Polychlorinated biphenyls and other organochlorine compounds in marine zooplankton off the east coast of Newfoundland, Canada

Marine zooplankton samples collected in 1993 and 1994 at 25 stations along the east coast of Newfoundland and Labrador were analyzed for polychlorinat ed biphenyls (PCBs) and persistent organochlorine (OC) compounds. Concentra tions of these compounds were low (< 1 ng/g wet weight). A few trichloro-, tetrachloro- and pentachlorobiphenyl congeners were detected in zooplankton . Hexachlorobenzene (HCB), alpha-hexachlorocyclohexane (alpha HCH) and some components of technical chlordane were also detected in the samples. Dichl orodichlorophenylethylene (DDE) and Dichlorodiphenyltrichloroethane (DDT) w ere consistently present in zooplankton at approximately equal concentratio ns. Analysis of variance with data calculated on either a wet weight or a l ipid-normalized basis indicated that there were no significant differences in contaminant concentrations that could be attributed to sampling year or to the towing methods used to collect samples. Principal component analysis (PCA) of analytical data indicated that there were no spatial trends evide nt in either the concentrations or patterns of contamination, The patterns of PCB and OC contamination are consistent with the patterns previously rep orted in zooplankton from the Arctic. The concentrations of trace contamina nts reported in this study are well below the concentrations reported for N orth Atlantic zooplankton sampled in the 1970s. (C) 1999 Elsevier Science L td. All rights reserved.