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Laboratory Estimation of Net Trophic Transfer Efficiencies of PCB Congeners to Lake Trout Salvelinus namaycush from Its Prey
Published on: August 29, 2014
Spatio-temporal trends of PCBs in the Swedish freshwater environment 1981-2012
Elisabeth Nyberg1, Sara Danielsson, Ulla Eriksson
1Department of Environmental Research and Monitoring, Swedish Museum of Natural History, Box 50007, 114 18, Stockholm, Sweden, Elisabeth.Nyberg@nrm.se.
Abstract:
Polychlorinated biphenyls (PCBs) have been monitored in perch (Perca fluviatilis), pike (Esox lucius), and Arctic char (Salvelinus alpinus) in reference lakes since the late 1960s. Temporal trends and spatial patterns are currently monitored in nine and 32 lakes, respectively. Overall, PCB concentrations are decreasing. However, this is not consistent for all congeners across all lakes and species. Perch has comparatively low PCB concentrations relative to suggested target levels, but individual congener concentrations in some lakes are concerningly high. No temporal trend is seen for CB-118 and CB-153 in perch, but significant decreasing trends exist for Arctic char and pike, for which monitoring started earlier than for perch. The lower/higher chlorinated congener ratio decreased over time in most lakes, indicating fewer new emissions. CB-118 and CB-153 concentrations in perch show spatial gradients across Sweden, with higher concentrations found near urban/industrial areas.

