A major Calanus finmarchicus overwintering population inside a deep fjord in northern Norway: implications for cod larvae recruitment success

High Calanus finmarchicus abundances were recorded in wintertime in Vestfjorden, close to the main cod breeding grounds off Lofoten and Vesteralen, northern Norway. The mean abundance for locations with water depth >500 m was similar to 37 000 ind. m(-2) (range: 26 700-49 000 ind.m(-2)). To our knowledge, this is the first report of massive overwintering of C. finmarchicus on the Norwegian shelf. Because of the observed size and location of this population, we argue that local overwintering on the northern Norwegian shelf can contribute significantly to sustain a C. finmarchicus population on the shelf during the period of first feeding for cod larvae. This is supported by a particle tracking model.