Distribution and abundance of norwegian spring spawning herring during the spawning season in 1998

Abstract

During the period 17.02. -23.03.98 the mature and spawning herring were distributed along the Norwegian coast from 57°N - 69°N. Between 61°N and 69°N the biomass and abundance estimates were 5,3 million tonnes and 22,5 billion individuals respectively, whereas between 57°N and 60°N the respective estimates were 77 thousand tonnes and 344 million individuals. The 1992 year class predominated with 47% whereas the 1991 year class comprised 30%. The proportion of the 1991 year class inreased north of 62°N. Lenght specific somatic weight did not differ significantly with latitude. Spawning temperature decreased northwards and southwards from 62°N.