September 30, 2014

Mining & Energy Commission ATTN: Oil and Gas Program 1612 Mail Service Center Raleigh, NC 27699-1612

RE: Comments on Proposed Oil and Gas Rules

The Center for Biological Diversity (“Center”), on behalf of itself and its members, submits the following comments in response to the proposed Oil and Gas Rules published by the N.C. Department of Environment and Natural Resources, State Mining and Energy Commission on July 15, 2014 (the “Draft Rules”). The Center is very concerned that the Draft Rules do not provide sufficient protections for habitat and water resources, and do not contain any assurances that the state will ensure Endangered Species Act (“ESA” or “Act”) protections during gas operations.

There are several federally listed endangered or threatened species potentially impacted by future fracking operations in North Carolina. These include several species of mussels, such as Appalachian Elktoe, Carolina Heelsplitter, Cumberland Bean Pearlymussel, Dwarf Wedgemussel, James Spinymussel, Littlewing Pearlymussel, Tar River Spinymussel and Noonday Globe, as well as several fish species including Cape Fear Shiner, Roanoke Logperch, Shortnose Sturgeon, Spotfin Chub, Waccamaw Silverside and Atlantic Sturgeon.

Allowing fracking activities that may harm these species opens up the state and private actors to liability under Section 9 of the ESA. Under section 9(a)(1)(B) of the Act, it is illegal to engage in any activity that “takes” an endangered species. 16 U.S.C. § 1538(a)(1)(B). Regulations adopted by the FWS under section 4(d) of the Act, id. § 1533(d), apply the Endangered Species Act’s take prohibition to threatened species. 50 C.F.R. § 17.31; Id. § 17.21 (making it “unlawful for any person . . . to commit, to attempt to commit, to solicit another to commit or to cause to be committed . . . take”).

Congress intended the term “take” to be defined in the “broadest possible manner to include every conceivable way” in which a person could harm or kill wildlife. S. Rep. No. 93-307, 93d Cong., 1st Sess. 1, reprinted in 1973 USCAAN 2989, 2995. The term “take” is defined in the statute to include “to harass, harm, pursue, hunt, shoot, wound, kill, trap, capture, or collect, or to attempt to engage in any such conduct.” 16 U.S.C. § 1532(18).

The implementing regulations for the Act define “harm” to include “significant habitat modification or degradation where it actually kills or injures wildlife by significantly impairing essential behavioral patterns, including breeding, feeding or sheltering.” 50 C.F.R. § 17.3. The term “harass” is defined to mean “an intentional or negligent act or omission which creates the likelihood of injury to wildlife by annoying it to such an extent as to significantly disrupt normal behavioral patterns which include, but are not limited to, breeding, feeding, or sheltering.” Id. § 17.3.

Persons subject to the prohibition on take includes individuals and corporations, as well as “any officer, employee, agent, department, or instrumentality . . . of any State.” 16 U.S.C. § 1532(13). The ESA provides for civil penalties of up to $25,000 per violation, and criminal penalties of up to $50,000 and one year imprisonment per violation. 16 U.S.C. § 1540(a), (b).

Where a violation of the section 9 “take” prohibition is alleged, a court must issue an injunction if a plaintiff establishes by a preponderance of the evidence that there is “a reasonably certain threat of imminent harm to a protected species.” Defenders of Wildlife v. Bernal, 204 F.3d 920, 925 (9th Cir. 2000). Because Congress has accorded the protection of endangered species the highest of priorities, courts do not have the discretion to withhold injunctive relief where it is necessary to prevent an imminent and likely violation of the ESA. Tennessee Valley Auth. v. Hill, 437 U.S. 153, 184 (1978).

It is without question that fracking can cause harm to habitat and species, including those listed under the ESA. Attached to these comments are several articles and studies that discuss the impacts of fracking on the natural environment, which the Center hereby incorporates by reference, and requests that they be included in the administrative record in this docket. These studies explain how fracking can negatively impact surface and groundwater, poison habitat, and cause habitat fragmentation.

As one study notes, “if you look down on a heavily ‘fracked’ landscape, you see a web of well pads, access roads and pipelines that create islands out of what was, in some cases, contiguous habitat.” Biotic Impacts of Energy Development from Shale: Research Priorities and Knowledge Gaps. Frontiers in Ecology and the Environment. Article published online Aug. 1, 2014 (available at http://www.esajournals.org/doi/abs/10.1890/130324). The authors found that one of the greatest threats to animal and plant life identified in the study is the impact of rapid and widespread shale development, which has disproportionately affected rural and natural areas. A single gas well results in the clearance of 3.7 to 7.6 acres (1.5 to 3.1 hectares) of vegetation, and each well contributes to a collective mass of air, water, noise and light pollution that has or can interfere with wild animal health, habitats and reproduction.

Other studies note the intense water usage that fracking requires, which can threaten surface waters through altered streamflow and toxic flowback. See Entrekin et al. Rapid Expansion of Natural Gas Development Poses a Threat to Surface Waters. Frontiers in Ecology (published online 6 Oct 2011) (available at http://www.cce.cornell.edu/EnergyClimateChange/NaturalGasDev/Documents/PDFs/Ent rekin%20et%20al%20Frontiers%20in%20Ecology%20and%20the%20Environment.pdf). Studies specific to the Eastern United States have noted the potential for water degradation, ground waster salinization, forest fragmentation, air pollution and other harm associated with fracking; yet the proposed rules do not incorporate mechanisms to protect North Carolina’s ecosystems from those harms. See Gillen and Kiviat, Hydraulic Fracturing Threats to Species with Restricted Geographic Ranges in the Eastern United States. Environmental Practice (2012) (available at http://hudsonia.org/wp- content/uploads/2013/03/GillenKiviatFracking.pdf). See also Diana M. Papoulias and Anthony L. Velasco, Histopathological Analysis of Fish from Acorn Fork Creek, Kentucky, Exposed to Hydraulic Fracturing Fluid Releases. Southeastern Naturalist, Volume 12, Special Issue 4 (2013) (available at http://www.eaglehill.us/SENAonline/articles/SENA-sp-4/18-Papoulias.shtml)

The Center is concerned that the draft rules provide only a 500 foot setback from the boundary of a drilling unit for a “perforated” well bore. Given that fractures have been documented to extend as much as ½ mile from a perforated well bore, a minimum distance of 1,000 feet from drilling unit boundaries must be required to prevent harm to habitat and species, and protect surface and groundwater. The Draft Rules further provide setbacks from well head, edge of waste pits, production equipment and tanks; however, these are insufficient to protect public health and the environment. 200 foot buffers from rivers, lakes, streams and wetlands and a 100 foot setback for intermittent streams is entirely insufficient to ensure that habitat will be protected. These minimal buffers pose a high likelihood that toxic runoff will be carried into navigable waterway, and poses a risk to people and the environment.

The Center believes that a setback of gas wells from surface waters must be increased from 200 to at least 1,000 feet on level ground (less than 5% slope), and even greater buffers are required on sloped surfaces, to prevent runoff from well pads on which toxic materials are stored and handled from reaching public waters and habitat areas. Wellheads must be at least 500 feet from intermittent streams. Without these protections, the Draft Rules pose a hazard to North Carolina’s natural communities, and to species such as the Eastern Hellbender Salamander, which has been threatened by habitat encroachment.

The Center is further concerned that the Draft Rules allow groundwater withdrawals to continue until the closest drought monitor indicates water levels are below the 5th percentile of historic water levels for the area. This allows for withdrawal to dangerous levels, which can impact the available groundwater for drinking water, and may harm habitat and species by creating drought conditions. The Center notes that there is no requirement in the rules of an overall record of total water being withdrawn from groundwater (including quarry sources, often fed by groundwater) and from surface water. The withdrawals across the whole local area in which fracking is taking place need to be reviewed together and a plan developed to coordinate water withdrawals across the whole area where hydraulic fracturing is taking place.

More must be done to ensure that North Carolina does not cause harm to people, property and the environment. Larger setbacks, more reporting and limitations on groundwater and surface water withdrawals, and monitoring requirements for habitat are necessary to ensure adequate protections. The Center further urges North Carolina to engage the Fish and Wildlife Service and/or National Marine Fisheries Service regarding the potential impacts to listed species and critical habitat from the proposed rules, in order to avoid Section 9 take violations from the impacts of allowing fracking under the proposed Draft Rules.

Respectfully submitted,

/s/ Jared M. Margolis_____ Jared M. Margolis CENTER FOR BIOLOGICAL DIVERSITY 2852 Willamette St. PO Box 171 Eugene, OR 97405 Phone: (971) 717-6403 Email: [email protected]

ENVIRONMENTAL REVIEWS AND CASE STUDIES

Hydraulic Fracturing Threats to attention has been paid to the effects of toxic chemicals, salt, habitat fragmentation, truck traffic, air pollution, noise, Species with Restricted night lighting, and water withdrawals on ecosystems and Geographic Ranges in the their wild animals and plants ~Davis and Robinson, 2012; Entrekin et al., 2011; Kiviat and Schneller-McDonald, 2011! Eastern United States The great spatial extent of industrialization and the rapid pace of development of shale-gas resources associated with Jennifer L. Gillen, Erik Kiviat fracking in the eastern United States ~US! may result in environmental impacts disproportionate to economic ben- efits ~Davis and Robinson, 2012!. Many serious impacts of High-volume horizontal hydraulic fracturing (fracking)isa gas and oil mining on biodiversity have been documented in the US and Canadian West ~Naugle, 2011!. For example, new technology that poses many threats to biodiversity. compressor noise from gas-drilling installations was found Species that have small geographic ranges and a large over- to interfere with ovenbird ~Seiurus aurocapilla! pairing suc- lap with the extensively industrializing Marcellus and Utica cess and alter population age structure ~Habib, Bayne, and shale-gas region are vulnerable to environmental impacts of Boutin, 2007!. In the Marcellus shale-gas region, it is ex- pected that fracking will exacerbate the natural migration fracking, including salinization and forest fragmentation. We of salt from the deep shale beds into shallow aquifers reviewed the ranges and ecological requirements of 15 spe- ~Warner et al., 2012!, which could adversely affect wild cies (1 mammal, 8 salamanders, 2 fishes, 1 butterfly, and 3 species adapted to strictly fresh groundwaters or to surface vascular plants), with 36%–100% range overlaps with the waters into which groundwaters discharge. Marcellus-Utica region to determine their susceptibility to shale-gas activities. Most of these species are sensitive to The largest occurrence of commercially exploitable gas shales—the Marcellus and Utica shale-gas region—extends forest fragmentation and loss or to degradation of water beneath approximately 285,000 km2 of the Appalachian quality, two notable impacts of fracking. Moreover, most are Basin ~calculated from the US agency maps cited in this rare or poorly studied and should be targeted for research article’s Methods section!. This region supports high spe- and management to prevent their reduction, extirpation, or cies diversity and many endemic species with small geo- graphic ranges and narrow habitat affinities. The Appalachian extinction from human-caused impacts. region is a global megadiversity region for salamanders, Environmental Practice Page 1 of 12 stream fishes, freshwater mussels, and crayfishes, and is home to more than 150 imperiled species ~Stein, Kutner, and Adams, 2000!. Because organisms with geographic ranges he new technology of high-volume horizontal hydrau- concentrated in shale-gas regions are at greater risk from lic fracturing to extract natural gas, known as frack- T fracking impacts ~Kiviat and Schneller-McDonald, 2011!,we ing, has gained attention in the past few years. Fracking is reviewed the potential impacts of fracking on animal and the process of drilling vertically and then horizontally plant species with ranges substantially restricted to areas through deeply buried shale beds, and pumping water, underlain by the Marcellus and Utica shale-gas region. sand, and chemicals at high pressures into the shales to release the natural gas. Part of this chemical and water mixture returns to the surface as frack water, which con- Affiliation of authors: Jennifer L. Gillen, Environmental and Urban tains toxicants such as benzene and toluene from the frack- Studies Program, Bard College, Annandale, New York. Erik Kiviat, PhD, Executive Director, Hudsonia Ltd., Annandale, New York. ing fluids, as well as radium and salt from the shales Address correspondence to: Erik Kiviat, Executive Director, Hudsonia ~Rowan et al., 2011; Schmidt, 2011!. Although the impacts of Ltd., PO Box 5000, Annandale, NY 12504; ~phone! 845-758-7273; ~fax! fracking in the eastern states on drinking-water supplies 845-758-7033; ~e-mail! [email protected]. and public health have been discussed extensively, little © National Association of Environmental Professionals 2012

doi:10.10170S1466046612000361 Hydraulic Fracturing Threats to Species 1 Methods portions of its range, we believe it is important to protect this plant within the US regardless of its status in Canada. We focused on species that have geographic ranges of which Another species, northern blue monkshood, which occurs 35% or more is underlain by the Marcellus and Utica in small areas of Wisconsin, Iowa, Ohio, and New York shale-gas region; we refer to these species as quasi-endemic ~USDA, 2012!, may be part of a widespread western species, to the Marcellus-Utica region. The cutoff of 35% has prec- Columbian monkshood ~Aconitum columbianum; Cole and edent in conservation science and is considered a high Kuchenreuther, 2001!. However, because there is a disjunc- percentage overlap in the Natural Capital Project’s habitat tion of 800 km between the Ohio and Wisconsin popula- risk assessment model ~Arkema, Bernhardt, and Verutes, tions, suggesting the potential for evolutionary divergence, 2011!. By reviewing publicly available range maps, we se- we have included only the Ohio–New York populations in lected 15 species that met the 35% criterion and are cur- our analysis. Evolutionary potential must also be consid- rently accepted as full species in standard taxonomic ered when determining the ecological effects of fracking. treatments @e.g., US Department of Agriculture ~USDA!, We assessed potential impacts at the species level, but ge- 2012#. netic variation below the species level may have an even higher overlap with the shales. We then studied each species’ natural history, habitat needs, and legal status for indications of vulnerability to the phys- ical and chemical effects of fracking. For example, eight Results and Discussion species are salamanders in the family Plethodontidae. These lungless salamanders are particularly sensitive to environ- We reviewed 15 species with restricted geographic ranges mental changes because they respire through their skin having 35%–100% overlap with the Marcellus and Utica and require constant contact with moisture ~Welsh and shale-gas region ~Table 1 and Figure 1!. Of the 15 species Droege, 2001!. After selecting species, geographic informa- selected, there are 8 plethodontid salamanders, 2 stream tion system ~GIS! software was used to calculate the per- fishes, 1 mammal, 1 butterfly, and 3 plants. The total geo- centage overlap with the gas shales. We obtained geographic graphic range size varies from 3 to 292,261 km2, with a range data for mammals and amphibians from the Inter- mean of 91,075.3 km2 and median of 59,988 km2. The mean national Union for Conservation of Nature ~IUCN! Red overlap with the shale-gas region is 64.4%, and the median List Spatial Data Download website ~2012!, for plants from is 68%. Ten species have 50% or greater overlaps with the the USDA ~2012!, for fishes from NatureServe ~2011!, and shales, and four have 40%–49% overlap. These overlap for butterflies from Butterflies and Moths of North Amer- figures indicate the potential for impacts to occur over ica ~BAMONA, 2012!. We combined digital maps of the large portions of these species’ ranges and, given the cu- Marcellus and Utica shale formations obtained from the mulative impacts of other intensive land uses such as coal US Energy Information Administration ~2012! and the US mining, agriculture, residential development, and logging, Geological Survey ~2002! to create a single map layer show- raise substantial concerns about species survival. The sen- ing the region underlain by both formations. We used sitivities of these species to habitat degradation at the land- ArcMap 10.0 ~ESRI, Redlands, CA! to establish the overlap scape and regional levels are suggested by the data in between each species’ range and the shale boundary, to Table 1. Of the 15 species, 4 are listed as endangered or calculate the percentage overlap, and to create the maps threatened at the federal level or in at least one state where depicting the species ranges in relation to the Marcellus the species occurs. Of the 15 species, 11 are stated to depend and Utica shale-gas region. on good water quality, 10 to be sensitive to habitat frag- mentation, 13 are either stenotopic ~have narrow habitat Various federal agency maps indicate that the area of the affinities! or are sensitive to changes in habitat, and 11 are combined Marcellus and Utica shales is in the range of threatened by deforestation ~Table 1!. 268,000 to 340,000 km2. We use the conservative figure of 285,000 km2 for our analyses. Species with smaller geographic ranges are more vulnerable to extinction than are species with larger ranges ~Payne and One of the selected species, Bailey’s sedge, extends north- Finnegan, 2007!, and species with smaller populations ~num- ward into a small area of Québec, yet we have analyzed bers of individuals! are more vulnerable than are species only the US portion of its range. Because Canadian and US with larger populations ~Noss and Cooperrider, 1994; Slo- practices differ with regard to managing this rare species, bodkin, 1986!. Thus, reductions in range size are expected to and the species undoubtedly varies genetically in different make a species more vulnerable to extinction. Reductions in

2 Environmental Practice Table 1. Selected species of animals and plants with restricted geographic ranges and a high degree of overlap with the combined Marcellus and Utica shale-gas region.

Range Shale Water Species (km2 )a (%)b Statusc qualityd Fragmentatione Stenotopicf Forestg References

Appalachian cottontail ~Sylvilagus obscurus! 94,345 46 X X Barry and Lazell, 2008 Allegheny mountain dusky salamander ~Desmognathus 292,261 70 X X X X Duncan et al., 2011 ochrophaeus! Gibbs et al., 2007 Welsh and Droege, 2001 West Virginia spring salamander ~Gyrinophilus subterraneus! 3 100 E ~WV! X X X X Welsh and Droege, 2001 Wehrle’s salamander ~Plethodon wehrlei! 114,481 82 X X X X Duncan et al., 2011 Hammerson, 2004 Welsh and Droege, 2001 Wyman, 2003 Valley and ridge salamander ~Plethodon hoffmani! 59,988 68 X X X X Duncan et al., 2011 Welsh and Droege, 2001 Wyman, 2003 Cheat Mountain salamander ~Plethodon nettingi! 1,286 100 T ~federal! X X X X Duncan et al., 2011 Welsh and Droege, 2001 Wyman, 2003 White-spotted salamander ~Plethodon punctatus! 11,143 45 X X X X Duncan et al., 2011 Welsh and Droege, 2001 Wyman, 2003 Shenandoah Mountain salamander ~Plethodon virginia! 2,472 77 X X X X Duncan et al., 2011 Welsh and Droege, 2001 Wyman, 2003 Northern ravine salamander ~Plethodon electromorphus! 113,396 58 X X X X Duncan et al., 2011 Welsh and Droege, 2001 Wyman, 2003 Tonguetied minnow ~Exoglossum laurae! 31,622 67 X ? USEPA, 2010 Bluebreast darter ~Etheostoma camurum! 75,917 51 C ~NY! X X Losey, Roble, and Hammerson, 2011 yrui rcuigTrast pce 3 Species to Threats Fracturing Hydraulic I ~OH, VA! Appalachian azure ~Celastrina neglectamajor! 244,038 36 X X X NYNHP, 2011 Shale-barrens pimpernel ~Taenidia montana! 29,310 42 E ~PA! X USDA, 2012 Walton, Ormes, and Morse, 2012 Bailey’s sedge ~Carex baileyi! 279,581 44 ? ? X ? MNHESP, 2009 Northern blue monkshood ~Aconitum noveboracense! 16,281 81 E ~OH! X X X Edmondson et al., 2009 T ~federal, NY! ONHP, 2007 a Total area of geographic range ~calculations do not account for the fragmented ranges of some species, thus area occupied may be smaller than the figures shown!. b Percentage of geographic range that overlaps the Marcellus-Utica shale-gas region. c E ~endangered! or T ~threatened! listing by federal or state agencies; C ~critically imperiled! or I ~imperiled! ranking by NatureServe ~see references cited!. d Reported as sensitive to water quality ~see references cited!. e Reported as sensitive to habitat fragmentation ~see references cited!. f Reported as having narrow habitat affinities or as sensitive to habitat change ~see references cited!. g Reported as dependent on forested environments or sensitive to deforestation ~see references cited!. MNHESP, Massachusetts Natural Heritage and Endangered Species Program; NYNHP, New York Natural Heritage Program; ONHP, Ohio Natural Heritage Program; USDA, US Department of Agriculture; USEPA, US Environmental Protection Agency. Figure 1. Maps showing the area underlain collectively by the Marcellus and Utica shale-gas region, the geographic ranges of selected species, and the overlap between shales and species: (a) Marcellus–Utica Shale outline, (b) Appalachian cottontail, (c) Allegheny mountain dusky salamander, (d) West Virginia spring salamander, (e) Wehrle’s salamander, (f) valley and ridge salamander, (g) Cheat Mountain salamander, (h) white-spotted salamander, (i) Shenandoah Mountain salamander, (j) northern ravine salamander, (k) tonguetied minnow, (l) bluebreast darter, (m) Appalachian azure, (n) shale-barrens pimpernel, (o) Bailey’s sedge, and (p) northern blue monkshood. Range maps for species are from the International Union for Conservation of Nature ~2011!, the US Department of Agriculture ~2012!, and Butterflies and Moths of North America ~2012!. See Table 1 for calculated areas of the geographic ranges and percentage overlaps with the shales. forest area may result in great reductions of the number of species cannot yet be managed in a targeted way ~Bunch species ~Drakare, Lennon, and Hillebrand, 2006!, and most et al., 2012!. The Appalachian cottontail is declining and of the species in our sample are closely associated with the number of local populations is decreasing due to hab- forests. The remainder of this discussion addresses the eco- itat destruction, fragmentation, and forest maturation ~Barry logical requirements of the various groups of organisms and Lazell, 2008; Harnishfeger, 2010!. Fracking uses large that may make them vulnerable to fracking impacts. areas of land for drill pads and pipelines, and roads must be constructed to enable truck traffic back and forth from Mammals drill sites. An average of 8.8 acres of forest is cleared for each Marcellus drill site and, with an additional indirect The Appalachian cottontail, recently separated by systematists impact ~through edge effects! on 21.2 acres, an average of from the New England cottontail, is found in mixed-oak 30 acres of forest is impacted at each site ~Johnson, 2010!. forests with ericaceous ~heath family! shrub cover ~Bunch For a species that is threatened by habitat destruction and et al., 2012! and has a highly fragmented range, extending fragmentation, fracking could further reduce population from Pennsylvania to Alabama ~Barry and Lazell, 2008!. and cause endangerment. The IUCN lists the Dolly Sods Habitat needs are most likely different from those of the Wilderness Area, West Virginia, as a major source popula- New England cottontail, but because this is not known, the tion for smaller populations of Appalachian cottontails

4 Environmental Practice Figure 1. Continued

Hydraulic Fracturing Threats to Species 5 Figure 1. Continued

6 Environmental Practice Figure 1. Continued

Hydraulic Fracturing Threats to Species 7 Figure 1. Continued

~Barry and Lazell, 2008!, and if this population were se- been shown to reduce terrestrial salamander movement by verely affected by habitat destruction or fragmentation caused 51%, and multiple roads could reduce dispersal by up to by fracking, those populations that depend on Dolly Sods 97%. Although roads may not have major implications for for gene flow would be negatively impacted. species with large ranges and high abundances, species with limited ranges and low abundances may be severely Salamanders affected by new roads because they are already impacted by fragmentation, logging, and other human activities ~Marsh, The Plethodontidae, which is the largest family of sala- Gorham, and Beckman, 2005!. Plethodontids such as the manders, represents significant diversity ~Petranka, 1998!. white-spotted salamander and the Cheat Mountain sala- Plethodontids are rapidly evolving, and too little is known mander have small distributions and are currently affected about 43% of species to manage them successfully ~Wyman, by fragmentation and deforestation ~Hammerson, 2004; 2003!. Many plethodontids, such as the Shenandoah Moun- Hammerson and Mitchell, 2004!; multiple roads and truck tain salamander and the northern ravine salamander traffic, when compounded with many other destructive ~Table 1!, have only recently been recognized as species, factors, could imperil these species’ survival. After clear- and their habitat requirements and management needs are cutting, salamander communities take decades to recover poorly understood ~Highton, 1999!. There is especially a from the drying of soils in logged areas, changes in the lack of knowledge about the vulnerable juvenile terrestrial prey community, and the difficulty many salamander spe- plethodontids ~Wyman, 2003!. cies have in crossing nonforested habitats ~e.g., Ash, 1997; Bratton and Meier, 1998; Mitchell, Wicknick, and Anthony, Terrestrial salamanders have difficulty crossing roads, and 1996; Petranka, Eldridge, and Haley, 1993!. The perforation roads may reduce both their abundance and genetic diver- of forests by well pads, access roads, and pipeline rights- sity. Roads not only fragment habitats but may also be of-way, with associated microclimatic drying, salinization, obstacles to salamanders ~Wyman, 2003!. Forest roads have and other changes, presumably reduces or eliminates local

8 Environmental Practice populations of many salamander species in fracking land- Butterflies scapes, and this could contribute cumulatively to a decline or loss of species over large areas. The Appalachian azure inhabits deciduous forests, and its larval food plant is black cohosh ~Actaea racemosa!.The butterfly is scarce and has difficulty moving between forest The wastewater from fracking installations is another po- fragments. Black cohosh is potentially threatened by non- tential threat to salamanders. After well fracking is com- native plants and white-tailed deer ~Odocoileus virgin- pleted, 30%–70% of the water injected into the well returns ianus!~New York Natural Heritage Program, 2011!, both of to the surface with contaminants from the shales and the which are likely to benefit from fracking. fracking chemicals ~Schmidt, 2011!. In Pennsylvania and West Virginia, frack water has been sprayed on land, diluted in municipal sewage treatment plants, stored in Plants open pits, partially reused, leaked, and spilled ~Kiviat and Plants will also be affected by fracking through fragmen- Schneller-McDonald, 2011!. Preliminary data from Penn- tation, increased salinity levels, and pollution by toxic chem- sylvania streams indicate that conductivity was higher icals. The northern wild monkshood is a federally threatened and biotic diversity ~including salamanders! was lower in plant at risk of soil contamination, drying due to canopy small watersheds where fracking had occurred ~Anony- loss, and nonnative plants. The monkshood occurs in only mous, 2010!. Saline wastewater can pollute streams and four states, of which New York and Ohio overlap with the other bodies of water, and many stream-dwelling and Marcellus and Utica shale-gas region. Monkshood has nar- water-dependent organisms are salt sensitive. Salaman- row habitat affinities, grows slowly, is very sensitive to ders, especially those with aquatic larvae, are sensitive to disturbance, and there is probably little gene flow among water quality ~Duncan et al., 2011!. The West Virginia the isolated populations ~Edmondson et al., 2009; Ohio spring salamander has been found in a single cave in Natural Heritage Program, 2007!; forest fragmentation and Greenbrier County, West Virginia; the adults reside in the increased salinity caused by fracking could imperil an al- mud banks next to the stream passage, and the aquatic ready threatened species. Forest fragmentation is known to larvae develop in the stream ~Besharse and Holsinger, facilitate the spread of nonnative, potentially invasive, plants 1977!. Fewer than 250 mature individuals of this species ~e.g., Yates, Levia, and Williams, 2003!. exist, and all of these salamanders are dependent on the stream that runs through the General Davis Cave ~Ham- merson and Beachy, 2004!—if this stream were to be polluted by salt or fracking chemicals, the species would Potential Benefits to Biodiversity be in danger of extinction. Although much of the tox- icological research has been conducted on frogs rather Fracking may benefit some species as well as harm others. than salamanders, amphibians in general are vulnerable Industrial activity creates habitats that may be used by rare to many contaminants, including organic chemicals, heavy or economically important species. For example, Noel et al. metals, and metalloids ~Herfenist et al., 1989!. ~1998! documented caribou ~Rangifer tarandus! using gravel pads associated with oil drilling for insect relief habitat. Schmidt and Kiviat ~2007! found a globally rare clam shrimp Fishes @Cyzicus ~Caenestheriella! gynecia# in rain pools on a gas pipeline road in New Jersey. However, artificial industrial There is a high probability of water pollution from spills of habitats tend to support common species that are ecolog- fracking wastewater ~Rozell and Reaven, 2012!, and stream ical generalists ~E. Kiviat, personal observations! rather fishes are vulnerable to this impact. The tonguetied min- than species of conservation concern. We expect that frack- now is intolerant of water pollution ~US Environmental ing installations will provide habitats for a few noteworthy Protection Agency, 2010!, although there is not enough species while degrading the environment for many others. information on this species to determine how it would be Appalachian cottontail is known to use shrublands and affected by fracking. The bluebreast darter is critically im- several-year-old clear-cuts ~Cannings and Hammerson, 2012!; periled in New York, imperiled in both Ohio and Virginia, thus, gas-pipeline rights-of-way and abandoned well pads and vulnerable in West Virginia and requires good water might provide acceptable habitat. Undoubtedly, other spe- quality ~Losey, Roble, and Hammerson, 2011; Pennsylvania cies of conservation concern could be managed for in Natural Heritage Program, 2012!, making it particularly fracking landscapes, and research to provide the basis for vulnerable to fracking activities. such management is urgently needed. Forest fragmenta-

Hydraulic Fracturing Threats to Species 9 tion in fracking landscapes, because of the dispersed char- fracking could be greater than the percentages in Table 1 acter of the industry, cannot be avoided. suggest. Also, ecological impacts like mountaintop-removal mining, logging, climate change, and other industrial ac- Summary tivities will compound the effects of fracking, making these species vulnerable to decline and extinction. Future studies Hydraulic fracturing poses serious threats to a diverse group should include a broader range of taxa and field research of species, including plants, butterflies, fishes, and salaman- that can measure the impacts of fracking while considering ders, that have restricted geographic ranges overlapping how these impacts may be compounded by other threats to substantially with the Marcellus and Utica gas shales. Of biodiversity. the 15 species we reviewed, many are so little known that targeted management would be based on insufficient evi- Biodiversity at all levels, from genes to ecosystems, consti- dence. Of these, 13 have narrow habitat affinities and 11 are tutes many important values to human society and eco- dependent on good water quality ~Table 1!, making them system functions, as well as the intrinsic importance of particularly vulnerable to fracking effects such as elevated each species ~Wilson, 1992!. Conserving biodiversity is im- salinity and other pollution. portant because each species has unique compounds, be- haviors, and other information that we may be able to use to improve human health, biotechnology, and enjoyment. Conclusions Biodiversity is also of great value to the function of ecosystems—and we do not know how the elimination of Although fracking will likely be permitted in most states certain species will affect ecosystem function. Many of the underlain with gas shales, if biodiversity and human im- species selected not only have restricted geographic ranges, pacts are well studied, appropriate regulations can be but live in small, isolated populations that would be neg- implemented. Because New York has not yet permitted atively affected by further fragmentation. A number of high-volume horizontal hydraulic fracturing, there is an these species are also recently described species, and most opportunity to protect the quasi-endemic species whose are little known ecologically. Intensive industrial activities ranges extend into New York, including northern blue such as fracking that potentially affect an almost 300,000- monkshood, Wehrle’s salamander, Allegheny mountain km2 region need to be thoroughly studied so that research- dusky salamander, and Appalachian azure. Many organ- ers and natural resource managers can assess impacts on isms are undergoing poleward range shifts caused by cli- biodiversity and humanity. mate change, but because changes in range limits are species specific and subject to many biological and abi- otic interactions ~Wyman, 1991!, we cannot know whether overlap percentages with gas shales will increase or de- Acknowledgments crease. Range contraction ~local or regional extirpation! We are grateful to Felicia Keesing ~Bard College! for discussions and due to other causes may increase the percentage overlap comments on a draft. Karen Schneller-McDonald ~Hickory Creek Con- of the remaining range with the Marcellus-Utica region, sulting! also discussed the subject with us. Maxine Segarnick and Jordan thus cumulatively increasing the risk posed by fracking; Michael Kincaid ~Bard College Center for Environmental Policy! pre- the Allegheny woodrat ~Neotoma magister; LoGiudice, 2003! pared the maps and calculated the areas of the geographic ranges and the may be an example. percentage overlaps with the shales. Prototype maps were drafted earlier by Robyn Glenney and Laura Steadman, with assistance from Gretchen Stevens, and Kristen Bell Travis edited the maps for publication. This is We reviewed species for which range maps are available; a Bard College Field Station–Hudsonia Contribution. there are many more species with no range maps or so little ecological information that it would be impossible to assess how fracking may affect them. There are almost certainly many species of invertebrates, plants, lichens, and References other organisms that are quasi-endemic to the Marcellus- Anonymous. 2010. Academy of Natural Sciences: Marcellus Shale Needs Utica region, but lack of access to range maps and ecolog- Scientific Study to Set Guidelines. PA Environment Digest,October18, ical information prohibited their inclusion in our study. 2010. http://www.paenvironmentdigest.com/newsletter/default.asp? The species selected in this study may actually have a much NewsletterArticleID517078 ~accessed May 1, 2012!. greater overlap with the shales ~because habitat range maps Arkema, K., J. Bernhardt, and G. Verutes. 2011. Habitat Risk Assessment. are generalized or out of date!, and thus potential effects of Natural Capital Project, Stanford University, Stanford, CA. Available

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12 Environmental Practice REVIEWS REVIEWS REVIEWS Rapid expansion of natural gas development 503 poses a threat to surface waters

Sally Entrekin1*, Michelle Evans-White2, Brent Johnson3, and Elisabeth Hagenbuch4

Extraction of natural gas from hard-to-reach reservoirs has expanded around the world and poses multiple environmental threats to surface waters. Improved drilling and extraction technology used to access low per- meability natural gas requires millions of liters of water and a suite of chemicals that may be toxic to aquatic biota. There is growing concern among the scientific community and the general public that rapid and exten- sive natural gas development in the US could lead to degradation of natural resources. Gas wells are often close to surface waters that could be impacted by elevated sediment runoff from pipelines and roads, alteration of streamflow as a result of water extraction, and contamination from introduced chemicals or the resulting wastewater. However, the data required to fully understand these potential threats are currently lacking. Scientists therefore need to study the changes in ecosystem structure and function caused by natural gas extraction and to use such data to inform sound environmental policy.

Front Ecol Environ 2011; 9(9): 503–511, doi:10.1890/110053 (published online 6 Oct 2011)

atural gas drilling has dramatically expanded with describe the threats to surface waters associated with Nadvances in extraction technology and the need for increased natural gas development in shale basins and high- cleaner burning fuels that will help meet global energy light opportunities for research to address these threats. demands. Natural gas is considered a “bridge fuel” to renew- able energy resources because its combustion releases fewer n Horizontal drilling and hydraulic fracturing contaminants (eg carbon dioxide [CO2], nitrogen oxide [NOx], sulfur oxide [SOx]) than compared with that of coal Gas-well drilling has historically used a single vertical well or petroleum. Horizontal drilling and hydraulic fracturing to access gas trapped in permeable rock formations (eg (“hydrofracking” or “fracking”) now allow the extraction of sandstone) where gas flows freely through pore spaces to the vast shale gas reserves previously considered inaccessible or wellbore. Unlike these conventional sources, unconven- unprofitable. Shale gas production in the US is expected to tional gas reservoirs are low permeability formations, such increase threefold and will account for nearly half of all nat- as coal beds, dense sands, and shale, that require fracturing ural gas produced by 2035 (EIA 2011). This widespread and propping (addition of sand or other granular material proliferation of new gas wells and the use of modern drilling suspended in the fracturing fluid to keep fractures open) and extraction methods have now been identified as a before gas can travel freely to the wellbore. Hydrofracking global conservation issue (Sutherland et al. 2010). Here, we uses high-pressure fracturing fluids, consisting of large vol- umes of water and numerous chemical additives, to create fractures, while added propping agents, such as sand, allow In a nutshell: the gas to flow. Although hydrofracking was first used in the • The construction of pipelines and roads coupled with the 1940s, the practice was not widely applied until the 1990s, extraction of natural gas from shale basins may pose environ- when natural gas prices increased and advances in horizon- mental threats • Streams and rivers near newly drilled natural gas wells are tal drilling made the technique more productive. vulnerable to sediment runoff, reduced streamflow, and possi- Horizontal drilling increases the volume of rock a single ble contamination from introduced chemicals and the result- well can access, thereby reducing the total number of wells ing wastewater required at the surface. The horizontal leg of a gas well is • Federal and state environmental regulations may not prevent fractured in discrete lengths of 91–152 m, allowing up to 15 or mitigate damaging effects to surface waters • Scientific studies are needed to understand the possible envi- separate hydrofrack “events” along one horizontal well ronmental effects caused by activities associated with natural (Kargbo et al. 2010). Fracturing depth depends on target gas extraction rock formations but varies from 150 m to more than 4000 m for the major shale formations in the US (US DOE 2009).

1 Biology Department, University of Central Arkansas, Conway, AR n Extent of resources *([email protected]); 2Department of Biological Sciences, University of Arkansas, Fayetteville, AR; 3National Exposure Research Laboratory, The US currently has 72 trillion cubic meters (tcm) of US Environmental Protection Agency (EPA), Cincinnati, OH; potentially accessible natural gas – enough to last 110 4Dynamac Corporation, contracted by the US EPA, Cincinnati, OH years, based on 2009 rates of consumption (EIA 2011).

© The Ecological Society of America www.frontiersinecology.org Natural gas development and surface waters S Entrekin et al.

504 (a) (b) water (eg brines). However, the use of hydraulic fracturing poses additional environmental threats due to water withdrawals and contamination from fracking-fluid chemicals. Extraction of gas from shale formations may also pro-

duce considerably more methane (CH4) than conventional wells and could have a larger greenhouse-gas footprint than Well density other fossil-fuel development (Howarth High et al. 2011). Furthermore, gas wells are Low 0 375 750 1500 kilometers 0 37.5 75 150 kilometers often located adjacent to rivers and US shale streams and may occur at high densities gas regions US shale in productive shale basins, resulting in gas basins cumulative impacts within watersheds. Environmental and human health con- cerns associated with hydrofracking have stirred much debate, and the prac- tice has received extensive attention from the media (Urbina 2011) and from researchers (US EPA 2004; Kargbo et al. 2010; Osborn et al. 2011; US EPA 2011; Number of wells drilled Colborn et al. in press). Research that addresses concerns regarding increased drilling and hydrofracking in shale 0 100 200 400 kilometers (c) (d) basins has primarily focused on contam- inants that threaten drinking water and Figure 1. (a) National map of all recognized potential areas for unconventional groundwater, whereas data collection to natural gas exploration in the contiguous US; (b) density of wells in the Fayetteville address concerns associated with surface unconventional natural gas basins; (c) number of gas wells installed in the water and terrestrial ecosystems has Fayetteville and Marcellus basins from 2005 to 2010; and (d) density of wells in the largely been overlooked. Marcellus shale basins. We calculated densities using the kernel density tool in Our goal here is to provide back- ArcMap 9.3.1. ground information on shale develop- ment in the US that may inform Approximately 23 tcm of that gas is found in unconven- future ecological studies that assess the potential for tional (ie low permeability) gas reservoirs; development environmental impacts. We use data from the of such reservoirs has increased by 65% since 1998 (US Fayetteville and Marcellus shale formations to demon- DOE 2009). There are 29 known shale basins spanning strate the recent accelerated drilling activity, well prox- 20 states, which are expected to contribute 45% of the imity to streams, and well density relationships with total US gas produced by 2035 (EIA 2011; Figure 1a). stream turbidity. We also review other potential threats Furthermore, the US gas supply represents only a fraction to aquatic freshwater ecosystems as a result of increased of the total global estimate of potentially accessible nat- natural gas development. ural gas (~459 tcm) and, outside of North America, only 11% has so far been recovered (MIT 2010). Development n Focus areas of potentially accessible natural gas is expected to increase with rising global demand and the transfer of The Fayetteville and Marcellus shale basins are among drilling technologies overseas. the most productive in the US. The Fayetteville shale basin underlies more than 23 000 km2 of Arkansas and n Threats to surface waters eastern Oklahoma, at a depth of 300–2000 m (Figure 1a). The number of gas wells sited in this area has increased The rapid expansion in natural gas development threat- nearly 50-fold, from 60 to 2834 wells since 2005, in a ens surface-water quality at multiple points, creating a concentrated area of north-central Arkansas (Figure 1, b need to assess and understand the overall costs and bene- and c). The Marcellus shale basin spans 240 000 km2 at a fits of extracting this resource from shale reservoirs. Gas- depth of 1200–2500 m and underlies six states in the well development of any type creates surface disturbances upper Mid-Atlantic, including much of the Appalachian as a result of land clearing, infrastructure development, region (Figure 1d). Estimates indicate natural gas reserves and release of contaminants produced from deep ground- in the Marcellus to be 14 tcm, or 59% of the total esti-

www.frontiersinecology.org © The Ecological Society of America S Entrekin et al. Natural gas development and surface waters mated unconventional reserves in the US (US DOE respectively (Table 1). Although wells are generally con- 505 2009). As of summer 2010, the Marcellus had 3758 nat- structed far from public drinking-water sources, there is ural gas wells, with projections of up to 60 000 wells being potential for wastewater to travel long distances, given constructed in the region over the next 30 years (Johnson that many of the components of produced waters (ie a 2011). The Marcellus formation also underlies sensitive mixture of fracking fluids and natural geologic formation watersheds, such as the threatened upper Delaware River, water flowing back out of the well), such as brines, will a designated wild and scenic river that supplies drinking not settle out or be assimilated into biomass. water to > 15 million people (DRBC 2008). The rapid Furthermore, the NHD underestimates the density of development of gas wells in relatively concentrated areas headwater stream channels (Heine et al. 2004), so our may increase the likelihood of ecological impacts on sur- proximity measures probably underestimate the threat to rounding forests and streams. streams. We therefore used geographic information sys- tem (GIS) tools to generate detailed drainage-area net- n Proximity of gas-well development to water works in portions of the Fayetteville and Marcellus shale resources reservoirs where gas wells occur at high densities. The terrain processing tools in ArcHydro Tools 9 version 1.3 We initially assessed the proximity of active gas wells to (an ArcGIS extension) were used to generate drainage water resources using state well-location data and the area lines from 10-m digital elevation models (http:// National Hydrography Dataset (NHD) flowlines (ie seamless.usgs.gov/ned13.php) in a subset of drainage streams and rivers mapped from 1:24 000 Digital Line areas in each shale basin. A stream threshold of 500 Graph hydrography data). Spatial analysis indicated that, (50 000 m2) was used to define stream channels in the for both the Fayetteville and Marcellus shale formations, model. Gas-well proximity was analyzed again with a sub- gas wells were sited, on average, 300 m from streams, yet set of modeled stream drainage areas and the same subset several hundred wells were located within 100 m of of NHD flowlines for comparison (Figure 2; Table 2). stream channels (Table 1). Gas wells were located, on Active gas wells were an average of 130 m and 153 m average, 15 km from public surface-water drinking sup- from modeled drainage areas, as compared with 230 m plies, and 37 km and 123 km from public well water sup- and 252 m from NHD flowlines, in the Fayetteville and plies in the Marcellus and Fayetteville shale reservoirs, Marcellus shale reservoirs, respectively. Over 80% of the

Table 1. Number of unconventional gas wells drilled each year since 2005 for Arkansas, New York, Ohio, Pennsylvania, and West Virginia Total # (percent) of wells within Distance to Distance to NHD public water public drinking- flowlines wells water intakes Total Total (mean ± SD, 100 m of NHD 200 m of NHD 300 m of NHD (mean ± SD, (mean ± SD, State wells operators range, m) flowlines flowlines flowlines range, km) range, km) 319 ± 171 25.83 ± 17.93 14.83 ± 10.06 PA 2091* 59 (8–1172) 74 (4) 577 (28) 1141 (55) (0.32–79.60) (0.60–50.23)

214 ± 143 52.32 ± 32.81 11.16 ± 5.36 WV 1599† 86 (1–850) 409 (26) 798 (50) 1198 (75) (0.55–125.42) (0.53–33.32)

230 ± 153 71.85 ± 28.29 14.15 ± 8.38 OH 42‡ 12 (46–691) 8 (19) 23 (55) 33 (79) (26.46–138.17) (1.54–29.87)

Marcellus 247 ± 182 10.47 ± 7.11 16.59 ± 9.06 NY 26§ 9 (27–631) 9 (35) 12 (46) 14 (54) (2.58–34.19) (4.58–35.63)

All four 273 ± 168 37.51 ± 28.88 13.27 ± 8.55 states 3758 (1–1172) 500 (13) 1410 (38) 2386 (64) (0.32–138.17) (0.53–50.23) combined

353 ± 241 123.67 ± 11.12 15.15 ± 7.49 AR 2834¶ 21 (7–1642) 269 (10) 900 (32) 1434 (51) (78.94–156.12) (0.66–133.43) Fayetteville

Notes: *PA: Pennsylvania Department of Environmental Protection Bureau of Oil and Gas (records available through 30 Sep 2010), www.dep.state.pa.us/dep/deputate/minres/ oilgas/reports.htm; †WV: West Virginia Geological and Economic Survey (records available through early Sep 2010), www.wvges.wvnet.edu/www/datastat/devshales.htm; ‡OH: Ohio Department of Natural Resources Division of Mineral Resources Management (records available through 30 Sep 2010), www.dnr.state.oh.us/ mineral/database/tabid/17730/Default.aspx; §NY: New York State of Environmental Conservation (records available through 30 Sep 2010), www.dec.ny.gov/energy/1603.html; ¶AR: Arkansas Oil and Gas Commission (records available through 30 Sep 2010), www.aogc.state.ar.us/ (data downloaded from: ftp://www.aogc.state.ar.us/).

© The Ecological Society of America www.frontiersinecology.org Natural gas development and surface waters S Entrekin et al.

506 (a) NHD flowlines Drainage lines fracking fluids, and sedimentation from infrastructure development (eg pipelines and roads).

n Environmental regulation

Environmental regulation of oil and gas drilling is complex and varies greatly

Elevation Well between states. The Safe Drinking locations High 0 750 1500 3000 meters 0 750 1500 3000 meters Hydrology Water Act (SDWA) provides federal Shale gas laws for protecting surface and ground- Low regions (b) waters and human health, but with the exception of diesel-fuel injection, hydraulic fracturing operations are exempt as a result of the 2005 Energy Policy Act. State agencies are therefore primarily responsible for regulation and enforcement of environmental issues 0 500 1000 2000 meters 0 500 1000 2000 meters associated with natural gas develop- ment. The rapid growth and expansion Figure 2. Proximity of gas wells to stream channels in a subset of the Fayetteville and of US gas drilling has made regulation Marcellus unconventional natural gas reservoirs. Blue squares represent the areas modeled by difficult, and violations are common; in GIS in the Fayetteville shale ([a] drainage area modeled and represented by the blue square Pennsylvania alone, there were more was 5809 km2) and the Marcellus shale ([b] drainage area modeled and represented by the than 1400 drilling violations between blue square was 4041 km2). Topographic maps are example areas that demonstrate January 2008 and October 2010 differences between the National Hydrography Dataset and modeled drainage area networks. (PADEP 2010). Of these, nearly half dealt with surface-water contamination active gas wells were located within 300 m of modeled and included direct discharge of pollutants, improper ero- drainage areas (Table 2). Because the modeled drainage sion control, or failure to properly contain wastes. In con- areas estimate some intermittent and ephemeral channels, trast, the Arkansas Department of Environmental Quality the proximity of wells to stream channels (and the poten- cited only 15 surface-water violations in the Fayetteville tial for downstream impacts) is greater than that reflected shale in 2010; however, over half of these dealt with per- by NHD flowline data. This process may provide a more mitting and discharge violations associated with natural gas accurate assessment of potential stream impacts, particu- development (ADEQ 2010). The discrepancy in the num- larly if shale gas development continues at its current rate. bers of violations between states demonstrates the variable As gas-well densities continue to increase, the proximity degree of regulation at the state level and is probably based of wells to stream channels may also increase, resulting in on differences in regulations as well as available regulatory a greater risk of streamflow reductions from pumping, con- resources. The number and proportion of violations associ- tamination from leaks and spills from produced waters or ated with natural gas development indicates that sediments

Table 2. Proximity of natural gas wells to stream channels modeled by terrain processing tools in ArcHydro Tools 9 (version 1.3) to generate drainage area lines from a 10-m digital elevation model (http://seamless.usgs.gov/ ned13.php) as compared with well proximity to National Hydrography Dataset flowlines Previous distances Previous distances Subset (in Marcellus, PA only) Subset (in Marcellus, PA only) range mean ± SD range mean ± SD within within within within within within (m) (m) (m) (m) 100 m 200 m 300 m 100 m 200 m 300 m * Drainage area lines 4–316 153 ± 56 – – 17% 80% 100% – – – NHD flowlines 48–681 252 ± 114 8–1172 319 ± 171 5% 39% 70% 4% 28% 55% Marcellus ** Drainage area lines 0–420 130 ± 70 – – 32% 71% 82% – – – NHD flowlines 1–933 230 ± 136 7–1642 353 ± 241 12% 43% 61% 10% 32% 51% Fayetteville

Notes: *Processed for 615 of 3758 wells (16%), processed 42 of 559 HUC-12 Units containing well point locations (8%). **Processed for 2372 of 2834 wells (84%), processed 55 of 84 HUC-12 Units containing well point locations (65%).

www.frontiersinecology.org © The Ecological Society of America S Entrekin et al. Natural gas development and surface waters

Hydraulic fracturing 507

Supporting Drilling and fracturing Treatment/waste Activity infrastructure process handling

Reuse Flowback/produced Source Roads Pipelines Well Fracking Source Waste storage Treatment UIC pads fluids water water facilities

Withdrawal

Landscape alteration Spillage/leakage Base Land application/burial Riparian loss flow Inadequate Potential stressors treatment and pathways Runoff Direct discharge Runoff/leaching

Secondary effects

Organic Chemical Sediment TDS Metals Organics TENORM matter Nutrients additives

Ecological Stream ecosystem structure/function endpoint

Figure 3. Simplified diagram of potential threats due to natural gas development through coupled horizontal drilling with hydraulic fluid fracturing in unconventional natural gas reservoirs. Exposure pathways that may result in structural and functional alterations to aquatic ecosystems will vary, depending on geographic location and rigor of best management practices applied. UIC = underground injection control; TDS = total dissolved solids; TENORM = technologically enhanced naturally occurring radioactive materials. Dotted lines indicate secondary effects from gas development. "Flowback" is underlined to indicate that it may be recycled and reused. and contaminants associated with drilling are making their We identified seven streams in the Fayetteville shale with way into surface waters, and yet there are few studies exam- a variety of different well densities within their drainage ining their ecological effects. Primary threats to surface areas, to test the prediction that stream turbidity would be waters and potential exposure pathways (Figure 3) include positively related to the density of gas wells. The seven sediments, water withdrawal, and release of wastewater. stream drainages were delineated through the use of the ArcHydro extension in ArcMap (version 9.3.1 ESRI). Sediments Using gas-well location data obtained from the Arkansas Oil and Gas Commission (ftp://www.aogc.state.ar.us/GIS_Files/), Excessive sediment levels are one of the primary threats to we quantified well density within each drainage area as the US surface waters (US EPA 2006) and have multiple nega- total number of wells divided by the drainage area. Turbidity tive effects in lotic (river, stream, or spring) food webs was measured with a Hach Lamotte 2020 meter in April (Wood and Armitage 1999). Gas-well installation activities 2009, during high spring flow. Pearson product moment cor- can negatively affect lotic ecosystems by increasing sediment relations identified a positive relationship between stream- inputs from well pads and supporting infrastructure (eg water turbidity and well density (Figure 4). Turbidity was not roads, pipelines, stream crossings), as well as loss of riparian positively correlated to other land-cover variables, but there area. Typically, at least 1.5–3.0 ha of land must be cleared for was a strong negative correlation between turbidity and each well pad, depending on the number of wells per pad; drainage area and percent pasture cover in the watershed where these occur in high densities, well pads can cumula- (Table 3). These preliminary data suggest that the cumula- tively alter the landscape. Land clearing and stream distur- tive effects from gas well and associated infrastructure devel- bance during well and infrastructure development can opment may be detectable at the landscape scale. increase sediments in surface-water runoff (Williams et al. 2008), resulting in increased suspended and benthic sedi- Water withdrawal may alter flow regime ments in surface waters. Nutrients, such as phosphorus, bound to these sediments may also have negative impacts on Surface waters may serve as sources for necessary drilling surface waters by contributing to eutrophication. and fracking fluids – each well uses between 2–7 million

© The Ecological Society of America www.frontiersinecology.org Natural gas development and surface waters S Entrekin et al.

508 12 hydrofracking or treatment and disposal processes, when the potential for accidental spills and leaking is greatest. 10 Contamination from hydrofracking wastes can also occur through inadequate waste treatment practices, improper 8 waste storage, inadequately constructed impoundments 6 or well casings, and improper disposal of solid wastes (eg in poorly lined impoundments that are buried onsite) 4 that may leach into nearby surface waters. Wastewater

Turbidity (NTU) Turbidity impoundment ponds can therefore also pose a threat to 2 wildlife and livestock. Fracturing fluids typically include a combination of 0 additives that serve as friction reducers, cross-linkers, 0 2 4 6 8 10 12 14 breakers, surfactants, biocides, pH adjusters, scale Well density (number per 1000 ha) inhibitors, and gelling agents (NYSDEC 2010). The aim of additives is to achieve an ideal viscosity that encour- Figure 4. Well density and stream turbidity measured in April ages fracturing of the shale and improves gas flow, but dis- 2009 during high flows in seven stream drainages. NTU = courages microbial growth and corrosion that can inhibit nephelometric turbidity unit. recovery efficiency (US DOE 2009). Composition of the fracturing fluids can vary greatly among wells and shale gallons (~7.5–26 million liters) of source water. Several formations. Specific content is often proprietary, wells may be fractured per well pad over the life span of although some states require disclosure of constituents well development, which may last several decades. This and companies may voluntarily register the chemicals concentration of fracturing effort within a small area they use with regulatory agencies. A recent Congres- should compound water use. Many gas wells are installed sional investigation revealed that, over a 4-year period, in regions where water is already being withdrawn for 14 leading gas companies used over 2500 hydrofracking agriculture, and thus may further stress the resource. products that contained 750 different chemicals, 29 of Streamflow may be negatively affected if streams are which were highly toxic or known carcinogens. dammed to create holding ponds or if water is directly Fracturing fluids used over the period totaled 780 million extracted for the fracturing process. The rapid and con- gallons or ~2.9 billion liters (not including dilution centrated extraction of water could create regional short- water), and included lead, ethylene glycol, diesel, and ages during periods of drought, resulting in an altered formaldehyde, as well as benzene, toluene, ethylbenzene, flow regime and the further degradation of critical habitat and xylene compounds (US House of Representatives for aquatic biota, particularly if low-order streams are pri- Committee on Energy and Commerce 2011). The vol- mary sources. A reduction in streamflow may also result ume of fracking fluids recovered is also highly variable, in secondary effects, such as increased contaminant con- but unrecovered amounts can be substantial. Only centrations and reduced downstream water quality, 10–30% of fracture fluids are typically recovered from because less water is available for dilution. wells in portions of the Marcellus shale (NYSDEC 2010); there is currently no information on the fate and trans- Release of wastewaters port of the unrecovered chemicals. Produced waters pose a threat to surface waters because Surface-water contamination from hydrofracking fluids they typically contain not only fracking additives but also and produced water is most likely to occur during elevated levels of metals, dissolved solids (eg brine), organics, and radionuclides that occur naturally in deep Table 3. Pearson product moment correlations* and groundwaters. Onsite waste impoundments or evapora- associated P values between turbidity (NTU) and other tion ponds could overflow, spill, or leach into groundwa- landscape-level variables, including land cover (Gor- ter and contaminate nearby streams. Even after treat- ham and Tullis 2007) and drainage area ment, total dissolved solids (TDS) in produced waters are Correlates rPvalue very high and remaining salts are often disposed of Well density 0.91 0.003 through land application or used as road salts, which are Drainage area –0.86 0.01 known to enter surface waters and contribute to increased Low-impact urban 0.35 0.44 stream salinization (Kaushal et al. 2005). Recovered Wood/herbaceous –0.63 0.12 wastewaters are most often transported offsite for deep- Forest –0.36 0.42 well injection or to a domestic wastewater treatment Pasture –0.88 0.008 plant (WWTP) and/or conventional waste treatment facility. After fracturing, initially recovered flowback *Quantifies the strength of the directional relationship. Analyses were run in water is sometimes reused as fracking fluid for other wells. SigmaPlot 11. Reuse of recovered fluids is becoming more common, but

www.frontiersinecology.org © The Ecological Society of America S Entrekin et al. Natural gas development and surface waters still requires a substantial amount of fresh water because species’ effects, causing changes in community structure. 509 of low recovery volumes and the need to dilute flowback Ecologists studying the environmental effects of natural water containing high concentrations of chlorides, sul- gas extraction can therefore contribute to scientific fates, barium, and other potentially harmful substances. understanding by examining the effects of sediment and Domestic WWTPs are not capable of treating the high contaminants from natural gas development on species TDS (5000 to >100 000 mg L–1) typical of recovered and community interactions. wastewater. Many WWTPs have therefore been forced to In addition to the need for traditional bioassessments, limit their intake of recovered hydrofracking waste to the inevitable alteration in land use that will occur as a remain in compliance with effluent limitations (Veil result of rapid and expanded drilling offers a template for 2010). Industrial WWTPs are better equipped to treat conducting novel experiments in an ecosystem context. recovered wastes using reverse osmosis, filtration, or Ecosystem functions, such as decomposition rates, are chemical precipitation, but such facilities are costly and affected by multiple abiotic and biotic factors, making not widely available. Therefore, although billions of liters them well-suited for detecting large-scale alterations of produced water are being generated annually on a (Bunn et al. 1999). For example, reduced streamflows, national scale by hydrofracking (Clark and Veil 2009), contaminants from produced wastewater and fracking flu- water treatment options are limited, and the potential ids, and elevated sediment inputs would alter ecosystem ecological impacts of wastes on terrestrial and aquatic functions, such as whole-stream metabolism, decomposi- ecosystems are not well studied. tion of organic matter, and accrual of macroinvertebrate biomass over time. However, it is not known how natural n Challenges and potential for new research gas development could influence biological processing rates. The potential effects may stimulate or inhibit spe- Quantifying the effects of natural gas development on cific ecosystem functions. For example, excessive sedi- surface waters in shale basins is difficult because multiple mentation or chemical contamination associated with companies often work in the same geographical area and natural-gas-well development could stimulate macroin- use different fracturing techniques (eg varied and often vertebrate production by expanding habitat for tolerant, proprietary composition of fracturing fluids), resulting in multivoltine (species that produce several broods per sea- uncoordinated timing of infrastructure development and son) taxa (Stone and Wallace 1998) or lead to a decline well fracturing. In addition, the degree to which these in production by eliminating sensitive taxa representing a companies adhere to best management practices, such as majority of community growth and/or biomass (Wood- buffer strips and erosion control devices, varies among cock and Huryn 2007). A move to incorporate ecosystem companies as a result of the differing regulations among functions into mainstream biological assessment and states and agencies. Furthermore, wells occur across restoration protocols is currently underway (Fritz et al. human-impacted watersheds with characteristics that 2010), yet few studies have been conducted to inform may confound our ability to attribute effects from gas-well their implementation and interpretation in the context development. of concurrent structural changes (Young and Collier Most studies that examine the effects of sediments on 2009). The rapid expansion of gas development across biological communities focus on shifts in abundance, bio- the US could provide a framework for the implementa- mass, diversity, or community composition (Wood and tion of concurrent structural and ecosystem experiments Armitage 1999); few studies have analyzed how sedi- to inform process-based ecological assessment. ments alter species’ roles and their interactions (but see Furthermore, ecological studies relating to natural gas Hazelton and Grossman 2009). In addition, contaminant extraction could be combined with similar studies for sur- effects are often assessed through single-species labora- face mining (Fritz et al. 2010; Bernhardt and Palmer tory acute and chronic toxicity tests with standardized 2011), to gain a more holistic view of the environmental test organisms (eg Daphnia, fathead minnows [Pimephales costs associated with fossil-fuel extraction. promelas]; Cairns 1983) and with single contaminants. The distinct elemental composition and isotopic signa- Studies are therefore needed to assess the toxicity of con- tures of produced water provide unique opportunities for taminant mixtures (eg produced water and fracking tracer studies that could indicate aquatic system expo- fluids) and their effects on more complex communities sure. Stable isotopes of strontium and carbon have been and ecosystems, to predict effects in the real world used to trace water from coalbed natural gas production (Clements and Newman 2002). Sediment and contami- wells to surface waters and hyporheic zones (Brinck and nants associated with recovered wastewater will likely Frost 2007). Osborn et al. (2011) used isotopes of water, affect organism behavior and alter ecological interactions carbon, boron, and radium to test for hydraulic fracturing at sublethal levels (Evans-White and Lamberti 2009). contamination of shallow aquifers overlying the Reductions in feeding efficiencies (Sandheinrich and Marcellus and Utica shale formations in Pennsylvania Atchison 1989) can lead to negative effects on reproduc- and New York, respectively, and found significant tion (Burkhead and Jelks 2001) and growth (Peckarsky changes in CH4 concentrations in drinking-water wells 1984), and may alter the magnitude or sign (+ or –) of near locations where gas wells have been drilled. Limited

© The Ecological Society of America www.frontiersinecology.org Natural gas development and surface waters S Entrekin et al.

510 research has also suggested that CH -derived carbon is Brinck EL and Frost CD. 2007. Detecting infiltration and impacts 4 of introduced water using strontium isotopes. Ground Water 45: assimilated into stream food webs (Kohzu et al. 2004; 554–68. Trimmer et al. 2010). Many gas-bearing geological forma- Bunn SE, Davies PM, and Mosisch TD. 1999. Ecosystem measures tions also contain elevated levels of naturally occurring of river health and their response to riparian and catchment radioactive materials, such as radon (222Rn) and radium degradation. Freshwater Biol 41: 333–45. (226Ra, 228Ra), that can be used as hydrological tracers Burkhead NM and Jelks HL. 2001. Effects of suspended sediment on the reproductive success of the tricolor shiner, a crevice- (Genereux and Hemond 1990). The extent to which spawning minnow. T Am Fish Soc 130: 959–68. metals, organics, or other contaminants from the drilling Cairns JJ. 1983. Are single-species toxicity tests alone adequate for and hydrofracking process may ultimately enter aquatic estimating environmental hazard? Hydrobiologia 100: 47–57. and terrestrial food webs remains unknown. Clark CE and Veil JA. 2009. Produced water volumes and manage- ment practices in the United States. Argonne, IL: Argonne National Laboratory, Environmental Science Division; n Conclusions doi:10.2172/1007397. Clements W and Newman M. 2002. Community ecotoxicology. Natural gas exploration will continue to expand globally. West Sussex, UK: John Wiley & Sons Ltd. In addition to the potential threats to groundwater and Colborn TC, Kwiatkowski C, Shultz K, and Backstrom M. Natural drinking-water sources, increasing environmental stress gas operations from a public health perspective. Int J Hum Ecol Risk Assess. In press. to surface-water ecosystems is of serious concern. DRBC (Delaware River Basin Commission). 2008. 2008 Annual Scientific data are needed that will inform ecologically Report. Trenton, NJ: DRBC. sound development and decision making and ensure pro- EIA (Energy Information Administration). 2011. Annual 382 tection of water resources. Elevated sediment runoff into energy outlook. Washington, DC: EIA, US Department of streams, reductions in streamflow, contamination of Energy. DOE/EIA-0383ER(2011). Evans-White MA and Lamberti GA. 2009. Direct and indirect streams from accidental spills, and inadequate treatment effects of a potential aquatic contaminant on grazer–algae practices for recovered wastewaters are realistic threats. interactions. Environ Toxicol Chem 28: 418–26. Gas wells are often sited close to streams, increasing the Fritz KM, Fulton S, Johnson BR, et al. 2010. Structural and func- probability of harm to surface waters, and preliminary tional characteristics of natural and constructed channels data suggest the potential for detectable effects from sedi- draining a reclaimed mountaintop removal and valley fill coal mine. J N Am Benthol Soc 29: 673–89. mentation. Regulations that consider proximity of nat- Genereux D and Hemond H. 1990. Naturally occurring radon 222 ural gas development to surface waters may therefore be as a tracer for streamflow generation: steady state methodology needed. Further ecological research on impacts from and field sample. Water Resour Res 26: 3065–75. developing natural-gas-well infrastructure are sorely Gorham BE and Tullis JA. 2007. Final report: 2006 Arkansas land needed, and will inform future regulatory strategies and use and land cover (LULC). Fayetteville, AR: Center for Adavanced Spatial Technologies (CAST), University of improve our understanding of the factors affecting com- Arkansas. munity structure and ecosystem function. Hazelton PD and Grossman GD. 2009. Turbidity, velocity and interspecific interactions affect foraging behaviour of rosyside n dace (Clinostomus funduloides) and yellowfin shiners (Notropis Acknowledgements lutippinis). Ecol Freshw Fish 18: 427–36. Heine R, Lant C, and Sengupta R. 2004. Development and com- We thank A Bergdale, R Adams, G Adams, and L Lewis parison of approaches for automated mapping of stream chan- for early conversations that helped develop our interest in nel networks. Ann Assoc of Am Geogr 94: 477–90. this topic. E D’Amico provided valuable assistance on spa- Howarth RW, Santoro R, and Ingraffea A. 2011. Methane and the tial analysis of well placement and suggestions that helped greenhouse-gas footprint of natural gas from shale formations. to shape the manuscript. A Bergdale, W Dodds, M Drew, Climatic Change 106: 679–90. Johnson N. 2011. Pennsylvania energy impacts assessment: report K Fritz, and K Larson provided comments on early drafts 1: Marcellus shale natural gas and wind. Philadelphia, PA: The of the manuscript. The US Environmental Protection Nature Conservancy. Agency (EPA) through its Office of Research and Kargbo DM, Wilhelm RG, and Campbell DJ. 2010. Natural gas Development partially funded and collaborated in the plays in the Marcellus shale: challenges and potential opportu- research described here under contracts EP-D-06-096 and nities. Envir Sci Tech Lib 44: 5679–84. EP-D-11-073 to Dynamac Corporation. The views Kaushal SS, Groffman PM, Likens GE, et al. 2005. Increased salin- ization of fresh water in the northeastern United States. P Natl expressed in this article are those of the author(s) and do Acad Sci USA 102: 13517–20. not necessarily reflect the views or policies of the US EPA. Kohzu A, Kato C, Iwata T, et al. 2004. Stream food web fueled by methane-derived carbon. Aquat Microb Ecol 36: 189–94. n References MIT (Massachusetts Institute of Technology). 2010. The future of ADEQ (Arkansas Department of Environmental Quality). 2010. natural gas: an interdisciplinary MIT study. Cambridge, MA: Water violations database. www.adeq.state.ar.us/legal/cao_info. MIT. 978-0-9828008-0-5. asp. Viewed 25 Aug 2010. NYSDEC (New York State Department of Environmental Bernhardt ES and Palmer MA. 2011. The environmental costs of Conservation). 2010. Well permit issuance for horizontal mountaintop mining valley fill operations for aquatic ecosys- drilling and high-volume hydraulic fracturing to develop the tems of the central Appalachians. Ann NY Acad Sci 1223: Marcellus shale and other low-permeability gas reservoirs. 39–57. www.dec.ny.gov/energy/58440.html. Viewed 5 Nov 2010.

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Osborn SG, Vengosh A, Warner NR, and Jackson RB. 2011. US EPA (US Environmental Protection Agency). 2006. Wadeable 511 Methane contamination of drinking water accompanying gas- stream assessment: a collaborative survey of the nation’s well drilling and hydraulic fracturing. P Natl Acad Sci USA streams. Washington, DC: EPA. EPA 841-B-06-002. 108: 8172–76. US EPA (US Environmental Protection Agency). 2011. Draft plan PADEP (Pennsylvania Department of Environmental Protection). to study potential impacts of hydraulic fracturing on drinking 2010. Violations database. www.dep.state.pa.us/dep/deputate/ water resources. Washington, DC: EPA. EPA/600/D-11/001. minres/OILGAS/OGInspectionsViolations/OGInspviol.htm. US House of Representatives Committee on Energy and Com- Viewed 8 Dec 2010. merce. 2011. Chemicals used in hydraulic fracturing. http:// Peckarsky B. 1984. Do predaceous stoneflies and siltation affect democrats.energycommerce.house.gov/sites/default/files/ structure of stream insect communities colonizing enclosures? documents/Hydraulic%20Fracturing%20Report%204.18.11.pdf. Can J Zoolog 63: 1519–30. Viewed 31 Aug 2011. Sandheinrich M and Atchison G. 1989. Sublethal copper effects Urbina I. 2011. Drilling down (series). New York Times. http://topics. on bluegill, Lepomis macrochirus, foraging behavior. Can J Fish nytimes.com/top/news/us/series/drilling_down/index.html. Aquat Sci 46: 1977–85. Viewed 27 Apr 2011. Stone MK and Wallace JB. 1998. Long-term recovery of a moun- Veil JA. 2010. Final report: water management technologies used tain stream from clearcut logging: the effects of forest succes- by Marcellus shale gas producers. Washington, DC: US DOE. sion on benthic invertebrate community structure. Freshwater National Energy Technology Laboratory Award No FWP Biol 39: 151–69. 49462. Sutherland WJ, Bardsley S, Bennun L, et al. 2010. Horizon scan of Williams HFL, Havens DL, Banks KE, and Wachal DJ. 2008. Field- global conservation issues for 2011. Trends Ecol Evol 26: 10–16. based monitoring of sediment runoff from natural gas well sites Trimmer M, Maanoja S, Hildrew AG, et al. 2010. Potential carbon in Denton County, Texas, USA. Environ Geol 55: 1463–71. fixation via methane oxidation in well-oxygenated riverbed Wood PJ and Armitage PD. 1999. Sediment deposition in a small gravels. Limnol Oceanogr 55: 560–68. lowland stream – management implications. Regul River 15: US DOE (US Department of Energy). 2009. Modern shale gas 199–210. development in the United States: a primer. Washington, DC: Woodcock TS and Huryn AD. 2007. The response of macroinver- US DOE. DoE-FG26-04NT15455. tebrate production to a pollution gradient in a headwater US EPA (US Environmental Protection Agency). 2004. Evalua- stream. Freshwater Biol 52: 177–96. tion of impacts to underground sources of drinking water by Young RG and Collier KJ. 2009. Contrasting responses to catchment hydraulic fracturing of coalbed methane reservoirs study. modification among a range of functional and structural indica- Washington, DC: EPA. EPA 816-F-04-017. tors of river ecosystem health. Freshwater Biol 54: 2155–70.

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© The Ecological Society of America www.frontiersinecology.org 2013 Ecology and Conservation of the SoutheasternThreatened Blackside Naturalist Dace, ChrosomusVol. cumberlandensis 12, Special Issue 4 2013 D.M. SoutheasternPapoulias and Naturalist A.L. Velasco 12(Special Issue 4):92–111 Histopathological Analysis of Fish from Acorn Fork Creek, Kentucky, Exposed to Hydraulic Fracturing Fluid Releases

Diana M. Papoulias1,* and Anthony L. Velasco2

Abstract - Fracking fluids were released into Acorn Fork, KY, a designated Outstanding State Resource Water, and habitat for the threatened Chrosomus cumberlandensis (Black- side Dace). As a result, stream pH dropped to 5.6 and stream conductivity increased to 35,000 µS/cm, and aquatic invertebrates and fish were killed or distressed. The objective of this study was to describe post-fracking water quality in Acorn Fork and evaluate if the changes in water quality could have extirpated Blackside Dace populations. Semotilus atromaculatus (Creek Chub) and Lepomis cyanellus (Green Sunfish) were collected from Acorn Fork a month after fracking in lieu of unavailable Blackside Dace. Tissues were his- tologically analyzed for indicators of stress and percent of fish with lesions. Fish exposed to affected Acorn Fork waters showed general signs of stress and had a higher incidence of gill lesions than unexposed reference fish. Gill lesions observed were consistent with expo- sure to low pH and toxic concentrations of heavy metals. Gill uptake of aluminum and iron was demonstrated at sites with correspondingly high concentrations of these metals. The abrupt and persistent changes in post-fracking water quality resulted in toxic conditions that could have been deleterious to Blackside Dace health and survival.

Introduction Development of methods to inject fluids under high pressure to fracture subsurface rock, hydraulic fracturing or “fracking”, has allowed exploitation and recovery of new sources of natural gas and oil. However, chemicals used in fracking have degraded water quality and injured aquatic ecosystems (Kargbo et al. 2010, Wiseman 2009). Mixtures of several different chemicals are used in fracturing fluids, and acids are a key component to inhibit scale and to dissolve rock (Colburn et al. 2011, EPA 2004). Fracking fluids and waste releases may be toxic to fish and wildlife if not contained and disposed of properly (Osborn et al. 2011, Pennsylvania Land and Trust Association 2010, The Academy of Natural Sciences 2010). In 2007, fracking fluids used during the development of four natural gas wells in Knox County, KY were released into Acorn Fork, a second-order tribu- tary of Stinking Creek in the upper Cumberland River basin. Fracking effluent overflowed the retention pits directly into Acorn Fork. As a result, hydrochloric acid, dissolved minerals and metals, and other chemicals entered Acorn Fork, significantly reducing stream pH (from pH 7.5 to 5.6) and increasing stream con- ductivity (from 200 to 35,000 µS/cm). Subsequently, long reaches of the stream

1US Geological Survey, Columbia Environmental Research Center, 4200 New Haven Road, Columbia, MO 65201. 2US Fish and Wildlife Service - Environmental Contami- nants Division, Kentucky Ecological Services Field Office, J.C. Watts Federal Building - Suite 265, 330 West Broadway, Frankfort, KY 40601-1922. *Corresponding author - [email protected]. 92 2013 Southeastern Naturalist Vol. 12, Special Issue 4 D.M. Papoulias and A.L. Velasco developed a suspended, and later precipitated, orange-red flocculent assumed to be composed of an organo-colloidal complex of iron, aluminum, and other met- als. In some places the flocculent was several inches thick. As a result of these releases, fish and aquatic invertebrates were killed or displaced for months in over 2.7 km of the approximate 5 km of affected waters in Acorn Fork. The federally threatened Chrosomus cumberlandensis (Starnes and Starnes) (Blackside Dace) was among the fishes killed as a result of the sudden and persistent change in water chemistry. Prior to the discharge of the fracking fluids, Acorn Fork had maintained adequate water quality and habitat conditions needed to support a healthy population of Blackside Dace (USFWS 2001). The dace occupies cool headwater streams with slow-moving pools under extensive forest canopy (Starnes and Starnes 1981). Formerly ranging throughout the upper Cumberland River drain- age, Blackside Dace have declined and now occupy only a small portion of their historic range (see McAbee et al. 2013[this issue]:supplemental appendix 1). Wide- spread extirpation of Blackside Dace populations is believed to have been caused by natural resource extraction activities such as surface mining, logging, and natural gas and oil development (Starnes and Starnes 1981, USFWS 1988). It is not known how many dace were killed during the 2007 event because two wells had already been fracked, and peak mortality was likely missed before re- searchers arrived to document the incident. However, one dead, one moribund, and several living but distressed Blackside Dace, along with three distressed Semotilus atromaculatus (Mitchill) (Creek Chub) were observed. Physico-chemical changes in water quality associated with mining is known to affect the morphology and thereby the function of superficial tissues in fish (Daye and Garside 1976, Henry et al. 2001, Ledy et al. 2003). Therefore, the objective of this opportunistic study was to assess whether fracking-related degradation in Acorn Fork water quality could have harmed or resulted in mortality of the federally protected Blackside Dace. Tissues from Creek Chub and Lepomis cyanellus (Rafinesque) (Green Sunfish), proxies for unavailable Blackside Dace, exposed to affected Acorn Fork waters were histologically analyzed for indicators of stress and lesion prevalence, and these results were compared to results for the same measurements on fish from a section of creek where no gas development was taking place.

Field Site Description The study was conducted in Acorn Fork mainstem, its west branch, and two unnamed tributaries that join the west branch (Fig. 1). Acorn Fork is located in Knox County approximately 40 km southeast of London, KY. The watershed is mainly undeveloped with few residences. A 2.4-hectare fishing lake is situ- ated immediately below wells #1 and #2 on Unnamed Tributary 1 (Fig. 1B). An earthen dam separates the lake from a short section of stream that flows into a meadow and network of slow-flowing pools backed-up by small beaver dams. Unnamed Tributaries 1 and 2 join below well #3 and flow as the west branch of Acorn Fork for a short segment before entering another small network of beaver pools and streamlets (Fig. 1B). This network again collects into a small stream 93 2013 Southeastern Naturalist Vol. 12, Special Issue 4 D.M. Papoulias and A.L. Velasco before entering a small culvert downstream of well #3. The confluence of the west branch of Acorn Fork and its mainstem occurs about 75 m downstream of a plunge-pool created by a large culvert that directs the mainstem Acorn Fork un- der the trail leading up to the four wells. From this point, Acorn Fork continues approximately 2 km to the confluence with Carter-Roark Branch, and flows for another 1 km before emptying into Stinking Creek (Fig. 1A).

Methods Fish collection Gas well #2 was fracked on 14 May 2007, and well #1 was fracked on 23 May 2007; well #3 was fracked on 12 June 2007, and well #4 was fracked on 18 June 2007 (John Brumley, Kentucky Division of Water, Lexington, KY, pers. comm.). Water and fish samples were collected opportunistically and as close to the fracking events as possible, at various locations along the mainstem, branch, and tributaries (collectively called Acorn Fork) to best represent affected and unaffected areas of the creek. Creek Chub and Green Sunfish, the only relatively numerous species available, were targeted for collection by seining or dipnetting.

Figure 1. Location of gas wells and sample collection sites on Acorn Fork. Panel (A) shows the entire Acorn Fork system to the confluence with Stinking Creek and site 1. Panel (B) shows in detail the spatial relationship among the gas wells and sites 2–4. Yel- low circles indicate gas wells, green circles indicate sampling sites, and white circles indicate culverts. 94 2013 Southeastern Naturalist Vol. 12, Special Issue 4 D.M. Papoulias and A.L. Velasco We first collected fish from Acorn Fork (sites 1 and 2) for this study on 10 July 2007, although limited measurements and observations were made of creek condition and fish presence at these and other locations within the study site back to 23 May 2007. On 24 July 2007, we collected 18 fish from the mainstem Acorn Fork plunge-pool, an unaffected area with no wells, just upstream of the confluence of Acorn Fork with the west branch. Four fish collected at this site (hereafter referred to as the fish reference site) were euthanized to serve as unaf- fected reference samples (hereafter referred to as reference fish). The remaining 14 fish were transported to site 3 and used for on-site testing. On-site testing involved timed treatments holding unaffected fish in 19-L buckets (n = 8) of the affected west branch stream water, and freely (n = 6) in an isolated slow-moving pool in this same affected area for 3 and 48 hours, respectively, before collecting and preserving the fish for histology. On 9 August 2007 the west branch (site 4), near site 3, was sampled and 3 Creek Chubs, believed to have recently moved downstream to this area (the area was fishless in June and July 2007), were col- lected for histology. Upon collection, fish were stunned with a blow to the head, and abdomens of all fishes were slit. Fish were preserved whole in 10% neutral buffered formalin, and then later shipped to Columbia Environmental Research Center (CERC) for histological analysis.

Fish histology Fish specimens were rinsed in buffer to remove formalin before dissection. Sections of liver, head and trunk kidney, spleen, and gonad were removed and placed in tissue cassettes for processing in a Shanndon Excelsior automatic tissue processor (Thermo Fisher Scientific, Waltham, MA). Tissue processing followed a routine paraffin protocol, and blocks were sectioned at 7 microns, with 3–4 sections per slide for 2 slides. Sections were cut at 3 different depths to ensure microscopic evaluations were representative of the entire tissue. Sections were stained with hematoxylin and eosin (H & E; Luna 1968). Gill tissue was treated similarly but was decalcified for 1 hour (Surgipath® Decalcifier II, Medical In- dustries, Inc., Richmond, IL) to soften boney structures for cutting, prior to tissue processing. Following Denton and Oughton (2010), gills were also stained with acid solochrome azurine to identify aluminum (blue) and iron (red). Gonad sections were evaluated to assign sex and stage of reproductive matu- rity. Testes were classified as follows: immature—spermatogonia are the primary component of lobules; spermatogenic—lobules contain primarily spermatocytes and spermatids, with limited spermatozoa; mature—spermatozoa are prominent. Ovaries were classified as follows: pre-vitellogenic—contain young oogonia with no vitellogenin deposition; mid-vitellogenic—oogonia undergoing vitellogenesis, and the germinal vesicle has not migrated to the animal pole; mature—oocyte filled with vitellogen, and the germinal vesicle has migrated to the animal pole. Juvenile fish had undifferentiated germ cells and could not be assigned to a sex. Gill, gonad, liver, head and trunk kidney, and spleen were qualitatively evaluat- ed using a light microscope (Nikon Eclipse 90i, Nikon Instruments Inc., Mellville,

95 2013 Southeastern Naturalist Vol. 12, Special Issue 4 D.M. Papoulias and A.L. Velasco NY) for presence of stress indicators and lesions associated with exposure to low pH and to heavy metals. Gills are vulnerable to environmental stressors due to their exposure to the environment and their delicate, highly vascularized structure (Lau- rent and Perry 1991, Roberts 1978). Stress in fish may be reflected in the condition of liver and spleen tissues. An increase or decrease in hepatic lipid or glycogen content can indicate exposure to an environmental stressor and result in the dis- ruption of metabolism (Chindah et al. 2008, Ferguson 1989). A calm, unstressed fish will have a large spleen filled with erythrocytes, whereas a fish that is stressed will have a thin spleen and erythrocytes will have been released (Takashima and Hibiya 1995). In this study, histological sections of reference fish were evaluated for the presence and severity of stress indicators and lesions, and then fish exposed to the affected Acorn Fork water were blindly scored. The incidence of fish with le- sions from affected sites or of healthy fish exposed to water from affected sites was compared to the number of reference fish with lesions. Lipids and glycogen appear as vacuolar structures in paraffin-embedded, H & E-stained liver sections. Lipids tend to form round structures, and glycogen forms irregularly shaped structures (Takashima and Hibiya 1995). Liver sections (Creek Chub only) were scored as high–moderate or low–none for lipid and glycogen collectively, as an indicator of metabolic condition. As an indicator of stress, spleen sections were scored as high– moderate or low–none for blood cell content.

Water quality Conductivity was measured on-site using an Oakton 300 series multimeter (Cole-Palmer, IL) when fish and water samples were collected. Field pH mea- surements were made 15 June 2007 with Fisher Scientific ALKACID® Test Ribbon on water collected 23 May, 30 May, and 5 June 2007 into Mason® jars and kept at room temperature. Kentucky Division of Water tested water pH, con- ductivity, and hardness on 25 June 2007 at selected locations on Acorn Fork. Water samples for elemental analysis were collected 22 June 2007 at the approximate time and place dead Blackside Dace were discovered (site 4). Ad- ditional water samples were collected above well #4 to serve as an unaffected water reference sample (no water was collected at the fish reference site and no fish were collected at the water reference site), and at sites 1, 2, and 3 on 10 July 2007. No water was collected at site 4 on 9 August 2007 when fish were col- lected. Water samples were collected directly from the creek into 500-mL I-Chem Certified 300 Series chemically cleaned sample jars (Thermo Fisher Scientific, Waltham, MA). Samples were chilled to 4 °C until overnight shipment on wet ice to Alpha Analytical Laboratories, Inc. (Mansfield, MA) for analysis. Water samples at each site were collected in 2 jars: one sample was filtered using vacuum filtration and 0.45-mm filter paper, and the filtrate was used for ion analyses and metals scan; the other water sample was not filtered and was used for a metals scan only. Samples for metals scans were prepared for ICP-MS (EPA Method 6020A) using a routine acid-digestion procedure (PerkinElmer - 2− Corp. 1985). Chloride ions (Cl ) and sulfate ions (SO4 ) were measured by ion

96 2013 Southeastern Naturalist Vol. 12, Special Issue 4 D.M. Papoulias and A.L. Velasco chromatography following EPA Method 300.0 (EPA 2003). Blanks, duplicates, and spikes were included. Only filtered results are presented. Hardness values from the water reference site (maximum value) and site 3 (minimum value) were used to calculate hardness-specific water-quality standards for dissolved metals using equations provided in Kentucky Surface Water Standards (State of Kentucky 2011). Water-quality results were evaluated against Kentucky Surface Water Standards criteria when available (State of Kentucky 2011).

Statistics Only one water sample at each site was collected and analyzed; therefore no statistical comparisons among sites could be made using the water-chemistry data. Differences in the odds ratio for incidence of fish with gill and kidney le- sions between the reference fish site and sites 1–4, where fish were exposed to affected Acorn Fork water, were tested with a one-sided Fisher’s Exact test due to small sample size. A significant difference between results from the reference site and the exposed sites was set at P ≤ 0.05.

Results A small population of Blackside Dace, Green Sunfish, Creek Chub, and other fishes persisted in Unnamed Tributary 1 in the creek below the lake to the conflu- ence with Unnamed Tributary 2 for the entire period of our assessment (May– September, 2007). However, Acorn Fork appeared to be completely devoid of all fishes, invertebrates, and other biota downstream from this confluence for greater than 2 km. On 22 and 27 June 2007 a dead dace and a moribund dace, respec- tively, were collected in the west branch below well #3 and above the confluence with Acorn Fork mainstem (site #3). Three living but severely distressed dace were also seen here on 27 June 2007. These fish were observed uncharacteristi- cally at the surface, rostrum pointed downward, slowly rocking back and forth. The Blackside Dace in this condition were easily caught by dipnet, whereas healthy Blackside Dace would typically avoid capture and quickly swim away. On 9 August 2007, only 3 Creek Chub were observed and collected in a shallow, isolated pool near this same reach (site 4). Their swimming was atypically erratic and agitated— swimming erratically and dashing their sides against the substrate. However, once collected, they appeared to be in good physical condition. Downstream, small groups of fishes were also occasionally collected from Carter-Roark Branch near its confluence with the affected portions of the main- stem Acorn Fork. Further downstream to the confluence with Stinking Creek, larger fishes of each species were sometimes collected. A total of 38 Creek Chubs and 7 Green Sunfish were captured and evaluated for this study. A few small tissues were lost in processing for some individuals, such that a complete set of tissues was not available for 16 fish. Mean (± SD) length and weight of Creek Chubs were 86 ± 20 mm and 7.74 ± 4.87 g, respec- tively. Mean (± SD) length and weight of Green Sunfish were 78 ± 15 mm and 9.75 ± 5.16 g, respectively. The collection consisted of 18 females, 12 males, 14 97 2013 Southeastern Naturalist Vol. 12, Special Issue 4 D.M. Papoulias and A.L. Velasco immature, and 1 unsexed fish. No lesions were observed in the gonads of any fish. Creek Chubs were either immature or non/post-reproductive, with the exception of 1 female which appeared to have recently spawned and was used for on-site testing. Green Sunfish were either mature or immature, with the exception of 1 female which appeared to have recently spawned and was used for on-site testing.

Figure 2. Histological sections of gill tissue stained with hemotox- ylin and eosin (A, B, C) from Creek Chub taken from locations in Acorn Fork unaffected by fracking fluids (A) and where fracking fluids had contami- nated the stream (B and C). Panel (B) is an example of extensive lamellar hyperplasia (asterisk) and touching of gill filament tips (ar- row). Panel (C) shows examples of epithelial lifting (arrow) on sec- ondary lamellae, curl- ing (arrowhead), and clubbing (open trian- gle). Scale bar is 100 microns.

98 2013 Southeastern Naturalist Vol. 12, Special Issue 4 D.M. Papoulias and A.L. Velasco Histological observations Gills of reference fish. Gills of Creek Chubs (n = 2) and Green Sunfish (n = 2) from the fish reference site (Fig. 2A) had focal areas of slight epithelial hyperpla- sia of the primary and secondary lamellae, and occasional touching, fusion, and swelling of secondary lamellae.

Gills of exposed fish, sites 1 and 2. All Creek Chubs (nsite 1 = 9, nsite 2 = 11) and Green Sunfish (nsite 1 = 2, nsite 2 = 1) had gills with epithelial hyperplasia of primary and secondary lamellae, and the condition was diffuse and pervasive in 78% of fish from site 1. The hyperplasia was diffuse, pervasive, and severe in 83% of site 2 fish (Fig. 2B). Concomitantly with the hyperplasia, touching of secondary lamellae often occurred, sometimes fusing, as did extensive and severe swelling of secondary lamellae. One Creek Chub (site 2) had extensive areas of hemangioendothelio sarcoma (vascular tumor). Curling or clubbing of the tips of the secondary lamellae was not observed in the reference fish but was apparent in 44% of fish from site 1 and 9% from site 2 (Psite 1 = 0.27, Psite 2 = 0.56, Figs. 2C, 3A). Lifting of epithelium away from the secondary lamellae

Figure 3. Percent num- ber of fish with gills showing clubbing or curling at ends of gill filaments (A) and sepa- ration of the epithelium from the secondary la- mella (epithelial lifting; B). Asterisks indicate a signficant difference between results at the fish reference site (Ref- erence) and the affected site (Fisher Exact Test, P < 0.05).

99 2013 Southeastern Naturalist Vol. 12, Special Issue 4 D.M. Papoulias and A.L. Velasco was observed in fish from sites 1 (55%) and 2 (83%), but not reference fish

(Psite 1 = 0.12, Psite 2 = 0.01; Figs. 2C, 3B). Gills of reference fish exposed on-site, site 3. Reference fish (Creek Chubs, n = 8) exposed for 3 hours developed hyperplasia of the epithelium on the prima- ry and secondary lamellae, and the condition was diffuse, severe, and pervasive for 50% of the fish. All fish (Creek Chubs, n = 4; Green Sunfish, n = 2) exposed for 48 hours had epithelial hyperplasia on primary and secondary lamellae, and the condition was severe on the primary lamellae for 50% of the fish. Epithelial lifting was apparent in 88% of the fish exposed for 3 hours; the condition was se- vere in 50% of these, and some swelling of secondary lamellae was observed (P = 0.01, Fig. 3B;). All the fish exposed for 48 hours had swollen secondary lamellae, and 50% had epithelial lifting (P = 0.17). Curling of the secondary lamellae oc- curred in 75% and 50% or the fish exposed for 3 and 48 hours, respectively (P3h = 0.03, P48h = 0.17, Fig. 3A). Gills of exposed fish, site 4. The Creek Chubs collected at site 4 (n = 3) all had slight epithelial hyperplasia of the secondary lamellae but only focal or none on the primary lamellae. Swollen secondary lamellae were observed in all fish but it was not extensive, and only 1 fish had curled lamellae (P = 0.43). None of the fish from site 4 was observed to have epithelial lifting or edema. Gill uptake of Al and Fe. Distinct differences in gill sections among fish col- lected from the 5 sites were observed after staining with acid solochrome azurine. Gills of fish from the fish reference site had little Al or Fe uptake, whereas a gradient of these metals was seen in gill tissues of fish collected from affected waters at sites below the wells (sites 1 and 2) and those exposed on-site (site 3) to contaminated creek water (Fig. 4). Gill tissues of Creek Chub from site 1 were a

Figure 4. Gill sections from fish collected from the fish reference site and 4 sites in Acorn Fork below fracked wells. Sections were stained with acid solochrome azurine for alumi- num (blue color) or iron (red color). 100 2013 Southeastern Naturalist Vol. 12, Special Issue 4 D.M. Papoulias and A.L. Velasco reddish color, indicating Fe had passed across the epithelial membrane, whereas gills of Creek Chub from sites 2, 3, and 4 were stained blue to varying degrees, indicating that Al had been taken-up. Creek Chub that were collected at sites 2 and 4 had much less Al than those fish continuously exposed for 3 and 48 hours to affected water at site 3. Liver. Creek Chubs (n = 2) collected from the fish reference site and from site 4 (n = 3) were scored as having moderate to high liver glycogen/lipid. Fifty-percent of the Creek Chubs from site 1 (n = 10) and 64% from site 2 (n = 18) had low to no glycogen/lipid. Thirty-eight percent of Creek Chubs (n = 8) exposed for 3 hours had low to no glycogen/lipid, whereas 50% of those (n = 4) exposed for 48 hours had low to no glycogen/lipid. No lesions were observed in the liver. Spleen. Spleens of all Creek Chubs (n = 2) collected from the fish reference site were moderately to highly perfused with red blood cells. In contrast, spleens of 37% of Creek Chubs from site 1 (n = 11) and 50% from site 2 (n = 10) were moderately to highly perfused with red blood cells. Spleens of 63% of Creek Chubs treated for 3 hours (n = 8) at site 3 were moderately to highly perfused with red blood cells, whereas 25% of those exposed for 48 hours (n = 4) scored similarly. No Creek Chubs at site 4 (n = 1) had moderate to high amounts of red blood cells. No lesions were observed in the spleen. Kidney. Reference fish (n = 3) and those collected from site 4 (n = 3) were without head or trunk kidney abnormalities. Varying numbers of fish exposed to affected Acorn Fork water had granulomatous inflammation, but only at site 2 was the incidence significantly greater than at the fish reference site (Psite 1 = 0.80, Psite 2 = 0.02, Psite 3 = 0.06, Psite 4 = 0.18, Fig. 5). Water quality Conductivity measured at the water reference site above well #4 between 15 June and 9 August 2007 ranged from 430–639 µS/cm. At the fish reference site, conductivity was 190 µS/cm and 244 µS/cm on 15 June and 24 July 2007, re- spectively. At the time of fish sampling (10 July 2007), conductivity at site 1 was 1917 µS/cm having decreased from a high of 2690 µS/cm on 22 June 2007; by 24 July 2007, conductivity at site 1 was still elevated at 1265 µS/cm (Table 1). Conductivity measured at site 2 ranged between 279 and 308 µS/cm from 22 June to 9 August 2007 and was 291 µS/cm on 10 July 2007 when fish were collected

Table 1. Conductivity measured between 22 June 2007 and 9 August 2007 in water at four fish- collection sites in Acorn Fork and its unnamed tributaries.

Conductivity (µS/cm) Date Site 1 Site 2 Site 3 Site 4 June 22 2690 279 8190 35,900 July 10 1917 291 8380 29,200 July 24 1265 293 7650 25,200 July 26 5500 August 9 308 4620 12,610

101 2013 Southeastern Naturalist Vol. 12, Special Issue 4 D.M. Papoulias and A.L. Velasco for this study (Table 1). Conductivities at sites 3 and 4 were the highest on 22 June 2007 (greater than 8000 and 35,000 µS/cm, respectively) and were still up to 50 times greater than reference sites when reference fish were collected and on-site testing occurred 24 July 2007 (Table 1). On 9 August 2007, nearly 7 weeks after wells #3 and #4 were fracked, conductivity at site 4 remained el- evated at 12,610 µS/cm. Water from two locations uninfluenced by wells (i.e., above wells #1 and #4) measured pH 7.1 and 7.8 on 25 June. Creek water had a pH of 5.5 on 23 May and 5 June 2007 just below the confluence of the Acorn Fork mainstem with the west branch. On 25 June 2007, creek water below well #3 and above site 4 was pH 6.5; pH was 7.31 at Site 2; 5.61 at site 4; and 7.25 at site 1. No other pH measurements were made. On 25 June 2007, hardness mea- sured 41.7 mg/L CaCO3 at the water reference site, 30.1 mg/L CaCO3 at site 1; 45.5 mg/L CaCO3 at site 2, and 10.9 mg/L CaCO3 at site 3. On 22 June 2007, approximately 1 week after wells #3 and #4 were fracked, when conductivity at site 4 was over 35,000 µS/cm (the highest measured), chloride ions, sulfate ions, and all the metals except Al and Fe were also at the highest levels measured at any site in this study (Table 2). With the ex- ception of sulfate, water concentrations of the other analytes were greatest at sites 3 and 4 and greater at site 1 when compared to site 2 (Table 2). Sulfates were highest (450 mg/L) at the water reference site, followed by sites 2 and 1

Figure 5. Percent number of fish with kidney tisue showing granulomatous inflammation. Asterisk indicates a signficant difference between results at the fish reference site (Refer- ence) and the affected site (Fisher’s Exact Test, P < 0.05).

102 2013 Southeastern Naturalist Vol. 12, Special Issue 4 D.M. Papoulias and A.L. Velasco (Table 2). The water reference site was similar to sites 1 or 2 for most elements except chloride, Fe, and Mn (Table 2). Chloride at site 1 was elevated over concentrations at site 2 and the water reference site (Table 2). Chloride con- centrations exceeded Kentucky water-quality standards only at sites 3 and 4 (Table 2). Iron and Mn were slightly higher at sites 1 and 2 compared to the water reference site (Table 2). At least 3 heavy metals exceeded Kentucky

Table 2. Concentrations of selected elements measured in unfiltered water samples collected from Acorn Fork and tributaries in 2007. Acute and chronic surface water standard values are from State of Kentucky (2011) unless otherwise noted. NC = not collected. < = below detection. Dashes indi- cate no aquatic-life standard available. Symbol (§ or *) indicates an exceedance above correspond- ing standard value for CaCO3 (acute or chronic, respectively). Cond. = conductivity.

Element (mg/L) Date Cond. - B (2007) Site (µS/cm) Al Cd Cl Cr2 Cu Fe 24-Jul Ref (fish) 244 NC NC NC NC NC NC 10-Jul Ref (water) 430 0.196* <0.0001 <1 0.0006 0.0023§ 1 10-Jul 1 1917 0.075 <0.0001 480 0.0013 0.0041§ 2** 10-Jul 2 291 0.108* <0.0001 17 0.0008 0.0024§ 1** 10-Jul 3 8380 1.670§§ 0.0003§ 2900§§ 0.0018 0.0114§§ 251§§ 22-Jun 4 35,900 0.355* 0.0005§ 8500§§ 0.0048 0.0349§§ 41§§

Standard values as mg/L CaCO3 10.9 mg/L = § - 0.0002 - - 0.0017 - 41.7 mg/L = §§ 0.750A 0.0009 1200 0.0061 4

10.9 mg/L = * 0.0870A 0.0001 - - 0.0014 - 41.7 mg/L = ** - 0.0001 600 0.0044 1

Element (mg/L) Date 2 – (2007) Site Mg Mn Ni Pb SO4 Sr Zn 24-Jul Ref (fish) NC NC NC NC NC NC NC 10-Jul Ref (water) 31 0.1 0.002 <0.0005 450 0.2 0.006 10-Jul 1 31 0.1 0.005 <0.0005 150 1.8 0.061§§ 10-Jul 2 15 1.8 0.002 <0.0005 200 0.1 <0.005 10-Jul 3 133 12.0 0.047** 0.0028** 8 4.6 0.053§ 22-Jun 4 330 19.6 0.071** 0.0038** 35 44.6 0.064§§

Standard values as mg/L CaCO3 10.9 mg/L = § - - 0.010 0.0050 - - 0.018 41.7 mg/L = §§ - - 0.224 0.0270 - - 0.057

10.9 mg/L = * - - 0.008 0.0002 - - 0.018 41.7 mg/L = ** - - 0.025 0.0010 - - 0.057 AValues (CMC and CCC for aquatic life) from EPA (2009) are not hardness specific. BTotal chromium. There are no Kentucky surface water standards for aquatic habitats for total chromium. Values for chromium VI are not hardness specific and are 0.016 and 0.011 for acute

and chronic values, respectively; chromium III acute and chronic at 41.7 mg/L CaCO3 are 0.881 and 0.294 mg/L, respectively; chromium III acute and chronic at 10.9 mg/L CaCO3 are 0.042 and 0.014 mg/L, respectively.

103 2013 Southeastern Naturalist Vol. 12, Special Issue 4 D.M. Papoulias and A.L. Velasco water-quality standards at all sites (Table 2). Kentucky water-quality standards for Al were exceeded at sites 2, 3, and 4 and for Zn at sites 1, 3, and 4 (Table 2). Chromium was the only metal of the 11 measured to not exceed the Kentucky water criterion at sites 3 and 4 (Table 2).

Discussion Distress and tissue injury can occur in freshwater fishes with osmoregulatory systems not suited to rapid changes in pH or conductivity such as that which occurred during the spill incident in Acorn Fork. Fishes have a defined range of tolerance to aquatic pH and dissolved solids measured as specific conductivity. A pH between 6.5 and 9.0 is required by most freshwater fishes (Fromm 1980). Although technical problems with a field pH meter did not permit measurements on all dates, the present study shows that creek waters of the Acorn Fork system unaffected by fracking normally have a pH 7.0 or higher, conductivities less than 500 µS/cm, low to moderate hardness, and are low in dissolved elements. Re- cently, the EPA (2011) established a chronic field-based aquatic-life benchmark for conductivity of 300 µS/cm specifically for the Appalachian region including eastern Kentucky, where the pH-neutral waters are dominated by salts of Ca2+, 2+ 2− 3− Mg , SO4 , and HCO . This benchmark is consistent with the upper limit of 240 µS/cm identified by Black et al. (2013[this issue]) as a good predictor of streams occupied by Blackside Dace populations. Acorn Fork water downstream of fracked wells was observed to be as low as 5.6 pH and as high as 35,900 µS/cm conductivity. Overall, the water elemental and ionic laboratory analyses were consistent with field-measured conductiv- ity, such that elements and ions tended to be elevated in water samples from sites where conductivity also was elevated. Conductivity, elements, and ions were higher nearer to wells #3 and #4 than further downstream. However, well fracking activity effects on water quality were still notable at site 1, a distance of approximately 3 km downstream of the wells. Elevated sulfates, at the water reference site above well #4, suspected to be due to historic coal mining activity, may explain the higher conductivity values at this site. Conductivity was consis- tently lowest at site 2. Site 2 is below a 2.4-ha lake into which fracking effluent flowed and was diluted. State and federal standards established to protect aquatic life were exceeded for heavy metals and chloride ions at some or all affected sites (EPA 2009, State of Kentucky 2011). No measurements of the reference water exceeded standards. Three of the 11 metals exceeded standards at sites 1 and 2, whereas 7 of the metals and chloride ions exceeded levels protective of aquatic life at sites 3 and 4. The toxicity of many metals is increased in soft waters low in calcium and magnesium ions (Allen and Janssen 2006). Moreover, the toxicity of waters con- taining heavy metals tends to increase under reduced pH because the elements are maintained in the water column where they are bioavailable (Manahan 1972). Creek Chubs, and to a lesser extent Green Sunfish, exposed to Acorn Fork water contaminated with fracking effluent showed more tissue damage and stress than 104 2013 Southeastern Naturalist Vol. 12, Special Issue 4 D.M. Papoulias and A.L. Velasco fish from an unaffected reference site. The most severely affected fish were those collected at site 2, and the reference site fish exposed on-site to contaminated water at site 3. Fewer signs of tissue damage were observed in fish collected in August at site 4, despite higher conductivities here than at any other site. How- ever, behavioral observations and spleen condition of these fish indicated they were experiencing stress. It is likely these Creek Chubs had only recently moved downstream into this area where previously all fish had been killed by a large pulse of wastewater. Fish at site 1, 3 km downstream from the wells, showed signs of tissue damage and stress, but generally fewer individuals were affected than at sites 2 and 3. The magnitude of effects of aquatic acidification on fish will vary depen- dent on the source of the hydrogen ions, water calcium ion concentration, the presence of heavy metals, and their speciation (Henry et al. 2001). Aquatic acidification changes the biochemical properties of the gill tissue and disrupts the flow of ions (e.g., sodium and chloride) at the gill-water interface, subse- quently changing blood ion concentrations (Evans 1987). Respiratory distress also can occur from exposure to low environmental pH as a result of excess ep- ithelial hyperplasia and mucus accumulation on gills (Daye and Garside 1976, Evans 1987). The same gill lesions observed on Creek Chubs and Green Sun- fish exposed to Acorn Fork waters (epithelial lifting and edema, epithelial cell hyperplasia and swelling, curling of secondary lamellae, touching and fusion of lamellae) have been reported for many fish species exposed to low environ- mental pH, dissolved heavy metals, or both (Chevalier et al. 1985, Evans et al. 1988, Figueiredo-Fernandes et al. 2007, Gill et al. 1988, Karan et al. 1988, Visoottiviseth et al. 1999). Granulomatous inflammation is commonly observed in fish organs dueto disease and parasites (Hedrick et al. 1993, Rahimian 1998). Chronic exposure to very low pH has been reported to affect fish kidney morphology (Saenphet et al. 2009), but no reports were found of renal granulomas as a result of exposure to acidic conditions or from exposure to heavy metals. Although granulomatous inflammation was only observed in fish exposed to affected Acorn Fork water, its association with the degraded water quality may be a secondary response in chronically stressed fish. Metals can affect gill tissue by adsorbing to the surface and by active or pas- sive transport across the gill epithelia. Metal ions will vary in their ability to form ionic bonds at the surface of gill tissue or to move across epithelia to form covalent bonds in cytosol (Wepener et al. 2001). Modes of action of these met- als are variable but generally involve interference with enzymes, resulting in adverse consequences for osmoregulation, respiration, and reproduction (Goyer and Clarkson 2001). Metals detected in this study also have been shown to af- fect behaviors such as avoidance, coughing, and changes in ventilation rate at or below guidance levels (Atchinson et al. 1987). Two of the metals, Al and Fe, were elevated in water samples and were also detected by histochemistry only in gill tissue of fish collected from the

105 2013 Southeastern Naturalist Vol. 12, Special Issue 4 D.M. Papoulias and A.L. Velasco affected areas of Acorn Fork. The toxicity of Al to fishes has been well- studied (Sparling and Lowe 1996). National aquatic life guidance criteria for Al (i.e., for chronic exposure, 87 µg/L at pH 6.5–9.0; EPA 2009) were ex- ceeded at sites 2, 3, and 4. However, site-specific water quality, particularly pH, calcium ion concentration, and presence of organic or inorganic com- plexing agents, together with the species and life-stage of the fish determine the degree of Al toxicity (see references in DeLonay et al. 1993). Observed accumulation of Al in gill tissue of fish collected in this study reflected the concentration of Al measured in water samples (i.e., site 1 < site 2 < site 4 < site 3). Although Al was not measured at the fish reference site, the absence of Al in gill tissue is consistent with expected low concentrations of Al at the conductivity measured, based on historical records of unaffected stream wa- ters of eastern Kentucky (Dyer and Curtis 1977). Unlike Al, Fe toxicity to fish has not been as thoroughly tested. Guidance levels for chronic exposure to iron have been suggested at 1000 µg/L total Fe (Buchman 2008), but toxicity is highly dependent on the ionic form of Fe pres- ent (Teien et al. 2008). Total Fe was 40–250 times this level at sites 3 and 4, but only slightly higher than 1000 µg/L at sites 1 and 2. Iron uptake, however, was evident only in gills of fish from site 1. Although Fe concentrations were greater at sites 3 and 4, site-specific water quality, increased transepithelial movement of Al over Fe, or both, may explain why no Fe was detected in gills of fish from these sites by histochemistry. The results of this histological evaluation of Creek Chub and Green Sun- fish exposed to affected Acorn Fork water provides evidence that the releases of fracking fluids degraded water quality sufficiently to cause lesions or exac- erbate general stress-indicators in these and likely other fish species present, including Blackside Dace. Differences were observed in type and severity of lesions when compared to fish from a reference site, despite uncertainties re- garding where collected fish originated, and for how long they were exposed to affected Acorn Fork water at sites 1 and 2. Furthermore, fish collected from sites with elevated Al and Fe concentrations bioaccumulated these metals. Laboratory studies that remove the additional environmental stressors present in the stream environment could aid in identifying specific causes of the le- sions and stress. The major loss of fish habitat due to decreased environmental pH andin- creased conductivity has been attributable to drainage from active and abandoned mine operations (Sams and Beer 2000), as well as activities associated with land-based gas and oil exploration (Sidhu and Mitsch 1987). The water quality of natural mountain stream waters of eastern Kentucky is typified by low conduc- tivity (<100 µS/cm), near neutral pH, moderate buffering (Ca+ <6.5 mg/L, Mg+ - 2− - ≤3.5 mg/L, HCO3 <25 mg/L, SO4 <30, Cl <5 mg/L), and low concentrations of dissolved iron (<0.25 mg/L) and aluminum (<0.07 mg/L) (Dyer and Curtis 1977). Fishes of the Appalachian mountain region, such as Blackside Dace, evolved under and adapted to these conditions (Jones 2005). The abrupt and persistent

106 2013 Southeastern Naturalist Vol. 12, Special Issue 4 D.M. Papoulias and A.L. Velasco post-fracking changes in water quality within the Blackside Dace habitat that resulted in very high conductivity, lowered pH, and lowered alkalinity, coupled with toxic concentrations of metals, could be expected to be deleterious to Blackside Dace health and survival. The timing of this incident was especially injurious to the species because it occurred during the spawning season. More- over, the adverse effects of this incident in the Acorn Fork headwater extended over several months, likely causing long-term local and downstream disruption of ecosystem function (Freeman et al. 2007). As efforts accelerate to unleash new energy sources, application of technolo- gies such as hydraulic fracturing can, if not carefully developed, compound the effects of ecosystem degradation caused by past resource extraction (Groat and Grimshaw 2012). This is clearly the case in the Appalachian Highlands, where mining, logging, agriculture, and development have cumulatively degraded aquatic ecosystems, fragmenting freshwater fish populations to the extent that population mixing and gene flow have become restricted (Freund 2004, Pond 2012, Warren et al. 2000). The findings of this study will be useful in assessing injury to the threatened Blackside Dace and its habitat, and demonstrate the util- ity of on-site field exposures, histology, and histochemistry when investigating impacts of hydraulic fracturing on small streams.

Acknowledgments The authors are grateful to Bob Snow, Mindi Lawson, Michael Floyd, and Mike Armstrong (US Fish and Wildlife Service) for their many long days of field support; also to John Brumley (Kentucky Division of Water) and John Williams (Kentucky Department of Fish and Wildlife Resources), and their crews, with post-release field assessments. Special thanks to Ryder Velasco for his assistance during the in situ treatment, and in particular to Valerie Hudson (former Deputy Commissioner of the Energy and Environment Cabinet), whose support, coordination, vision, and spirit helped maintain steady progress. The authors thank Mandy Annis and Vanessa Veléz for preparation of fish samples for histopathology. Susan Finger assisted with initial study design, supplies, and advice. Julia Towns-Campbell provided invaluable library support. Dr. Jeffrey Wolf (Experimental Pathology Laboratories) reviewed some of the histology slides. Marcia Nelson, CERC Outreach Coordinator, assisted with graphics and publication outreach. Finally, we are grateful for the determination of the Reverend Ova Grubb, a life-long resident of Acorn Fork, who called agencies and experts until he could resolve the environmental damage occurring to the aquatic ecosystem near his residence. This work was partially supported with funding from US Fish and Wildlife Service, under contract agreement No. 401818N502.

Disclaimer Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the US Government. The findings and conclusions in this article are those of the authors and do not necessarily represent the views of the US Fish and Wildlife Service.

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111 REVIEWS REVIEWS REVIEWS 330 Biotic impacts of energy development from shale: research priorities and knowledge gaps

Sara Souther1*, Morgan W Tingley2, Viorel D Popescu3,4, David TS Hayman5,6,7, Maureen E Ryan3,8, Tabitha A Graves9, Brett Hartl10, and Kimberly Terrell11

Although shale drilling operations for oil and natural gas have increased greatly in the past decade, few studies directly quantify the impacts of shale development on plants and wildlife. We evaluate knowledge gaps related to shale development and prioritize research needs using a quantitative framework that includes spatial and tem- poral extent, mitigation difficulty, and current level of understanding. Identified threats to biota from shale development include: surface and groundwater contamination; diminished stream flow; stream siltation; habitat loss and fragmentation; localized air, noise, and light pollution; climate change; and cumulative impacts. We find the highest research priorities to be probabilistic threats (underground chemical migration; contaminant release during storage, during disposal, or from accidents; and cumulative impacts), the study of which will require major scientific coordination among researchers, industry, and government decision makers. Taken together, our research prioritization outlines a way forward to better understand how energy development affects the natural world. Front Ecol Environ 2014; 12(6): 330–338, doi:10.1890/130324

apid development of fossil-fuel resources has the nology is well studied (with >1000 peer-reviewed publi- R potential to transform landscapes and biological cations), surprisingly little research has focused on the communities before the resulting impacts are fully under- biotic impacts of shale development. While the biologi- stood. In the US, the extraction of gas and oil reserves cal effects of other methods for extracting fossil fuels are trapped in shale rock (known as “shale-gas” and “tight better understood, these studies generally lack clear oil”, respectively) through hydraulic fracturing (also mechanistic links to fuel extraction and are limited to a called “fracking” or “hydrofracking”) has grown exponen- small number of species, countries, and ecoregions tially since 2007 (Figure 1; EIA 2011). Such technology (Northrup and Wittemyer 2012). Moreover, shale devel- exploits previously inaccessible natural gas reserves opment differs from other forms of fossil-fuel extraction through the deep injection of high-pressure aqueous in multiple ways, including a broad and diffuse geo- chemicals into shale rock to create fractures, releasing graphic footprint and an extremely high water demand. trapped gas (Figure 2; see “Additional references” section Therefore, many of the biotic impacts of shale develop- in the web-only materials [WOM]). Although this tech- ment are unique and cannot be inferred from knowledge of other forms of oil and natural gas extraction. Understanding the impacts of shale development is In a nutshell: essential because many shale basins, particularly those in • Exploitation of oil and gas reserves trapped in shale rock, the eastern US, occur in regions of exceptional biological including the extraction process known as “fracking”, poses diversity (Figure 3); for instance, the most rapidly growing substantial and unexplored risks to living creatures source of natural gas in the US (ie the Marcellus Shale in • Understanding the biotic impacts of operations that fracture shale to access reserves is hindered by the unavailability of the Appalachian Basin) underlies one of the country’s high-quality data about fracturing fluids, wastewater, and highest diversity areas for amphibians and freshwater fish spills or violations (Collen et al. 2013). In the US and Europe (Figure 4), • The risks of chemical contamination from spills, deep well shale basins often overlap with areas already experiencing failures, storage leaks, and underground fluid migration are severe threats to freshwater resources. In conjunction with top research priorities • Cumulative effects of shale development may represent the other anthropogenic activities, environmental change most severe threats to plants and animals, but are particularly associated with shale operations may cumulatively affect challenging to study living organisms in unknown, potentially calamitous, ways. Here, we identify and prioritize research needs related to shale development using a quantitative framework. We 1Department of Botany, University of Wisconsin, Madison, consider the entire process of shale development, exam- Madison, WI *([email protected]); 2Woodrow Wilson School, ining the threats to animals and plants from site develop- Princeton University, Princeton, NJ; 3Earth to Ocean Research ment and maintenance, water sourcing, well operation Group, Department of Biological Sciences, Simon Fraser and fracturing, and storage and disposal of injection fluids University, Burnaby, Canada (continued on p 338) (Figure 2). We classify impacts as probabilistic (ie

www.frontiersinecology.org © The Ecological Society of America S Souther et al. Research priorities for shale development unplanned or accidental) or deterministic (ie planned or 331 unavoidable) following the structure developed by Rahm and Riha (2012). Our focus is on biota because plants, animals, and other living organisms have largely been omitted from other reviews, which tend to emphasize abi- otic effects (eg Entrekin et al. 2011; Howarth et al. 2011a), and because shale formations often lie beneath global hotspots of species diversity. Our goal is to improve research of the biotic impacts associated with shale devel- opment by prioritizing research needs and highlighting associated challenges. n Prioritization scheme EcoFlight We assessed potential effects of shale development on liv- Figure 1. Proliferation of natural gas wells in the Jonah Field, ing organisms based on four criteria: current understand- Wyoming, US. Inset: historical and predicted natural gas ing, spatial extent, temporal extent, and mitigation diffi- production in the US. Data from EIA (2011). culty (Table 1). For each impact, we ranked current understanding as low, medium, or high and assigned a cor- resulted in direct mortality and stress of fish and aquatic responding value of 3, 2, or 1 (where 3 is low understand- invertebrates (Papoulias and Velasco 2013). A propor- ing, suggesting high research needs) based on the number tion of this fluid – the amount varies substantially among of relevant studies (additional methods provided in geologic formations, but can be as high as 90% – remains WebPanel 1). The three remaining risk-based criteria were underground after its application (Entrekin et al. 2011; assigned values of 1, 2, or 3, corresponding to low, medium, Vidic et al. 2013). The fate and potential biotic impacts of or high ratings (where 3 represents high risk to biota for a unrecovered fracturing fluids are highly uncertain. criterion). For each impact, the research priority was calcu- Due to the depth of most hydraulically fractured shale-gas lated by averaging criteria values, where current under- formations (900–2800 m; Vidic et al. 2013), the contamina- standing was weighted by a factor of 3 to reflect the impor- tion of groundwater by subsurface migration of fracturing tance of existing scientific information in determining fluid is considered unlikely (Engelder 2011; Vidic et al. research needs. Average values corresponded to final rank- 2013). Nevertheless, geologic pathways for chemical migra- ings as follows: low (1.0–1.5), medium-low (1.6–1.9), tion have been identified (Warner et al. 2012). Moreover, medium (2), medium-high (2.1–2.5), and high (>2.5). drinking water contamination with fracturing chemicals

and/or methane (CH4) has been reported (DiGiulio et al. n Probabilistic impacts 2011; Osborn et al. 2011; Jackson et al. 2013), although some of these studies have been criticized as providing Probabilistic impacts to biota from shale development do insufficient evidence to attribute water contamination to not occur as an unavoidable outcome of development but shale development (eg Davies 2011). Future research must do occur with a certain frequency. Although some of determine whether hydraulic fracturing causes CH4 conta- these impacts may be rare occurrences (ie the result of mination and whether, in the absence of equipment failure “unexpected” events), because most relate to the release and accidents, chemicals do migrate from fractured shale of potentially toxic chemicals into the environment, the beds. Given the limited understanding (WebTable 1) of the possibility of biotic harm can be great. likelihood, frequency, and spatiotemporal extent of such contamination events, and the few options for mitigation, Underground migration of contaminants this is a high research priority (Table 1).

During well fracturing, chemicals suspended in an aque- Contamination from equipment failure, illegal ous medium are injected under high pressure into shale to activities, and accidents release natural gas. Fracturing fluid generally includes a mix of acids, biocides, friction-reducing agents, and other In addition to chemical migration from fractured shale, chemicals to facilitate gas retrieval (Vidic et al. 2013). freshwater contamination may result from well blowouts, Many of the chemicals (eg methanol, xylene, naphtha- casing failures, illegal discharge, and spills during fluid lene, hydrochloric acid, toluene, benzene, and formalde- transport and storage (Figure 2). Many such contamina- hyde) are regulated in the US by the Safe Drinking Water tion events involve the release of recovered fluid (called Act, the Clean Water Act (40 CFR Section 401.15), or “produced water”), which consists of fracturing fluid and the Clean Air Act (US EPA 2012) and have been linked salts, heavy metals, hydrocarbons, and radioactive material to negative health effects in humans (Colborn et al. accumulated from natural underground sources (Howarth 2011). Releases of fracking fluid into streams have et al. 2011a). The high saline content of recovered fluid

© The Ecological Society of America www.frontiersinecology.org Research priorities for shale development S Souther et al.

332 ically occurred on the well pad, with nearly 20% of reports documenting contamina- tion of land or surface water. Location (on- pad versus off-pad) was specified in fewer than half of the reports (42%), and spatial extent of contamination was rarely (5%) described. The time between the spill and reporting was noted in <10% of cases (median = 5.75 hours; range = 1 hour to 6 weeks). In addition to the lack of data describing the nature and extent of spills, spill frequency was probably underesti- mated. Many reports were ambiguous, and companies routinely violated Pennsylva- nia’s reporting requirement (only 59% of documented spills were reported by the drilling company). Collectively, poor data quality and lack of consistent reporting represent a major obstacle to understand- ing the impacts of chemical contamina- tion from shale development. Ecological

S Friedrich impacts of spills and accidents are also a Figure 2. Shale development includes multiple processes focused around natural gas high research priority, given the limited extraction via hydraulic fracturing. Impacts of shale development on biota can knowledge, the potential for lasting and include probabilistic (1, 6, 7, 8) and deterministic (2, 3, 4, 5, 9) effects of these widespread adverse environmental con- various processes. Contamination of aquatic and terrestrial systems may occur due to sequences, and the difficulty in mitigating spills, leaks, or accidents during hydraulic fracturing (6), waste storage (1, 8), and such contamination events. transport (5). Permanent removal of water from the hydrologic cycle and subsequent effects on water quality (9), habitat loss and fragmentation (4), and air (2) and Release of contaminants during noise and light (3) pollution are unavoidable consequences of shale development, waste storage and disposal although technological advances and appropriate planning can minimize biotic effects.

Shale development contributes to climate change in various ways, including CH4 As in the case of contamination from release during well venting (2) as well as fossil-fuel use during site development, well spills and accidents, lack of data on fracturing, and waste disposal (eg 5). wastewater disposal impedes environ- mental assessment. Waste volume, com- alone poses risks to biota, given that increases in salinity position, and fate vary among drilling companies, states, of as little as 1 g L–1 can harm or kill aquatic plants and and geologic formations (Entrekin et al. 2011; Rozell and invertebrates (Hart et al. 1991). Reaven 2011; Rahm and Riha 2012; Rahm et al. 2013). Currently, the frequency and extent of freshwater contam- Industry-reported data from PADEP revealed a 570% ination due to spills, accidents, and violations is poorly quan- increase in wastewater production since 2004 from devel- tified. Of the 24 US states with active shale gas reservoirs, opment of the Marcellus Shale (Maloney and Yoxtheimer only Pennsylvania, Colorado, New Mexico, Wyoming, and 2012; Lutz et al. 2013). Drill cuttings were principally dis- Texas maintain public records of spills or violations for oil posed of in landfills, and wastewater (ie recycled fluid) was and gas drilling operations. We examined the frequency and most frequently treated at industrial facilities or injected nature of violations in the Pennsylvania Department of into deep wells (a large proportion of wastewater was re- Environmental Protection’s (PADEP’s) oil and gas manage- used prior to disposal; Maloney and Yoxtheimer 2012). ment compliance-reporting database (data analyzed in Risk of waste migration from deep injection wells to fresh- WebTable 2). A total of 523 violations at 279 permitted wells water aquifers is poorly understood and, notably, deep well were detected in 2013, representing ~2.5% of inspections injection has been linked to increased seismic activity (12 452 total) and 5% of wells (5580 total). The three most (Frohlich et al. 2011). Containment ponds frequently serve common violations included: failure to properly store, trans- as temporary wastewater storage at drilling sites, and these port, process, or dispose of residual waste (n = 85); failure to vary substantially in structural integrity. Inadequately adopt required or prescribed pollution prevention measures designed ponds can overflow during heavy rain, may leak (n = 48); and failure to plug a well upon abandonment (n = as liners degrade, are accessible to wildlife, and are poten- 43). Spills were detected at 37% of wells found in violation tial sources of air pollution as chemicals volatilize and were generally small (median = 265 L; range = 4–43 000 (Entrekin et al. 2011). While the frequency of con- L), although there were nine spills of over 3500 L. Spills typ- tainment pond failure has not been quantified, our in-

www.frontiersinecology.org © The Ecological Society of America S Souther et al. Research priorities for shale development vestigation of Pennsylvania’s Table 1. Research priorities based on the relative extent, difficulty mitigating, and 333 2013 well inspection data current understanding of potential impacts (described above) detected Source of ecological Type of Spatial Temporal Mitigation Current Research numerous violations (eg 27 impact occurrence* extent** extent difficulty understanding† priority‡ violations citing “Pit and Underground Unknown Unknown High Low High tanks not constructed with migration of Probabilistic (3) (3) (3) (3) (3.0) sufficient capacity to contain contaminants pollutional substances”), indi- Contamination of cating that some containment surface water from Unknown Unknown High Low High facilities fail to prevent escape equipment failure, Probabilistic (3) (3) (3) (3) (3.0) of contaminants. Inappropri- illegal activities, ate management of waste and accidents products, including the direct Release of contaminants during Unknown Unknown High Low High discharge of industrial waste Probabilistic into streams, comprised 34% waste storage or (3) (3) (3) (3) (3.0) of the total violations issued disposal Unknown Unknown Unknown Low High by PADEP (WebTable 2). Cumulative impacts Probabilistic There is virtually no empir- (3) (3) (3) (3) (3.0) ical information about the Land application of Low Medium Medium Low Medium-High Deterministic biotic risks associated with wastewater (1) (2) (2) (3) (2.3) disposal of produced water Climate-change High High High High Medium Deterministic and drill cuttings (WebTable contribution (3) (3) (3) (1) (2) 1). Given this paucity of data, Habitat High High Medium High Medium-Low Deterministic the unquantified spatial and loss/fragmentation (3) (3) (2) (1) (1.8) temporal extent of contami- Diminished stream Medium Medium Low Medium Medium-Low nation, and few mitigation Deterministic flow (2) (2) (1) (2) (1.8) options, the pathways and Low Low Medium Medium Medium-Low consequences of environmen- Air pollution Deterministic tal contamination from waste (1) (1) (2) (2) (1.7) Medium Medium Medium High Low storage and disposal represent Siltation Deterministic high research priorities (Table (2) (2) (2) (1) (1.5) 1). A critical first step in this Low Low Low High Low Noise pollution Deterministic research is improving basic (1) (1) (1) (1) (1.0) reporting to generate accurate Low Low Low High Low Light pollution Deterministic data describing waste compo- (1) (1) (1) (1) (1.0) sition and fate. For each Notes: *Following Rahm and Riha (2012). **Values in parentheses correspond to numerical rankings, as explained in text. Box method of wastewater dis- color reflects the severity of each criterion, from minor (blue) to severe (orange). †Weighted by a factor of 3 to reflect impor- posal, future research should tance of current knowledge in determining research priorities. ‡Final rankings in parentheses correspond to weighted average of individual rankings. determine the concentration of toxins released into the environment, exposure duration and potential pathways untarily disclosed non-proprietary fluid components, and (eg ingestion, inhalation, or contact), and the effects on ten states currently participate in the FracFocus aquatic and terrestrial biota. A general evaluation of cur- (www.fracfocus.org) national registry as a means of chemi- rent above- and belowground remediation strategies is cal disclosure. We investigated the proportion of propri- needed to address whether current technologies are capa- etary components for 150 randomly selected wells repre- ble of removing contaminants and what site characteristics senting three of the top producing states (ie Texas, enhance or preclude effective remediation. Pennsylvania, and North Dakota) in the registry (data presented in WebTable 3). Overall, 67% of wells in our Disclosure of fracturing chemicals sample were fractured with fluid containing at least one undisclosed chemical, and 37% were fractured with five or Although not a biotic impact on its own, the lack of disclo- more undisclosed chemicals. Some wells (18%) were frac- sure regarding many fracturing chemicals can hamper the tured with a complex fluid containing 10 or more undis- ability of researchers to understand, predict, and mitigate closed components. Importantly, many disclosed chemi- adverse environmental effects. Certain chemicals in frac- cals lacked Chemical Abstracts Service (CAS) numbers turing fluids are classified as confidential business informa- or concentration values. Most wells (82%) were fractured tion under Section 14(c) of the US Toxic Substances with fluid containing either undisclosed components or Control Act (US EPA 2012). Many companies have vol- disclosed chemicals lacking this information. Chemical

© The Ecological Society of America www.frontiersinecology.org Research priorities for shale development S Souther et al.

334 information was sometimes omitted for “non-hazardous” n Deterministic impacts components, but chemicals that are innocuous to humans (eg some salts) can be lethal to freshwater organisms. No Most of the foreseeable ecological impacts of shale devel- chemical information was provided for produced water, opment (eg pollution, habitat loss, siltation) are also asso- making it impossible to formulate these reclaimed fluids ciated with other forms of anthropogenic disturbance. for experimental research. A centralized source of chemi- While much knowledge can (and should) be drawn from cal information would greatly facilitate research. The cur- other disciplines, certain aspects of shale development rent FracFocus registry has major limitations, including: have unique temporal, geographic, spatial, and/or mecha- incomplete state participation; failure to consistently pro- nistic attributes. The challenge for the scientific commu- vide concentrations and CAS numbers for disclosed nity is to determine what new information is needed to chemicals; and non-disclosure of a substantial proportion understand and mitigate these impacts in the specific of chemicals. Because compounds in mixtures can have context of shale development. synergistic or antagonistic effects (Altenburger et al. 2003), full chemical disclosure of fracturing fluid and Siltation and diminished stream flow wastewater is essential for understanding the associated risks to biota, including the effects of leaks, spills, and Only 21% of river and stream length in the US is in “good direct terrestrial or aquatic application. biological condition”, and major threats to freshwater biota include siltation and water extraction (US EPA Cumulative impacts 2013b). Quantifying the effect of shale development on siltation is difficult, but the factors that determine siltation The biological impacts of shale energy development are (eg well density and proximity to surface waters) are rela- numerous, and include water scarcity, habitat loss, and tively well studied. In the US, more than 6000 rivers are various forms of pollution (see “Deterministic impacts” impaired as a result of sediment pollution (US EPA 2014), section below). Many of these threats (Figure 2) cross ter- and the causes, consequences, and mitigation of siltation restrial and aquatic boundaries, extend beyond the imme- have been studied for decades (Berkman and Rabeni 1987; diate footprint of the operation, and may interact to Donohue and Garcia Molinos 2009; Gellis and Mukundan affect ecosystems in unexpected ways. Given that the 2013). The contribution of shale development to sediment overall impact of shale development will likely outweigh load will vary geographically, depending on local hydrol- that of any individual stage of the process, risk assess- ogy, geology, and existing forms of land disturbance. In the ments should incorporate cumulative impacts on biota. Marcellus region, habitats affected by shale development Importantly, this assessment framework should be are likely to include lower-order (eg headwater) streams extended to consider the contributions of unrelated but with relatively little sediment input from other sources co-occurring stressors (eg resource extraction or residen- (Olmstead et al. 2013). Given the extensive amount of rel- tial development). evant scientific literature about stream siltation The few studies that consider cumulative impacts sug- (WebTable 1), the moderate spatial and temporal extent of gest that shale-gas development will affect ecosystems on this problem, and the existence of well-developed mitiga- a broad scale (Kiesecker et al. 2009; Jones and Pejchar tion strategies as compared with other impacts, this threat 2013; Evans and Kiesecker 2014). For example, Evans and is a low research priority (Table 1). Kiesecker (2014) found that energy development – pri- While many forms of land use contribute to siltation, marily from shale – in a large portion of the Marcellus shale development consumes an exceptionally large Shale could result in the construction of >500 000 ha of quantity of fresh water. An average of nearly 20 million L impervious surface, leaving >400 000 ha of affected forest. of water is required to fracture a shale well over its life- Given the overall absence of knowledge regarding cumu- time (Entrekin et al. 2011; Howarth et al. 2011a). Given lative impacts, and the potential for synergistic, negative this massive water demand, well pads are typically con- interactions of shale-gas development impacts on ecosys- structed near freshwater sources. As of September 2010, tems, this area represents another high research priority more than 750 shale wells had been drilled within 100 m (Table 1). Using a cumulative-impacts framework, of rivers and streams in five eastern US states (Entrekin et researchers should specifically address how the density and al. 2011), and nearly 4000 wells drilled within 300 m of spatial configuration of shale wells interact with the tim- these freshwater habitats (Entrekin et al. 2011). The close ing and frequency of drilling operations (eg water with- proximity of well sites to freshwater sources exacerbates drawals or site clearing) to develop strategies for minimiz- the risk of chemical contamination and sedimentation of ing negative biological impacts. As cumulative impacts’ aquatic ecosystems (Gregory et al. 2011). Water extrac- methodology and knowledge improve, research should tion can substantially alter local hydrology by reducing move toward detecting synergies between shale develop- stream water levels and flow rates, which can result in ment and other likely drivers of extinction, such as cli- warmer water temperatures, increased concentrations of mate change, as site-specific or single variable risk assess- pollutants, and less dissolved oxygen for aquatic life. ments likely underestimate threats to ecological health. Certain aspects of freshwater removal for hydraulic frac-

www.frontiersinecology.org © The Ecological Society of America S Souther et al. Research priorities for shale development turing are unique (ie volume and geographic (a) 335 pattern of water withdrawals). Although in- stream flow is well studied in other contexts, there is virtually no relevant empirical data for shale development (WebTable 1). Given the modest level of scientific understanding, potential ease of mitigation (eg by restricting water withdrawals), and relatively moderate spatial and temporal extent, this threat repre- sents a medium to low priority for research (Table 1). The minimum stream flow rates and water volumes necessary to sustain bio- logical function will vary among habitats and (b) (c) life stages, and should be studied at fine spa- tial scales.

Habitat loss and fragmentation

Construction of wells and associated infra- structure (eg access roads, pipelines) disrupts habitat. On average, 1.5–3.1 ha of vegetation are cleared during the development of a sin- (d) (e) gle well pad (Entrekin et al. 2011). Although this footprint is relatively small, the vast number of shale wells equates to considerable habitat loss. Furthermore, the amount of land cleared for pipelines and other infrastructure can far exceed that of the well pad (Slonecker et al. 2012). In Pennsylvania’s Bradford and Washington counties (together representing ~280 000 ha of forest), shale- drilling operations disturbed nearly 2500 ha Figure 3. Freshwater biodiversity in relation to the extent of shale gas basins: of land between 2004 and 2010, and dispro- normalized species richness (a) globally and (b) within the US; US-only (c) portionally affected the interior forests that amphibian species richness, (d) crayfish species richness, and (e) fish species richness. provide important habitat for rare species Biodiversity data (a–d) were derived from Collen et al. (2013); data in (e) were (Slonecker et al. 2012); in the Susquehanna derived from Hoekstra et al. (2010; downloaded from www.databasin.org and used River basin, more than one-quarter of shale under a Creative Commons Attribution 3.0 License, http://creativecommons. well pads were constructed in previously org/licenses/by/3.0). All freshwater biodiversity data are shown in relation to the intact forest habitat (Drohan et al. 2012). In extent of shale gas basins assessed by the US Energy Information Administration the western US, natural gas development has (www.eia.gov) and represent known extents as of May 2011; countries/regions decreased secure habitat for pronghorn included in the global shale gas assessment are: Mexico, Canada, Colombia, (Antilocapra americana; Bechmann et al. Venezuela, Argentina, Chile, Uruguay, Paraguay, Bolivia, Brazil, Algeria, 2012) and mule deer (Odocoileus hemionus; Tunisia, Libya, South Africa, France, Germany, Netherlands, Norway, Denmark, Sawyer et al. 2009), and disrupted breeding Sweden, the UK, Poland, Ukraine, Lithuania, Romania, Bulgaria, Hungary, sagebrush bird communities (Gilbert and China, India, Pakistan, Turkey, and Australia. Chalfoun 2011) including greater sage- grouse (Centrocercus urophasianus; Webb et al. 2012). et al. 2006; Fischer and Lindenmayer 2007). The resulting Well pads and infrastructure result in major habitat frag- edge habitat generally benefits common and generalist mentation. Shale development in known basins (Figures 3 species at the expense of rare and more vulnerable species and 4) threatens to disrupt ~500 natural corridors in west- (Ries et al. 2004). Opening of formerly remote areas can ern North America (Theobald et al. 2012). Such corridors facilitate poaching of imperiled and sensitive species, serve are crucial to maintaining healthy wildlife populations in a as a conduit for invasive and non-native species (including changing climate (Lawler et al. 2013). While fragmentation pathogens), and provide a gateway to further and more per- effects of shale development have been poorly studied manent development (Fahrig 2003). Although habitat loss (Northrup and Wittemyer 2012), fragmentation from any and fragmentation occur on broad scales and are moder- source can reduce dispersal, foraging, and mating success, ately difficult to mitigate, these processes are relatively well thereby increasing species’ risk of local extinction (Aguilar studied (WebTable 1) and represent a medium-low research

© The Ecological Society of America www.frontiersinecology.org Research priorities for shale development S Souther et al.

336 (a) references” in the WOM). In addition to their

direct toxicity, NOx and VOCs contribute to ozone (O3) formation. Natural gas operations emit nearly 30 times the VOCs as compared with coal operations, primarily during extrac- tion and transport (US EPA 2013a). Ground-

level O3 is a strong pulmonary and respiratory irritant in mammals (Watkinson et al. 2001) and negatively affects growth, reproduction, and survival of plants (Karnofsky et al. [2005] and references within). Dangerous concentra-

(b) tions of surface O3 have been detected near large oil and gas operations (Martin et al. 2011), including in winter (Carter and Seinfeld 2012).

As O3 pollution is normally a warm-weather problem, its potential impacts on animals and plants as a year-round phenomenon are entirely unknown. Given the limited scale of noise and light pollution, along with the ease of mitigation and relatively well-developed state of knowl- edge, these threats are low research priorities (Table 1). Air pollution is a slightly higher (medium to low) research priority because it is more challenging to mitigate; thus, aspects unique to shale development warrant further

study (eg wintertime O3). Figure 4. (a) Global and (b) US distribution of pre-existing threats to freshwater biodiversity in relation to the extent of shale gas basins. The Incident Biodiversity Climate-change contribution Threat index for freshwater biodiversity was derived by Vörösmarty et al. (2010; downloaded from www.databasin.org and used under a Creative Commons Shale development will affect biota indirectly, Attribution 3.0 License, http://creativecommons.org/licenses/by/3.0), and ranges but substantially, through climate change. from 0 (lowest threat) to 1 (highest threat). Areas in white denote regions with an These impacts occur primarily through the

average annual runoff <10 mm (see supplementary materials from Vörösmarty routine venting of CH4 during well fracturing, et al. [2010] for full description). but also from the release of carbon dioxide

(CO2) and other greenhouse gases during site priority (Table 1). Notably, however, new extraction tech- development, fracturing, and waste disposal (Howarth et niques have made it economical to develop historically al. 2011b, 2012; Petron et al. 2012). Climate change poses unprofitable gas reserves, threatening terrestrial biota in for- one of the greatest global threats to biota (Thomas et al. merly intact areas (Northrup and Wittemyer 2012). 2004), has spatially and temporally expansive impacts, and Moreover, the diffuse, branching pattern of habitat loss asso- is extremely challenging to mitigate. However, because ciated with hydraulic fracturing distinguishes it from other greenhouse gases and the chemical basis for climate change forms of land-use change (Northrup and Wittemyer 2012). are well understood (WebTable 1), we rank this threat as a medium research priority in the context of shale develop- Light, noise, and air pollution ment (Table 1).

Shale operations create light, noise, and air pollution. Land application of wastewater Anthropogenic light and noise can negatively affect fitness across a broad group of species, including mammals, amphib- As of 2011, certain states – including West Virginia, ians, birds, insects, and aquatic invertebrates (see “Addi- Arkansas, and Colorado – permitted wastewater disposal via tional references” in the WOM). Noise pollution generated direct application to land or roadways, often as a de-icing by natural gas extraction causes some avian species to avoid agent (Adams 2011). Direct land application guarantees breeding sites (Blickley et al. 2012), resulting in reduced bird immediate and widespread contamination of ecosystems. abundance (Bayne et al. 2008). Shale operations emit nitro- Land application of wastewater has caused rapid, complete

gen oxides (NOx), sulfur dioxide (SO2), carbon monoxide mortality of vegetation and 56% mortality of trees within 2 (CO), volatile organic compounds (VOCs), and particulate years (Adams 2011). Other research supports these findings matter, each of which is harmful to biota (see “Additional and indicates that even low concentration of wastewater

www.frontiersinecology.org © The Ecological Society of America S Souther et al. Research priorities for shale development can alter species composition (DeWalle and Galeone 1990). early version of this manuscript was sent as a letter to the 337 Because current understanding of this threat is limited, miti- US Geological Survey, the Environmental Protection gation is difficult, and impacts can persist for several years Agency, and the US Department of the Interior; we thank (Adams 2011), the impact of wastewater application is a these agencies for their review and assistance in improving medium-high research priority (Table 1). the manuscript. We also thank M Böhm and B Collen for providing the freshwater species richness data, and S n Conclusion Friedrich for graphic design of Figure 2.

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