Heavy metals in crustaceans from the Iberian deep sea plain

Trace metals (Cd, Cu, Pb and Zn) were analysed in different well-defined mixed copepod and euphausiid samples as well as in individually analysed decapods collected during a cruise on board "RV Walther Herwig III" to the Iberian Deep Sea Plain in March and April, 2002. We found a substantial interspecific heterogeneity with partially high mean Cd levels in the decapods: 1.9 mg kg(-1) dry weight in samples of the genus Sergia; 6.1 mg kg(-1) in Acanthephyra pelagica (Risso, 1816) and Acanthephyra acanthithelsonis Bate, 1888; 10.7 mg kg(-1) in Bentheogennema intermedia (Bate, 1888); 14.9 mg kg(-1) in Benthesicymus iridescens (Bate 1881) and 16.3 mg kg(-1) in Systellaspis debilis (A. Milne Edwards, 1881). The agreement of these high Cd concentrations with those reported for polar crustaceans, and Cu concentrations (17-56 mg kg(-1)) that indicate that the total metabolic requirements have probably not been met, support the hypothesis that the frequently reported Cd-anomaly in polar crustaceans might be extended to other relatively deep ocean waters like the Iberian Deep Sea Plain and that this might be related to a corresponding Cu deficiency. Zn concentrations in decapods from this study (52-80 mg kg(-1)) are within the worldwide range, which indicates that decapods are able to regulate their Zn body concentrations. Our preliminary data on mixed zooplankton samples suggest that Pb concentrations far below 1 mg Pb kg(-1) might serve as a regional background value for comparison in biomonitoring studies. Results for Cd, Cu and Zn are largely within the reported range, especially for data from the Central and Southern North Sea.