Mercury exposure in songbird communities along an elevational gradient on Whiteface Mountain, Adirondack Park (New York, USA)
Mercury exposure in songbird communities along an elevational gradient on Whiteface Mountain, Adirondack Park (New York, USA)
复制标题
阿迪朗达克公园（美国纽约）白脸山沿海拔梯度鸣禽群落的汞暴露
作者：
A. Sauer;C. Driscoll;D. Evers;E. Adams;Yang Yang
汞（Hg）是一种强效的神经毒素，在食物网中生物放大。已有文献记载与接触高汞水平有关的鸟类不良影响。高海拔的北方森林通常接受更高的大气汞沉积，区域研究随后发现，居住在这些山地栖息地的鸣鸟血液中汞浓度升高。本研究的总体目标是研究纽约州阿迪朗达克公园白面山沿海拔梯度的鸣禽汞暴露的空间和季节性模式。2009年6月至2010年7月，在海拔450-1400米的13个研究点沿海拔梯度采集了鸣鸟血液样本，重点采集了包括隐士画眉、斯温森画眉和比内尔画眉在内的Catharus画眉。研究结果表明：(1)血汞浓度随海拔高度的增加呈线性上升趋势，且在海拔梯度范围内，所有画眉品种血汞浓度在海拔1075 m处呈非线性上升趋势，此后呈下降趋势；(2)目标物种的血汞浓度总体呈先升高后降低的非线性季节性模式。与低海拔森林相比，鸟类暴露模式似乎是由高海拔栖息地大气汞沉积升高和甲基汞生物利用度增加驱动的。季节模式可能受到与饮食选择和年度换羽周期相关的复杂和动态变量的综合影响。考虑到在区域鸣禽研究的背景下进行的高海拔分析很少，该项目补充了类似研究的结果，并强调了进一步监测鸟类群落环境汞污染的必要性。
Mercury (Hg) is a potent neurotoxin that biomagnifies within food webs. Adverse effects have been documented for avian species related to exposure of elevated Hg levels. High elevation, boreal forests generally receive higher atmospheric Hg deposition and regional studies have subsequently identified elevated blood Hg concentrations in songbird species inhabiting these montane habitats. The overall goal of this study was to investigate spatial and seasonal Hg exposure patterns in songbird species along an elevational gradient on Whiteface Mountain in the Adirondack Park of New York State. Songbird blood samples were collected from June–July in 2009 and 2010 along an elevational gradient at 13 study plots (450–1400 m) with a focus on Catharus thrushes, including the hermit thrush, Swainson’s thrush, and Bicknell’s thrush. The main results of this study documented: (1) an overall linear pattern of increasing blood Hg concentrations with increasing elevation, with additional analysis suggesting a nonlinear elevational pattern of increasing blood Hg concentrations to 1075 m, followed by decreasing concentrations thereafter, for all Catharus thrush species across the elevational gradient; and (2) an overall nonlinear seasonal pattern of increasing, followed by decreasing blood Hg concentrations across target species. Avian exposure patterns appear driven by elevated atmospheric Hg deposition and increased methylmercury bioavailability within high elevation habitats as compared with low elevation forests. Seasonal patterns are likely influenced by a combination of complex and dynamic variables related to dietary selection and annual molting cycles. Considering that few high elevation analyses have been conducted within the context of regional songbird research, this project complements the results from similar studies and highlights the need for further monitoring efforts to investigate environmental Hg contamination within avian communities.