Escaped farmed Atlantic salmon grow, migrate and disperse throughout the Arctic Ocean like wild salmon

This paper describes the first observations of escaped farmed Atlantic salmon Salmo salar in the Arctic Ocean. Among 138 individuals of Atlantic salmon captured at the west coast of the Spitsbergen Island at Svalbard in the period 2008-2010, 11 individuals (8%) were classified as escaped farmed salmon based on genetic analysis and scale characters. The escaped individuals entered the ocean as a result of several different escape events. They had all escaped either at the smolt stage or early in the post-smolt stage, and had stayed one winter at sea. The growth of the escaped fish while at sea and their sizes were similar to those of wild fish captured at the same time in the same area. This suggests that farmed Atlantic salmon that have escaped early during the post-smolt period may grow, migrate, and disperse throughout the ocean like their wild counterparts, and survive to adulthood.