Open access publications in the SLU publication database

<p>The pink salmon (Oncorhynchus gorbuscha) belongs to a genus of twelve species, commonly referred to as pacific salmons. Several species within the genus, including the pink salmon, are semelparous, i.e. they spawn only once and die soon after spawning is completed. The pink salmon is the smallest of the Pacific salmons and is the most numerous of them in the Pacific Ocean. Several of the species within the genera, including the pink salmon, have been introduced at different sites in the world - beyond the natural range of the species. There is a well-founded concern that invasive alien species will adversely affect domestic species. A review made in 2004 showed that invasive species are involved directly or indirectly in 6 % of all extinctions or severe population reductions of native species worldwide. In Sweden there are currently about 2000 introduced species of which 350 are classified as invasive, i.e. they threaten biodiversity and ecosystem services. Pink salmon has recently been caught or observed along the Norwegian coast, the Swedish west coast, Jutland in Denmark as well as in Ireland and Scotland, especially during 2017. These individuals of pink salmon originate from Russian (Soviet) stockings at or near the Kola Peninsula during the period 1956 - 1998. It is certain that the species is established in the northern Arctic Ocean and is now in a rapid expansion phase. The possibilities of eradicating the species are probably completely gone and it is uncertain whether the Russian authorities have the desire or the possibility to take any actions in that direction. The species may adversely affect native salmonids and, from a fauna-welfare perspective, it would be beneficial if the pink salmon could be limited, both its numerals and its dispersal. The pink salmon has a strict two-year cycle and in the Pacific origins there are both odd and even-year stocks. As it is the stockings of odd-year populations that succeeded best in northwestern Russia, probably fewer individual of pink salmon will be observed in 2018, but possibly more than 2019, fewer 2020, more 2021, and so on. <br /></p>