar Cichlid were found in waterways in 2017.
Mr Moore said the find was concerning at the time but did not appear a huge cause for alarm because of the fish were so small.
The species have populated further at the Gooseponds since 2018 and electro-fishing at Fursdon Creek in 2019 uncovered three large adult fish.
Mr Moore said the species was well suited to survive in local waterways and posed a risk, in particular, to juvenile barramundi.
"They just eat fish," he said. "Where they are located here is the same place as the nursery ground of barramundi.
"They are a threat to all fish that live (in the area)."
Currently the species is confined to the lower Pioneer River down from Dumbleton Rocks.
The only other outbreak of the species was successfully eradicated in Western Australia from an enclosed waterway - however the task would be more difficult in Mackay as the water is free flowing.
A Queensland researcher said the introduction and spread of non-native species posed a significant threat to freshwater ecosystems, and was the single biggest danger to the survival of threatened species in Australia.
Mackay Fish Stocking Association is doing its bit to stop the scourge of invasive fish.
Association spokesman Keith Day said stocking native fish across the region helped, but it was like fighting a losing battle if other measures were not employed to help.
The association stocks barramundi and sooty grunters, which are both native to Mackay, to boost numbers for fishing and keep pest populations under control.
"With tilapia it is almost impossible to stop," he said.
"You need a good environment so native fish survive well and eat as many (pests) as they can."
If you catch a suspected exotic fish, take a photograph and report it to the Department of Agriculture & Fisheries online report a pest fish page, or phone the DAF call centre on 13 25 23.