Abstract The past 150 years have seen enormous advances in the development of genetics theory and molecular methods to survey genetic variability in natural populations. In the late 1800s, the identification of “races” among populations of fishes paralleled concepts in the human Eugenics movement at the time. Later, the developments of population genetics theory and of statistical tests provided the foundations for the application of genetic concepts to fishery problems. The methods used to study natural populations were restricted to the analysis of phenotypic traits, such as morphology and meristics, which had an unknown genetic basis. Tag recoveries and analyses of otoliths, scale rings, fin and vertebral counts, and spawning timing were used to define biologically discrete population units. Genetic markers to define genetic boundaries between stocks of fish appeared only in the 1960s. Early methods included the electrophoretic analyses of proteins to produce genetic population tags that could be rigorously analysed with statistics. The analysis of DNA was initiated in the 1970s with the discovery of restriction enzymes to probe DNA sequence variation. The development of the polymerase chain reaction to amplify specific regions of DNA led to the development of random amplified polymorphic DNA markers, microsatellite markers, DNA sequences (especially of mitochondrial DNA), and more recently single nucleotide polymorphisms. The analysis of DNA in archived tissues, such as fish scales and otoliths used for aging, provides insights into historical population dynamics and the analysis of environmental DNA aids in biodiversity assessments. The development of cost-effective genomic DNA analysis underpins new approaches for better understanding adaptation to local habitats. From its inception, the ICES Journal of Marine Science has published articles that recognized the importance of incorporating genetic principles into fishery management. While the Journal has published genetic research on numerous species, this review follows the development of genetic methods in three commercially important species: Atlantic herring, Atlantic cod and Atlantic salmon.
W. Stewart Grant (Sat,) studied this question.