THE ACOUSTIC METHOD AS USED IN THE ABUNDANCE ESTIMATION OF CAPELIN (MALLOTUS-VILLOSUS MULLER) AND HERRING (CLUPEA-HARENGUS LINNE) IN THE BARENTS SEA

Regular acoustic surveys for the abundance estimation of capelin have been carried out in the Barents Sea since the early 1970s, while for s mall herring, this has been done since 1983. The estimates are used in assessment, ecological studies and, for herring, in modelling of the natural mortality rate to assess recruitment. The surveys, which are w orked jointly between Norway and Russia, cover large parts of the Bare nts Sea region twice a year. There have been problems in estimating th e capelin as 1 year-olds, but with increased coverage of the total dis tribution area, it seems, as if this problem has been solved, and the acoustic method has developed to be the only realistic method of estim ating abundance at age of the small pelagic species in the area. This work is a presentation of the application of the acoustic method as us ed in the abundance estimation of small pelagic fish. (C) 1998 Elsevie r Science B.V.