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Kevin A Ryan

Kevin is a Hydrologist in the Integrated Ecosystems Studies Section in the New York Water Science Center.

Kevin uses long-term monitoring records and environmental sensors to assess the influence of humans and climate on water resources broadly. Kevin’s research focuses on aquatic biogeochemistry, carbon cycling, and climate change. Kevin works closely with the Soil and Low-Ionic-Strength Water Quality Laboratory in Troy, NY. Prior to joining the USGS in 2022, Kevin completed his doctoral research on the transport of natural organic matter and nutrients in New England watersheds and the impacts of land-based aquaculture on rivers in southern Chile.

Professional Experience

  • 2022 - Present, Hydrologist, New York Water Science Center, USGS

Education and Certifications

  • Ph.D. Marine and Environmental Science, Northeastern University, 2022

     

  • B.S. Winthrop University, 2011

Science and Products

Underwater flashlights: What light can tell us about water quality

Water is essential for life. The particles and dissolved chemicals found in rivers, lakes, and oceans are constantly changing with weather, seasons, and human activities. The substances found in water can be helpful or harmful to humans and other organisms. New technologies allow scientists to use waterproof computers (called sensors) to record the quality of water as it changes throughout the day
Authors
Kevin Alexander Ryan, Douglas A. Burns
By
Water Resources Mission Area, New York Water Science Center

Widespread chemical dilution of streams continues as long-term effects of acidic deposition slowly reverse

Studies of recovery from acidic deposition have focused on reversal of acidification and its associated effects, but as recovery proceeds slowly, chemical dilution of surface waters is emerging as a key factor in the recovery process that has significant chemical and biological implications. This investigation uses long-term chemical records from 130 streams in the Adirondack region of New York, U
Authors
Gregory B. Lawrence, Kevin Alexander Ryan
By
Water Resources Mission Area, New York Water Science Center

Recent, widespread nitrate decreases may be linked to persistent dissolved organic carbon increases in headwater streams recovering from past acidic deposition

Long-term monitoring of water quality responses to natural and anthropogenic perturbation of watersheds informs policies for managing natural resources. Dissolved organic carbon (DOC) and nitrate (NO3−) in streams draining forested landscapes provide valuable information on ecosystem function due to their biogeochemical reactivity and solubility in water. Here we evaluate a 20-year record (2001−20
Authors
Kevin Alexander Ryan, Gregory B. Lawrence
By
Water Resources Mission Area, New York Water Science Center

Optical properties of dissolved organic matter in throughfall and stemflow vary across tree species and season in a temperate headwater forest

Tree-derived dissolved organic matter (DOM) comprises a significant carbon flux within forested watersheds. Few studies have assessed the optical properties of tree-derived DOM. To increase understanding of the factors controlling tree-derived DOM quality, we measured DOM optical properties, dissolved organic carbon (DOC) and calcium concentrations in throughfall and stemflow for 17 individual rai
Authors
Kevin A Ryan, Thomas Adler, Ann T. Chalmers, Julia Perdrial, Stephen Sebestyen, James B. Shanley, Aron Stubbins
By
Water Resources Mission Area, Climate Research and Development Program, New England Water Science Center

Using dissolved organic matter fluorescence to predict total mercury and methylmercury in forested headwater streams, Sleepers River, Vermont USA

Aqueous transport of mercury (Hg) across the landscape is closely linked to dissolved organic matter (DOM). Both quantity and quality of DOM affect Hg mobility, as well as the formation and transport of toxic methylmercury (MeHg), but only a limited number of field studies have investigated Hg and MeHg with respect to specific DOM components. We investigated these interactions at the 41-ha foreste
Authors
James B. Shanley, Vivien F. Taylor, Kevin A. Ryan, Ann T. Chalmers, Julia Perdrial, Aron Stubbins
By
Water Resources Mission Area, New England Water Science Center

Evaluating streamwater dissolved organic carbon dynamics in context of variable flowpath contributions with a tracer-based mixing model

This study focuses on characterizing the contributions of key terrestrial pathways that deliver dissolved organic carbon (DOC) to streams during hydrological events and on elucidating factors governing variation in water and DOC fluxes from these pathways. We made high-frequency measurements of discharge, specific conductance (SC), and fluorescent dissolved organic matter (FDOM) during 221 events
Authors
James E. Saiers, Jennifer Burlingame Hoyle Fair, James B. Shanley, J.D. Hosen, Serena Matt, Kevin A Ryan, P.A. Raymond
By
Water Resources Mission Area, Climate Research and Development Program, New England Water Science Center

Event scale relationships of DOC and TDN fluxes in throughfall and stemflow diverge from stream exports in a forested catchment

Aquatic fluxes of carbon and nutrients link terrestrial and aquatic ecosystems. Within forests, storm events drive both the delivery of carbon and nitrogen to the forest floor and the export of these solutes from the land via streams. To increase understanding of the relationships between hydrologic event character and the relative fluxes of carbon and nitrogen in throughfall, stemflow and streams
Authors
Kevin A. Ryan, Thomas Adler, Ann Chalmers, Julia Perdrial, James B. Shanley, Aron Stubbins
By
Water Resources Mission Area, New England Water Science Center

Non-USGS Publications**

Ryan, K.A., Chaverra Palacios, L., Encina, F., Graeber, D., Osorio, S., Stubbins, A., Woelfl, S., Nimptsch, J. (2022), Assessing inputs of aquaculture-derived nutrients to streams using dissolved organic matter fluorescence, Science of The Total Environment, Volume 807, Part 2, 150785, ISSN 0048-9697, doi: 10.1016/j.scitotenv.2021.150785.

Stubbins A, Ryan K and Van Stan J. (2022), How Trees Make Tea. Front. Young Minds, 10:703704, doi: 10.3389/frym.2022.703704.

**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.

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USGS gage 01135150, Pope Brook near North Danville, Vermont

Sleepers River Research Watershed

The Sleepers River Research Watershed in Danville, Vermont has been the site of active hydrologic research since 1959, when the Agricultural Research Service (ARS) of the U.S. Department of Agriculture (USDA) established a research program in the watershed. The Sleepers River site is now operated by the USGS, in cooperation with several other Federal agencies and universities.
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New England Water Science Center
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Sleepers River Research Watershed

The Sleepers River Research Watershed in Danville, Vermont has been the site of active hydrologic research since 1959, when the Agricultural Research Service (ARS) of the U.S. Department of Agriculture (USDA) established a research program in the watershed. The Sleepers River site is now operated by the USGS, in cooperation with several other Federal agencies and universities.
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Weighing soils into crucibles for the determination of percent dry and loss-on-ignition

Soil and Low-Ionic-Strength Water Quality Laboratory

The New York Water Science Center of the U.S. Geological Survey (USGS) in Troy, N.Y., operates a state-of-the-science laboratory for the chemical analysis of soil and water.
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New York Water Science Center
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Soil and Low-Ionic-Strength Water Quality Laboratory

The New York Water Science Center of the U.S. Geological Survey (USGS) in Troy, N.Y., operates a state-of-the-science laboratory for the chemical analysis of soil and water.
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wooden boards with V cutout and monitoring equipment in a stream

Adirondack Long-Term Stream and Soil Monitoring

The current Adirondack Long-Term Monitoring Program combines monitoring of streams and soils based on a watershed design. Not only are headwater streams an important component of Adirondack ecosystems, they are closely tied to the terrestrial environment through runoff that is strongly influenced by soil and vegetation processes. This linkage makes headwater streams a useful tool for monitoring
By
New York Water Science Center
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Adirondack Long-Term Stream and Soil Monitoring

The current Adirondack Long-Term Monitoring Program combines monitoring of streams and soils based on a watershed design. Not only are headwater streams an important component of Adirondack ecosystems, they are closely tied to the terrestrial environment through runoff that is strongly influenced by soil and vegetation processes. This linkage makes headwater streams a useful tool for monitoring
Learn More

Measurements of Acid-Neutralizing Capacity, Conductance, and Calcium Concentrations in Adirondack Headwater Streams of New York, 1988 to 2022

This data release contains measurements of acid-neutralizing capacity, conductance at 25 degrees Celsius, and Ca concentrations for headwater stream samples collected from 1988 to 2022 in the Adirondack region of New York. Sample analyses were performed by the Adirondack Lake Survey Corporation (ALSC) laboratory and are adjusted here to be consistent with measurements made in the USGS New York Wat
By
New York Water Science Center

Streamflow, Dissolved Organic Carbon, and Nitrate Input Datasets and Model Results Using the Weighted Regressions on Time, Discharge, and Season (WRTDS) Model for Buck Creek Watersheds, Adirondack Park, New York, 2001 to 2021

This data release supports an analysis of changes in dissolved organic carbon (DOC) and nitrate concentrations in Buck Creek watershed near Inlet, New York 2001 to 2021. The Buck Creek watershed is a 310-hectare forested watershed that is recovering from acidic deposition within the Adirondack region. The data release includes pre-processed model inputs and model outputs for the Weighted Regressio
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New York Water Science Center

Mercury, methylmercury, cations, dissolved organic carbon, and dissolved organic matter optical properties in small forest streams during five synoptic sampling campaigns at Sleepers River, Vermont, 2017-2018

The dataset describes mercury and dissolved organic matter concentration and quality over five synoptic sampling campaigns at 12 stream sites within the 41-hectare (ha) forested W-9 catchment at Sleepers River, Vermont, with an additional site at the downstream W-3 gage (837 ha). The five campaigns included a large (79 millimeter (mm)) fall storm, spring snowmelt, and spring, summer, and fall base
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New England Water Science Center

Aqueous chemistry database, Sleepers River Research Watershed, Danville, Vermont, 1991-2018

The Sleepers River Research Watershed, near Danville, Vermont, is a 111-square-kilometer watershed established in 1958 by the Agricultural Research Service.The research watershed has since been operated by three other federal agencies: National Weather Service, U.S. Army Cold Regions Research and Engineering Laboratory (CRREL), and U.S. Geological Survey (USGS). USGS started at the site in collabo
By
New England Water Science Center

Storm Event Dissolved Organic Carbon and Total Dissolved Nitrogen Concentrations and Yields for Precipitation, Throughfall, Stemflow, and Stream Water and Hourly Streamflow and Precipitation Record for the W-9 Catchment, Sleepers River Research Watershed,

This dataset describes water yields for precipitation, throughfall, and stemflow for 22 rain events within the 40.5-hectare (ha) forested W-9 catchment at Sleepers River, Vermont. Sampling occurred during the summer and fall of 2018. Dissolved organic carbon (DOC) and total dissolved nitrogen (TDN) concentrations are reported for each sampled event. The dataset also includes 5-minute catchment nor
By
New England Water Science Center

Science and Products