Food Research Division, Bureau of Chemical Safety, Food Directorate, Health Products and Food Branch, Health Canada, Ottawa, Ontario, Canada. bob.dabeka@hc-sc.gc.ca
Source
Food Addit Contam Part A Chem Anal Control Expo Risk Assess. 2011 Jun;28(6):740-3
Total mercury was analysed in 188 samples of predatory fish purchased at the retail level in Canada in 2005. The average concentrations (ng g(-1), range) were: sea bass 329 (38-1367), red snapper 148 (36-431), orange roughy 543 (279-974), fresh water trout 55 (20-430), grouper 360 (8-1060), black cod 284 (71-651), Arctic char 37 (28-54), king fish 440 (42-923), tilefish 601 (79-1164) and marlin 854 (125-2346). The Canadian standard for maximum total mercury allowed in the edible portions of fish sold at the retail level is 1000 ng g(-1) for shark, swordfish, marlin, orange roughy, escolar and both fresh and frozen tuna. The standard is 500 ng g(-1) for all other types of fish. In this study, despite the small number of samples of each species, the 1000 ng g(-1) maximum was exceeded in five samples of marlin (28%). The 500 ng g(-1) maximum was exceeded by six samples of sea bass (20%), four of tilefish (50%), five of grouper (24%), six of king fish (40%) and one of black cod (13%).