title: Individual variation in biomarkers of health: influence of persistent organic pollutants in Great skuas (Stercorarius skua) breeding at different geographical locations.
abstract: Persistent organic pollutants (POPs) have been shown to cause adverse effects on a number of biomarkers of health in birds. POPs may impair immune function and alter the stress response, defined as a suite of behavioral and physiological responses to environmental perturbations. Recent studies have also proposed that POPs can induce oxidative stress. Nevertheless, there is a lack of studies simultaneously assessing the potential damaging effects of POPs on the latter biomarkers. In this study, we examined the contribution of legacy (organochlorines; (OCs)) and emerging (flame retardants; PBDEs) POPs to individual variations in stress levels (feather corticosterone), humoral immunity (plasma immunoglobulin Y levels) and oxidative stress occurring in three breeding colonies of a top predator seabird, the Great skua (Stercorarius skua), distributed from temperate regions to the high Arctic: Shetland (60°N), Iceland (63°N) and Bjørnøya (74°N). Our results demonstrated that plasma concentrations of OCs in Great skuas from Bjørnøya are among the highest in North Atlantic seabirds, with up to 7900 μg/kg (ww) ∑OCs. Yet, a latitudinal gradient in POP levels was observed with all compounds being significantly higher in Bjørnøya than in Iceland and Shetland (on average 4-7 fold higher for OCs and 2.5-4.5 for PBDEs, respectively). Contrary to our predictions, skuas breeding at the least contaminated site (i.e., Shetland) experienced the poorest physiological condition; i.e., the highest levels of stress hormones (25% higher) and oxidative stress (50% higher) and the lowest immunoglobulin levels (15% lower) compared to the two other colonies. Finally, our results failed to point out consistent within-colony relationships between biomarkers of health and POPs. Overall, it is suggested that other ecological factors such as food availability could constrain physiological indicators more than anthropogenic contaminants.
authors.affiliation: Norwegian Institute for Nature Research (NINA), FRAM Centre, Tromsø, Norway. sophie.bourgeon@nina.no
authors.forename: Sophie
authors.initials: S
authors.lastname: Bourgeon
authors.forename: Eliza H K
authors.initials: EH
authors.lastname: Leat
authors.forename: Ellen
authors.initials: E
authors.lastname: Magnusdóttir
authors.forename: Aaron T
authors.initials: AT
authors.lastname: Fisk
authors.forename: Robert W
authors.initials: RW
authors.lastname: Furness
authors.forename: Hallvard
authors.initials: H
authors.lastname: Strøm
authors.forename: Sveinn Are
authors.initials: SA
authors.lastname: Hanssen
authors.forename: Aevar
authors.initials: A
authors.lastname: Petersen
authors.forename: Kristin
authors.initials: K
authors.lastname: Olafsdóttir
authors.forename: Katrine
authors.initials: K
authors.lastname: Borgå
authors.forename: Geir W
authors.initials: GW
authors.lastname: Gabrielsen
authors.forename: Jan Ove
authors.initials: JO
authors.lastname: Bustnes
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000097:blood*; D001717:Birds / Q000502:physiology*; D001947:Breeding; D003345:Corticosterone / Q000032:analysis; D004785:Environmental Pollutants / Q000633:toxicity*; D005241:Feathers / Q000737:chemistry; D006304:Health Status; D007136:Immunoglobulins / Q000097:blood; D009930:Organic Chemicals / Q000633:toxicity*; D018384:Oxidative Stress
chemical_list: D015415:Biomarkers; D004785:Environmental Pollutants; C016512:IgY; D007136:Immunoglobulins; D009930:Organic Chemicals; D003345:Corticosterone