ASFB Home > 2003 > Biological Invasions: Consequences for Parasites, Pathogens, Emerging Diseases, and Fisheries in the Marine Environment.

CARPSIM: A Tool for Evaluating Management Strategies for Carp (Cyprinus Carpio L.)

P. Brown¹ and T. Walker²

¹Marine and Freshwater Resources Institute, Snobs Creek, Private Bag 20, Alexandra Victoria, 3714 Australia.
²PO Box 114, Queenscliff, Victoria 3225 Australia
Email: paul.brown@nre.vic.gov.au

Common carp (Cyprinus carpio L.) are widely implicated in freshwater aquatic habitat degradation and are thus considered an important invasive pest fish species in Australasia for which resource managers and broader communities are currently seeking effective control measures.

Extensive sampling of Victorian carp stocksincluding age-validation and over 6000 age-determinations, and rigorous reproductive biology investigations has substantially increased our knowledge of feral carp population dynamics.

CARPSIM was developed as a simple age-based model to simulate the effects of a range of management scenarios on feral carp stocks. The model simulates change in population biomass by age and sex-specific growth; and simulates change in population abundance through recruitment and sex-specific mortality. Using empirical published stock-recruitment data and stochastic recruitment weighting-factors derived from local hydrological data or the southern oscillation index the model simulates the population dynamics of carp populations during a 200-year period.

Carp management scenarios simulated included the effects of fishing the spawning stock; of fishing the whole stock; of spawning or recruitment sabotage; and of driving the population sex ratio towards male dominance (eg. via daughterless carp). This paper compares outcomes of the simulated management using previously estimated biological parameters for two populations, as inputs.

Model predictions suggests that faster growing, shorter-lived populations may be better controlled by biasing sex-ratios to male-dominance, or spawning-sabotage methods whereas slower growing, long-lived populations may respond best to removal type approaches.

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