Identification of fish communities in the Barents Sea: Is there a faunal discontinuity across the Polar Front?

Abstract

Fish species inhabiting the Barents Sea display great seasonal and between-year variation in abundance and distribution. This study describes the assemblages and distributions of fish species in the south-western part of the Barents Sea which includes the Polar front. The area has an unpredictable environment due to variable inflow of Atlantic water and assemblages and distributions of fish species differ between Arctic and Atlantic water masses. These assemblages can be identified as distinct groups corresponding to the different environments. In the period 1997 – 1999, 57 fish species and shrimp were identified and 32 species/species groups were used in the statistical analyses. Cluster and Correspondence analyses (CA) showed that the fish community consists of four different assemblages: A Northern, a Southern, a Deep and a Central group. In the Northern assemblage, species composition and spatial distribution varied least. The Central assemblage was the most variable. The Northern group included Polar cod, Atlantic poacher, spotted snake blenny and two species from the sculpin family. The Southern group included haddock and Norway pout. The Deep group included northern wolffish and long rough dab. Temperature explained 22% of the variation in the species data, and depth 12% of the variation. The assemblages are coherent with previous zoogeographic studies from the Barents Sea.