The response of freshwater aquatic microbial communities to Marcellus Shale natural gas extraction

Caroline Solomon (1), Ryan Trexel (1), Regina Lamendella (1)

(1) Juniata College s

abstract

Marcellus Shale natural gas extraction has increased dramatically in Pennsylvania over the past six years. Due to the alacrity of exploration and delay in regulation and monitoring, the combination of horizontal drilling and hydraulic fracturing may potentially lead to environmental pollution through a variety of pathways. Because microbial communities can shift dramatically in response to changes in environmental parameters, they can be used as a biomarker to assess ensuing environmental threats. The purpose of our study is to determine the potential shift in microbial community structure of headwater stream ecosystems found within Marcellus Shale impacted watersheds. In order to determine the members of the microbial community and their response to hydraulic fracturing inputs, we used high throughput Illumina sequencing of the 16S rRNA gene on the MiSeq platform. The QIIME pipeline has allowed us to analyze millions of sequences to assess the microbial changes associated with Marcellus Shale impacts. To date, we have identified significant changes in abiotic parameters (especially pH) in sites with documented spills and contaminations within their watersheds. We expect to see microbial community remodeling in response to abiotic perturbations. To our knowledge, the response of microbial communities to unconventional natural gas exploration in the Marcellus Shale formation had not been studied. Thus, by identifying shifts in the microbial community structure in response to natural gas extraction, we can potentially highlight target organisms for the degradation of spills and pollution.