Polychlorinated biphenyls and chlorinated insecticides in plasma of Caspian terns: relationships with age, productivity, and colony site tenacity in the Great Lakes

Results are reported from a study on the concentrations of chlorinated hydrocarbons in blood plasma of 111 adult Caspian terns (Sterna caspia) of known age, nesting in several areas of the upper Great Lakes. The plasma contained much higher concentrations of polychlorinated biphenyls (PCB) than of DDE, dieldrin, or trans-nonachlor. PCB concentrations were not correlated with age and bioaccumulations were seasonal. There was a significant negative correlation between mean PCB concentrations by region and percentage of terns returning to their region of birth. Birds nesting in Green bay and Saginaw bay were most likely to be affected by PCB. There are 44 references.