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 fo r 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 E ROD and PROD activities. No differences between the colonies were obse rved regarding embryonic O2/CO2 exchange, egg weight, eggshell thickne ss, hatchling weight or liver weight/body weight ratio. It is conclude d that hepatic EROD activity is usable as a relative sensitive biochem ical indicator for early exposure to planar halogenated polyaromatics in the early life stage of the common tem.