Bustnes Jan O, Erikstad Kjell E, Hanssen Sveinn A, Tveraa Torkild, Folstad Ivar, Skaare Janncehe U
Norwegian Institute for Nature Research, The Polar Environmental Centre, 9296 Tromsø, Norway.
Proc Biol Sci. 2006 Dec 22;273(1605):3117-22. doi: 10.1098/rspb.2006.3687.
Recent studies have shown that the detrimental effects of anthropogenic pollutants may be worse if organisms are exposed to natural stress. In this study, we examined whether negative effects of organochlorines (OCs) could be influenced by parasites. In two breeding seasons, we administered an anti-helminthic drug to groups of breeding glaucous gulls (Larus hyperboreus), whereas control groups were placebo treated. In all birds, blood residues of the most important OCs in the study population (hexachlorobenzene, oxychlordane, p,p'-dichlorodiphenyldichloroethylene and polychlorinated biphenyl), were measured. The relationships between OCs and fitness components (i.e. nesting success and return rate between breeding seasons) were then compared between the birds receiving anti-parasite treatment and the controls. Among untreated males, higher blood residues of OCs were associated with lowered nesting success, while in males receiving anti-parasite treatment, there was no detrimental effect of OCs on fitness. Return rate was not affected by treatment or OCs. Our findings suggest that parasites may be an important factor in triggering reproductive effects of such pollutants, and that relatively low levels of OCs may have serious reproductive consequences in natural populations when stress from other sources is high.
最近的研究表明，如果生物体暴露于自然压力下，人为污染物的有害影响可能会更严重。在本研究中，我们调查了寄生虫是否会影响有机氯（OCs）的负面影响。在两个繁殖季节，我们对繁殖期的白鸥（Larus hyperboreus）群体施用了抗蠕虫药物，而对照组则接受安慰剂治疗。对所有鸟类测量了研究种群中最重要的有机氯（六氯苯、氧氯丹、p,p'-二氯二苯二氯乙烯和多氯联苯）的血液残留量。然后比较了接受抗寄生虫治疗的鸟类和对照组之间有机氯与繁殖适应性成分（即筑巢成功率和繁殖季节之间的回巢率）之间的关系。在未处理的雄性中，较高的有机氯血液残留量与较低的筑巢成功率相关，而在接受抗寄生虫治疗的雄性中，有机氯对繁殖适应性没有有害影响。回巢率不受治疗或有机氯的影响。我们的研究结果表明，寄生虫可能是引发此类污染物生殖效应的一个重要因素，并且当来自其他来源的压力较高时，相对较低水平的有机氯可能会对自然种群产生严重的生殖后果。
