Exploitable biological vulnerabilities of common carp

CarpVulnerabilities_coverThis project synthesises the outputs of various projects supported by the Freshwater Products and Strategies Program of the Invasive Animals Cooperative Research Centre (IA CRC) in order to assess weaknesses of carp that can be exploited for their control.
Some of the key vulnerabilities identified that may contribute to carp management in Australia include:

Limited number of carp spawning sites:
It was found that although adult carp populations were widespread and abundant across the MDB; these populations were supported by a limited number of areas where juveniles were presen. This suggests carp reproduction is localised and restricted to a relatively small number of ‘hotspots’ within the MDB. Such identification of hotspots allows carp  control to be targeted at a key number of recruitment sources rather than scattered over tens of thousands of river kilometres.

Limited carp movement:
It was found that adult carp move at relatively small scales between sub-catchments in the MDB, particularly in low-flow conditions. Limited adult carp movement suggests there is strong potential for using cost-effective, targeted physical, chemical and/or biological control strategies at local and regional scales since control of adult carp may be sustained in certain areas by consistent methods that prevent either re-colonisation of juveniles or the reproduction of new colonisers.

Innate behaviours:
Research confirmed that carp have innate behaviours. Juvenile and adult carp migrate annually between river and wetland habitats for spawning from early August onwards. During spawning times, carp were attracted to flowing water and moved upstream towards the source of the flow. Carp also had an innate ability to push past or jump over barriers, even in shallow waters < 40 cm. Therefore carp control strategies that focus on intercepting and harvesting carp at wetland entrances are particularly desirable as migrating carp are vulnerable to trapping.

Genetic structure:
Within the Murray-Darling Basin, three discernible strains of carp were identified descendant from the European/central-Asian subspecies Cyprinus carpio carpio. Most importantly the three strains were found in distinct locations within the regional scale. The identification of specific locations for carp strains within catchments builds upon the evidence that there are discrete management units that could be routinely targeted at the local scale for carp control programs.

Reference type Report
Secondary title PestSmart
Author Gehrig SL and Thwaites LA
Year 2013
Place published Canberra
Publisher SARDI Aquatic Sciences
Institution Invasive Animals CRC
Pages 75
ISBN/ISSN Web ISBN: 978-1-921777-71-4
Region Australia - national
Documents Exploitable biological vulnerabilities of common carp  [2.4 Mb PDF]
Links PestSmart toolkit: Carp - www.pestsmart.org.au/pestsmart/carp/