Nestling blood of the white-tailed sea eagle (Haliaeetus albicilla) as an indicator of territorial exposure to organohalogen compounds -: An evaluation

This study was designed to evaluate the usefulness of nestling blood for monitoring' levers of organohalogen substances (OHS) in white-tailed sea eagles (Haliaeetus albicilla). The concentrations of polychlorinated biphenyls (PCBs), 2,2-bis(4-chlorophenyl)-1,1-dichloroethene (DDE), hexachlorobenzene (HCB),beta-hexachlorocyclohexane (beta-HCH), and one polybrominated phenoxyanisol in nestling blood were determined. In addition at least 22 hydroxylated PCBs were indicated. Eagle nestlings did not demonstrate any changes in concentrations of PCBs or DDE during 4-8 weeks of age. The variations in PCBs and DDE levels within a given territory between different years are similar to the corresponding variation observed in white-tailed sea eagle eggs. Regional differences in the pattern of OHS were also found. Thus, the results indicate that nestling blood provides a good measure of territorial exposure. However, to create a better basis for evaluation of contaminant levels, more than one sampling year from each breeding territory is recommended. There is a significant negative correlation between the concentration of 2,3',4,4',5-pentachlorobiphenyl and brood size. This observation indicates that present levels of coplanar PCBs may stilt influence the reproduction of white-tailed sea eagles on the Baltic coast.