Norwegian Institute for Nature Research (NINA), FRAM Centre, Tromsø, Norway.
Environ Res. 2012 Oct;118:31-9. doi: 10.1016/j.envres.2012.08.004. Epub 2012 Aug 24.
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.
持久性有机污染物（POPs）已被证明会对鸟类的许多健康生物标志物产生不良影响。POPs 可能会损害免疫功能并改变应激反应，应激反应定义为一系列对环境干扰的行为和生理反应。最近的研究还提出，POPs 可以诱导氧化应激。然而，目前缺乏同时评估 POPs 对后者生物标志物潜在破坏性影响的研究。在这项研究中，我们研究了遗留（有机氯农药；（OCs））和新兴（阻燃剂；PBDEs）POPs 对三种繁殖群体中压力水平（羽毛皮质酮）、体液免疫（血浆免疫球蛋白 Y 水平）和氧化应激个体变化的贡献，顶级捕食者海鸟大贼鸥（Stercorarius skua），分布范围从温带地区到北极：设得兰群岛（60°N）、冰岛（63°N）和比约克岛（74°N）。我们的结果表明，比约克岛大贼鸥血浆中 OCs 的浓度在北大西洋海鸟中是最高的，高达 7900 μg/kg（ww）∑OCs。然而，我们观察到了 POP 水平的纬度梯度，所有化合物在比约克岛的浓度均显著高于冰岛和设得兰群岛（OCs 平均高 4-7 倍，PBDEs 高 2.5-4.5 倍）。与我们的预测相反，在污染最少的地点（即设得兰群岛）繁殖的贼鸥经历了最差的生理状况；即应激激素水平最高（高 25%）和氧化应激水平最高（高 50%），免疫球蛋白水平最低（低 15%），与其他两个群体相比。最后，我们的结果未能指出健康生物标志物与 POPs 之间一致的群体内关系。总的来说，与人为污染物相比，其他生态因素，如食物供应，可能会更限制生理指标。
