GENETIC-MARKERS AND MIXED STOCK FISHERIES

This paper reviews and discusses the uses of genetic markers in analyz ing the composition of population mixtures of fishes. Such analyses re quire (1) the existence of genetic differences identified in base-line data from contributing populations, and (2) an adequate sampling of i ndividuals from the mixture to characterize its composition. Genetic a nalyses of complex population mixtures of salmonids began around 1980 and subsequently have been increasing; applications have included esti mates of geographic origins in marine and freshwater fisheries, and of ancestral origins in populations reestablished from multiple sources. The potential for applications of genetic analyses of population mixt ures is more limited in most marine species because such species are t ypically less genetically subdivided than salmonid species. However ge netic analyses are feasible in any species in areas of intermingling o f genetically distinguishable populations. In addition, genetic markin g by preferential breeding of genetically distinguishable individuals may be used to establish genetically distinct cultured populations wit hin species amenable to artificial propagation.