ASFB Home > The effects of spatial and temporal factors on the abundance of seven key finfish species along south-western Australia.

GENEtag: Pilot Studies Using Genetic Tagging to Monitor Fishing Mortality Rates and Catchability in Northern Australian Fisheries: A New Technique With Potential for Broad Application.

Rik Buckworth, Jenny Ovenden, Simon Hoyle, and Geoff McPherson

THEME: ASFB (Poster)

Measuring the impact of fishing is problematic in many fisheries: using Catch Per Unit Effort as an index of abundance has been widely discredited; surveys (eg trawl or net) are, especially for small fisheries, too expensive or simply not feasible, and tagging approaches are limited by tag shedding, mortality and under-reporting, as well as by expense. But even with considerable investment in monitoring and assessment programs, there have been notable catastrophic fishery collapses. Clearly we need additional monitoring methods for Australian fisheries The Fisheries Research and Development Corporation has funded a new approach to mark-recapture monitoring of fisheries, which we have termed 'GENEtag'. The basis of the approach is in situ collection of tissue samples, which provide genetic identification of individuals using microsatellite DNA - 'DNA fingerprinting'. These are thus tagged. The catch is subsequently screened for matches to these animals -recaptures. The fishing mortality rate is simply calculated from the recapture rate and the known screening fraction. The basic technical feasibility of in situ tissue collection and of the genetic methods have already been demonstrated. The FRDC program is to refine these techniques, with application at fishery scale as monitoring methods. Concurrent conventional tagging will be used no only as a control, but also as an auxiliary data source.