Does Corbicula fluminea Respond to Dissolved Metal(loid)s in Laboratory Exposure Bioassays?

Benthic organisms are widely used in metal contamination monitoring systems in aquatic environments. But the chemical concentration stored in their tissues depends on the environmental fate and the bioconcentration skills of the species. The freshwater clam C. fluminea is used to monitor metal pollution due to its great resistance to the contaminated environments. Nevertheless, it may act in contrarily when exposed to different polymetallic environments. This study aimed to understand the bioaccumulative behaviour of Corbicula fluminea when is exposed to different environments contaminated by individual elements (As, Cd, Cr, Co, Cu, Fe, Ni, Pb, Sb and Zn), environments containing a mixture of the elements in lower concentrations, and mining residues (acid mine drainage lixiviate). Acute toxicity bioassays were carried out to observe valve closure, clam mortality and metal bioconcentration in soft tissue. Results revealed that the Asian clam shows a greater metal(loid) bioconcentration response under polymetallic environments than under individual metal-contaminated environments