ABSTRACT
This chapter considers some empirical methods and models which are designed to assess temporal and spatial changes in the composition of exploited multispecies fish assemblages. C.F. Koch has provided one such study which indicated that most species occur rather infrequently in samples of species assemblages, and therefore, sample size effects may be large relative to the faunal patterns often reported. It is hoped that this material will provide a general overview of the logarithmic series distribution and that it will provide some rationale for an interest in its applications as they relate to tropical multispecies stock assessment methodologies. FAUNSIM was used to compare the demersal fish communities at a number of stations within the Samar Sea, Philippines in both time and space. Changes in assemblages of organisms are sometimes quantified by means of diversity indices.
