Biodiversity Research Institute, 276 Canco Road, Portland, ME, 04103, USA.
Department of Biology, Syracuse University, Syracuse, NY, 13244, USA.
Ecotoxicology. 2020 Dec;29(10):1815-1829. doi: 10.1007/s10646-019-02142-x. Epub 2020 Feb 9.
Mercury (Hg) is a potent neurotoxin that biomagnifies within both aquatic and terrestrial food webs resulting in adverse physiological and reproductive effects on impacted wildlife populations, including songbird communities. Due to reducing conditions, wetland ecosystems promote the formation of methylmercury. Regional studies have documented elevated blood mercury concentrations in songbird species within these habitat types. The overall goal of this research was to examine spatial and seasonal patterns of Hg exposure for targeted songbird species within Sphagnum bog wetland systems and compare these patterns with adjacent upland forests in the Adirondack Park of New York State. Project sampling was conducted at study plots within four Sphagnum bog and associated upland forest sites from May - August during the 2008, 2009, and 2011 field seasons. The overall results documented: (1) blood Hg concentrations were elevated in songbird species inhabiting Sphagnum bog habitats as compared to nearby upland forest species; (2) target species within each habitat type exhibited consistent species-level patterns in blood Hg concentrations at each study site; and (3) no seasonal change in blood Hg concentrations within Sphagnum bog habitats was documented, but an increasing, followed by a decreasing seasonal pattern in mercury exposure was detected for upland forest species. Habitat type was demonstrated to influence avian Hg exposure levels. Moreover, Sphagnum bog ecosystems may be contributing to elevated Hg concentrations in biota within the surrounding environment. Seasonal patterns for blood Hg concentrations were found to vary between habitat type and are likely related to a combination of variables including habitat-driven Hg concentrations in prey items, seasonal dietary shifts, and annual molting cycles. This project emphasizes the importance of prioritizing future research efforts within identified high Hg habitat types, specifically wetland systems, to better characterize associated avian exposure levels, estimate the spatial extent of wetland systems on the surrounding environment, and identify locations of potential biological hotspots across the Adirondack Park.
汞（Hg）是一种强效的神经毒素，在水生和陆地食物网中都具有生物放大作用，导致受影响的野生动物种群，包括鸣禽群落，出现不良的生理和生殖影响。由于还原条件，湿地生态系统促进了甲基汞的形成。区域研究记录了这些栖息地类型中鸣禽物种的血液汞浓度升高。这项研究的总体目标是研究目标鸣禽物种在斯潘格沼地湿地系统中的汞暴露的空间和季节性模式，并将这些模式与纽约州阿迪朗达克公园的相邻高地森林进行比较。项目采样在 2008 年、2009 年和 2011 年实地考察季节的 5 月至 8 月期间，在四个斯潘格沼地和相关的高地森林地点的研究地块上进行。总体结果记录如下：（1）与附近的高地森林物种相比，栖息在斯潘格沼地栖息地的鸣禽物种的血液汞浓度升高；（2）每种栖息地类型中的目标物种在每个研究点都表现出一致的物种水平血液汞浓度模式；（3）在斯潘格沼地栖息地中没有记录到血液汞浓度的季节性变化，但在高地森林物种中检测到汞暴露的季节性模式先增加后减少。栖息地类型被证明会影响鸟类的汞暴露水平。此外，斯潘格沼地生态系统可能导致周围环境中生物体内的汞浓度升高。在不同的栖息地类型之间发现了血液汞浓度的季节性模式差异，这可能与包括猎物中与栖息地相关的汞浓度、季节性饮食变化和年度换羽周期在内的多种变量有关。本项目强调了在确定的高汞栖息地类型（特别是湿地系统）内优先开展未来研究工作的重要性，以便更好地描述相关鸟类暴露水平，估计周围环境中湿地系统的空间范围，并确定阿迪朗达克公园内潜在生物热点的位置。
