Department of Entomology and Wildlife Ecology, University of Delaware, Newark, DE 19717, USA.
Environ Monit Assess. 2010 Dec;171(1-4):671-9. doi: 10.1007/s10661-010-1312-z. Epub 2010 Feb 5.
Mercury (Hg) contamination from industrial sources is pervasive throughout North America and is recognized by the US Environmental Protection Agency as a health hazard for wildlife and humans. Avian species are commonly used as bioindicators of Hg because they are sensitive to contaminants in the environment and are relatively easy to sample. However, it is important to select the appropriate avian species to use as a bioindicator, which should be directly related to the project objectives. In this study, we tested the utility of two tidal marsh sparrows, Seaside (Ammodramus maritimus) and Saltmarsh (Ammodramus caudacutus) sparrows, as bioindicator species of the extent of Hg contamination in tidal marshes along the Delaware Bay. To determine the possibility of using one or both of these species, we estimated sparrow blood Hg burden in five Delaware watersheds. We found no difference in Hg concentrations between species (F (1,133) < 0.01, P=0.99), but Saltmarsh Sparrows had limited sample size from each site and were, therefore, not appropriate for a Delaware Bay-wide Hg indicator. Seaside Sparrows, however, were abundant and relatively easy to sample in the five watersheds. Seaside Sparrow blood Hg levels ranged from 0.15 to 2.12 ppm, differed among drainages, and were greatest in two drainages distant from the Delaware Bay shoreline (F (4,95) =2.51, P=0.05). Based on a power analysis for Seaside Sparrow blood Hg, we estimated that 16 samples would be necessary to detect differences among sites. Based on these data, we propose that Seaside Sparrows may be used as a tidal marsh Hg bioindicator species given their habitat specificity, relative abundance, widespread distribution in marsh habitats, ease of sampling, and limited variation in blood Hg estimates within a sampling area. In Delaware Bay, Saltmarsh Sparrows may be too rare (making them difficult to sample) to be a viable tidal marsh Hg bioindicator.
汞（Hg）污染来自工业源，在整个北美洲都很普遍，美国环境保护署已将其视为野生动物和人类的健康危害。鸟类通常被用作汞的生物指标，因为它们对环境污染物敏感，并且相对容易采样。但是，选择合适的鸟类作为生物指标非常重要，这应与项目目标直接相关。在这项研究中，我们测试了两种潮汐沼泽麻雀，海滨（Ammodramus maritimus）和盐沼（Ammodramus caudacutus）麻雀，作为特拉华湾沿潮汐沼泽汞污染程度的生物指标物种。为了确定使用一种或两种这些物种的可能性，我们估计了五个特拉华流域麻雀的血液汞负担。我们发现物种之间的汞浓度没有差异（F（1,133）<0.01，P=0.99），但盐沼麻雀每个地点的样本量有限，因此不适合作为特拉华湾范围的汞指示剂。然而，海滨麻雀在五个流域中数量丰富且相对容易采样。海滨麻雀的血液汞水平范围为 0.15 至 2.12 ppm，在流域之间存在差异，在远离特拉华湾海岸线的两个流域中最大（F（4,95）=2.51，P=0.05）。根据海滨麻雀血液汞的功率分析，我们估计需要 16 个样本才能检测到站点之间的差异。基于这些数据，我们提出，鉴于海滨麻雀的栖息地特异性、相对丰度、在沼泽栖息地的广泛分布、采样的容易程度以及在采样区域内血液汞估计值的有限变化，它们可以用作潮汐沼泽汞生物指标物种。在特拉华湾，盐沼麻雀可能过于稀少（难以采样），无法成为可行的潮汐沼泽汞生物指标。
