Metal levels in economically important bivalve species from Turkey.

Concentrations of eight heavy metals (As, Cd, Cr, Cu, Hg, Ni, Pb and Zn) were determined in economically important bivalve species: oyster (Ostrea edulis), wedge clam (Donax trunculus), manila clam (Ruditapes philippinarium) and warty clam (Venus verrucosa) from the Marmara and Aegean seas. Samples were collected seasonally between 2008 and 2009. Metal levels of bivalves were found in the following ranges: As 0.02-3.40, Cd 0.02-2.80, Cr 0.19-0.82, Cu 0.82-25.06, Hg < LOD-0.12, Ni 0.09-0.73, Pb 0.05-4.16 and Zn 6.85-899 mg kg(-1). The most abundant elements were Zn > Cu > As. In addition, the results showed that oysters had the highest concentrations of Zn in all seasons. The next abundant heavy metal detected was Cu in oyster and other clam species. It was concluded that in the future, these metals should be monitored regularly.