Department of Environmental Biology, State University of New York College of Environmental Science and Forestry, Syracuse, NY, 13210, USA.
Finger Lakes Institute, Hobart and William Smith Colleges, Geneva, NY, 14556, USA.
Arch Environ Contam Toxicol. 2021 Jul;81(1):1-14. doi: 10.1007/s00244-021-00839-x. Epub 2021 Apr 1.
The northeastern United States receives elevated mercury (Hg) deposition from United States and global emissions, making it critical to understand the fate of Hg in watersheds with a variety of aquatic habitats and land use types, such as the Finger Lakes region of New York State. Bats are valuable and important organisms to study chronic Hg exposure, because they are at risk of sublethal effects from elevated Hg exposure. The objectives of this study were to: (1) determine total Hg (THg) and methylmercury (MeHg) concentrations in big brown bats (Eptesicus fuscus) of the Finger Lakes region; (2) assess whether morphometric, temporal, or spatial factors predict bat Hg concentrations; and (3) investigate the role of trophic position and diet represented by stable isotopes of carbon and nitrogen in explaining variations in bat Hg concentrations. We found comparable THg and MeHg concentrations to previous studies (THg range 1-45 ppm, MeHg range 0.5-38 ppm) in big brown bat fur collected throughout the Finger Lakes region. On average, MeHg made up 81% of THg in bat fur. Fifteen percent of our samples showed higher THg than a proposed toxicity threshold of 10 ppm. Together, dominant land cover and % wetland cover explained bat THg in the Finger Lakes. Trophic position (i.e., δN) was strongest in predicting bat THg in forests but was a weaker predictor of Hg bioaccumulation in bats from agricultural and urban areas. The range of Hg concentrations found in this study warrants further examination into the potential toxicological impacts of Hg to wildlife and the role of land use in Hg exposure to terrestrial organisms of the Finger Lakes.
美国东北部地区受到来自美国和全球排放的汞（Hg）沉降的影响，因此了解具有各种水生栖息地和土地利用类型的流域中 Hg 的归宿至关重要，例如纽约州的手指湖地区。蝙蝠是研究慢性 Hg 暴露的有价值且重要的生物体，因为它们面临着因 Hg 暴露而导致亚致死效应的风险。本研究的目的是：（1）确定手指湖地区大褐蝙蝠（Eptesicus fuscus）中的总汞（THg）和甲基汞（MeHg）浓度；（2）评估形态学、时间或空间因素是否预测蝙蝠 Hg 浓度；（3）通过碳和氮的稳定同位素来研究营养位置和饮食在解释蝙蝠 Hg 浓度变化中的作用。我们发现，与之前的研究相比，手指湖地区采集的大褐蝙蝠皮毛中的 THg 和 MeHg 浓度相当（THg 范围为 1-45 ppm，MeHg 范围为 0.5-38 ppm）。平均而言，MeHg 占蝙蝠皮毛中总 Hg 的 81％。我们有 15％的样本显示 THg 高于 10 ppm 的毒性阈值。在 Finger Lakes，主要的土地覆盖和湿地覆盖率解释了蝙蝠 THg。在森林中，营养位置（即 δN）是预测蝙蝠 THg 的最强因素，但在预测农业和城市地区蝙蝠中 Hg 生物积累的作用较弱。本研究中发现的 Hg 浓度范围需要进一步研究 Hg 对野生动物的潜在毒理学影响，以及土地利用在 Finger Lakes 陆地生物中 Hg 暴露中的作用。
