Water Mission Area, US Geological Survey, Reston, VA 20192;
Leetown Science Center, US Geological Survey, Kearneysville, WV 25430.
Proc Natl Acad Sci U S A. 2020 Feb 18;117(7):3670-3677. doi: 10.1073/pnas.1911458117. Epub 2020 Feb 3.
The number of horizontally drilled shale oil and gas wells in the United States has increased from nearly 28,000 in 2007 to nearly 127,000 in 2017, and research has suggested the potential for the development of shale resources to affect nearby stream ecosystems. However, the ability to generalize current studies is limited by the small geographic scope as well as limited breadth and integration of measured chemical and biological indicators parameters. This study tested the hypothesis that a quantifiable, significant relationship exists between the density of oil and gas (OG) development, increasing stream water concentrations of known geochemical tracers of OG extraction, and the composition of benthic macroinvertebrate and microbial communities. Twenty-five headwater streams that drain lands across a gradient of shale gas development intensity were sampled. Our strategy included comprehensive measurements across multiple seasons of sampling to account for temporal variability of geochemical parameters, including known shale OG geochemical tracers, and microbial and benthic macroinvertebrate communities. No significant relationships were found between the intensity of OG development, shale OG geochemical tracers, or benthic macroinvertebrate or microbial community composition, whereas significant seasonal differences in stream chemistry were observed. These results highlight the importance of considering spatial and temporal variability in stream chemistry and biota and not only the presence of anthropogenic activities in a watershed. This comprehensive, integrated study of geochemical and biological variability of headwater streams in watersheds undergoing OG development provides a robust framework for examining the effects of energy development at a regional scale.
美国水平钻探的页岩油和天然气井数量从 2007 年的近 28000 口增加到 2017 年的近 127000 口，研究表明，页岩资源开发的潜力可能会影响附近的溪流生态系统。然而，目前研究的推广能力受到地理范围小、测量的化学和生物指标参数的广度和综合度有限的限制。本研究检验了这样一个假设，即油气（OG）开发密度、增加的溪流水中已知 OG 提取地球化学示踪剂浓度与底栖大型无脊椎动物和微生物群落组成之间存在可量化的、显著的关系。研究采集了 25 条源自页岩气开发强度梯度的溪流。我们的策略包括在多个季节进行全面测量，以考虑地球化学参数的时间变化，包括已知的页岩 OG 地球化学示踪剂以及微生物和底栖大型无脊椎动物群落。OG 开发强度、页岩 OG 地球化学示踪剂或底栖大型无脊椎动物或微生物群落组成之间没有发现显著关系，而溪流化学物质存在显著的季节性差异。这些结果强调了在流域中不仅要考虑人为活动的存在，还要考虑溪流化学物质和生物区系的空间和时间变化的重要性。本研究对正在进行 OG 开发的流域中溪流的地球化学和生物学变异性进行了全面、综合的研究，为在区域尺度上研究能源开发的影响提供了一个强有力的框架。
