Department of Biology, University of Western Ontario, 1151 Richmond Ave., London, ON N6A 3K7, Canada.
Environ Pollut. 2013 Apr;175:8-15. doi: 10.1016/j.envpol.2012.12.005. Epub 2013 Jan 8.
Accumulation of selenium (Se) by lesser and greater scaup (Aythya affinis, A. marila) at staging and wintering areas could have contributed to the decline in their continental population. We exposed lesser scaup to background (0.8 μg/g), moderate (8.1 μg/g) and high (20.7 μg/g) levels of dietary Se in captivity and measured survival rates and indices of health in relation to hepatic Se concentrations. There was 100% survival in scaup exposed to Se for 10-weeks (average staging duration at Great Lakes), but ducks in the high treatment group had less lipids. There was 93% survival after 23-weeks (average wintering duration at Great Lakes), but no differences among treatment groups in body composition. There were no effects of Se on oxidative stress and cell-mediated immunity; rather we recorded immuno-stimulatory effects on antibody production. Results from our captive study suggest Se alone did not cause the continental decline in scaup populations.
在迁徙中途停歇地和越冬地，斑背潜鸭（Aythya affinis，A. marila）和大斑潜鸭（Aythya marila）体内硒（Se）的蓄积可能导致其大陆种群数量下降。我们将斑背潜鸭关在饲养笼中，让它们摄入背景（0.8μg/g）、中等（8.1μg/g）和高（20.7μg/g）水平的膳食硒，并测量与肝脏硒浓度有关的存活率和健康指数。在暴露于硒 10 周（大湖地区的平均迁徙时间）的潜鸭中，存活率为 100%，但高剂量组的鸭子脂肪含量较低。在暴露于硒 23 周后（大湖地区的平均越冬时间），存活率为 93%，但各组之间在身体成分方面没有差异。硒对氧化应激和细胞介导的免疫没有影响，反而记录到对抗体产生的免疫刺激作用。我们的圈养研究结果表明，硒本身并不是导致斑背潜鸭大陆种群数量下降的原因。
