Effects of length and locality on the mercury content of blacklip abalone, Notohaliotis ruber (Leach), blue mussel, Mytilus edulis planulatus (Lamarck), sand flathead, Platycephalus bassensis Cuvier & Valenciennes, and long-nosed flathead, Platycephalus caeruleopunctatus (McCulloch), from Port Phillip Bay, Victoria

Abstract

Mean concentrations of mercury in the foot tissue and inedible viscera of N. ruber were 0.02 µg g^-1 wet weight (range 0.01-0.03 µg g^-1) and 0.04 µg g^-1 wet weight (range 0.01-0.12 µg g^-1), respectively. The mean mercury concentration in the soft tissues of M. e. planulatus was 0.02 µg g^-1 (range 0.01-0.07 µg g^-1), that in axial muscle tissues of P. bassensis was 0.50 µg g^-1 (range 0.06-1.1 µg g^-1), and that in P. caeruleopunctatus was 0.56 µg g^-1 (range 0.10-2.8 µg g^-1). Concentrations of mercury were affected by the lengths of sand and long-nosed flathead but not by the lengths of blacklip abalone or blue mussels. For sand and long-nosed flathead, the effect of locality on concentration was highly significant and indicated a trend for the mercury concentrations of samples to increase from north to south in the region of Port Phillip Bay north of latitude 37º57's. and a reversal of this trend for the region south of this latitude; in the westernmost region of the bay mercury concentrations were of intermediate value. Although not statistically significant, the results for locality of the blacklip abalone and blue mussels were consistent with these trends.