Mercury Content in Pacific Troll-Caught Albacore Tuna (Thunnus alalunga)

Ninety-one albacore tuna (Thunnus alalunga) captured during the 2003 commercial fishing season were tested for total mercury content in muscle tissue. The fish were harvested between 32.72°N (off Southern California) and 48.30°N (off the northern tip of Washington) between July and November. Fish weighed from 3.14 to 11.62 kg and were 50.8-86.4 cm long. Total mercury content in the albacore muscle tissue ranged from 0.027 ppm (μg/g) to 0.26 ppm. The average total mercury content was 0.14 ± 0.05 ppm, which is below the U.S. Food and Drug Administration action level and Canadian standards (1.0 ppm methylmercury and 0.50 ppm total mercury, respectively). Total mercury concentrations showed positive correlations with length and weight of albacore (R2= 0.40 and 0.38, respectively), but there was no correlation with date of capture or lipid content. Results indicate that Pacific troll-caught albacore have low levels of total mercury in the edible flesh and are well within international safety standards for mercury levels in fish.