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Pennsylvania Water Science Center

We work in cooperation with federal, state, and local agencies to collect scientific data and conduct scientific studies of the source, quantity, quality, ecology, and use of Pennsylvania's water resources.

News

Drought Watch Lifted for All Pennsylvania Counties

Drought Watch Lifted for All Pennsylvania Counties

Pennsylvania Waters - Spring 2025 - Issue 14

Pennsylvania Waters - Spring 2025 - Issue 14

York County Water Quality Monitoring

York County Water Quality Monitoring

Publications

Regional high-frequency monitoring revealed chloride concentrations in exceedance of ecological benchmarks in urban streams across the Delaware River Basin, USA Regional high-frequency monitoring revealed chloride concentrations in exceedance of ecological benchmarks in urban streams across the Delaware River Basin, USA

Rising chloride concentrations pose critical risks to freshwater stream ecosystems in temperate regions like the Delaware River Basin (DRB), USA, where winter deicer applications (i.e., road salt) are common. Increasing chloride concentrations have been documented in the region, but the extent to which chloride exceeds regulatory benchmarks remains unclear because detection of...
Authors
Rosemary Fanelli, Michelle Morency, Brandon Fleming, Joel Moore, Deanna Hardesty, Megan Shoda

Tracking status and trends in seven key indicators of river and stream condition in the Chesapeake Bay watershed Tracking status and trends in seven key indicators of river and stream condition in the Chesapeake Bay watershed

Freshwater streams and rivers are recognized as vital habitats within the Chesapeake Bay watershed, which has been undergoing extensive restoration efforts for more than 30 years. Resource managers need to understand stream and river condition and how these conditions are changing over time to determine whether regional long-term restoration and conservation goals are being met. The...
Authors
Lindsey Boyle, Samuel Austin, Matthew Cashman, Zachary Clifton, John Clune, James Colgin, Kaitlyn Elliott, Rosemary Fanelli, Ellie Foss, Nathaniel Hitt, Elizabeth Hittle, Coral Howe, Emily Majcher, Kelly Maloney, Christopher Mason, Marina Metes, Douglas Moyer, Trevor Needham, Karli Rogers, Joshua Thompson, Guoxiang Yang, Tammy Zimmerman

Deformity, erosion, lesion, tumor, and parasite (DELT) anomalies in fish communities of the Chesapeake Bay watershed, USA: A regional assessment and potential landscape drivers Deformity, erosion, lesion, tumor, and parasite (DELT) anomalies in fish communities of the Chesapeake Bay watershed, USA: A regional assessment and potential landscape drivers

Fish diseases in freshwater ecosystems pose significant ecological and socioeconomic challenges, yet monitoring them in wild populations is complex due to interactions between pathogens, hosts, and environmental conditions. We examine the prevalence and watershed-scale landscape drivers of external deformity, erosion, lesion, tumor, and parasite (DELT) anomalies in 57 riverine fish...
Authors
Sara Breitmeyer, Paul McLaughlin, Vicki S. Blazer, Gregory Noe, Kelly Smalling, Timothy Wertz, Tyler Wagner

Science

Pennsylvania and the Delaware River Basin

In Pennsylvania, the USGS's water-resources roots date back to the late 1800's, with the initiation of streamflow gaging on the Delaware and Susquehanna Rivers and assessments of groundwater resources near Philadelphia. The USGS Pennsylvania Water Science Center continues to provide scientific information about the water resources of the Delaware River Basin, in cooperation with regional and local...
Pennsylvania and the Delaware River Basin

Pennsylvania and the Delaware River Basin

In Pennsylvania, the USGS's water-resources roots date back to the late 1800's, with the initiation of streamflow gaging on the Delaware and Susquehanna Rivers and assessments of groundwater resources near Philadelphia. The USGS Pennsylvania Water Science Center continues to provide scientific information about the water resources of the Delaware River Basin, in cooperation with regional and local...
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Invasive flathead catfish now top predators in Susquehanna River in Pennsylvania

New study suggests that smallmouth bass and channel catfish are changing what they eat to avoid having to compete with or being eaten by the invader
Invasive flathead catfish now top predators in Susquehanna River in Pennsylvania

Invasive flathead catfish now top predators in Susquehanna River in Pennsylvania

New study suggests that smallmouth bass and channel catfish are changing what they eat to avoid having to compete with or being eaten by the invader
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A regional assessment of fish health in the Chesapeake Bay watershed

Fish diseases in freshwater ecosystems pose significant ecological and socioeconomic challenges; yet, monitoring them in wild populations is complex due to interactions between pathogens, hosts, and environmental conditions. External DELT (deformity, erosion, lesion, tumor, and parasite) data (fig. 1) provide a rapid and broad measure of fish health but are a relatively coarse indicator that...
A regional assessment of fish health in the Chesapeake Bay watershed

A regional assessment of fish health in the Chesapeake Bay watershed

Fish diseases in freshwater ecosystems pose significant ecological and socioeconomic challenges; yet, monitoring them in wild populations is complex due to interactions between pathogens, hosts, and environmental conditions. External DELT (deformity, erosion, lesion, tumor, and parasite) data (fig. 1) provide a rapid and broad measure of fish health but are a relatively coarse indicator that...
Learn More
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