Trace metals in two populations of the fireworm Eurythoe complanata from Mazatlán Bay: effect of body size on concentrations

Trace metal concentrations (Cd, Co, Cr, Cu, Mn, Ni, Pb, Zn) were measured in two populations of the polychaete Eurythoe complanata collected in Mazatlán Bay (southeastern Gulf of California). With the exception of Cd, the trace metal concentrations fell within the ranges of other species of polychaetes collected elsewhere. The population of E. complanata collected from a site near to the sewage outfall (2.1 km) showed higher levels of Cu and Pb (following the same tendency of sediments) than the population from a site located 16 km away from the sewage outfall, where Cd worm concentrations were higher. Size-dependent relationships were observed for Cd, Ni, Pb and Zn only and the correlation was negative for the four elements. Evidently, this reveals different metabolic requirements in young (small) and old (larger) polychaetes.