From previous studies, it remains unclear whetherpolychlorinated biphenyls (PCBs) are biomagnified inzooplankton or if concentrations are simply governed bypassive partitioning. In this study, in the Gullmar Fjord on theSwedish west coast, field-determined lipid-normalizedpartition coefficients (log
Klip) were compared to equilibriumpartition coefficients from laboratory sorption experimentswith dead and preserved zooplankton. There was nosignificant difference between the linear regressions oflog
Klip-log
Kow (analysis of covariance [ANCOVA],
p < 0.05)for field and laboratory-determined partition coefficients,supporting passive partitioning being the dominant uptakepathway for PCBs in the Gullmar Fjord zooplankton. The field-observed partition coefficients were also suggestive of passivepartitioning, as all field-log
Klip-log
Kow regressionswere significant (
p < 0.05,
r2 = 0.74-0.95) and apparentlylinear. Further, there was generally no positive correlationbetween apparent biomagnification factors (BMF;concentration in zooplankton [pg/kgoc]/concentration inphytoplankton [pg/kgoc]) and trophic level (on the basis of
15N). The in-situ organic carbon (-oc)-normalizedconcentrations in zooplankton (>200
m) were notstatistically different from oc-normalized concentrations inphytoplankton (0.7-50
m), which supports the absenceof significant biomagnification.