Estimation of Population Ecological Characteristics of Small Yellow Croaker, Pseudosciaena polyactis off Korea

Abstract

This paper deals with the estimation of population ecological parameters, including growth parameters, survival rates, instantaneous coefficient of natural mortality and age at first capture, of the small yellow-croaker, Pseudosciaena Polyactis in Korean waters, which determine fluctuations in stock abundance. For describing the growth of the small yellow croaker, von Bertalanffy growth equation was recommended for the purpose of stock assessment, although the Gompertz model yielded the closest fit. The survival rate (S) of the croaker was estimated to be 0.219 (variance=0.0000262), and the instantaneous coefficient of natural mortality (M) was 0.4year−1. From the estimates of S and M, the instantaneous coefficient of fishing mortality (F) was calculated to be 1.11year−1 implying an impact from fishing three times that of natural mortality. Finally, the age at first capture (tc) was stimated to be 0.602.