Assessing heavy metal accumulation in the invasive blue crab (Callinectes sapidus): environmental and human health implications.

Abstract

Heavy metals are increasingly becoming a significant environmental concern, especially regarding food safety and security. This is especially concerning as the consumption of harvested marine species can pose potential health concerns. The arrival of the blue crab, Callinectes sapidus, to the Balearic Islands has led to the need to evaluate its environmental implications and potential as a food source as part of management efforts. In the present study, the concentrations of cadmium (Cd), lead (Pb), and mercury (Hg) in the muscle tissue of C. sapidus were evaluated at several locations in the Balearic Islands in the western Mediterranean Sea. A total of eighty-three blue crabs were examined (45 males and 38 females) and the concentrations of the heavy metals were evaluated. Regarding metal concentrations, overall, Hg was the most present followed by Cd and then Pb. Concentrations were also site dependent, with Es Grau having the highest Hg concentrations while in s'Albufereta the highest Cd concentrations were observed. Moreover, differences in metal accumulation were also observed between sexes, with juveniles and females exhibiting higher Cd concentrations than males. Furthermore, regarding potential human health concerns for consumption, the margin of exposure (MOE) for Pb were all above 1 and the estimated weekly ingestion (EWI) for Cd and Hg, were all below the established guidelines for food safety. These results highlight that the consumption of C. sapidus from the Balearic Islands does not currently pose a health risk the recreational fisheries sector. Considering these findings, the muscle tissue of C. sapidus is a valuable bioindicator for monitoring heavy metal levels, and continued site-specific monitoring is recommended for the coastal ecosystems of the Balearic Islands.