Carp cages are helping to clean up the Lachlan River as part of a carp cleanup program organised by NSW DPI, the Lachlan Catchment Management Authority, the South Australian Research and Development Institute and the Invasive Animal Cooperative Research Centre.
Fisheries Minister Ian Macdonald said the River Revival Lachlan River Carp Cleanup project involved the installation of a carp separation cage at the Island Creek weir, 20km east of Condobolin, in the state’s Central West.
“Carp cages have been successfully used in several locations along the Murray River as part of carp eradication programs,” he said. “The density of carp in the Lachlan catchment is the highest of any catchment in the State.
“The beauty of the carp separation cage is that is can assist in controlling the pest fish without impacting on native species.”
The research leader of the DPI’s Aquatic Ecosystems Unit, Dr Bob Creese, said the cage worked because carp tend to jump out of the water when they were faced with a barrier, in an effort to get over it.
“This effectively results in the pest fish jumping into a large steel trap with no exit, enabling their removal from the river system,” he said.
“Native fish do not show this jumping behaviour and instead tend to swim down to the riverbed and find passage underneath the barrier.”
The DPI will work in close conjunction with State Water, who own and maintain the Island Creek Weir, in a 12-month trial of the cage before handing the management of the cage over to the community or a commercial fishing interest.
The trap is designed to hold up to 500kg of carp, Dr Creese said. During the warmer months, which are peak time for carp movement, the trap may need to be emptied up to twice a week, which would be a significant result.
Further cages in other locations within the Lachlan catchment, such as the Bumbuggan Weir, are currently being considered.
Other known and potential carp breeding hot spots in the lower Lachlan are the Great Cumbung Swamp, Lake Brewster, Lake Cargelligo and Lake Cowal.
This cage will complement other carp control works under way in the Lachlan catchment, including the targeting of carp breeding hot spots such as Lake Brewster and the Great Cumbumg Swamp, commercial fishing feasibility studies and recreational fishing events sponsored by the River Revival Lachlan River Carp Cleanup.
NSW DPI has recently completed a two-year benchmarking phase to determine the status of the carp population in the Lachlan catchment.
Anglers who capture a tagged carp are eligible for a small reward such as a hat, drink cooler or lure. Report captures and the tag number on the tag return hotline on by phoning 1800 185 027.
– DPI FisheriesReads: 5897