The migration of norwegian herring to icelandic waters and the environmental conditions in may-june, 1961-1964

Abstract

The present material on zooplankton, temperature and herring have been collected in the Norwegian Sea, from the Faroes along the east and north-east coast of Iceland to Jan Mayen as a part of the Norwegian herring investigations, in collaboration with Iceland and U.S.S.R. during May and June 1961-1964. Zooplankton was collected in vertical hauls from 50 m to the surface with a Juday net (1961-62) and a Hensen net (1963-64). Temperature was measured at standard depths from surface to 500 m. A termograph measured the surface temperature (at 4 m) throughout the cruises. Herring were located by horizontal and vertical accoustic fish detection devices (sonar, echo sounders). The herring have been observed migrating across the East Icelandic Current east or north-east of Langanes in waters below 3°C. The distribution and migrations of herring in relation to temperature, plankton biomass (ml/m³) and the distribution of the copepodite stages of Calanus finmarchicus are discussed.