Impending Peril of Urban ForestsAugust 2, 2013
Camping EthicsAugust 16, 2013
by Lauren Alleman, M.S.
Hydraulic fracturing has a strong foothold in Pennsylvania – with 9,000 wells drilled and many more anticipated. This blog isn’t about the pros and cons of this energy extraction process, regulations and violations, or the controversies circulating through various stakeholder groups throughout the country. Instead, this blog highlights the opportunities to limit impacts to brook trout habitat as fracking continues in the Keystone state, as well as the potential to develop partnerships between trout conservation groups and natural gas companies.
The East Coast is home to the beautiful brook trout (Salvelinus fontinalis), most certainly “the handsomest of our game fishes” if you ask me. My home state of Pennsylvania has some pretty amazing places to catch native brook trout in streams that are clean, shaded, and highly oxygenated. The brook trout, an East Coast native, has a narrower niche than its cousins, the rainbow and brown trout (which are native to the West Coast and were brought here starting in the 1870s for recreational fisheries).
Brook trout prefer colder stream temperatures (59°F is optimal) and tolerate less turbidity than the other trout species. However, the pristine streams that provide these suitable conditions are increasingly rare in Pennsylvania due to factors such as development, abandoned mine drainage, sedimentation, and competition with stocked trout. Centuries of pressure, beginning with European settlement and concurrent logging throughout the East Coast, have eliminated much of the brook trout’s historic range – but they still have a few strongholds (albeit only 1% of historically inhabited subwatersheds in Pennsylvania). There are still 679 miles of Class A brook trout water in the state (streams with naturally reproducing wild trout capable of supporting a recreational fishery).
Natural gas extraction in the Marcellus shale, the geologic deposit that underlies a vast majority of the historic range of brook trout in Pennsylvania, is a new and serious threat to remaining brook trout populations.
Fracking requires the construction of access roads and the clearing of land, which can dramatically impact the watershed. For example, each well pad requires the clearing of 8.8 acres of forest (Johnson et al. 2010). Fracking, combined with scenarios of reduced habitat suitability under future climate change scenarios (Wenger et al. 2011), is cause for concern for brook trout aficionados. The Nature Conservancy reports that “70% of [Pennsylvania’s] remaining brook trout watersheds are likely to see Marcellus gas development, with more than 50 well pads in some watersheds.”
In light of the brook trout’s vulnerability to fragmentation and development due to fracking, conservation groups and natural gas companies can work to ensure the long-term sustainability of the remaining brook trout populations by restoring and conserving the habitat requirements of this species.
Brook trout need clean, cold water to survive
Sedimentation can reduce the habitat suitability by causing an increase in turbidity, which can smother macroinvertebrate communities, affect egg survival, and limit light penetration. Sedimentation in trout streams can be caused by the construction of roads and gas pads which can lead to extreme runoff and erosion if not properly controlled. Gas companies can work with state agencies to choose the optimal location for gas pad construction and install proper erosion control measures (including vegetating slopes with fast-growing cover and using silt fencing) to capture runoff before it ends up in streambeds.
Wetlands and riparian zones are at risk of fragmentation and degradation when a new rural area opens up to development. Hurdy et al. 2008 found that high nitrate and sulfate deposition accurately predict declining brook trout populations. Intercepting nutrients before they reach trout water can be accomplished in a variety of ways including: riparian buffer planting, wetland restoration, and agricultural best management practices. Recently, Trout Unlimited has teamed up with the Chesapeake Bay Foundation to connect Pennsylvania landowners with state and Federal resources to create better riparian buffers along stream corridors.
Logging and forest pathogens (such as the woolly adelgid) have decreased hemlock canopy cover over the years. The overall reduction in tree canopy cover in brook trout waters leads to higher instream temperatures. Fracking requires active clearing of trees also reducing the tree canopy cover. Restoring canopy cover can be accomplished with disease-resistant species like white pine (Pinus strobus), high bush blueberry (Vaccinium corymbosum), Rhododendron spp., and willows (Salix spp). A great example of successful riparian zone restoration for thermal pollution abatement is the Smith Creek Restoration Project, which documented a 2 to 3° C decrease in stream temperature after planting trees.
Population viability depends on habitat connectivity
Pennsylvania brook trout streams are typically small, isolated headwaters with a sometimes steep grade that can experience low flow during certain times of the year.
Occasionally, channel morphology changes after floods or sediment deposition events, resulting in a stream that is wide and shallow. Ideally, streams have a 1:1 riffle-to-pool ratio to allow for feeding and spawning [and hold over during winter and summer months (Raleigh 1982). Habitat improvements like stream deflectors, cross-vanes, and j-hooks can create pools and wide, deep runs that will provide holdover areas during periods of low flow (Lutz 2007). These types of habitat enhancements can compensate for direct impacts to trout streams or water quality.
The removal of unnecessary or outdated culverts and dams can be a creative way to receive mitigation credit or offsets for impacts to waterways or wetlands caused by fracking. Culvert and dam removal is a huge step towards restoring landscape connectivity and opening up new areas of the watershed for fish to migrate through. Last year Pennsylvania removed 11 dams, more than any other state, according to a report released by American Rivers. The Eastern Brook Trout Joint Venture recently removed two dams in Potter County, PA, opening up 8.5 miles of brook trout habitat.
These brook trout restoration strategies can offset or compensate for impacts caused by fracking in Pennsylvania. Natural gas companies can partner with local and regional stakeholders to prioritize restoration within watersheds that undergo fracking and gas extraction. Huge opportunities exist for collaborative partnerships; a cooperative approach grounded in the best restoration science is likely to lead to the greatest gains for both sides of the fracking debate – and the sweet little brook trout will probably manage to hang on just a little while longer…
Eastern Brook Trout of Pennsylvania: Roadmap to Restoration. Pennsylvania Council of Trout Unlimited.
Eastern Brook Trout: Status and Threats. Trout Unlimited
Hurdy, M. T.M. Thieling, N. Gillespie, and E.P. Smith. 2008. Distribution, Status, and Land Use Characteristics of Subwatersheds withinthe Native Range of Brook Trout in the Eastern United States. North American Journal of Fisheries Management. 28(4): 1069-1085.
Johnson, N. 2010. Pennsylvania Energy Impacts Assessment. The Nature Conservancy. 46 pp.
Kennedy, Kit. The Role of Natural Gas in America’s Energy Mix. The Nature Conservancy.
Lutz, K.J. 2007. Habitat Improvement for Trout Streams. Habitat Management Division, Pennsylvania Fish & Boat Commission. 40 pp.
Raleigh, R.F. 1982. Habitat suitability index models: Brook trout. U.S. Department of the Interior, Fish and Wildlife Service. FWS/OBS-82/10.24. 42 pp.
Snyder, Samuel. Review: An Entirely Synthetic Fish. MidCurrent. MidCurrent, 2010. Web. 09 Aug. 2013
Wenger, S.J. D.J. Isaak, C.H. Luce, H.M. Neville, K.D. Fausch, J.B. Dunham, D.C. Dauwalter, M.K. Young, M.M. Elsner, B.E. Rieman, A.F. Hamlet, and J.E. Williams. 2011. Flow regine, temperature, and biotic interactions drive differential declines of trout species under climate change. Proceedings of the National Academy of Sciences 108(34): 14175-14180