The development of tools for tracing and evaluating the genetic impact of fish from aquaculture
Escapes or releases of domesticated aquaculture fish pose a potential risk of adverse effects on native fish gene pools. In order to assure a prosperous and sustainable future for European aquaculture, the development of tools for identifying wild and farmed fish, interbreeding between them and effects on key fitness traits (survival and reproduction) is essential. AquaTrace will develop innovative molecular genetic tools, which will vastly improve the ability for tracing farmed fish in the wild and for documentation of their potential effects on wild conspecifics. The project will also contribute to environmental protection under the Marine Strategy Framework Directive (MSFD) with focus on biological diversity and non-indigenous species.
The rationale behind AquaTrace is to develop reliable and cost-effective molecular tools for the identification of the genetic origin of both wild and farmed fish (genetic traceability), as well as for the detection of interbreeding between farmed and wild stocks. This work will be carried out on three marine fishes of economic significance and with growing aquaculture activities, the European sea bass, gilthead sea bream and turbot. Until now, samples of fish have been collected across their
native distribution areas and from the majority of the main farms across Europe. Controlled experiments are ongoing with farmed and wild Atlantic salmon and brown trout in order to address the expected magnitude of effects of interbreeding of farmed fish on wild conspecifics. Such experiments serve to examine links between key fitness and life-history differences and specific functional genetic differences at the DNA level. AquaTrace scientific objective is to address and assess the genetic impact of
aquaculture escapees. Such non-indigenous fish can potentially introduce genes to wild populations that have been undergoing adaptation to farmed conditions through breeding and domestication selection. The methods and aims developed in the project also contribute to general knowledge on adaptation to local environmental conditions in wild populations, and thus also apply in a restocking context. It is further essential that the tools under development are validated to internationally recognized forensic standards to allow uptake by end-users. The application of tools for monitoring and mitigation must be seen as being supportive to the industry. It represents one of the many approaches that should be used to secure growth, economic prosperity and social acceptance. Similarly, traceability of products has become a specific request of consumers, sustained by national and European policies. Here, genetic tools offer cost-effective strategies for supporting quality plans, enforceable by law where required, aimed at tracing and monitoring the origin of aquaculture products.
The project is using cutting-edge genomic methods for developing thousands of SNP (Single Nucleotide Polymorphisms) genetic markers for the marine species and will start to apply these markers to baseline samples of wild and aquaculture fish. Subsequently, small, specific, powerful and cost effective SNP panels for determining the origin of the fish are developed as end-user traceability tools. Already developed large SNP panels for salmon and trout are now being applied to these species maintained under controlled experimental conditions, allowing identification of the genetic background of the fitness effects of domestication and interbreeding.