A New Methodology for Rapidly Acquiring

Comparative methods are presented which allow for quick and relatively reliable growth parameter estimates when growth data are not at hand. One of these methods involves the use of a newly developed "au ximetric grid.". An empirical equation for the estimation of natural mortality of any fish stock, given a set of growth parameters, is briefly reviewed. . . The methods are applied to data from the Gulf of Thailand trawl fishery, and the mortality caused by this fishery is estimated. '. '. The equations and data needed to derive stock recruitment relationships given catch, effort, and fishing mortality data are stated, and stock recruitment. relationships are given as examples which pertain to the false trey.allv Lactarius Jactarius and to the Indian halibut Psettodes erumei. In the lat~r fish, the demonstration is made that both recruitment and prerecruitment mortality, from 1960 to 1972, have been closely related to the size of the total demersal standing stock in the Gulf of Thailand. These various exercises are presented in order to demonstrate that an exhaustive analysis of the data available to date from tropical stocks and fisheries would contribute greatly to our understanding of the dynamics of tropical multispecies stocks. .