OCCURRENCE AND EFFECTS OF PCBS, PCDDS AND PCDFS IN HATCHLINGS OF THE COMMON TERN (STERNA-HIRUNDO)

From eight common tem (Sterna hirundo) colonies eggs were collected for laboratory incubation. Significant differences between colonies were found for yolk sac concentrations of polychlorinated biphenyls (PCBs), polychlorinated dibenzofurans (PCDFs) and polychlorinated dibenzo-p-dioxins (PCDDs). Corresponding differences were observed for hepatic EROD and PROD activities. No differences between the colonies were observed regarding embryonic O2/CO2 exchange, egg weight, eggshell thickness, hatchling weight or liver weight/body weight ratio. It is concluded that hepatic EROD activity is usable as a relative sensitive biochemical indicator for early exposure to planar halogenated polyaromatics in the early life stage of the common tem.