Evaluating genetic traceability methods for captive-bred marine fish and their applications in fisheries management and wildlife forensics

摘要

Growing demands for marine fish products is leading to increased pressure on alreadydepleted wild populations and a rise in aquaculture production. Consequently, more captive-bred fishare released into the wild through accidental escape or deliberate releases. The increased mixing ofcaptive-bred and wild fish may affect the ecological and/or genetic integrity of wild fish populations.Unambiguous identification tools for captive-bred fish will be highly valuable to manage risks(fisheries management) and tracing of escapees and seafood products (wildlife forensics). Using singlenucleotide polymorphism (SNP) data from captive-bred and wild populations of Atlantic cod Gadusmorhua L. and sole Solea solea L., we explored the efficiency of population and parentage assignmenttechniques for the identification and tracing of captive-bred fish. Simulated and empirical data wereused to correct for stochastic genetic effects. Overall, parentage assignment performed well when alarge effective population size characterized the broodstock and escapees originated from early generationsof captive breeding. Consequently, parentage assignments are particularly useful from a fisheriesmanagement perspective to monitor the effects of deliberate releases of captive-bred fish on wildpopulations. Population assignment proved to be more efficient after several generations of captivebreeding, which makes it a useful method in forensic applications for well-established aquaculturespecies. We suggest the implementation of a case-by-case strategy when choosing the best method.