Suppression of natural killer cell activity in harbour seals (Phoca vitulina) fed Baltic Sea herring

• Published in: Aquatic Toxicology
• Main Authors: Ross, P.S. (Peter), Swart, R.L. (Rik) de, Timmerman, H.H. (Helga), Reijnders, P.J.H., Vos, J.G. (Joseph), Loveren, H. (Henk) van, Osterhaus, A.D.M.E. (Albert)
• Format: Article in Journal/Newspaper
• Language: English
• Published: 1996
• Subjects: Phoca vitulina
• Online Access: http://repub.eur.nl/pub/39764; https://doi.org/10.1016/0166-445X(95)00031-X

Mass mortalities among marine mammal populations in recent years have raised questions about a possible contributory role of contaminants accumulated through the marine food chain. While viruses were shown to be the primary cause of the outbreaks, an immunotoxic action by organochlorine chemicals in affected animals could not be ruled out. We carried out a 2 1/2 -year immunotoxicological experiment in which two groups of 11 harbour seals each were fed herring from either the relatively contaminated Baltic Sea or the relatively uncontaminated Atlantic Ocean. Seals in the Baltic Sea group accumulated 3-4 times higher levels of Ah-receptor-mediated 2,3,7,8-TCDD Toxic Equivalents in blubber than did their Atlantic counterparts following 2 years on the respective diets. Blood was sampled a total of 17 times during the course of the experiment for immunological evaluation, during which time the natural cytotoxic activity of peripheral blood mononuclear cells isolated from seals fed Baltic Sea herring declined to a level approximately 25