PUSHY carp are being captured in a novel new trap.
South Australian scientists have built a trap that taps into the carp's urge to push through objects to gain access to wetland spawning grounds.
Carp swim through the trap's funnel entrance and are confronted by a row of weighted stainless-steel fingers.
- Watch the video of the trap in action.
- See the pictures by clicking on the picture gallery to the right.
Once they push through the fingers they become trapped in a containment cage that can be winched out of the trap.
The South Australian Aquatic Science Centre developed the trap after observing carp ramming their heads against mesh barriers in a bid to enter wetlands during spawning in September and October.
"Carp don't give a stuff if you're standing right next to them they're just so determined to get past these barriers," team leader Ben Smith said. "They'll damage their heads, even tear off their own jaws."
Dr Smith said native fish were relatively lazy and would often stay in the trap's first section where they could be released.
A 5kg female carp can lay a million eggs a year in three spawning cycles.
The jumping behaviour of carp has already been exploited by Torrumbarry weir keeper Alan Williams, who built a trap already in use along the Murray River.
But the SA team wanted a trap that could be installed in smaller wetland outlets, where carp go to breed.
A prototype has already been installed at Banrock Station in SA, incorporating push and jump traps.
About half the fish were caught in the push trap, although this increased during the peak spawning period.
The SA team is willing to advise community groups and catchment management authorities on designing and building push traps. They do not build or sell traps.
For details, phone Dr Smith on (08) 8207 5329 or email on smith.ben2@saugov.sa.gov.au
