Abundance and distribution of 0-group Arcto-Norwegian cod and haddock 1965 - 1982

Abstract

The trawl data from the International 0-group fish surveys in the Baretns Sea are reanalysed for cod and haddock. Relative indices of yearclass abundance are estimated on a logarithmic scale. The most abundant yearclasses at the 0-group stage, for cod, are the 1970, 1973 and 1975 yearclasses and the 1970, 1974 and 1975 yearclasses for haddock. The estimated indices of yearclass strength give a correlation of 0.92 for cod and 0.89 for haddock with VPA (Virtual Population Analysis) estimates for the corresponding yearclasses at age 3 for yearclasses 1970-1976. 0-group haddock show a more western distribution than cod which may be related to a more western spawning area for haddock. Both cod and haddock show similar trends in changes in the east-west distribution over time. This is probably related to hydrographical factors such as changes in the relative strenght of the different currents in the area. A good correlation is found for both cod and haddock between the part of a yearclass found in the Barents Sea and the temperature anomalies in the Kola Meridian hydrographical section, but no correlation was found between the part of a yearclass in the Spitsbergen/Bear Island area and temperature anomalies in the Bear Island West hydrographical section.