Carping on over feral fish menace
GIANT feral fish, some up to a metre long, are infesting waterways on the Northern Rivers.
Carp are breeding in huge numbers in sections of the Richmond River and Bungawalbyn Creek. And the pest fish are spreading, with European carp also spotted in the Wilsons River at Lismore.
Richmond River County Council floodplain services manager, Michael Wood, said some of the fish spotted near Lismore were at least half-a-metre in length.
Koi carp about a metre long have been reported downstream near Tuckurimba.
Mr Wood said carp were amajor pest that caused serious environmental damage. They were introduced from Asiain 1887.
“It was one of those big mistakes, like cane toads,” he said.
“Carp are known as the rabbits of the waterways and they are agrowing problem in our region.
“We work hard to restore our creeks and waterways. We fix them up, but then these fish come along and do a lot of damage.
“They feed from the bottom, so they stir up the water and undermine creek banks.
“It makes waterways unattractive, reduces the abundance of aquatic plants and other fish, and can render the water unsuitable for livestock.”
Solving the carp problem will be difficult, Mr Wood admitted.
He said strategies to reduce numbers in other areas included releasing sterile fish into rivers to interrupt the breeding cycle.
“But with that kind of strategy we won't see progress for many years,” he said.
“This is going to be a major challenge.”
Mr Wood will today give Lismore MP Thomas George a first-hand look at the damage the carp are causing to the waterways, as well as other management problems associated with the Wilsons River.
His council is working on an estuary management plan, which should be finished by the end of the year.
“There are a lot of different pressures on our estuaries,” Mr Wood said. These included soil run-off, poor water quality, degraded river banks and weeds, he said.