Amazon predator threatens barra in river
A PEST fish usually found in the Amazon in South America has reportedly been found in Mackay's Pioneer River, with the potential to wipe out millions of barramundi and sooty grunter in a few short years.
The Department of Agriculture and Fisheries yesterday said the reported find of an adult Peacock Bass "appears to be the first confirmed capture of this species in Queensland waters", advising any fishermen who hook the fish to "kill it humanely".
Mackay Area Fish Stocking Association founding chairman Keith Day is livid, saying the only way the fish could have made its way into the Pioneer River was "human intervention"; someone deliberately releasing the noxious pest from an aquarium.
"It's very aggressive and has the potential to completely wipe out all of our native fish in the river system," Mr Day said.
"Several breeding pairs of these peacock bass have been released by persons unknown into the Pioneer River.
"If anybody put them into our dams (as well) they could do exactly the same thing there."
What the experts say
Fisheries biologist with Catchment Solutions Matt Moore said the fish in the photo was "definitely a peacock bass".
The biologist says numerous local fishing and tackle shops had reported anglers catching the invasive species over the past few months, but this photo was enough proof to report it to the department and Biosecurity Queensland.
Because of their global reputation of being a "bucket-list game fish", as Mr Moore points out, it's resulted in a number of deliberate releases into waterways they shouldn't be in across the world.
"(The photo is) the only evidence at the moment so really, to take this further we need to undertake some community monitoring in the Pioneer River under Dumbleton Weir to confirm 100% that they exist there, what their potential distribution is and what the abundance of the fish is.
"But it does appear at this stage that they are at the Dumbleton Weir, in the Pioneer River.
"We're pretty confident. But as fish biologists, we have to be careful and I don't like to say 100% convinced until I have a fish in front of me... but from all reports, we're very very certain that (this is a peacock bass)."
How'd it get here?
Mackay Recreational Fishing Alliance president John Bennett believed the fish would have come "from someone's tank", with the species readily available over the internet.
"The biggest thing we want to do is alert the public on these fish so that if they catch them, they won't release them," Mr Bennett said.
The peacock bass has the potential to "wipe out all the work that MAFSA has done for the last 25 years", Mr Day emphasised.
"After all the publicity on tilapia over the past few years, for somebody to go and buy peacock bass and release them into one of our waterways is completely irresponsible, sheer lunacy," Mr Day said.
"If people want to go and catch a peacock bass, they should get on a plane, fly to South America and go up the Amazon and catch one. We do not want them here."
Mr Moore said in South America where they have been released into some reservoirs, within two years there had been a 90% decline in native fish populations.
"So the impact of this fish when it has been released into waters outside its natural distribution has been disastrous," Mr Moore said.
Mr Day said he would be lobbying the federal government to ban importing pest species into Australia.
"I can't understand how a government could let these things come into the country in the first place. We have a sad history of importing species into the country which turn out to be absolute pests - look at rabbits," he said.
"The problem is they're imported aquarium fish but once they're sold there's no control with what happens, who's got them, what they do with them so it's open slather.
"We've had 25 years of volunteer work by the fish stocking association put in jeopardy because someone wants to catch a big peacock bass. If they want to catch a big fish, there's plenty of metre-plus barramundi into our dams."
Why are they so bad?
"Peacock bass are a high-order predatory fish," Mr Moore explained.
"They have a high potential to predate on juvenile barramundi, mangrove jack and mullet are far greater than the other invasive pest fish well- known in Mackay, the tilapia," he said.
"Tilapia feed on some native fish and molluscs and plants, the peacock bass will predate primarily on fish. They are very aggressive, they're a mouth breeder, so the young are kept in the mouths of the adults who will guard the young and they're very aggressive and territorial.
Mr Moore said there were 15 species of peacock bass, with it not immediately clear which one had been found in Mackay.
"They are a freshwater fish species, they're not like tilapia which can move between catchments of salt and freshwater," he explained.
"They need certain temperature regimes to breed successfully, so it's not one that can spread out to lower temperature waterways down south.
"But it is living in Mackay and will do so quite happily and people have been breeding them in farm dams potentially, and that is how it appears to have been released from aquariums who have kept them in dams. The vector is people spreading it."
DAF confirmed they were notified of the capture of a single adult Peacock Bass on January 15, 2018 from the Dumbleton Weir in the Pioneer River.
"Peacock Bass are not known to exist in Queensland waters. This report appears to be the first confirmed capture of this species in Queensland waters," a DAF spokesperson said.
"DAF officers are assessing the report to gain an understanding of the extent of the incursion."
Mackay Regional Council's Development Services director Gerard Carlyon said council had also been made aware of reports the invasive pest species Peacock bass had been found locally.
"People need to be educated that it is not okay and often illegal to release exotic aquarium fish in our waterways," Mr Carlyon said.
"Anyone caught intentionally releasing exotic pest species in waterways can face huge fines. We have highlighted problems with other exotics, such as tilapia, in the media in the past as they compete with and displace our native fish like barramundi."
LNP Shadow Minister Tony Perrett said reports that four pairs had been released near Dumbleton Weir, west of Mackay, needed to be confirmed and any possible eradication actions undertaken as soon as possible.
Mr Perrett said the South American species was responsible for widespread environmental damage in riverine systems.
"There needs to be a full investigation and assessment of what, if anything, can be done to eradicate this pest," Mr Perrett said.
Mr Perrett called on recreational fishers around Mackay with any knowledge of the issue to report what they knew to Biosecurity Queensland on 13 25 23.
Report your findings
Anglers that catch or spot Peacock Bass in the Pioneer River can report it to DAF by emailing photos to firstname.lastname@example.org.
Ensure the details of where the fish was sighted or captured are included when reporting the pest fish.
Once pest fish like Peacock Bass become established in large, open waterways it can be very difficult to eradicate them.
DAF's advice is, if caught, anglers should not return it to the water. Rather, kill it humanely and dispose of it properly.