Sarah E Janssen
Sarah Janssen is an isotope geochemist working in the Mercury Research Lab (MRL) located within the Upper Midwest Water Science Center.
She has a PhD in environmental chemistry from Rutgers University and a bachelor’s in chemistry from
University of the Sciences in Philadelphia. Her work focuses on the application of stable isotope techniques for understanding sources and transformations of mercury (Hg) in the environment. Her research interests include Hg cycling in contaminated ecosystems, the investigation of microbial Hg transformations using stable isotopes, and development of analytical methods to improve Hg isotope measurements.
Current Projects
- Mercury Cycling and Source Identification in the St Louis River Estuary MN/WI (collaboration with US EPA and Minnesota Pollution Control Agency)
- Mercury Isotope Fractionation during Microbial Uptake and Transformations of Hg (collaboration with Rutgers University and University of Ottawa)
- Method Development for the Pre-concentration of Waters and Low Concentration Environmental Samples for Mercury Isotopic Analysis
Education and Certifications
Ph.D. 2016, Environmental Chemistry, Rutgers University, New Brunswick, NJ
B.S. 2011, Chemistry, University of the Sciences, Philadelphia, PA
Science and Products
Chemical characterization of water, sediments, and fish from Water Conservation Areas and Canals of the Florida Everglades (USA), 2012 to 2019
African fish mercury burden and isotopic composition from archived museum specimens
Mercury Concentrations and Loads in United States and Canadian Tributaries of Lake Superior
Source Identification of Mercury and Methylmercury using Stable Isotope Analysis in the Fox River, WI
Assessment of mercury sources in Alaskan lake food webs (version 1.1, September 2023)
Total and Methyl Mercury Water and Fish Concentrations within Everglades National Park
Isotopic Examination of Mercury Methylation and Demethylation Rates in Yellowstone National Park Thermal Features
Yellowstone Thermal Feature Mercury and Methylmercury Characterization
Mercury source identification in the Mobile and Tombigbee Rivers
Mercury and Methylmercury Stable Isotope Measurements in Giant Petrels
Chemical characterization of water and suspended sediment of the Snake River and Hells Canyon Complex (Idaho, Oregon) (ver. 3.0, November 2023)
Mercury Concentrations and Mercury Isotopes in Salmonid fishes from the Snake River and tributaries in Idaho and Oregon, 2015 and 2019 (ver. 2.0, February 2021)
Tracing the sources and depositional history of mercury to coastal northeastern U.S. lakes
Elevated mercury concentrations and isotope signatures (N, C, Hg) in yellowfin tuna (Thunnus albacares) from the Galápagos Marine Reserve and waters off Ecuador
Assessment of mercury in sediments and waters of Grubers Grove Bay, Wisconsin
Decadal trends of mercury cycling and bioaccumulation within Everglades National Park
Methylmercury stable isotopes: New insights on assessing aquatic food web bioaccumulation in legacy impacted regions
Using carbon, nitrogen, and mercury isotope values to distinguish mercury sources to Alaskan lake trout
Response to comment on “Mercury isotope fractionation by internal demethylation and biomineralization reactions in seabirds: Implications for environmental mercury science”: Principles and limitations of source tracing and process tracing with stable isot
Mercury isotope fractionation by internal demethylation and biomineralization reactions in seabirds: Implications for environmental mercury science
Isotope fractionation from In Vivo methylmercury detoxification in waterbirds
Examining historical mercury sources in the Saint Louis River estuary: How legacy contamination influences biological mercury levels in Great Lakes coastal regions
The influence of legacy contamination on the transport and bioaccumulation of mercury within the Mobile River Basin
Insights into mercury source identification and bioaccumulation using stable isotope approaches in the Hannibal Pool of the Ohio River
Non-USGS Publications**
**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.
Science and Products
Chemical characterization of water, sediments, and fish from Water Conservation Areas and Canals of the Florida Everglades (USA), 2012 to 2019
African fish mercury burden and isotopic composition from archived museum specimens
Mercury Concentrations and Loads in United States and Canadian Tributaries of Lake Superior
Source Identification of Mercury and Methylmercury using Stable Isotope Analysis in the Fox River, WI
Assessment of mercury sources in Alaskan lake food webs (version 1.1, September 2023)
Total and Methyl Mercury Water and Fish Concentrations within Everglades National Park
Isotopic Examination of Mercury Methylation and Demethylation Rates in Yellowstone National Park Thermal Features
Yellowstone Thermal Feature Mercury and Methylmercury Characterization
Mercury source identification in the Mobile and Tombigbee Rivers
Mercury and Methylmercury Stable Isotope Measurements in Giant Petrels
Chemical characterization of water and suspended sediment of the Snake River and Hells Canyon Complex (Idaho, Oregon) (ver. 3.0, November 2023)
Mercury Concentrations and Mercury Isotopes in Salmonid fishes from the Snake River and tributaries in Idaho and Oregon, 2015 and 2019 (ver. 2.0, February 2021)
Tracing the sources and depositional history of mercury to coastal northeastern U.S. lakes
Elevated mercury concentrations and isotope signatures (N, C, Hg) in yellowfin tuna (Thunnus albacares) from the Galápagos Marine Reserve and waters off Ecuador
Assessment of mercury in sediments and waters of Grubers Grove Bay, Wisconsin
Decadal trends of mercury cycling and bioaccumulation within Everglades National Park
Methylmercury stable isotopes: New insights on assessing aquatic food web bioaccumulation in legacy impacted regions
Using carbon, nitrogen, and mercury isotope values to distinguish mercury sources to Alaskan lake trout
Response to comment on “Mercury isotope fractionation by internal demethylation and biomineralization reactions in seabirds: Implications for environmental mercury science”: Principles and limitations of source tracing and process tracing with stable isot
Mercury isotope fractionation by internal demethylation and biomineralization reactions in seabirds: Implications for environmental mercury science
Isotope fractionation from In Vivo methylmercury detoxification in waterbirds
Examining historical mercury sources in the Saint Louis River estuary: How legacy contamination influences biological mercury levels in Great Lakes coastal regions
The influence of legacy contamination on the transport and bioaccumulation of mercury within the Mobile River Basin
Insights into mercury source identification and bioaccumulation using stable isotope approaches in the Hannibal Pool of the Ohio River
Non-USGS Publications**
**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.