Assimilation and retention of metals in teleost and elasmobranch fishes following dietary exposure

摘要: In a radiotracer study designed to evalu- ate the fate of metals from fish prey predator fish, we measured trophic transfer 7 trace elements (Am, Cd, Co, Cr, Cs, Mn, Zn) juvenile Mediterranean sea bream Sparus auratus 3 species, teleosts Psetta maxima and auratus, elasmobranch Scyliorhinus canicula. Prey S. were labeled by exposure metal radioisotopes in solution for period wk then fed predators, after which retention preda- tor was assessed. Mean assimilation efficiencies (AEs) ingested fishes ranged 6 15% Am, 63 74% Cs; significant differ- ences AEs noted between species Co Mn only. Efflux rate constants (ke) assimilated did not differ consistently among predators any metals. The mean ke 0.003 d -1 canicula 0.02 Cd Cs all Trophic factors (TTF) each determined assess potential biomagnification. TTF, calculated dividing product AE ingestion (IR) ke, exceeded 1 only Zn Cs. For most likely scenarios IR AE, TTF <1 these metals, suggesting that will biomagnify piscivorous fishes.