CCAMLR

Data collected during the krill target strength experiment [J. Acoust. Soc. Am. 87, 16-24( 1990)] are examined in the light of a recent zooplankton scattering model where the elongatedanimals are modeled as deformed finite cylinders [J. Acoust. Soc. Am. 86, 691-705 (1989)].Exercise of the model under assumption of an orientation distribution allows absolutepredictions of target strength to be made at each frequency. By requiring that the differencebetween predicted and measured target strengths be a minimum in a least-squares sense, it ispossible to infer the orientation distribution. This useful biological quantity was not obtainablein the previous analysis which involved the sphere scattering model.

Acoustic surveys are the most powerful tool of krill abundance estimation and distribution mapping. The International Community needs to prepare standard requirements and procedures for acoustic instrumentations to be used, as well as for survey design, data acquisition, processing, storing and analysis. In the paper possibilities and approaches to preparation of recommendations for acoustic surveys of different scales (macro, meso, micro) are reviewed. It’s concluded that the most items of the recommendations and standard procedures could be prepared and agreed basing on existing experiences and approaches to survey design and data analysis. The paper could be considered as a base for critical discussions of the recommendations to be prepared by international group of specialists.

Data on distribution and biomass of E.superba aggregations at Atlantic sector and near adjacent waters (subregions outside of the Scotia Sea are under pecular attention) are observed. Concentration of E.superba of the same order of biomass volume as in the Scotia Sea were observed at several subregions along the peripherie of Weddell Gyre and also nearshore of Antarctide. Offshore concentrations of E.superba show increased spatial irregularity. Development of fisheries activity in these new for catching areas should include the preliminar getting of knowledges on changeability of E.superba aggregation distribution prior to practical using of observed pattern of that changeability. It requires of additional complex of investigations, which should be directed to the evaluation of drift ways of E.superba as well as related changeability of aggregation location in the open-ocean environment. Exploitation of offshore aggregations of E.superba will be connected with regular search activity prior as well as at the course of every fishery season (year).