Abundance indices for the Arcto-Norwegian cod for the period 1979 -1986 based on investigations in June/July
Original version
This report is not to be cited without prior reference to the authorsAbstract
Postlarvae Surveys have been carried out in the western part of the
Barents Sea in June/July since 1977. The aim of the investigations
has been to study the distribution pattern of fish larvae and their
relation to the distribution of water masses; and to establish
abundance indices. It has been shown that mesoscale features of the
larval distribution are very pronounced, and that they are connected
to the circulation features. The survey strategies were changed in
1983, and emphasis was laid on the investigation of cod larvae. For
all years, except for 1986, postlarval cod have been especially
abundant at the bank Tromsøflaket. It is partly due to the reduced
diffusion by the existence of the anti-cyclonic vortex above the bank.
After three strong year classes in 1983, 1984 and 1985, the results
for 1986 indicate a very poor year class, and practically no larvae
were found at Tromsøflaket. The anomalous distribution in 1986 is
discussed. Postlarvae and 0-group indices arc discussed and compared,
and a correlation coefficient of 0.82 was found for the period
1979 -85.