We investigate the origin of wild corkwing wrasse captured in Flatanger, amidst Salmon farms where wrasses are currently used as cleaner fish and rely heavily on the import of wrasse from southern Norway and Sweden. We used the restriction-site associated DNA (RAD) sequencing method 2b-RAD to simultaneously discover and genotype thousands of SNPs (single nucleotide polymorphisms) across the entire genome. Our objective is to investigate whether the wild corkwing in Flatanger represent: 1) the leading edge of an ongoing northwards range expansion, 2) escaped wrasse from aquaculture with origin from Skagerrak and Kattegat, or 3) a mix of both. In order to answer these questions, we compared SNPs from corkwing wrasse collected in Flatanger with wrasse collected in: 1) western Norway, where wrasse is harvested but used locally, and 2) further south on the Skagerrak-Kattegat coast, where all wrasses are harvested for live transport to salmon farms in mid and northern Norway.</p><p>This is the raw data from this project