Megan Shoda
(She/her)Megan Shoda is a Hydrologist with the Water Mission Area Earth System Processes Division.
Meg's research interests include understanding how water quality affects water supply, enhancing the efficiency and productivity of working with large datasets, and creating communication products that deliver the expertise of the USGS in an accessible way.
Professional Experience
May 2022 to present: Hydrologist, Earth System Processes Division
May 2014 to April 2022: Hydrologist, Ohio-Kentucky-Indiana Water Science Center, Indianapolis, IN
May 2010 to April 2014: Biologist, Ohio-Kentucky-Indiana Water Science Center, Indianapolis, IN
Education and Certifications
M.S., Biology, University of Dayton
Science and Products
Filter Total Items: 16
River water quality in the Delaware River Basin—Concentrations and trends through 2018
IntroductionThe Delaware River Basin provides drinking water to 13.3 million people and supports endangered species, provides recreational opportunities, and is an essential resource to regional industries. The efforts of Federal and State governments have substantially improved overall water quality in the basin, which had been severely degraded prior to the mid-20th century. Recent trend analyse
Authors
Megan E. Shoda, Emily G Gain, Jennifer C. Murphy
Four decades of regional wet deposition, local bulk deposition, and stream-water chemistry show the influence of nearby land use on forested streams in Central Appalachia☆
Hydrologic monitoring began on two headwater streams (<1 km2) on the University of Kentucky's Robinson Forest in 1971. We evaluated stream-water (1974–2013) and bulk-deposition (wet + dust) (1984–2013) chemistry in the context of regional wet-deposition patterns that showed decreases in both sulfate and nitrate concentrations as well as proximal surface-mine expansion. Decadal time steps (1974–83,
Authors
Tanja N. Williamson, Kenton Sena, Megan E. Shoda, Chris D. Barton
Water-quality trends in the Delaware River Basin calculated using multisource data and two methods for trend periods ending in 2018
Many organizations in the Delaware River Basin (DRB) monitor surface-water quality for regulatory, scientific, and decision-making purposes. In support of these purposes, over 260,000 water-quality records provided by 8 different organizations were compiled, screened, and used to generate water-quality trends in the DRB. These trends, for periods of record that end in 2018, were generated for 124
Authors
Megan E. Shoda, Jennifer C. Murphy
Spatial patterns and seasonal timing of increasing riverine specific conductance from 1998 to 2018 suggest legacy contamination in the Delaware River Basin
Increasing salinization of freshwater threatens water supplies that support a range of human and ecological uses. The latest assessments of Delaware River Basin (DRB) surface-water-quality changes indicate widespread salinization has occurred in recent decades, which may lead to meaningful degradation in water quality. To better understand how and when salinity transport occurs and implications fo
Authors
Christine Rumsey, John C. Hammond, Jennifer C. Murphy, Megan E. Shoda, Alexander M. Soroka
Pesticides in US Rivers: Regional differences in use, occurrence, and environmental toxicity, 2013 to 2017
Pesticides pose a threat to the environment, but because of the substantial number of compounds, a comprehensive assessment of pesticides and an evaluation of the risk that they pose to human and aquatic life is challenging. In this study, improved analytical methods were used to quantify 221 pesticide concentrations in surface waters over the time period from 2013 to 2017. Samples were collected
Authors
Sarah M. Stackpoole, Megan E. Shoda, Laura Medalie, Wesley W. Stone
Pesticide mixtures show potential toxicity to aquatic life in U.S. streams, water years 2013-2017
During water years (WY) 2013–2017, the U.S. Geological Survey, National Water-Quality Assessment (NAWQA) Project, sampled the National Water Quality Network – Rivers and Streams (NWQN) year-round and reported on 221 pesticides at 72 sites across the United States in agricultural, developed, and mixed land use watersheds. The Pesticide Toxicity Index (PTI) was used to estimate the potential chronic
Authors
S. Alex Covert, Megan E. Shoda, Sarah M. Stackpoole, Wesley W. Stone
A historical look at changing water quality in the Delaware River basin
In 2019 the U.S. Geological Survey (USGS) launched a pilot regional Integrated Water Availability Assessment (IWAA) in the Delaware River Basin (fig. 1). IWAA is intended to explore, test, and refine systems and processes for assessing water availability for human and ecological uses and understanding their underlying controls. Water quality plays an important role in supporting ecological health
Authors
Jennifer C. Murphy, Megan E. Shoda
Pooling resources across organizations — Multisource water-quality data for the Delaware River Basin
The U.S. Geological Survey (USGS) recently launched a pilot Integrated Water Availability Assessment (IWAA) in the Delaware River Basin to explore, test, and refine systems and processes for assessing water availability for human and ecological uses based on water monitoring data. Water-quality monitoring provides citizens, managers, and scientists with the information needed to evaluate the healt
Authors
Jennifer C. Murphy, Megan E. Shoda
Influence of land use and region on glyphosate and aminomethylphosphonic acid in streams in the USA
Glyphosate is the most widely used herbicide in the United States for agricultural and non-agricultural weed control. Many studies demonstrate possible effects of glyphosate and its degradate AMPA on human and ecological health. Although glyphosate is thought to have limited mobility in soil, it is found year-round in many rivers and streams throughout the world in both agricultural and developed
Authors
Laura Medalie, Nancy T. Baker, Megan E. Shoda, Wesley W. Stone, Michael T. Meyer, Edward G. Stets, Michaelah C. Wilson
Water-quality trends in U.S. rivers, 2002 to 2012: Relations to levels of concern
Effective management and protection of water resources relies upon understanding how water-quality conditions are changing over time. Water-quality trends for ammonia, chloride, nitrate, sulfate, total dissolved solids (TDS), total nitrogen (TN) and total phosphorus (TP) were assessed at 762 sites located in the conterminous United States between 2002 and 2012. Annual mean concentrations at the st
Authors
Megan E. Shoda, Lori A. Sprague, Jennifer C. Murphy, Melissa L. Riskin
Data analysis considerations for pesticides determined by National Water Quality Laboratory schedule 2437
In 2013, the U.S. Geological Survey National Water Quality Laboratory (NWQL) made a new method available for the analysis of pesticides in filtered water samples: laboratory schedule 2437. Schedule 2437 is an improvement on previous analytical methods because it determines the concentrations of 225 fungicides, herbicides, insecticides, and associated degradates in one method at similar or lower co
Authors
Megan E. Shoda, Lisa H. Nowell, Wesley W. Stone, Mark W. Sandstrom, Laura M. Bexfield
Complex mixtures of dissolved pesticides show potential aquatic toxicity in a synoptic study of Midwestern U.S. streams
Aquatic organisms in streams are exposed to pesticide mixtures that vary in composition over time in response to changes in flow conditions, pesticide inputs to the stream, and pesticide fate and degradation within the stream. To characterize mixtures of dissolved-phase pesticides and degradates in Midwestern streams, a synoptic study was conducted at 100 streams during May–August 2013. In weekly
Authors
Lisa H. Nowell, Patrick W. Moran, Travis S. Schmidt, Julia E. Norman, Naomi Nakagaki, Megan E. Shoda, Barbara Mahler, Peter C. Van Metre, Wesley W. Stone, Mark W. Sandstrom, Michelle L. Hladik
Regional Water Availability Assessment: Delaware River Basin
Regional Water Availability Assessments are scientific assessments of water availability in different hydrologic regions across the Nation. In the Delaware River Basin, the USGS will conduct a focused assessment of increasing freshwater salinity and an integrated and comprehensive assessment of multiple water quantity, quality and use factors.
Integrated Water Availability Assessments
The USGS Water Resources Mission Area is assessing how much water is available for human and ecological needs in the United States and identifying where and when the Nation may have challenges meeting its demand for water.
Pesticides
About 1 billion pounds of conventional pesticides are used each year in the United States to control weeds, insects, and other pests. The use of pesticides has resulted in a range of benefits, including increased food production and reduction of insect-borne disease, but also raises questions about possible adverse effects on the environment, including water quality. The National Water Quality...
Data supporting a spatiotemporal trend analysis of specific conductivity, streamflow, and landscape attributes of selected sub-basins within the Delaware River watershed, 1980 to 2018
This data release makes available three data tables supporting a spatiotemporal analysis of riverine conductivity and streamflow trends within the Delaware River Basin. The listed datasets include baseflow and total flow time series for selected gaged basins, watershed attributes, water quality information and trend analysis results.
Surface Water Pesticide Detection Frequency and Benchmark Exceedance Data for the Conterminous United States, 2013-2017
This product consists of pesticide detections and benchmark exceedances in surface waters. These are time series data representing water years 2013 - 2017 for river sites associated with the U.S. Geological Survey National Water Quality Pesticide Monitoring Program.
Water-quality trends for rivers and streams in the Delaware River Basin using Weighted Regressions on Time, Discharge, and Season (WRTDS) models, Seasonal Kendall Trend (SKT) tests, and multisource data, Water Year 1978-2018
This data release provides water-quality trends for rivers and streams in the Delaware River Basin determined using the Weighted Regressions on Time, Discharge, and Season (WRTDS) model and the Seasonal Kendall Trend (SKT) test. Sixteen water-quality parameters were assessed, including nutrients (ammonia, nitrate, filtered orthophosphate, total nitrogen, total phosphorus, and unfiltered orthophosp
Pesticide Toxicity Index (PTI) and maximum Toxic Unit (TUmax) scores and information for fish, cladocerans, and benthic invertebrates from water samples collected at National Water Quality Network sites during Water Years 2013-2017
During 2013-2017, the U.S. Geological Survey, National Water-Quality Assessment (NAWQA) Project, collected water samples year-round from the National Water Quality Network - Rivers and Streams (NWQN) and reported on 221 pesticides at 72 sites across the US in agricultural, developed, and mixed land use watersheds. Pesticide Toxicity Index (PTI) scores, a screening-level tool that uses an additive,
Glyphosate and aminomethylphosphonic acid (AMPA) in National Water Quality Network Streams and Rivers in the U.S., Water Years 2015-2017
The U.S. Geological Survey (USGS) National Water Quality Network - Rivers and Streams (NWQN) is comprised of 110 surface-water monitoring sites designed to track ambient water-quality conditions across the nation. Although numerous constituents, including pesticides, have been collected at many of these sites since 1991, glyphosate and its metabolite aminomethylphosphonic acid (AMPA) were not rout
Multi-source surface-water-quality data and U.S. Geological Survey streamgage match for the Delaware River Basin
Jointly managed by multiple states and the federal government, there are many ongoing efforts to characterize and understand water quality in the Delaware River Basin (DRB). Many State, Federal and non-profit organizations have collected surface-water-quality samples across the DRB for decades and many of these data are available through the National Water Quality Monitoring Council's Water Qualit
Replicate surface water and groundwater data analyzed by USGS National Water Quality Laboratory schedule 2437, 2013-15
Replicate water-quality samples are collected and prepared in the field and analyzed in the laboratory in identical ways so that they are considered to be the same in composition and analysis (Mueller and others, 2015). This data set includes one table of duplicate National Water-Quality Assessment Project (NAWQA) surface water and groundwater samples collected between October 1, 2012 and Septembe
Science and Products
Filter Total Items: 16
River water quality in the Delaware River Basin—Concentrations and trends through 2018
IntroductionThe Delaware River Basin provides drinking water to 13.3 million people and supports endangered species, provides recreational opportunities, and is an essential resource to regional industries. The efforts of Federal and State governments have substantially improved overall water quality in the basin, which had been severely degraded prior to the mid-20th century. Recent trend analyse
Authors
Megan E. Shoda, Emily G Gain, Jennifer C. Murphy
Four decades of regional wet deposition, local bulk deposition, and stream-water chemistry show the influence of nearby land use on forested streams in Central Appalachia☆
Hydrologic monitoring began on two headwater streams (<1 km2) on the University of Kentucky's Robinson Forest in 1971. We evaluated stream-water (1974–2013) and bulk-deposition (wet + dust) (1984–2013) chemistry in the context of regional wet-deposition patterns that showed decreases in both sulfate and nitrate concentrations as well as proximal surface-mine expansion. Decadal time steps (1974–83,
Authors
Tanja N. Williamson, Kenton Sena, Megan E. Shoda, Chris D. Barton
Water-quality trends in the Delaware River Basin calculated using multisource data and two methods for trend periods ending in 2018
Many organizations in the Delaware River Basin (DRB) monitor surface-water quality for regulatory, scientific, and decision-making purposes. In support of these purposes, over 260,000 water-quality records provided by 8 different organizations were compiled, screened, and used to generate water-quality trends in the DRB. These trends, for periods of record that end in 2018, were generated for 124
Authors
Megan E. Shoda, Jennifer C. Murphy
Spatial patterns and seasonal timing of increasing riverine specific conductance from 1998 to 2018 suggest legacy contamination in the Delaware River Basin
Increasing salinization of freshwater threatens water supplies that support a range of human and ecological uses. The latest assessments of Delaware River Basin (DRB) surface-water-quality changes indicate widespread salinization has occurred in recent decades, which may lead to meaningful degradation in water quality. To better understand how and when salinity transport occurs and implications fo
Authors
Christine Rumsey, John C. Hammond, Jennifer C. Murphy, Megan E. Shoda, Alexander M. Soroka
Pesticides in US Rivers: Regional differences in use, occurrence, and environmental toxicity, 2013 to 2017
Pesticides pose a threat to the environment, but because of the substantial number of compounds, a comprehensive assessment of pesticides and an evaluation of the risk that they pose to human and aquatic life is challenging. In this study, improved analytical methods were used to quantify 221 pesticide concentrations in surface waters over the time period from 2013 to 2017. Samples were collected
Authors
Sarah M. Stackpoole, Megan E. Shoda, Laura Medalie, Wesley W. Stone
Pesticide mixtures show potential toxicity to aquatic life in U.S. streams, water years 2013-2017
During water years (WY) 2013–2017, the U.S. Geological Survey, National Water-Quality Assessment (NAWQA) Project, sampled the National Water Quality Network – Rivers and Streams (NWQN) year-round and reported on 221 pesticides at 72 sites across the United States in agricultural, developed, and mixed land use watersheds. The Pesticide Toxicity Index (PTI) was used to estimate the potential chronic
Authors
S. Alex Covert, Megan E. Shoda, Sarah M. Stackpoole, Wesley W. Stone
A historical look at changing water quality in the Delaware River basin
In 2019 the U.S. Geological Survey (USGS) launched a pilot regional Integrated Water Availability Assessment (IWAA) in the Delaware River Basin (fig. 1). IWAA is intended to explore, test, and refine systems and processes for assessing water availability for human and ecological uses and understanding their underlying controls. Water quality plays an important role in supporting ecological health
Authors
Jennifer C. Murphy, Megan E. Shoda
Pooling resources across organizations — Multisource water-quality data for the Delaware River Basin
The U.S. Geological Survey (USGS) recently launched a pilot Integrated Water Availability Assessment (IWAA) in the Delaware River Basin to explore, test, and refine systems and processes for assessing water availability for human and ecological uses based on water monitoring data. Water-quality monitoring provides citizens, managers, and scientists with the information needed to evaluate the healt
Authors
Jennifer C. Murphy, Megan E. Shoda
Influence of land use and region on glyphosate and aminomethylphosphonic acid in streams in the USA
Glyphosate is the most widely used herbicide in the United States for agricultural and non-agricultural weed control. Many studies demonstrate possible effects of glyphosate and its degradate AMPA on human and ecological health. Although glyphosate is thought to have limited mobility in soil, it is found year-round in many rivers and streams throughout the world in both agricultural and developed
Authors
Laura Medalie, Nancy T. Baker, Megan E. Shoda, Wesley W. Stone, Michael T. Meyer, Edward G. Stets, Michaelah C. Wilson
Water-quality trends in U.S. rivers, 2002 to 2012: Relations to levels of concern
Effective management and protection of water resources relies upon understanding how water-quality conditions are changing over time. Water-quality trends for ammonia, chloride, nitrate, sulfate, total dissolved solids (TDS), total nitrogen (TN) and total phosphorus (TP) were assessed at 762 sites located in the conterminous United States between 2002 and 2012. Annual mean concentrations at the st
Authors
Megan E. Shoda, Lori A. Sprague, Jennifer C. Murphy, Melissa L. Riskin
Data analysis considerations for pesticides determined by National Water Quality Laboratory schedule 2437
In 2013, the U.S. Geological Survey National Water Quality Laboratory (NWQL) made a new method available for the analysis of pesticides in filtered water samples: laboratory schedule 2437. Schedule 2437 is an improvement on previous analytical methods because it determines the concentrations of 225 fungicides, herbicides, insecticides, and associated degradates in one method at similar or lower co
Authors
Megan E. Shoda, Lisa H. Nowell, Wesley W. Stone, Mark W. Sandstrom, Laura M. Bexfield
Complex mixtures of dissolved pesticides show potential aquatic toxicity in a synoptic study of Midwestern U.S. streams
Aquatic organisms in streams are exposed to pesticide mixtures that vary in composition over time in response to changes in flow conditions, pesticide inputs to the stream, and pesticide fate and degradation within the stream. To characterize mixtures of dissolved-phase pesticides and degradates in Midwestern streams, a synoptic study was conducted at 100 streams during May–August 2013. In weekly
Authors
Lisa H. Nowell, Patrick W. Moran, Travis S. Schmidt, Julia E. Norman, Naomi Nakagaki, Megan E. Shoda, Barbara Mahler, Peter C. Van Metre, Wesley W. Stone, Mark W. Sandstrom, Michelle L. Hladik
Regional Water Availability Assessment: Delaware River Basin
Regional Water Availability Assessments are scientific assessments of water availability in different hydrologic regions across the Nation. In the Delaware River Basin, the USGS will conduct a focused assessment of increasing freshwater salinity and an integrated and comprehensive assessment of multiple water quantity, quality and use factors.
Integrated Water Availability Assessments
The USGS Water Resources Mission Area is assessing how much water is available for human and ecological needs in the United States and identifying where and when the Nation may have challenges meeting its demand for water.
Pesticides
About 1 billion pounds of conventional pesticides are used each year in the United States to control weeds, insects, and other pests. The use of pesticides has resulted in a range of benefits, including increased food production and reduction of insect-borne disease, but also raises questions about possible adverse effects on the environment, including water quality. The National Water Quality...
Data supporting a spatiotemporal trend analysis of specific conductivity, streamflow, and landscape attributes of selected sub-basins within the Delaware River watershed, 1980 to 2018
This data release makes available three data tables supporting a spatiotemporal analysis of riverine conductivity and streamflow trends within the Delaware River Basin. The listed datasets include baseflow and total flow time series for selected gaged basins, watershed attributes, water quality information and trend analysis results.
Surface Water Pesticide Detection Frequency and Benchmark Exceedance Data for the Conterminous United States, 2013-2017
This product consists of pesticide detections and benchmark exceedances in surface waters. These are time series data representing water years 2013 - 2017 for river sites associated with the U.S. Geological Survey National Water Quality Pesticide Monitoring Program.
Water-quality trends for rivers and streams in the Delaware River Basin using Weighted Regressions on Time, Discharge, and Season (WRTDS) models, Seasonal Kendall Trend (SKT) tests, and multisource data, Water Year 1978-2018
This data release provides water-quality trends for rivers and streams in the Delaware River Basin determined using the Weighted Regressions on Time, Discharge, and Season (WRTDS) model and the Seasonal Kendall Trend (SKT) test. Sixteen water-quality parameters were assessed, including nutrients (ammonia, nitrate, filtered orthophosphate, total nitrogen, total phosphorus, and unfiltered orthophosp
Pesticide Toxicity Index (PTI) and maximum Toxic Unit (TUmax) scores and information for fish, cladocerans, and benthic invertebrates from water samples collected at National Water Quality Network sites during Water Years 2013-2017
During 2013-2017, the U.S. Geological Survey, National Water-Quality Assessment (NAWQA) Project, collected water samples year-round from the National Water Quality Network - Rivers and Streams (NWQN) and reported on 221 pesticides at 72 sites across the US in agricultural, developed, and mixed land use watersheds. Pesticide Toxicity Index (PTI) scores, a screening-level tool that uses an additive,
Glyphosate and aminomethylphosphonic acid (AMPA) in National Water Quality Network Streams and Rivers in the U.S., Water Years 2015-2017
The U.S. Geological Survey (USGS) National Water Quality Network - Rivers and Streams (NWQN) is comprised of 110 surface-water monitoring sites designed to track ambient water-quality conditions across the nation. Although numerous constituents, including pesticides, have been collected at many of these sites since 1991, glyphosate and its metabolite aminomethylphosphonic acid (AMPA) were not rout
Multi-source surface-water-quality data and U.S. Geological Survey streamgage match for the Delaware River Basin
Jointly managed by multiple states and the federal government, there are many ongoing efforts to characterize and understand water quality in the Delaware River Basin (DRB). Many State, Federal and non-profit organizations have collected surface-water-quality samples across the DRB for decades and many of these data are available through the National Water Quality Monitoring Council's Water Qualit
Replicate surface water and groundwater data analyzed by USGS National Water Quality Laboratory schedule 2437, 2013-15
Replicate water-quality samples are collected and prepared in the field and analyzed in the laboratory in identical ways so that they are considered to be the same in composition and analysis (Mueller and others, 2015). This data set includes one table of duplicate National Water-Quality Assessment Project (NAWQA) surface water and groundwater samples collected between October 1, 2012 and Septembe