Savannah River Ecology Laboratory, University of Georgia, Aiken, South Carolina, USA.
Environ Toxicol Chem. 2014 Jul;33(7):1631-7. doi: 10.1002/etc.2601. Epub 2014 May 21.
The creation of wetlands, such as urban and industrial ponds, has increased in recent decades, and these wetlands often become enriched in pollutants over time. One metal contaminant trapped in created wetlands is copper (Cu(2+)). Copper concentrations in sediments and overlying water may affect amphibian species that breed in created wetlands. The authors analyzed the Cu concentration in dried sediments from a contaminated wetland and the levels of aqueous Cu released after flooding the sediments with different volumes of water, mimicking low, medium, and high pond-filling events. Eggs and larvae of Ambystoma opacum Gravenhorst, a salamander that lays eggs on the sediments in dry pond beds that hatch on pond-filling, were exposed to a range of Cu concentrations that bracketed potential aqueous Cu levels in created wetlands. Embryo survival varied among clutches, but increased Cu levels did not affect embryo survival. At Cu concentrations of 500 µg/L or greater, however, embryos hatched earlier, and the aquatic larvae died shortly after hatching. Because Cu concentrations in sediments increase over time in created wetlands, even relatively tolerant species such as A. opacum may be affected by Cu levels in the posthatching environment.
近年来，人工湿地（如城市和工业池塘）的建设有所增加，这些湿地随着时间的推移往往会富集污染物。一种被捕获在人工湿地中的金属污染物是铜（Cu(2+)）。沉积物和上覆水中的铜浓度可能会影响在人工湿地中繁殖的两栖动物物种。作者分析了受污染湿地中干燥沉积物中的铜浓度以及用不同体积的水淹没沉积物后释放的水相铜水平，模拟了低、中、高池塘填充事件。卵和幼虫 Ambystoma opacum Gravenhorst，一种在干燥池塘床的沉积物上产卵并在池塘填充时孵化的蝾螈，暴露在一系列铜浓度下，这些浓度与人工湿地中潜在的水相铜水平相匹配。卵的存活率因卵堆而异，但铜水平的增加并不影响胚胎存活率。然而，在铜浓度为 500μg/L 或更高时，胚胎提前孵化，水生幼虫在孵化后不久就死亡。由于人工湿地中沉积物中的铜浓度随时间的推移而增加，即使是像 A. opacum 这样相对耐受的物种，也可能会受到孵化后环境中铜水平的影响。
