The acoustic method as used in the abundance estimation of capelin (Mallotus villosus Muller) and herring (Clupea harengus Linne) in the Barents Sea

Abstract

Regular acoustic surveys for the abundance estimation of capelin have been carried out in the Barents Sea since the early 1970s, while for small 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 worked jointly between Norway and Russia, cover large parts of the Barents Sea region twice a year. There have been problems in estimating the capelin as 1 year-olds, but with increased coverage of the total distribution area, it seems, as if this problem has been solved, and the acoustic method has developed to be the only realistic method of estimating abundance at age of the small pelagic species in the area. This work is a presentation of the application of the acoustic method as used in the abundance estimation of small pelagic fish.