Preliminary report of the Norwegian investigations on young cod and haddock in the Barents Sea
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Original versionThis report is not to be quoted without prior consultation with the General Secretary.
An acoustic survey and a bottom trawl survey for cod and haddock were carried out in the Barents Sea during the winter 1986. As a result of strong improvement in the recruitment for both species, most of the echo abundance is presently from the youngest age groups and the proportion of the biomass found pelagically has been rapidly growing during the last three years. Sampling with midwater trawl has therefore been increased. While the calculations previously were made by pooling all the data from midwater and bottom trawl, the calculations of numbers at age for 1985 and 1986 have been made using midwater trawl samples, for the pelagic echo abundance and bottom trawl samples for the echo abundance in the bottom layer. The main effect of this change of method is to shift the estimated age distribution from 1 and 2 year old fish to 3-4 year old fish. The results of the acoustic survey confirm the previous findings for cod that the 1983 year class is strong, and that the average recruitment for the period 1982-1985 is substantially higher than the long-term average. For haddock the estimates are much higher than those used in the stock assessment in 1985.
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