Report of the International Acoustic Survey on Blue Whiting in the Norwegian Sea

During August 1982 a coordinated acoustic survey on blue whiting was made in the Norwegian Sea. A total of 8 vessels from 5 countries participated, i.e. U.S.S.R., Norway, Faroe Islands, Iceland and German Democratic Republic. All vessels, but one had integrator.

Prior to the survey the acoustic instruments were. calibrated against a standard target (60 mm copper-sphere), which enabled the measured echo intensities to be converted into comparable units.

Blue whiting was found distributed over larger parts of the Norwegian Sea, on the warmer side of the polar front. Highest concentrations were recorded in the southern part, especially between Faroes and Iceland.

The acoustic estimate, based upon a fish length-dependent density coefficient, gave the result of 4.6 milI. tonnes of blue whiting within the are covered. This is considered to represent. the majority of the total stock in the northern area.