New invader as Mackay named nation’s pest fish capital
MACKAY is becoming the unofficial pest fish capital of Australia after after yet another foreign predator was spotted in the region's waterways.
Images of a large white and orange fish in The Gooseponds under the Willetts Rd bridge have alarmed ecologist and fisheries expert Matt Moore, who believed the creature was yet another introduced species.
The Catchment Solutions fish biologist said while it had not been confirmed, he was certain the fish was an albino oscar, a South American cichlid with the potential to decimate the region's native fish stocks.
He said the omnivorous fish was popular in pet shops and aquariums.
Mr Moore said cichlids were known to be "bullies" in the fish tank, and would push around and even eat other animals.
"It will eat anything that fits in its mouth," Mr Moore said.
And in the wild their "highly predatory" nature could destroy Mackay's fish stocks, he warned.
Mr Moore said the oscar was the latest fish to join the school of introduced pests in Mackay.
In November 2019 jaguar cichlids were found in large numbers in the lower Pioneer River, as one of only two reported cases in the entire country.
Mackay was also the first place in Australia for peacock bass to be discovered in the wild in 2018.
They join convict cichlids, which were found in 2016, and the pest fish tilapia, which were first hooked in The Gooseponds in 2014.
"Pest fish are an ecosystem health metric," Mr Moore said.
"That's a lot of new fish in a quick succession.
"Mackay is starting to get a reputation for pest fish."
Mr Moore said Mackay's tropical climate matched the South American climate where many of the pests originated.
But he said the main reason for the pest fish explosion was human, not environmental.
"It looks like people are doing this on purpose," Mr Moore said.
Mackay Area Fish Stocking Association chairman Keith Day said he was shocked "ignorant and stupid" residents were still releasing their unwanted aquarium fish.
"Obviously these pest fish do not walk there," Mr Day said.
"I find it hard to believe that any human with an ounce of intelligence can still do this.
"People have no concept of the damage these fish can cause to our waterways.
"Take the bloody thing back to the pet shop … or better yet cut the bloody thing's throat."
Mr Day said fish owners could give their unwanted fish to the MAFSA where they would humanely put it down.
Mr Day called for greater restrictions on pet shops selling the fish, including recording and tracking purchases.
"Any fish that is introduced that is not native to the waterway can potentially create an ecological disaster.
"There would be an uproar if pet should started selling jaguar or baby tigers.
"Imagine the furore if jaguars were let loose and started climbing trees and killing koalas.
"There would be an uproar."
A Biosecurity Queensland spokeswoman said if the oscars became established in Mackay, they would be virtually impossible to eradicate.
"Although a variety of methods have been tried, there is currently no single, effective broadscale control method," she said.
"If caught, it is illegal to release to oscar cichlids back into the environment.
"They should be buried above the high water mark or disposed of in an appropriate waste receptacle.
"At a local level, each local government must have a biosecurity plan that covers invasive plants and animals in its area."
She said anglers should report sightings and send photos of the oscar to Biosecurity Queensland via www.daf.qld.gov.au/fisheries/pest-fish/report-a-pest-fish-sighting or by calling 13 25 23.