(Table 1) Enantiomer fractions of egg yolk and plasma samples from Svalbard glaucous gulls (Larus hyperboreus)

Glaucous gulls (Larus hyperboreus) and their eggs from Svalbard (Norwegian Arctic) have been used as biomonitors of contaminants in the marine environment. In this study, the enantiomer fractions (EFs) of chiral chlordanes and atropisomeric polychlorinated biphenyl (PCB) congeners were determined in the blood plasma of adult male and female glaucous gulls from three breeding colonies in Svalbard. Plasma EFs were similar in magnitude and direction to EFs previously reported in glaucous gulls from other arctic food webs, suggesting overall similarities in the biochemical processes influencing the EFs of bioaccumulated organochlorine (OC) contaminants within the food webs at those locations. Additionally, EFs in yolk of eggs collected concurrently from within the same nesting colonies varied with location, laying date, and OC concentrations, and may be influenced by changes in the local feeding ecology between those colonies. No differences were found between the EFs for any analyte in female gulls compared to those found in egg yolk, indicating that processes involved in the maternal transfer of chlordanes and PCBs to eggs do not modulate the stereochemical ratio between enantiomers. Therefore, the use of eggs as a valuable and noninvasive means of OC biomonitoring may also extend to enantiomer compositions in glaucous gulls, and perhaps also in other seabird species from arctic regions.

来自挪威北极地区斯瓦尔巴群岛的灰背鸥（Glaucous gulls，学名Larus hyperboreus）及其卵，曾被用作海洋环境污染物的生物监测指示物。本研究对斯瓦尔巴群岛3个繁殖聚居地的成年雌雄灰背鸥血浆中的手性氯丹类化合物及阻转异构性多氯联苯（polychlorinated biphenyl, PCB）同系物的对映体分数（enantiomer fractions, EFs）进行了测定。血浆对映体分数的数值大小与变化方向，与此前其他北极食物网中灰背鸥的相关报道结果一致，表明上述地点食物网内影响生物累积性有机氯（organochlorine, OC）污染物对映体分数的生化过程整体相似。此外，同期从同一繁殖聚居地内采集的卵黄样本中，对映体分数随采样地点、产卵日期及有机氯污染物浓度发生变化，或受这些聚居地之间本地摄食生态差异的影响。未发现雌性灰背鸥体内任意分析物的对映体分数与卵黄中的对应数值存在显著差异，这表明灰背鸥母体将氯丹类化合物与多氯联苯转运至卵的相关过程，并未改变对映体间的立体化学比例。因此，将卵用作有机氯污染物生物监测的高效非侵入性手段这一应用，也可拓展至灰背鸥的对映体组成分析，或许同样适用于北极地区的其他海鸟物种。