A comparison of trace element composition of the two groups of salmon ( Tables 3 and 4) reveals that the mercury in Western Pacific salmon is about the same as in Atlantic salmon, although the concentration of this strictly regulated element is the lowest in the muscle of Pacific pink salmon. Arsenic is distributed more uniformly in the wild Pacific salmon samples, ranging from 0.89 ppm in pink salmon to 1.36 ppm in chum salmon. The greatest variability among the Atlantic salmon bred in the rearing channels is ob-served in the Norwegian fish fillets. It ranges from 0.45 to 2.33 ppm, while the average arsenic concentrations are quite similar in both groups of salmon. Cadmium concentrations in the Norwegian samples that were measured in different years differ by an order of magnitude, ranging from undetectable traces to 0.11 ppm. In cadmium content, Pacific salmon stands between the Norwegian and Canadian fish.