Metal concentrations in the edible claw and body muscle of a popular recreational crab species (Scylla serrata)

Abstract

In crabs, metal concentrations differ among tissues, but may also differ in edible white meat (muscle) in different parts of the body. This case study compared metal contaminants in the claw and body muscle for a popular crab species (Giant Mud Crab, Scylla serrata). For lead and nickel, body muscle concentrations were generally lower than claw concentrations, while the converse was true for arsenic, cadmium and mercury. When body and appendage meat proportions were used to weight body and claw metal concentrations the estimated concentration in total edible muscle closely reflected the claw muscle for zinc, but remained elevated relative to claw muscle (to varying degrees) for arsenic, cadmium and mercury. Linear models for these relationships allowed the total edible muscle concentration to be estimated from measured claw muscle concentrations. The relationships reported are useful for modelling exposure risk, and in crab ecotoxicology more broadly.