USGS provides monitoring, analysis, modeling and research on streams and water quality to better understand the fate and transport of nutrients and sediment to the Susquehanna and other rivers, and their tributaries, and eventually to the Chesapeake Bay. Additional research focuses on emerging contaminants and other stressors that effect human and aquatic life in the watershed and estuary.
The Susquehanna River drains the largest watershed (48 percent) and supplies 55 percent of the freshwater flowing into the Chesapeake Bay. In 2010, the largest and most complex total maximum daily load (TMDL) in the Nation was initiated in the Chesapeake Bay for nitrogen, phosphorus, and sediment. These pollution allocations were further divided by major river basins and states. Pennsylvania contributes approximately 44 percent of the nitrogen load and 24 percent of the phosphorus load to the Bay (Chesapeake Bay TMDL Document).
Also see regional science at Chesapeake Bay Activities
Improving Understanding and Coordination of Science Activities for Per- and Polyfluoroalkyl Substances (PFAS) in the Chesapeake Bay Watershed
USGS Chesapeake Publication Receives National Award for Superior Communication Product
Susquehanna River and Basin
Greatest Opportunities for Future Nitrogen Reductions to the Chesapeake Bay Watershed are in Developed and Agricultural Areas
Summarizing Scientific Findings for Common Stakeholder Questions to Inform Nutrient and Sediment Management Activities in the Chesapeake Bay Watershed
Updated 2020 Nutrient and Suspended-Sediment Trends for the Nine Major Rivers Entering the Chesapeake Bay
Data-sharing agreement renewed to evaluate conservations practices and water quality in the Chesapeake Watershed
Water Quality Monitoring to Inform Conservation Management, Fishing Creek, Clinton County, Pennsylvania
Sediment Response of Stream Restoration Practices, Turtle Creek, Union County, Pennsylvania
USGS develops tool to further examine nutrient and sediment trends in the Chesapeake Bay Watershed
New Synthesis Describes Current Understanding of Factors Driving Nutrient Trends in Streams of the Chesapeake Bay Watershed
Sediment and Stream Health - Pennsylvania
Datasets
Chesapeake Bay Nontidal Network 1985 - 2018: Daily High-Flow and Low-Flow Concentration and Load Estimates
Nitrogen sources to and export from the Chesapeake Bay watershed, 1950 to 2050
Physico-chemical characteristics and sediment and nutrient fluxes of floodplains, streambanks, and streambeds in the Chesapeake Bay and Delaware River watersheds
Annual winter-spring nitrogen loads for the Susquehanna and Potomac Rivers, 1985 to 2018
Hormone, pesticide, pharmaceutical and other organic compound data for select water and bed sediment samples collected in Chesapeake Bay watershed in parts of Maryland, Pennsylvania, Virginia, and West Virginia, 2006-2014
Multimedia
Nitrogen in the Chesapeake Bay Watershed: A Century of Change
Narrated presentation that provides a unique, long-term perspective (1950-2050) of the major drivers of nitrogen change up to the present, and forecasts how they may affect nitrogen into the future for the Chesapeake Bay watershed. Information is based off of U.S. Geological Survey Circular 1486.
Publications
Nitrogen in the Chesapeake Bay watershed—A century of change, 1950–2050
Identifying key stressors driving biological impairment in freshwater streams in the Chesapeake Bay watershed, USA
Predicting near-term effects of climate change on nitrogen transport to Chesapeake Bay
Power analysis for detecting the effects of best management practices on reducing nitrogen and phosphorus fluxes to the Chesapeake Bay watershed, USA
Quantifying regional effects of best management practices on nutrient losses from agricultural lands
Nitrogen in the Chesapeake Bay watershed—A century of change, 1950–2050
Targeted and non-targeted analysis of young-of-year smallmouth bass using comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry
Perfluoroalkyl substances in plasma of smallmouth bass from the Chesapeake Bay Watershed
Environmental and anthropogenic drivers of contaminants in agricultural watersheds with implications for land management
Modeling estrogenic activity in streams throughout the Potomac and Chesapeake Bay watersheds
Nutrient trends and drivers in the Chesapeake Bay Watershed
Factors affecting nitrate concentrations in stream base flow
Spatiotemporal variation in occurrence and co-occurrence of pesticides, hormones, and other organic contaminants in rivers in the Chesapeake Bay Watershed, United States
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- Overview
USGS provides monitoring, analysis, modeling and research on streams and water quality to better understand the fate and transport of nutrients and sediment to the Susquehanna and other rivers, and their tributaries, and eventually to the Chesapeake Bay. Additional research focuses on emerging contaminants and other stressors that effect human and aquatic life in the watershed and estuary.
The Susquehanna River drains the largest watershed (48 percent) and supplies 55 percent of the freshwater flowing into the Chesapeake Bay. In 2010, the largest and most complex total maximum daily load (TMDL) in the Nation was initiated in the Chesapeake Bay for nitrogen, phosphorus, and sediment. These pollution allocations were further divided by major river basins and states. Pennsylvania contributes approximately 44 percent of the nitrogen load and 24 percent of the phosphorus load to the Bay (Chesapeake Bay TMDL Document).
Annual nitrogen loads exported to the Chesapeake Bay by source, 1950–2050. Fertilizer and manure are combined into a single agricultural source for the modeled time period. After 2010, the two future agricultural scenarios represent (1) increased intensity of both crop and animal agriculture, and (2) decreased intensity of both crop and animal agriculture. Only the future scenario for constant wastewater treatment technology is shown (from Nitrogen in the Chesapeake Bay watershed—A century of change, 1950–2050). - Science
Also see regional science at Chesapeake Bay Activities
Filter Total Items: 13Improving Understanding and Coordination of Science Activities for Per- and Polyfluoroalkyl Substances (PFAS) in the Chesapeake Bay Watershed
Issue: Per- and polyfluoroalkyl substances (PFAS) have been manufactured and used in a variety of industries in the United States since the 1940s. PFAS are ubiquitous and persistent in the environment and have the potential to have adverse human and ecological health effects. The Chesapeake Bay Program (CBP) partnerships has concerns about how PFAS will affect the Chesapeake Bay ecosystem. The CBP...USGS Chesapeake Publication Receives National Award for Superior Communication Product
The Award USGS received a 2022 Blue Pencil & Gold Screen Award, in the category of Technical/Statistical Reports, from the National Association of Government Communications (NAGC) for the U.S. Geological Survey Circular titled Nitrogen in the Chesapeake Bay Watershed—A Century of Change, 1950–2050. Each year the NAGC recognizes products that provide excellence in government communications and the...Susquehanna River and Basin
In Pennsylvania, the USGS's water-resources roots date back to the late 1800's, with the initiation of streamflow gaging on the Susquehanna and Delaware 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 Susquehanna River Basin, in cooperation with regional and...Greatest Opportunities for Future Nitrogen Reductions to the Chesapeake Bay Watershed are in Developed and Agricultural Areas
Issue: As human population has increased, land-use changes have led to increases in nutrients (nitrogen and phosphorus) and sediment into the Bay. The excess nutrients cause algal blooms which contribute to water-quality impairments such as low oxygen or hypoxia (dead zones), and poor water clarity in the Chesapeake Bay. Management efforts to improve water quality focus on dissolved oxygen needed...Summarizing Scientific Findings for Common Stakeholder Questions to Inform Nutrient and Sediment Management Activities in the Chesapeake Bay Watershed
Issue: The Chesapeake Bay Program (CBP) partnership is striving to improve water-quality conditions in the Bay by using a variety of management strategies to reduce nutrient and sediment loads. The partnership uses monitoring results and modeling tools to implement management strategies, relying on the scientific community to synthesize existing information and direct new research to address...Updated 2020 Nutrient and Suspended-Sediment Trends for the Nine Major Rivers Entering the Chesapeake Bay
Issue: The amount of nutrients and suspended sediment entering the Chesapeake Bay affect water-quality conditions in tidal waters. Excess nutrients contribute to algal blooms that lower the oxygen levels in tidal waters that are important for fish and shellfish. The algal blooms, along with suspended sediment, also decrease visibility in shallow waters for submerged aquatic grasses. The grasses...Data-sharing agreement renewed to evaluate conservations practices and water quality in the Chesapeake Watershed
Issue: The U.S. Geological Survey (USGS) and the Natural Resources Conservation Service (NRCS) have a mutual interest in meeting the goals of the Chesapeake Bay Watershed Agreement, and in determining the benefits and challenges of agricultural conservation practices on water-quality patterns. Understanding the sources of nutrients and sediment and how these nutrients move into streams and...Water Quality Monitoring to Inform Conservation Management, Fishing Creek, Clinton County, Pennsylvania
USGS conducted synoptic sampling of major-ion chemistry and the nitrogen and oxygen isotopic composition of nitrate in Fishing Creek during base flow to evaluate the occurrence and distribution of nutrients and to characterize biogeochemical processes.Sediment Response of Stream Restoration Practices, Turtle Creek, Union County, Pennsylvania
USGS is providing data and analyses to assess stream restoration effectiveness in Turtle Creek, Union County, Pennsylvania, by measuring differences in sediment erosion and deposition in restored and eroded stream reaches.USGS develops tool to further examine nutrient and sediment trends in the Chesapeake Bay Watershed
The U.S. Geological Survey (USGS) has developed the nontidal network mapper to share the short-term (2009-2018) water-year nutrient and suspended-sediment load and trend results for the Chesapeake Bay Program’s (CBP) non-tidal network (NTN). The network is a cooperative effort by USGS, the U.S. Environmental Protection Agency (USEPA), and agencies in the states of the Chesapeake watershed and the...New Synthesis Describes Current Understanding of Factors Driving Nutrient Trends in Streams of the Chesapeake Bay Watershed
Issue: Excessive nitrogen and phosphorus in Chesapeake Bay since the 1950s have contributed to low dissolved oxygen leading to fish kills, and poor water clarity and associated loss of submerged aquatic vegetation. The Chesapeake Bay Program partnership has been working to improve aquatic conditions in the Bay and its tidal tributaries, and streams in the watershed, by reducing inputs of nutrients...Sediment and Stream Health - Pennsylvania
Sediment in streams, from land surface erosion in watersheds, is an important factor in determining the quality of Pennsylvania's surface waters and of downstream water bodies such as the Delaware Estuary and Chesapeake Bay. The USGS has a long-standing tradition of measuring suspended-sediment concentrations and estimating loads. Recent technological advances allow real-time estimates of... - Data
Datasets
Chesapeake Bay Nontidal Network 1985 - 2018: Daily High-Flow and Low-Flow Concentration and Load Estimates
Nitrogen, phosphorus, and suspended-sediment loads, and changes in loads, in rivers across the Chesapeake Bay watershed have been calculated using monitoring data from the Chesapeake Bay Nontidal Network (NTN) stations for the period 1985 through 2018. Nutrient and suspended-sediment loads and changes in loads were determined by applying a weighted regression approach called WRTDS (Weighted RegresNitrogen sources to and export from the Chesapeake Bay watershed, 1950 to 2050
This U.S. Geological Survey data release contains datasets that combine past data with future projections of nitrogen sources and nitrogen export to the Chesapeake Bay watershed for the years 1950-2050. To help understand the effect of human and environmental changes over this time period, data for nitrogen sources from wastewater, agricultural fertilizer and manure, and atmospheric deposition arePhysico-chemical characteristics and sediment and nutrient fluxes of floodplains, streambanks, and streambeds in the Chesapeake Bay and Delaware River watersheds
Dataset includes site averages of measurements of floodplain and streambank sediment physico-chemistry and long-term (dendrogeomorphic) vertical and lateral geomorphic change, and reach scale floodplain width, streambank height, channel width, and streambed particle size. This information was used to calculate fluxes of sediment, fine sediment, sediment-C, sediment-N, and sediment-C of floodplainsAnnual winter-spring nitrogen loads for the Susquehanna and Potomac Rivers, 1985 to 2018
Winter-spring nitrogen loads as measured at the Susquehanna River at Conowingo Maryland and Potomac River at Washington, D.C. have been determined to be an effective indicator of summer anoxic and hypoxic volume in Chesapeake Bay. The U.S. Geological Survey (USGS) provides an estimate of winter-spring nitrogen loadings to support an annual forecast of summer Chesapeake Bay conditions. The specificHormone, pesticide, pharmaceutical and other organic compound data for select water and bed sediment samples collected in Chesapeake Bay watershed in parts of Maryland, Pennsylvania, Virginia, and West Virginia, 2006-2014
These data represent water and bed sediment samples analyzed for a variety of organic compounds. The samples were collected in streams and rivers in the Chesapeake Bay watershed from 2006-2014. Water samples were collected from 61 sites and analyzed for hormones (SH2434 method; Tables 1A and 1B), pharmaceuticals (SH2080 method; Tables 2A and 2B), wastewater indicators (SH1433 method; Tables 3A and - Multimedia
Multimedia
Nitrogen in the Chesapeake Bay Watershed: A Century of Change
Narrated presentation that provides a unique, long-term perspective (1950-2050) of the major drivers of nitrogen change up to the present, and forecasts how they may affect nitrogen into the future for the Chesapeake Bay watershed. Information is based off of U.S. Geological Survey Circular 1486.
- Publications
Publications
Nitrogen in the Chesapeake Bay watershed—A century of change, 1950–2050
ForewordSustaining the quality of the Nation’s water resources and the health of our diverse ecosystems depends on the availability of sound water-resources data and information to develop effective, science-based policies. Effective management of water resources also brings more certainty and efficiency to important economic sectors. Taken together, these actions lead to immediate and long-term eAuthorsJohn W. Clune, Paul D. Capel, Matthew P. Miller, Douglas A. Burns, Andrew J. Sekellick, Peter R. Claggett, Richard H. Coupe, Rosemary M. Fanelli, Ana Maria Garcia, Jeff Raffensperger, Silvia Terziotti, Gopal Bhatt, Joel D. Blomquist, Kristina G. Hopkins, Jennifer L. Keisman, Lewis C. Linker, Gary W. Shenk, Richard A. Smith, Alex Soroka, James S. Webber, David M. Wolock, Qian ZhangFilter Total Items: 33Identifying key stressors driving biological impairment in freshwater streams in the Chesapeake Bay watershed, USA
Biological communities in freshwater streams are often impaired by multiple stressors (e.g., flow or water quality) originating from anthropogenic activities such as urbanization, agriculture, or energy extraction. Restoration efforts in the Chesapeake Bay watershed, USA seek to improve biological conditions in 10% of freshwater tributaries and to protect the biological integrity of existing healtAuthorsRosemary M. Fanelli, Matt J. Cashman, Aaron J. PorterPredicting near-term effects of climate change on nitrogen transport to Chesapeake Bay
Understanding effects of climate change on nitrogen fate and transport in the environment is critical to nutrient management. We used climate projections within a previously calibrated spatially referenced regression (SPARROW) model to predict effects of expected climate change over 1995 through 2025 on total nitrogen fluxes to Chesapeake Bay and in watershed streams. Assuming nitrogen inputs andAuthorsScott Ator, Gregory E. Schwarz, Andrew Sekellick, Gopal BhattPower analysis for detecting the effects of best management practices on reducing nitrogen and phosphorus fluxes to the Chesapeake Bay watershed, USA
In 2010 the U.S. Environmental Protection Agency established the Total Maximum Daily Load (TMDL) which is a “pollution diet” that aims to reduce the amount of nitrogen and phosphorus entering the Chesapeake Bay, the largest estuary in the United States, by 25 and 24% percent, respectively. To achieve this goal the TMDL requires the implementation of Best Management Practices (BMPs), which are acceAuthorsPaul McLaughlin, Richard Alexander, Joel Blomquist, Olivia H. Devereux, Gregory B. Noe, Tyler Wagner, Kelly SmallingQuantifying regional effects of best management practices on nutrient losses from agricultural lands
Nitrogen (N) and phosphorus (P) losses from agricultural areas have degraded the water quality of downstream rivers, lakes, and oceans. As a result, investment in the adoption of agricultural best management practices (BMPs) has grown, but assessments of their effectiveness at large spatial scales have lagged. This study applies regional Spatially Referenced Regression On Watershed-attributes (SPAAuthorsVictor L. Roland, Ana María García, David A. Saad, Scott W. Ator, Dale M. Robertson, Gregory E. SchwarzNitrogen in the Chesapeake Bay watershed—A century of change, 1950–2050
ForewordSustaining the quality of the Nation’s water resources and the health of our diverse ecosystems depends on the availability of sound water-resources data and information to develop effective, science-based policies. Effective management of water resources also brings more certainty and efficiency to important economic sectors. Taken together, these actions lead to immediate and long-term eAuthorsJohn W. Clune, Paul D. Capel, Matthew P. Miller, Douglas A. Burns, Andrew J. Sekellick, Peter R. Claggett, Richard H. Coupe, Rosemary M. Fanelli, Ana Maria Garcia, Jeff Raffensperger, Silvia Terziotti, Gopal Bhatt, Joel D. Blomquist, Kristina G. Hopkins, Jennifer L. Keisman, Lewis C. Linker, Gary W. Shenk, Richard A. Smith, Alex Soroka, James S. Webber, David M. Wolock, Qian ZhangTargeted and non-targeted analysis of young-of-year smallmouth bass using comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry
Smallmouth bass in the Susquehanna River Basin, Chesapeake Bay Watershed, USA, have been exhibiting clinical signs of disease and reproductive endocrine disruption (e.g., intersex, male plasma vitellogenin) for over fifteen years. Previous histological and targeted chemical analyses have identified infectious agents and pollutants in fish tissues including organic contaminants, mercury, and perfluAuthorsPaige Teehan, Megan K. Schall, Vicki S. Blazer, Frank L DormanPerfluoroalkyl substances in plasma of smallmouth bass from the Chesapeake Bay Watershed
Smallmouth bass Micropterus dolomieu is an economically important sportfish and within the Chesapeake Bay watershed has experienced a high prevalence of external lesions, infectious disease, mortality events, reproductive endocrine disruption and population declines. To date, no clear or consistent associations with contaminants measured in fish tissue or surface water have been found. Therefore,AuthorsVicki S. Blazer, Stephanie Gordon, Heather L. Walsh, Cheyenne R. SmithEnvironmental and anthropogenic drivers of contaminants in agricultural watersheds with implications for land management
If not managed properly, modern agricultural practices can alter surface and groundwater quality and drinking water resources resulting in potential negative effects on aquatic and terrestrial ecosystems. Exposure to agriculturally derived contaminant mixtures has the potential to alter habitat quality and negatively affect fish and other aquatic organisms. Implementation of conservation practicesAuthorsKelly Smalling, Olivia H. Devereux, Stephanie Gordon, Patrick J. Phillips, Vicki S. Blazer, Michelle Hladik, Dana W. Kolpin, Michael T. Meyer, Adam Sperry, Tyler WagnerByEcosystems Mission Area, Water Resources Mission Area, Contaminant Biology, Environmental Health Program, Toxic Substances Hydrology, California Water Science Center, Central Midwest Water Science Center, Chesapeake Bay Activities, Eastern Ecological Science Center, Kansas Water Science Center, New Jersey Water Science Center, New York Water Science Center, Pennsylvania Water Science CenterModeling estrogenic activity in streams throughout the Potomac and Chesapeake Bay watersheds
Endocrine-disrupting compounds (EDCs), specifically estrogenic endocrine-disrupting compounds, vary in concentration and composition in surface waters under the influence of different landscape sources and landcover gradients. Estrogenic activity in surface waters may lead to adverse effects in aquatic species at both individual and population levels, often observed through the presence of interseAuthorsStephanie Gordon, Daniel Jones, Vicki S. Blazer, Luke R. Iwanowicz, Brianna Williams, Kelly SmallingNutrient trends and drivers in the Chesapeake Bay Watershed
The Chesapeake Bay Program maintains an extensive nontidal monitoring network, measuring nitrogen and phosphorus (nutrients) at more than 100 locations on rivers and streams in the watershed. Data from these locations are used by United States Geological Survey to assess the ecosystem’s response to nutrient-reduction efforts. This fact sheet summarizes recent trends in nitrogen and phosphorus in nAuthorsKenneth E. Hyer, Scott W. Phillips, Scott W. Ator, Doug L. Moyer, James S. Webber, Rachel Felver, Jennifer L. Keisman, Lee A. McDonnell, Rebecca Murphy, Emily M. Trentacoste, Qian Zhang, William C. Dennison, Sky Swanson, Brianne Walsh, Jane Hawkey, Dylan TaillieFactors affecting nitrate concentrations in stream base flow
Elevated nitrogen concentrations in streams and rivers in the Chesapeake Bay watershed have adversely affected the ecosystem health of the bay. Much of this nitrogen is derived as nitrate from groundwater that discharges to streams as base flow. In this study, boosted regression trees (BRTs) were used to relate nitrate concentrations in base flow (n = 156) to explanatory variables describing nitroAuthorsSusan Wherry, Anthony J. Tesoriero, Silvia TerziottiSpatiotemporal variation in occurrence and co-occurrence of pesticides, hormones, and other organic contaminants in rivers in the Chesapeake Bay Watershed, United States
Investigating the spatiotemporal dynamics of contaminants in surface water is crucial to better understand how introduced chemicals are interacting with and potentially influencing aquatic organisms and environments. Within the Chesapeake Bay Watershed, USA, there are concerns about the potential role of contaminant exposure on fish health. Evidence suggests that exposure to contaminants in surfacAuthorsCatherine M. McClure, Kelly Smalling, Vicki S. Blazer, Adam Sperry, Megan K. Schall, Dana W. Kolpin, Patrick J. Phillips, Michelle Hladik, Tyler Wagner - News
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