 Female carp secrete pheramones to attract
potential mates - and this can be used to
trap male carp.
Image: czanner/iStockphoto Researchers are using carp's sensitive sense of smell as one of the latest weapons against them as part of the "River Revival - Lachlan River Carp Cleanup" program. Staff from Industry & Investment NSW (I&I NSW) will be trialling the new technology developed for the Invasive Animals Cooperative Research Centre (CRC) at Hillston on the Lower Lachlan River from 25 October to 4 November. I&I NSW senior research scientist, Dr Dean Gilligan, said the technology had been developed by Professor Peter Sorensen from the University of Minnesota, USA. "Normally, when a mature female carp is ready to lay her eggs, she secretes pheromones to attract all the potential mates in the area. "The males attracted by her smell jostle for position around the female until she is ready to spawn. "Once she has layed her eggs, she stops producing the pheromones and the group of males disperses," he said. This would naturally occur over a quite short period of time in the wild. However, Dr Gilligan, said Professor Sorensen had devised a way to surgically implant an osmotic pump into female carp, which forces them to secrete these highly attractive pheromones continuously during a fourteen-day period. "By putting female carp implanted with osmotic pumps inside traps, we predict that we will be able to attract and capture large numbers of the sexually mature male carp from reaches where the "pheromone traps" are set. "We hope that these traps increase our catch rates and make it easier to attract and trap large male carp. "The traps will not be the "silver bullet" for carp control, but used in conjunction with other carp control strategies may give us the best chance of not only improving the health of the Lachlan River, but proving to the world that pest carp populations can be controlled," Dr Gilligan said. This research builds on the work undertaken between 2007-2009 by a collaborative team (comprising I&I NSW, Lachlan Catchment Management Authority, South Australian Research and Development Institute, Department of Sustainability and Environment, State Water Corporation, Kingfisher Research Pty Ltd and the commercial carp fishers K & C Fisheries Global Pty Ltd) to establish a demonstration site in the lower Lachlan catchment to trial and show-case carp control technologies developed by the Commonwealth funded Invasive Animals CRC. The project team also established carp exclusion plots, installed a carp separation cage on a fishway on Island Creek, identified the breeding hotspots of the local carp population and tagged and released more than 3000 carp, which can then be used to assess the relative efficiency of the range of carp removal tools available. "Since April 2009 the team has been removing carp from the Lachlan system. The intention for the ongoing second stage of this project is to demonstrate that it is possible to control carp through a variety of methods over a sustained period of time. "To date, hundreds of thousands of carp have been removed from the Lachlan catchment. Additional carp separation cages are currently being designed and installed at Bumbuggan Weir and at Booligal fishways with negotiations underway to install a fourth at Lake Cargelligo," Dr Gilligan said.
Editor's Note: Original news release can be found here. |
