Mercury concentrations of the axial muscle tissues of some marine fishes of the continental shelf adjacent to Tasmania

Abstract

The mercury concentrations of 35 commercial and potentially commercial fish species from Tasmanian waters were determined. Four species had mean total mercury concentrations above 0.5 mg kg^-1 wet weight and in all four there were individuals with concentrations above 1.5 mg kg^-1 wet weight. Two species of shark, Parascyllium ferrugineum and Cephaloscyllium laticeps (with sample sizes of 4 and 1, respectively), had total mercury concentrations above the limit of a mean of 1.0 mg kg^-1 wet weight set by the Tasmanian Public Health regulations. Concentrations in the species were compared with published data. Organic mercury concentrations in different species ranged from 40 to 96% of the total mercury concentrations. In fewer than half the species were total mercury concentration and total length or weight significantly correlated, indicating that neither total length nor weight could be used as a universal management tool to control human mercury intake from fish consumption.