Ecological Risks of Shale Oil and Gas Development to Wildlife, Aquatic Resources and their Habitats

Abstract

Technological advances in hydraulic fracturing and horizontal drilling have led to the exploration and exploitation of shale oil and gas both nationally and internationally. Extensive development of shale resources has occurred within the United States over the past decade, yet full build out is not expected to occur for years. Moreover, countries across the globe have large shale resources and are beginning to explore extraction of these resources. Extraction of shale resources is a multistep process that includes site identification, well pad and infrastructure development, well drilling, high-volume hydraulic fracturing and production; each with its own propensity to affect associated ecosystems. Some potential effects, for example from well pad, road and pipeline development, will likely be similar to other anthropogenic activities like conventional gas drilling, land clearing, exurban and agricultural development and surface mining (e.g., habitat fragmentation and sedimentation). Therefore, we can use the large body of literature available on the ecological effects of these activities to estimate potential effects from shale development on nearby ecosystems. However, other effects, such as accidental release of wastewaters, are novel to the shale gas extraction process making it harder to predict potential outcomes. Here, we review current knowledge of the effects of high-volume hydraulic fracturing coupled with horizontal drilling on terrestrial and aquatic ecosystems in the contiguous United States, an area that includes 20 shale plays many of which have experienced extensive development over the past decade. We conclude that species and habitats most at risk are ones where there is an extensive overlap between a species range or habitat type and one of the shale plays (leading to high vulnerability) coupled with intrinsic characteristics such as limited range, small population size, specialized habitat requirements, and high sensitivity to disturbance. Examples include core forest habitat and forest specialists, sagebrush habitat and specialists, vernal pond inhabitants and stream biota. We suggest five general areas of research and monitoring that could aid in development of effective guidelines and policies to minimize negative impacts and protect vulnerable species and ecosystems: (1) spatial analyses, (2) species-based modeling, (3) vulnerability assessments, (4) ecoregional assessments, and (5) threshold and toxicity evaluations.

Land cover changes associated with recent energy development in the Williston Basin; Northern Great Plains, USA

“…With the adoption and expansion of pad drilling (2010)(2011)(2012)(2013)(2014), the number of well bores being drilled from each pad continued to increase, which reduced the land requirement per well relative to single bore pads. Although different shale plays utilize different well densities per pad, the average pad area between 2010 and 2014 in the Williston Basin (1.7 ha) is similar to the average area of shale oil and gas pads nationally (1.2-2.7 ha; Brittingham et al, 2015). Finally, the amount of land required for NOG wells showed a rapid increase beginning in 2007 and then a precipitous drop in 2014.…”

Identifying the Relevant Local Population for Environmental Impact Assessments of Mobile Marine Fauna

“…To adequately characterize the impact of a proposed development or activity on a particular species, it is necessary to identify the relevant local population which may be impacted (Brittingham et al, 2014;Bastos et al, 2016;Brown et al, 2016). In highly fragmented landscapes, the relevant local population may be straightforward to delineate because of the geographical separation between the area affected by the development and the nearest other sites where the species may be found.…”

Shale Gas: A Review of the Economic, Environmental, and Social Sustainability

“…[116,159] All of this may also affect the local ecology,b ut the effects are still largely unknown, apart from afew studies.F or example,one study has suggested that specialized species and habitatsa round well pads are most at risk because of land and food-chain fragmentation. [160] It has also been found that noise pollution from compressors at well sites affects animal behavior. [161,162] Althoughs uch studies can help with mitigationp lans,c ertain activities and characteristics are unique to the regionw here shale gas extractioni st aking place,m aking it difficult to foresee all ecological impacts.…”