Mercury, lead, and cadmium in blue crabs, Callinectes sapidus, from the Atlantic coast of Florida, USA: A multipredator approach

Abstract

Blue crabs, Callinectes sapidus, from the Atlantic coast of Florida were analyzed for total mercury, methylmercury, lead, and cadmium. Paired samples of two tissue types were analyzed for each crab, (1) muscle tissue (cheliped and body muscles) and (2) whole-body tissue (all organs, muscle tissue and connective tissue), for evaluation of the concentration of metals available to human consumers as well as estuarine predators. There were clear patterns of tissue-specific partitioning for each metal. Total mercury was significantly greater in muscle tissue (mean=0.078µg/g) than in whole-body tissue (mean=0.055µg/g). Conversely, whole-body concentrations of lead and cadmium (means=0.131 and 0.079µg/g, respectively) were significantly greater than concentrations in muscle (means=0.02 and 0.029µg/g, respectively). There were no significant correlations between any metal contaminant and crab size. Cadmium levels were significantly greater in the muscle tissue of females, but, no other sex-related differences were seen for other metals or tissue types. Methylmercury composed 93–100% of the total mercury in tissues. Compared to previous blue crab studies from different regions of the United States, mean concentrations of mercury, lead, and cadmium were relatively low, although isolated groups or individual blue crabs accumulated high metal concentrations.