BONN, Germany (Landscape News) — Countries around the world are turning to the hydraulic fracturing of shale gas to boost their fossil fuel energy production and reduce their reliance on oil and gas imports. Most commonly known as fracking, the method has not been without its critics, and little is known about its impact on wildlife.
“The largest knowledge gap that exists right now when it comes to shale-gas development is how it affects our wildlife populations,” said Mack Frantz, a conservation biologist and Ph.D. candidate at West Virginia University in the United States.
Frantz has been making an effort to close that gap with a recent study on the Louisiana Waterthrush (parkesia motacilla) in the state’s Appalachian region. The small songbird breeds along forested headwater streams and feeds primarily on benthic macroinvertibrates, insects and worms that live in sediment.
The study, one of the first to demonstrate that shale-gas development can affect songbird reproductive success and productivity, was published in The Condor: Ornithological Applications.
“We saw general declines in waterthrush territory density, nest survival, nest productivity, and riparian habitat quality concurrent with a site-wide increase in disturbance related to shale gas development,” the paper states. “Our source–sink threshold suggested that individuals breeding in areas disturbed by shale gas development were potentially inhabiting sink habitat and that these populations were more at risk of decline than those in areas undisturbed by shale gas development.”
Frantz and his colleagues mapped waterthrush territories along 14 streams featuring varying amounts of disturbance from shale-gas development and contaminant runoff, said Frantz. They monitored nests for six years, from 2009 to 2011 and again from 2013 to 2015. They also mapped and measured disturbances to streams and to the forest canopy, using aerial photographs and satellite imagery.
“We were able to actively monitor each nest and based on the features of the nestlings, were able to determine when they were going to fledge, and also to follow them after fledging to actually make sure the parents are with their fledglings,” he said.
“Essentially the birds in the shale-gas developed areas are having to try several attempts at nesting. They have a long breeding season so they will just keep trying as long as they can,” he explained. “But they are just not producing as many fledglings as in areas that are unaffected by shale-gas development.”
Forest cover across the study area decreased from 95 percent in 2008 to 91 percent in 2015, while the area affected by shale gas development grew from 0.4 percent to 3.9 percent. Although there was less than 5 percent forest cover loss in the study area, the reduction in waterthrush numbers suggests that other factors contributed to their decline.
Because much of it overlays the prolific Marcellus Shale, West Virginia is experiencing some of the most rapid growth in shale-gas development in the United States, according to the U.S. Energy Information Administration. One survey, sponsored by the U.S. Department of Energy, predicts that more than 40,000 wells will be operational in the state by 2030, the Condor report says.
Other states, however, have banned the practice.
In Canada, fracking is a significant contributor to energy production. In Europe, however, the picture is mixed. Some nations, such as Germany, France and the Netherlands, have placed a moratorium on shale-gas extraction after vocal protests from citizen groups, while Britain and Poland are awarding exploration licenses for it.
China, meanwhile, is betting big on shale-gas extraction to reduce its dependency on coal, World Finance magazine reports. The country has huge reserves although they have been proving difficult to access.
“Development is outpacing the implementation of best management practices, so placing well pads farther away from water than currently permissible may be the most effective way to avoid multiple disturbances from shale gas development,” the paper said, adding that effective mitigation strategies at a regional level and additional species- and area-specific studies in response to shale gas disturbance are needed.
“Considering the pace at which development is occurring,” said Frantz, “it would be good for other countries to be able to put best-management practices into place and start long-term monitoring before development occurs.”
Aside from well-pad setbacks and avoiding building on steep grades, said the scientists, streams and aquatic prey should be protected from pollutants, spills and landscape erosion.