Polychlorinated Naphthalenes, -Biphenyls, -Dibenzo-p-dioxins, and -Dibenzofurans in Double-Crested Cormorants and Herring Gulls from Michigan Waters of the Great Lakes

Concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), naphthalenes (PCNs), and biphenyls (PCBs) were measured in eggs of double-crested cormorants and herring gulls collected from Michigan waters of the Great Lakes. Concentrations of PCNs in eggs of double-crested cormorants and herring gulls were in the ranges of 380−2400 and 83−1300 pg/g, wet wt, respectively. Concentrations of 2,3,7,8-substituted PCDDs and PCDFs were 10−200 times less than those of PCNs in eggs whereas those of total PCBs (380−7900 ng/g, wet wt) were 3−4 orders of magnitude greater. While the profile of PCB isomers and congeners between double-crested cormorants and herring gulls was similar, the PCN isomer profile differed markedly between these two species. PCN congeners 66/67 (1,2,3,4,6,7/1,2,3,5,6,7) accounted for greater than 90% of the total PCN concentrations in herring gulls, whereas their contribution to total PCN concentrations in double-crested cormorants ranged from 18 to 40% (mean, 31%). The r...