Carp in Australian Rivers: Problems and potential solutions
Gilligan, D., 2007. Carp in Australian Rivers: Problems and potential solutions. Oral presentation given at the 6th European Vertebrate Pest Management Conference, 11 – 15 September 2007, University of Reading, United Kingdom.
Common carp are one of Australia’s most despised introduced freshwater fish and have been implicated in the degradation of inland river systems. Although present in Australia for ~150 years, carp did not become a recognised pest until the appearance of the European Boolarra strain in the 1960s. Following colonisation of the Murray River, and aided by widespread flooding in 1974, carp populations rapidly spread throughout the Murray-Darling Basin and established populations in all states except the Northern Territory. Although commercial, anecdotal and some scientific data suggest that carp populations have since declined in many areas, the species continues to spread and invade new waterways. Numerous forums and workshops have been held to develop and progress potential carp control solutions. However, most assessments of potential control alternatives have failed to provide an effective means of managing the problem. These have included assessments of over-harvest, trapping, poisoning, exclusion, bio-controls, biotechnologies and habitat manipulation.
Over the last few years, at least four initiatives have begun to show some promise. These are: the Tasmanian Carp Management Program based on physical removal activities, carp separation devices which can remove carp as they migrate through fishways, a novel molecular genetic approach, ‘Daughterless Carp Gene Technology’, designed to integrate an inheritable gene into the population that limits the abundance of the highly fecund females, and the identification of discrete and finite carp breeding hot-spots within river systems to aid targeted control activities. The methods used to identify breeding hot-spots will be outlined and a project to trial the effectiveness of a control strategy based on targeting spawning/recruitment hotspots for catchment-wide carp control will be described.