MOLECULAR RESPONSES AS INDICATORS OF MARINE POLLUTION - DNA-DAMAGE AND ENZYME-INDUCTION IN LIMANDA-LIMANDA AND ASTERIAS-RUBENS

During a survey from 26 August through 13 September 1991, specimens of the flatfish, Limanda limanda (dab), and the asteroid echinoderm, Ast erias rubens (seastar), were collected at sampling locations along tra nsects radiating into the North Sea from the coastal zone of The Nethe rlands. In homogenates of liver tissue from male dab and the digestive gland (pyloric caeca) of female seastar, DNA damage (strand breaks) a nd induction of the cytochrome P450-dependent monooxygenase system (MO ) were determined. Areas could be described with significantly increas ed percentages of strand breaks (lower integrity) both in dab and seas tar. However, enhanced DNA strand breaks did not correspond with conta mination gradients, expressed as concentrations of polychlorinated bip henyls (PCBs) or polyaromatic hydrocarbons. MO enzyme induction in the hepatic 13,000g fraction of male dab, measured as 7-ethoxyresorulin-O -deethylase activity, was significantly enhanced in response to low am bient temperatures. Some evidence was found for the facilitation of be nzo[a]pyrene hydroxylase activity expressing the enzyme induction in t he microsomal fraction of pyloric caeca of seastars, at increasing PCB concentrations. DNA integrity and enzyme induction elucidate the phys iologic status and might be indicative for ambient impairment within r estricted areas, and not necessarily related to the presence of anthro pogenic or xenobiotic substances.