MERCURY LEVELS IN MAJOR HAWAIIAN COMMERCIAL FISH SPECIES

Barbara A. Brooks, Ph.D., Hazard Evaluation and Emergency Response Office, Hawaii Department of Health. Honolulu, HI.

In 2002, the Hazard Evaluation and Emergency Response Office, Hawaii Department of Health measured total mercury concentrations in nine major fish species caught in the vicinity of the Hawaiian Islands. Twenty tissue samples per species were obtained from the United Fishing Agency, in Honolulu, Hawaii. In addition to total mercury, methylmercury was measured in twenty percent of the samples from each species. The weight ranges sampled were chosen to represent weights landed in Hawaii and were based on data provided by the National Marine Fisheries Service . The results showed that there were wide variations in mercury concentrations within and between species. Some fish species showed a correlation between weight and mercury concentration. Moonfish showed the highest average methylmercury concentration, with moderate levels measured in Pacific blue marlin, bigeye tuna, yellowfin tuna, albacore and wahoo. Mercury concentrations in mahimahi, striped marlin and skipjack tuna were relatively low. Methylmercury was the predominant form of mercury in all species but Pacific blue marlin where approximately 75% of the mercury was inorganic. The results of the study combined with data from other sources were used to prepare a pamphlet entitled “A Local Guide to Eating Fish Safely” for pregnant women, nursing mothers and young children (http://hawaii.gov/doh/).