Development of an integrated carp management strategy for the Torrens Lake, Adelaide. Final report to the Adelaide city council.
Abstract
This is the final report of development of an integrated carp management strategy for the Torrens Lake, Adelaide, South Australia. The current project aims to: (1) use acoustic-tagged carp to evaluate movement patterns and the spatial and temporal habitat associations of carp within the Torrens Lake; (2) evaluate options of harvesting carp and gain knowledge of the species' densities through a targeted harvest/mark-recapture experiment; (3) provide recommendations for the cost effective control of carp within the Torrens Lake system. The data collected to date are important in determining the appropriate strategy to manage carp with in the Torrens Lake. Given that carp are predominately displaying exploratory movements throughout the system, passive control techniques that aim to exploit predictable/seasonal large-scale migration behaviour (e.g., carp separation cages) will have limited effect and a more active targeted approach is required. Of the harvesting strategies trialled, electrofishing proved to be the most efficient during the 2011 targeted harvest. Although netting was not as effective it should continue to be evaluated during an ongoing control program. The future application of these techniques will require careful planning, in-field evaluation and long-term monitoring to optimize a harvesting strategy (i.e. timing, duration, frequency). Ideally, this strategy should aim to achieve predefined management targets (i.e. reduce density to <50 kg/ha) and rely on an understanding of the ecology and population dynamics of carp (i.e. triggers for successful spawning/recruitment, population size/structure, etc).