Bustnes Jan Ove, Bakken Vidar, Skaare Janneche Utne, Erikstad Kjell Einar
Norwegian Institute for Nature Research, Division of Arctic Ecology, The Polar Environmental Center, N-9296 Tromsø, Norway.
Environ Toxicol Chem. 2003 Sep;22(9):2173-9. doi: 10.1897/02-456.
We studied the relationship between increasing age and blood concentrations of four persistent organochlorines (OCs), hexachlorbenzene (HCB), oxychlordane, p,p'-dichlorodiphenyldichloroethylene (DDE), and 2,2',4,4',5,5'-hexachlorbiphenyl (PCB-153), in arctic-breeding glaucous gulls (Larus hyperboreus). We measured OC concentrations in 31 individuals of known age and took repeated blood samples of 64 individuals in different years, either one year apart or three or four years apart. The age of individuals was not related to the blood concentrations for any of the four compounds, and in birds whose values were measured repeatedly, there was no effect of the length of time (number of years) between sampling events on the relative change in OC concentration. This indicates that steady-state levels were reached before the age of first breeding. However, breeding area significantly influenced the changes in OC concentration between sampling events. In areas in which birds fed on prey from higher trophic levels, the OC concentrations showed large increases between sampling events; in areas in which birds fed at lower trophic levels, OC concentrations increased relatively little or not at all. This indicates that individual birds had different equilibrium concentrations, which are reached at different ages depending on the intake of OCs through the food. It also indicates that some individuals had not reached steady-state concentrations at the onset of reproduction. Changes in body condition and amount of blood lipids were of lesser importance than trophic level and influenced the concentrations of HCB and oxychlordane more strongly than DDE and PCB-153. In conclusion, this study indicates that steady-state concentrations of persistent OCs are reached early in life in most glaucous gulls, considering the long life span of the species.
我们研究了北极繁殖的白翅鸥（Larus hyperboreus）年龄增长与四种持久性有机氯（OCs），即六氯苯（HCB）、氧化氯丹、p,p'-二氯二苯二氯乙烯（DDE）和2,2',4,4',5,5'-六氯联苯（PCB-153）血液浓度之间的关系。我们测量了31只已知年龄个体的OC浓度，并在不同年份对64只个体进行了重复采血，采血间隔为一年或三、四年。个体年龄与这四种化合物中的任何一种的血液浓度均无关联，并且在重复测量值的鸟类中，采样事件之间的时间长度（年数）对OC浓度的相对变化没有影响。这表明在首次繁殖年龄之前就达到了稳态水平。然而，繁殖区域显著影响了采样事件之间OC浓度的变化。在鸟类以较高营养级猎物为食的区域，采样事件之间OC浓度大幅增加；在鸟类以较低营养级食物为食的区域，OC浓度增加相对较少或根本没有增加。这表明个体鸟类具有不同的平衡浓度，这取决于通过食物摄入OCs的情况，在不同年龄达到平衡。这也表明一些个体在繁殖开始时尚未达到稳态浓度。身体状况和血脂含量的变化比营养级的影响小，并且对HCB和氧化氯丹浓度的影响比对DDE和PCB-153的影响更强。总之，考虑到该物种的长寿，这项研究表明大多数白翅鸥在生命早期就达到了持久性OCs的稳态浓度。
