Stillehavsøsters i Norden. Datainnsamling og bestandsvurderinger som grunnlag for forvaltning og høsting av nordiske bestander av stillehavsøsters, Crassostrea gigas

Mapping the invasion: spatiotemporal distribution of the Pacific oyster in Scandinavia

Master's thesis in Coastal ecology (BIO501) The Pacific oyster (Magallana/Crassostrea gigas) is an invasive species to Scandinavia, originating on the Pacific coasts of Asia. Introduction to Europe of these oysters was a result of farming initiatives, put in place following declines of the native oyster species (Ostrea edulis). The oysters were introduced to Denmark, Sweden, and Norway in farming trials during the 1970s, however Norwegian and Swedish populations have also been a consequence of larval drift. They are not currently commercially farmed in any of the three countries due to the effects that wild populations have on the areas they invade. To map historical and present distributio…