Mercury content of edible flesh from snapper, Chrysophrys auratus (Bloch & Schneider), in the Victorian commercial catch

Abstract

The concentrations of total mercury (range 0.1-1.5 µg /g) in 40 individual snapper, C. auratus, caught in two commercial fishing areas in Victorian waters were adequately correlated with fork length by a power-law relationship. From further relationships established between length and total weight, and between filleted weight and total weight, the mean mercury concentration in the edible flesh of this species was estimated for each of the six years (1973-78) for which information on the length-frequency distribution was available for the Victorian commercial catch. The annual estimates ranged from 0.47 to 0.52 µg/g wet weight, and 45-52% of the edible flesh had values exceeding the Victorian statutory limit of 0.5 µg/g.

Various management options available to health and fisheries agencies are discussed, and the methods of calculating the important parameters corresponding to these options are described. For example, graphs are presented from which can be read a legal maximum length of landed snapper, designed to reduce the mean mercury concentration of the catch to below a nominated level.