Researchers from Murdoch University’s Harry Butler Institute have captured the largest carp ever recorded in Perth, as part of a collaborative program where feral fish are removed from WA waterways.

The “whopper” female carp, measured at 823mm in length and 11.9kg in weight was ready to spawn, carrying more than 3 million eggs.

Cindy Palermo, Research Assistant at the Centre for Sustainable Aquatic Ecosystems, caught the carp in wetlands at Careniup Reserve, Gwelup, last month.

“When the fish was stunned by the electrofishing boat, I couldn’t believe the size of its head sticking out of the water,” she said.

“It was so heavy that it took two of us the bring it onboard the boat. Thankfully Tom Ryan and Dr. Jake Daviot were there to lend a hand.”

Feral fish species, such as carp and goldfish, have had a significant impact on Perth's freshwater systems.

They compete with native species for food, severely degrade habitat and water quality, and spread diseases, all of which directly impacts native aquatic biota.

The program, the WA Urban Carp and Goldfish Roundup, aims to address these issues by humanely stunning and removing feral fish from waterbodies using electrofishing.

“We have an ambitious program operating over the next 3 years over 21 different waterbodies where we plan to demonstrate the benefits of ongoing pest fish control programs on the health of urban wetlands on the Swan Coastal Plain,” Ms Palermo said.

The WA Urban Carp and Goldfish Roundup is funded by the Australian Government’s Natural Heritage Trust under the Urban Rivers and Catchments Program, with the support of Murdoch University's Centre for Sustainable Aquatic Ecosystems, OzFish Unlimited as well as Local Government Authorities of Western Australia.