Kartlegging av fremmede marine arter i Hordaland

Abstract

The method Rapid Coastal Survey was applied in a pilot project in the county of Hordaland in autumn 2010. The abundance of 21 introduced target species was investigated in 32 marinas in the area. No new species to Norway was found, but six species already established in Norway were observed at a number of sites. The ascidian Styela clava, native to northwest Pacific, was recorded for the first time in the county of Hordaland. This species is established along the southern coast of Norway and in the county of Rogaland. The method is well suited for mapping of sessile organisms in shallow waters, but is less applicable for recordings of mobile animals such as crustaceans. The method is recommended for further mapping of introduced sessile species in Norway, and we recommend establishment of a taxonomic network in Norway for validation of observations of introduced species.