Total mercury and methylmercury levels in commercially important fishes in Japan

ABSTRACT:   The distribution of mercury in the muscle and other tissues was determined in 23 species of fishes and invertebrates. This study reveals species-specific patterns of mercury accumulation in the muscle of tuna and alfonsino. Consistently high levels of total mercury were found in Beryx splendens (0.78 ± 0.56 µg/g), Atlantic Thunnus thynnus (0.42 ± 0.06 µg/g), Pacific T. thynnus (0.59 ± 0.34 µg/g), Thunnus obesus (0.98 ± 0.34 µg/g), Makaira nigricans (0.56 ± 0.05 µg/g), Tetraptrus audax (0.51 ± 0.08 µg/g), and Xiphias gladius (0.47 ± 0.24 µg/g). Other fish species had lower levels of total mercury or methylmercury in muscle than the maximum permitted level of mercury in fish in Japan (0.4 µg/g). Total mercury and methylmercury levels in the muscles of T. thynnus , T. obesus, and B. splendens were closely correlated with body weight.