Savannah River Ecology Laboratory, University of Georgia, Drawer E, Aiken, South Carolina 29802, USA.
Environ Sci Technol. 2013 Mar 19;47(6):2846-53. doi: 10.1021/es303989u. Epub 2013 Feb 27.
Bioaccumulation of contaminants and subsequent maternal transfer to offspring are important factors that affect the reproductive success of wildlife. However, maternal transfer of contaminants has rarely been investigated in amphibians. We examined maternal transfer of trace elements in southern toads ( Bufo[Anaxyrus] terrestris) residing in two locations: (1) an active coal combustion waste (CCW) disposal basin and adjacent 40-ha floodplain contaminated with CCW over 35 years ago and (2) an uncontaminated reference site. Our study is among the few to document tissue concentration-dependent maternal transfer of contaminants and associated adverse effects in amphibians. We found that females collected from the CCW-contaminated area had elevated concentrations of Ni, Se, and Sr; these females also transferred elevated levels of Cu, Pb, Se, and Sr to their eggs compared to females from the reference site. Overall reproductive success, estimated as a function of clutch size and offspring viability, was reduced by 27% in clutches collected from parents from the contaminated site compared to the reference site. Offspring viability negatively correlated with female and/or egg concentrations of Se and Ni. Reproductive success negatively correlated with Se and Cu concentrations in females, and Se concentrations in eggs. Our study highlights how exposure to CCW can negatively affect amphibian reproduction.
污染物的生物累积和随后向后代的母体转移是影响野生动物繁殖成功的重要因素。然而，在两栖动物中，对污染物的母体转移研究甚少。我们研究了生活在两个地点的南方蟾蜍（ Bufo[Anaxyrus] terrestris）中的微量元素的母体转移：（1）一个活跃的燃煤废物（CCW）处理盆地和毗邻的 40 公顷洪泛区，这些地区在 35 年前就被 CCW 污染；（2）一个未受污染的参考地点。我们的研究是为数不多的记录组织浓度依赖性污染物母体转移和相关对两栖动物的不良影响的研究之一。我们发现，从 CCW 污染地区采集的雌性个体的 Ni、Se 和 Sr 浓度升高；与来自参考地点的雌性个体相比，这些雌性个体也向其卵子中转移了更高水平的 Cu、Pb、Se 和 Sr。与来自参考地点的个体相比，来自污染地点的亲体所产的卵的总繁殖成功率（根据卵的大小和后代的活力来衡量）降低了 27%。后代的活力与雌性和/或卵子中的 Se 和 Ni 浓度呈负相关。繁殖成功率与雌性体内的 Se 和 Cu 浓度以及卵子中的 Se 浓度呈负相关。我们的研究强调了 CCW 暴露如何对两栖动物的繁殖产生负面影响。
