The purpose of this paper was estimating commercial fleet impact on krill population in different months over 1987-1990 fishing seasons, during which the Soviet fleet’s yields from Subareas 48.2 and 48.3 amounted to at least 95% of total catch. The calculations were based on the Soviet fleet haul-by-haul data using a model of probabilistic-statistical theory of fishery systems developed in the AtlantNIRO. Intensity of commercial fleet impact on krill population, on biomass and density of krill aggregated in the fishing grounds was assessed basing on 22800 haul data. The analysis of Soviet fleet operation during the seasons of its largest fishing pressing shows no fishing effect on the krill stock and, consequently, on krill-dependent predators. Krill fishery, neither by the removal value nor by intensity, was competitive with dependent predators for the krill resource. In this case, a certain spatial overlap of the ecological niche of dependent species and the fishery has taken place rather than functional overlap.