ABSTRACT
This chapter considers questions that related to the estimation of the state of commercial stocks. To estimate the state of the stocks by the acoustic method, an acoustic survey of the habitat of distribution of commercial items is carried out. While conducting acoustic surveys of biological resources in various fisheries basins, not only the overall biomass of items is estimated, but also their differential quantities of age composition. The survey periodicity depends on the state of the stocks of commercial items. More frequent surveys are necessary with an intensely harvested state of stocks or under anomalous natural conditions, when seasonal control is required. A major condition of efficient stock estimation consists of the choice of the time for initiation of an acoustic survey. For estimating a biomass of commercial concentrations within the water column, an acoustic survey is usually sufficient.
