Toxicology Letters 112 – 113 (2000) 103 – 109 Organochlorines in top predators at Svalbard — occurrence, levels and effects Janneche Utne Skaare a, *, Aksel Bernhoft a , Andrew Derocher c , Geir Wing Gabrielsen c , Anders Goksøyr d , Espen Henriksen c , Hans Jørgen Larsen b , Elisabeth Lie a , Øystein Wiig e a National Veterinary Institute, P.O. Box 8156 dep., N-0033 Oslo, Norway b Norwegian School of Veterinary Science, Oslo, Norway c Norwegian Polar Institute, Tromsø, Norway d Department of Molecular Biology, Uniersity of Bergen, Bergen, Norway e Zoological Museum, Uniersity of Oslo, Oslo, Norway Abstract Alarmingly high polychlorinated biphenyl (PCB) levels have been found in the top predators such as glaucous gull (Larus hyperboreus ) and polar bear (Ursus maritimus ) at Svalbard [Gabrielsen, G.W., Skaare, J.U., Polder, A., Bakken, V., 1995. Chlorinated hydrocarbons in glaucous gull (Larus hyperboreus ). Sci. Total Environ. 160/161, 337 – 346; Bernhoft, A., Skaare, J.U., Wiig, Ø., 1997. Organochlorines in polar bears (Ursus maritimus ) at Svalbard. Environ. Pollut. 95, 159 – 175; Henriksen, E.O., Gabrielsen, G.W., Trudeau, S., Wolkers, H., Sagerup, K., Skaare, J.U., 1999. Organochlorines and possible biochemical effects in glaucous gull (Larus hyperboreus ) from Bear Island, the Barents Sea. Arch. Environ. Contam. Toxicol. (in press).]. Studies of the possible toxic effects, particularly on the immune system and reproduction, of the very high PCB levels in these species are currently being investigated. Data obtained in the field (f.i. reproductive success in polar bears and intestinal nematodes in glaucous gulls), as well as levels of various biochemical and physiological parameters (f.i. thyroid hormones, retinol, EROD activity, CYP1A, IgG), have been coupled with the PCB levels [Skaare, J.U., Wiig, Ø., Bernhoft, A., 1994. Klorerte organiske miljøgifter; Niva ˚er og effekter i isbjørn. Norwegian Polar Institute Reportseries no. 86, 1–23 (in Norwegian); Bernhoft, A., Skaare, J.U., Wiig, Ø., 1997. Organochlorines in polar bears (Ursus maritimus ) at Svalbard. Environ. Pollut. 95, 159 – 175; Bernhoft, A., Skaare, J.U., Wiig, Ø., Derocher, A.E., Larsen, H.J., 2000. Possible immunotoxic effects of organochlorines in polar bears (Ursus maritimus ) at Svalbard (in press); Henriksen, E.O., Gabrielsen, G.W., Skaare, J.U., Skjegstad, N., Jensen, B.M., 1998a. Relationship between PCB levels, hepatic EROD activity and plasma retinol in glaucous gull, Larus hyperboreus. Marine Environ. Res. 46, 45 – 49; Henriksen, E.O., Gabrielsen, G.W., Trudeau, S., Wolkers, H., Sagerup, K., Skaare, J.U., 1999. Organochlorines and possible biochemical effects www.elsevier.com/locate/toxlet * Corresponding author. E-mail address: janneche.skaare@vetinst.no (J.U. Skaare) 0378-4274/00/$ - see front matter © 2000 Published by Elsevier Science Ireland Ltd. All rights reserved. PII:S0378-4274(99)00256-8