Review of Russian investigations of krill escape through the meshes of commercial trawls: approaches to estimating gross removal at krill fishery

In this study the review of Russian investigations of krill escapement through the trawl netting fulfilled by means of instrumental (acoustic observations, underwater observations, method of fine-meshed chafers) and analytical methods are presented. The main factors affected on krill escapement though trawl netting and escape mortality are shown. The author discusses the results of these studies in two aspects: the problems and approaches to elaboration of the efficient methodology for the escape mortality assessment per one fishing operation and development of approaches to the total «escape mortality» assessment in krill fishery. It is suggested to use the models of probability-statistical theory of fishing systems developed in AtlantNIRO, for solving the following tasks: quantitative understanding of the «escape mortality» process; obtaining standardized indices of krill mortality during one fishing operation; assessment of krill fishing mortality intensity and fishing gross removal intensity by the vessel group.