title: Relationships between reproductive performance and organochlorine contaminants in great black-backed gulls (Larus marinus).
abstract: The great black-backed gull Larus marinus is a top predator in subarctic and temperate marine ecosystems, and the aim of this study was to investigate if organochlorines (OCs) were related to reproductive performance in this species at the subarctic parts of the Norwegian Coast. We measured blood levels of various OCs in 53 breeding birds. The OC levels were relatively low compared to levels found in nearby arctic areas. In females, however, there was a significant positive relationship between blood concentrations of OCs, especially hexachlorobenzene (HCB) and, p,p'-dichlorodiphenyldichloroethylene (DDE), and egg laying date, and a positive relationship between the probability of nest predation and blood concentration of beta-hexachlorocyclohexane (beta-HCH), oxychlordane, and DDE. In females with high levels of OCs, especially persistent polychlorinated biphenyls (PCBs), there was also a decline in egg volume as egg laying progressed; i.e. the second and third laid egg were relatively smaller, compared to females with low OC levels. No relationships between reproductive parameters and OC levels were found in males.
authors.affiliation: Faculty of Science, Department of Biology, University of Tromsø, 9037 Tromsø, Norway.
authors.forename: Morten
authors.initials: M
authors.lastname: Helberg
authors.forename: Jan Ove
authors.initials: JO
authors.lastname: Bustnes
authors.forename: Kjell Einar
authors.initials: KE
authors.lastname: Erikstad
authors.forename: Kai Ove
authors.initials: KO
authors.lastname: Kristiansen
authors.forename: Janneche Utne
authors.initials: JU
authors.lastname: Skaare
mesh_terms: D000818:Animals; D001717:Birds / Q000097:blood* / Q000502:physiology; D017753:Ecosystem; D004785:Environmental Pollutants / Q000097:blood / Q000633:toxicity*; D005260:Female; D006843:Hydrocarbons, Chlorinated / Q000097:blood / Q000633:toxicity*; D007306:Insecticides / Q000097:blood / Q000633:toxicity*; D009664:Norway; D009792:Oceans and Seas; D012098:Reproduction / Q000187:drug effects*
chemical_list: D004785:Environmental Pollutants; D006843:Hydrocarbons, Chlorinated; D007306:Insecticides