Abstract
The proportion of methylmercury to total mercury in the flesh of salmon ( Salmo salar ) 1 to 7 years old and sea trout ( Salmo ocla ) 1 and 2 years old was found to average 93 percent with a range of 81 to 98 percent, and to be independent of the age of the fish. In salmon and sea trout 1 and 2 years old, methylmercury constituted 26 to 67 percent of the total visceral mercury, without age dependence.