AQUATRACE: PROVIDING MOLECULAR TOOLS FOR ASESSING AND MONITORING POTENTIAL GENETIC IMPACT OF AQUACULTURE ON NATIVE POPULATIONS

Einar Eg Nielsen* and the AquaTrace Consortium
* Technical University of Denmark, National Institute of Aquatic Resources, Vejlsøvej 39, 8600 Silkeborg , Denmark, een@aqua.dtu.dk.

The development of tools for identifying wild and farmed fish, interbreeding between them and effects on key fitness traits (survival and reproduction) is essential. The aim of the EU 7th Framework project AquaTrace is to develop innovative molecular genetic tools, which can vastly improve the ability for tracing marine farmed fish in the wild (European sea bass, gilthead sea bream and turbot) and for documentation of their potential effects on wild conspecifics with Atlantic salmon and brown trout as model species.

Extensive sample collection and DNA extraction from wild and aquaculture specimen for the three marine species has been conducted. In total more than 9.000 samples (3.500 gilthead seabream, 4.000 European sea-bass and 1.500 turbot) have been processed. More than 6.000 of these have been used for ddRAD (Double Digest RADseq) single-step genetic marker development and genotyping. SNPs (Single Nucleotide Polymorphisms) have been identified through bioinformatics analysis of the genomic data and 3611, 2177 and 5860 SNPs have been identified from European sea bass, sea bream and turbot, respectively.  Preliminary population genetic analyses have been carried out and we report on progress for all three species.

In relation to the model species the planned experiments on brown trout and salmon have been successfully completed. Extensive data on the relationship between the farmed/wild origin of a salmon/trout and their performance under different environmental conditions has been generated and is still being analyzed. Some results have, however, already emerged. For instance it has been shown that farmed salmon kept under different temperatures (on average) outgrew the wild fish in all treatments, while farmed/wild hybrids displayed intermediate growth. More progress from the trout and salmon experiments will be presented.

Based on the results from the marine and model species AquaTrace will be preparing a risk assessment, which will be an important document for mitigation of potential problems with escapees for the marine species across Europe. We report on the framework for this risk assessment and how it can contribute to a prosperous and sustainable development of European aquaculture.