Craig D Snyder (Former Employee)
Science and Products
Filter Total Items: 22
Shallow bedrock limits groundwater seepage-based headwater climate refugia Shallow bedrock limits groundwater seepage-based headwater climate refugia
Groundwater/surface-water exchanges in streams are inexorably linked to adjacent aquifer dynamics. As surface-water temperatures continue to increase with climate warming, refugia created by groundwater connectivity is expected to enable cold water fish species to survive. The shallow alluvial aquifers that source groundwater seepage to headwater streams, however, may also be sensitive...
Authors
Martin Briggs, John Lane, Craig Snyder, Eric White, Zachary Johnson, David Nelms, Nathaniel Hitt
Dermocystidium sp. infection in Blue Ridge Sculpin captured in Maryland Dermocystidium sp. infection in Blue Ridge Sculpin captured in Maryland
Raised pale cysts were observed on Blue Ridge Sculpin Cottus caeruleomentum during stream fish community surveys in Catoctin Mountain Park, Maryland. When examined histologically, preserved sculpin exhibited multiple cysts containing spherical endospores with a refractile central body characteristic of Dermocystidiumspp. Cysts were not observed on the gills or internally. The portion of...
Authors
Vicki S. Blazer, Nathaniel Hitt, Craig Snyder, Erin Snook, Cynthia Adams
Accounting for groundwater in stream fish thermal habitat responses to climate change Accounting for groundwater in stream fish thermal habitat responses to climate change
Forecasting climate change effects on aquatic fauna and their habitat requires an understanding of how water temperature responds to changing air temperature (i.e., thermal sensitivity). Previous efforts to forecast climate effects on brook trout habitat have generally assumed uniform air-water temperature relationships over large areas that cannot account for groundwater inputs and...
Authors
Craig Snyder, Nathaniel Hitt, John Young
Synthesis and interpretation of surface-water quality and aquatic biota data collected in Shenandoah National Park, Virginia, 1979-2009 Synthesis and interpretation of surface-water quality and aquatic biota data collected in Shenandoah National Park, Virginia, 1979-2009
Shenandoah National Park in northern and central Virginia protects 777 square kilometers of mountain terrain in the Blue Ridge physiographic province and more than 90 streams containing diverse aquatic biota. Park managers and visitors are interested in the water quality of park streams and its ability to support healthy coldwater communities and species, such as the native brook trout...
Authors
John Jastram, Craig Snyder, Nathaniel Hitt, Karen Rice
Significance of headwater streams and perennial springs in ecological monitoring in Shenandoah National Park Significance of headwater streams and perennial springs in ecological monitoring in Shenandoah National Park
Shenandoah National Park has been monitoring water chemistry and benthic macroinvertebrates in stream ecosystems since 1979. These monitoring efforts were designed to assess the status and trends in stream condition associated with atmospheric deposition (acid rain) and changes in forest health due to gypsy moth infestations. The primary objective of the present research was to determine...
Authors
Craig Snyder, James R. Webb, John Young, Zane Johnson
Shale Gas Development and Brook Trout: Scaling Best Management Practices to Anticipate Cumulative Effects Shale Gas Development and Brook Trout: Scaling Best Management Practices to Anticipate Cumulative Effects
Shale gas development may involve trade-offs between energy development and benefits provided by natural ecosystems. However, current best management practices (BMPs) focus on mitigating localized ecological degradation. We review evidence for cumulative effects of natural gas development on brook trout (Salvelinus fontinalis) and conclude that BMPs should account for potential watershed...
Authors
David Smith, Craig Snyder, Nathaniel Hitt, John Young, Stephen Faulkner
Experimental and environmental factors affect spurious detection of ecological thresholds Experimental and environmental factors affect spurious detection of ecological thresholds
Threshold detection methods are increasingly popular for assessing nonlinear responses to environmental change, but their statistical performance remains poorly understood. We simulated linear change in stream benthic macroinvertebrate communities and evaluated the performance of commonly used threshold detection methods based on model fitting (piecewise quantile regression [PQR]), data
Authors
Jonathan P. Daily, Nathaniel Hitt, David Smith, Craig Snyder
Relationship of Eastern hemlock (Tsuga canadensis) to the ecology of small streams in Delaware Water Gap National Recreation Area Relationship of Eastern hemlock (Tsuga canadensis) to the ecology of small streams in Delaware Water Gap National Recreation Area
Hemlock ravines in Delaware Water Gap National Recreation Area (DEWA) are highly valued because of their distinctive aesthetic, recreational and ecological qualities. We conducted a comparative study designed to determine the potential long-term consequences to aquatic communities of the suspected transition from hemlock-dominated forests to mixed hardwood forests as a result of hemlock...
Authors
David Lemarie, John Young, Craig Snyder, Robert Ross, David Smith, Randy M. Bennett
Assessment of landscape correlates of Eastern hemlock decline due to hemlock woolly adelgid Assessment of landscape correlates of Eastern hemlock decline due to hemlock woolly adelgid
Eastern hemlock (Tsuga canadensis) is in decline throughout its range in the eastern US due to infestation by an exotic insect pest, the hemlock woolly adelgid (Adelges tsugae). In Shenandoah National Park, the hemlock woolly adelgid (HWA) rapidly killed many stands of hemlock after first appearing in the late-1980’s, while having only minor impact in other stands. At present, few...
Authors
John Young, Craig Snyder, James Akerson, Gary Hunt
National Biological Service Research Supports Watershed Planning National Biological Service Research Supports Watershed Planning
The National Biological Service's Leetown Science Center is investigating how human impacts on watershed, riparian, and in-stream habitats affect fish communities. The research will provide the basis for a Ridge and Valley model that will allow resource managers to accurately predict and effectively mitigate human impacts on water quality. The study takes place in the Opequon Creek...
Authors
Craig Snyder
Science and Products
Filter Total Items: 22
Shallow bedrock limits groundwater seepage-based headwater climate refugia Shallow bedrock limits groundwater seepage-based headwater climate refugia
Groundwater/surface-water exchanges in streams are inexorably linked to adjacent aquifer dynamics. As surface-water temperatures continue to increase with climate warming, refugia created by groundwater connectivity is expected to enable cold water fish species to survive. The shallow alluvial aquifers that source groundwater seepage to headwater streams, however, may also be sensitive...
Authors
Martin Briggs, John Lane, Craig Snyder, Eric White, Zachary Johnson, David Nelms, Nathaniel Hitt
Dermocystidium sp. infection in Blue Ridge Sculpin captured in Maryland Dermocystidium sp. infection in Blue Ridge Sculpin captured in Maryland
Raised pale cysts were observed on Blue Ridge Sculpin Cottus caeruleomentum during stream fish community surveys in Catoctin Mountain Park, Maryland. When examined histologically, preserved sculpin exhibited multiple cysts containing spherical endospores with a refractile central body characteristic of Dermocystidiumspp. Cysts were not observed on the gills or internally. The portion of...
Authors
Vicki S. Blazer, Nathaniel Hitt, Craig Snyder, Erin Snook, Cynthia Adams
Accounting for groundwater in stream fish thermal habitat responses to climate change Accounting for groundwater in stream fish thermal habitat responses to climate change
Forecasting climate change effects on aquatic fauna and their habitat requires an understanding of how water temperature responds to changing air temperature (i.e., thermal sensitivity). Previous efforts to forecast climate effects on brook trout habitat have generally assumed uniform air-water temperature relationships over large areas that cannot account for groundwater inputs and...
Authors
Craig Snyder, Nathaniel Hitt, John Young
Synthesis and interpretation of surface-water quality and aquatic biota data collected in Shenandoah National Park, Virginia, 1979-2009 Synthesis and interpretation of surface-water quality and aquatic biota data collected in Shenandoah National Park, Virginia, 1979-2009
Shenandoah National Park in northern and central Virginia protects 777 square kilometers of mountain terrain in the Blue Ridge physiographic province and more than 90 streams containing diverse aquatic biota. Park managers and visitors are interested in the water quality of park streams and its ability to support healthy coldwater communities and species, such as the native brook trout...
Authors
John Jastram, Craig Snyder, Nathaniel Hitt, Karen Rice
Significance of headwater streams and perennial springs in ecological monitoring in Shenandoah National Park Significance of headwater streams and perennial springs in ecological monitoring in Shenandoah National Park
Shenandoah National Park has been monitoring water chemistry and benthic macroinvertebrates in stream ecosystems since 1979. These monitoring efforts were designed to assess the status and trends in stream condition associated with atmospheric deposition (acid rain) and changes in forest health due to gypsy moth infestations. The primary objective of the present research was to determine...
Authors
Craig Snyder, James R. Webb, John Young, Zane Johnson
Shale Gas Development and Brook Trout: Scaling Best Management Practices to Anticipate Cumulative Effects Shale Gas Development and Brook Trout: Scaling Best Management Practices to Anticipate Cumulative Effects
Shale gas development may involve trade-offs between energy development and benefits provided by natural ecosystems. However, current best management practices (BMPs) focus on mitigating localized ecological degradation. We review evidence for cumulative effects of natural gas development on brook trout (Salvelinus fontinalis) and conclude that BMPs should account for potential watershed...
Authors
David Smith, Craig Snyder, Nathaniel Hitt, John Young, Stephen Faulkner
Experimental and environmental factors affect spurious detection of ecological thresholds Experimental and environmental factors affect spurious detection of ecological thresholds
Threshold detection methods are increasingly popular for assessing nonlinear responses to environmental change, but their statistical performance remains poorly understood. We simulated linear change in stream benthic macroinvertebrate communities and evaluated the performance of commonly used threshold detection methods based on model fitting (piecewise quantile regression [PQR]), data
Authors
Jonathan P. Daily, Nathaniel Hitt, David Smith, Craig Snyder
Relationship of Eastern hemlock (Tsuga canadensis) to the ecology of small streams in Delaware Water Gap National Recreation Area Relationship of Eastern hemlock (Tsuga canadensis) to the ecology of small streams in Delaware Water Gap National Recreation Area
Hemlock ravines in Delaware Water Gap National Recreation Area (DEWA) are highly valued because of their distinctive aesthetic, recreational and ecological qualities. We conducted a comparative study designed to determine the potential long-term consequences to aquatic communities of the suspected transition from hemlock-dominated forests to mixed hardwood forests as a result of hemlock...
Authors
David Lemarie, John Young, Craig Snyder, Robert Ross, David Smith, Randy M. Bennett
Assessment of landscape correlates of Eastern hemlock decline due to hemlock woolly adelgid Assessment of landscape correlates of Eastern hemlock decline due to hemlock woolly adelgid
Eastern hemlock (Tsuga canadensis) is in decline throughout its range in the eastern US due to infestation by an exotic insect pest, the hemlock woolly adelgid (Adelges tsugae). In Shenandoah National Park, the hemlock woolly adelgid (HWA) rapidly killed many stands of hemlock after first appearing in the late-1980’s, while having only minor impact in other stands. At present, few...
Authors
John Young, Craig Snyder, James Akerson, Gary Hunt
National Biological Service Research Supports Watershed Planning National Biological Service Research Supports Watershed Planning
The National Biological Service's Leetown Science Center is investigating how human impacts on watershed, riparian, and in-stream habitats affect fish communities. The research will provide the basis for a Ridge and Valley model that will allow resource managers to accurately predict and effectively mitigate human impacts on water quality. The study takes place in the Opequon Creek...
Authors
Craig Snyder