Total mercury and methylmercury levels in commercially important fishes in Japan

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.