METHOD FOR EVALUATING OF COMMERCIAL FISH STOCK ON THE BASIS OF RESULTS OF ANNUAL OBSERVATIONS

摘要

FIELD: fish industry.;SUBSTANCE: method involves determining population of fish of first spawning age and spawning stock biomass; determining average individual fecundity of age group and number of fishes of the given age group related to year of birth, share of mature fishes produced at maturation peak stage, share of female fishes relative to spawning stock biomass and yearly fish survival coefficient before first spawning period; determining survival coefficient of population fecundity from formula: S = R_i/Σⁱ _nE_ind x N x m x r, and of spawning stock biomass: S_b=R_i/SSB, R_i is number of specimens of first commercial (spawning) stock generation related to year of birth; E_ind is average individual fecundity of age group; N is number of fishes of the given age group; m is share of mature fishes obtained at maturation peak stage; r is share of females in age group; SSB is spawning stock biomass; carrying out cluster analysis on the basis of results of annual observations of population of first commercial (spawning) specimens (Ri) and classifying into rich, average and poor generations; providing survival conditions classification on the basis of survival coefficients (S and Sb) for defining unfavorable, moderate and favorable conditions; on the basis of resultant data, providing classification of fish reproductive capacity into safe, minimal allowable (acceptable) and critical levels characterizing state of commercial fish stocks.;EFFECT: enhanced reliability in forecasting of reproductive capacity of commercial fish stock.;5 cl, 3 tbl