Application to shrimp stocks of objective meathods for the estimation of growth, mortality and recruitment-related parameters from length-frequency data (ELEFAN I and II)

Abstract

This paper presents applications to several shrimp stocks of a new, computer-based set of methods for the detailed analysis of length-frequency data. These applications include the objective estimation of growth parameters, including seasonally oscillating growth, and of total mortality as. estimated from length-converted catch curves and from mean lengths. A method for obtaining estimates of natural mortality in shrimps is discussed. Methods are also presented by which inferences can be drawn on the pattern of mesh selection prevailing in the fishery from which the length-frequency data were obtained. Finally, a method is presented which helps assessment of the seasonality of the recruitment of young shrimps into a fishery.