Genetic Resources of Atlantic Salmon (Salmo Salar L.) in Teno and Näätämö Rivers, Northernmost Europe

Protein electrophoresis was used to study genetic variation and population structure of anadromous Atlantic salmon in two rivers of northernmost Europe. Eye, liver, and muscle tissues were analyzed from a total of 1540 fish from 23 and 4 locations in Teno and Naatamo Rivers, and 14 proteins encoded by 36 loci were screened. Eight loci were variable, and mAAT-1,2* and PGDH* expressed variation not previously described in Atlantic salmon. All samples from different locations were in Hardy-Weinberg equilibrium at the 5 % significance level. Observed heterozygosities varied from 1.8 % to 4.8 % in different locations, with averages of 3.4 % and 4.3 % for Teno and Naatamo, respectively. Average unbiased genetic distance (NEI 1978) between locations was 0.0023, with a range from zero to 0.013. Hierarchical gene diversity analysis indicated that 0.3 % of the total genetic variation was distributed between the two drainages, 2.6 % among tributary systems within drainages, 3.5 % among sampling locations within tributary systems, and 93.6 % within sampling locations. The results suggest that there is a potential of local adaptations within sampling locations, and that genetic variation within a drainage is not negligible and should be recognized by fishery management practices, but we emphasize that genetic divergence in enzyme loci is only one criterion when defining fishery management units.