Uptake of metals and persistent organochlorines in crabs (Cancer pagurus) and flounder (Platichthys flesus) from contaminated sediments: Mesocosm and field experiments

In the mesocosm experiment, the crabs and flounders were exposed to sediments strongly contaminated with persistent organochlorine compounds (OCs). Uptake of OCs in fillet of flounder and crab hepatopancreas was observed. The final concentrations of PCDF/D, given as toxic equivalency factors (TEQ) in flounder and crabs were more than one order of magnitude below levels in the recipient area. In the field experiment uptake of Cr, Pb, Ni and Fe was observed in crabs. No clear uptake of Cu and As was observed, despite high concentrations in the sediment. In flounder, no evidence of increased concentration of metals could be seen after one month. The relative uptake of organochlorines (OCs) in the two experiments reflects the local degree of sediment contamination. The metal concentrations did not increase more than 6 times whereas the persistent OCs increased up to 100 times in crabs, illustrating the importance of sediments as a source especially for OCs contamination of the biota.