Assessment of fishable krill biomass on the basis of the acoustic surveys results using geostatistical methods

ABSTRACT Applicability of geostatistical methods in processing the acoustic fields of krill density based on the acoustic survey data is demonstrated. The results obtained indicate usefulness of these methods in studying the structure of krill density field for biomass assessment in compliance with different thresholds of their fishery importance. The structure of krill density field in Subarea 48.3 based on the surveys 2000 and 2002 indicates that krill fishable biomass is concentrated in small areas and constitutes only part of the total biomass concentrated within each coastal SSMU (SGW, SGE) in Subarea 48.3. The ratio between fishable biomass and total krill biomass may vary considerably by years and SSMUs reflecting inter-annual fluctuations of the krill density field structure. Keywords: acoustic survey, geostatistical methods, fishable biomass, density thresholds.