Sarah E Janssen
Sarah Janssen is an isotope geochemist working in the M3 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
Filter Total Items: 41
Walleye (Sander vitreus), Yellow Perch (Perca flavescens) and Surface Water Mercury Concentrations in Minnesota Lakes Walleye (Sander vitreus), Yellow Perch (Perca flavescens) and Surface Water Mercury Concentrations in Minnesota Lakes
Water quality and fish tissue samples were collected and measured for mercury concentrations in a total of 23 small to medium size lakes in Minnesota to assess the impact that zebra mussel (Dreissena polymorpha) invasion had on mercury bioaccumulation. Water samples were collected in October and November of 2021 from 22 lakes and analyzed for total mercury, methylmercury, dissolved...
Great Lakes Sediment Surveillance Program: Mercury Concentrations and Mercury Stable Isotopes in Sediments of the Laurentian Great Lakes Great Lakes Sediment Surveillance Program: Mercury Concentrations and Mercury Stable Isotopes in Sediments of the Laurentian Great Lakes
As part of the larger Great Lakes Sediment Surveillance Program (GLSSP), the U.S. Geological Survey Mercury Research Laboratory (MRL) partnered with the U.S. Environmental Protection Agency and the University of Minnesota-Duluth to assess contaminant concentrations within surface sediments and sediment cores from the Laurentian Great Lakes. Sediments were assessed for mercury...
Measurements of mercury stable isotopes during planktonic uptake and photochemical demethylation of methylmercury Measurements of mercury stable isotopes during planktonic uptake and photochemical demethylation of methylmercury
Laboratory experiments were performed between 2019 and 2020 to examine how dissolved organic matter (DOM) and phytoplankton (Raphidocelis subcapitata) cells alter mercury (Hg) uptake and isotope fractionation. Experiments were performed at ambient Hg to thiol ratios using natural organic matter isolates received from collaborators at the University of California-Davis. Two types of...
Mercury Stable Isotope Measurements in Water and Suspended Particulate Matter from Snake River Tributaries in Idaho and Oregon, USA Mercury Stable Isotope Measurements in Water and Suspended Particulate Matter from Snake River Tributaries in Idaho and Oregon, USA
This study was designed to examine mercury (Hg) stable isotope values in filtered water and suspended particulate matter from tributaries to the Snake River located in Oregon and Idaho. Water samples were collected from 21 tributary sites representing a range of watershed land use types (e.g., agriculture, forest, etc.) within the Snake River Basin. In 2018, water samples were collected...
Hydrological, Chemical, and Biological Characterization of the Snake River and Associated Tributaries and Irrigation Drains from River Mile 448 to 346, 2022 Hydrological, Chemical, and Biological Characterization of the Snake River and Associated Tributaries and Irrigation Drains from River Mile 448 to 346, 2022
This dataset includes field hydrologic measurements and laboratory analyses of surface and pore waters, sediments, benthic plants/biofilms, and biota along the Middle Snake River upgradient of the Hells Canyon Complex. The study region for this work focuses on a section of the Snake River heavily utilized for agriculture, with complex systems of irrigation diversion and return drainage...
Mercury stable isotopes in biota, sediment, groundwater, and waste piles, Clear Lake area, Lake County, California, 2019-2022 Mercury stable isotopes in biota, sediment, groundwater, and waste piles, Clear Lake area, Lake County, California, 2019-2022
Samples were collected from Clear Lake, California from 2019-2022 by the U.S. Geological Survey (USGS) California Water Science Center, the USGS Forest and Rangeland Ecosystem Science Center (FRESC), the US Environmental Protection Agency, and EA Engineering Science and Technology Inc. to assess the extent and cycling of legacy mercury (Hg) contamination from Sulphur Bank Mine. Samples...
Filter Total Items: 51
Increased mercury concentrations in walleye and yellow perch in lakes invaded by zebra mussels Increased mercury concentrations in walleye and yellow perch in lakes invaded by zebra mussels
Zebra mussels (Dreissena polymorpha) are invasive species that alter ecosystems and food webs with the potential to affect aquatic mercury cycling and bioaccumulation in fishes, although the effect of zebra mussels on fish tissue mercury has not been tested in inland lakes. We assessed differences in fish tissue mercury concentrations and food webs in Minnesota lakes with and without...
Authors
Naomi S. Blinick, Denver Link, Tyler D. Ahrenstoroff, Bethany J. Bethke, Abram B. Fleishman, Sarah E. Janssen, David P. Krabbenhoft, Jenna K.R. Nelson, Heidi M. Rantala, Claire L. Rude, Gretchen J.A. Hansen
Riparian methylmercury production increases riverine mercury flux and food web concentrations Riparian methylmercury production increases riverine mercury flux and food web concentrations
The production and uptake of toxic methylmercury (MeHg) impacts aquatic ecosystems globally. Rivers can be dynamic and difficult systems to study for MeHg production and bioaccumulation, hence identifying sources of MeHg to these systems is both challenging and important for resource management within rivers and main-stem reservoirs. Riparian zones, which are known biogeochemical...
Authors
Virginia Krause, Austin K. Baldwin, Benjamin D. Peterson, David P. Krabbenhoft, Sarah E. Janssen, James Willacker, Collin A. Eagles-Smith, Brett A. Poulin
Adaptable plasmonic membrane sensors for fast and reliable detection of trace low micrometer microplastics in lake water Adaptable plasmonic membrane sensors for fast and reliable detection of trace low micrometer microplastics in lake water
In freshwater environments, low-micrometer microplastics (LMMPs) have captured significant attention due to their prevalence and toxicity. Yet, rapid detection of LMMPs (1–10 μm) at the single-particle level within complex freshwater matrices remains a hurdle. We developed an adaptable plasmonic membrane sensor for fast detection of individual LMMPs in eutrophic lake waters. The...
Authors
Ziyan Wu, Sarah E. Janssen, Michael T. Tate, Hoaran Wei, Mohan Qin
Mesopelagic diet as pathway of high mercury levels in body feathers of the endangered Black-capped Petrel (Diablotin) Pterodroma hasitata Mesopelagic diet as pathway of high mercury levels in body feathers of the endangered Black-capped Petrel (Diablotin) Pterodroma hasitata
The Diablotin or Black-capped Petrel Pterodroma hasitata is an endangered gadfly petrel found in the western North Atlantic, Caribbean Sea, and northern Gulf of Mexico. An estimated ~2000 pairs nest at five known sites on Hispaniola, Greater Antilles, although only 120 nests have been located to date. We collected breast feathers and feces from breeding adults in the Dominican Republic...
Authors
Yvan G. Satgé, Sarah E. Janssen, Gemma Clucas, Ernst Rupp, J. Brian Patteson, Patrick G.R. Jodice
Hair mercury isotopes, a noninvasive biomarker for dietary methylmercury exposure and biological uptake Hair mercury isotopes, a noninvasive biomarker for dietary methylmercury exposure and biological uptake
Background. Fish and rice are the main dietary sources of methylmercury (MeHg); however, rice does not contain the same beneficial nutrients as fish, and these differences can impact the observed health effects of MeHg. Hence, it is important to validate a biomarker, which can distinguish among dietary MeHg sources. Methods. Mercury (Hg) stable isotopes were analyzed in hair samples from
Authors
Sarah E Rothenburg, Susan A Korrick, Donald Harrington, Sally W Thurston, Sarah E. Janssen, Michael T. Tate, YanFen Nong, Hua Nong, Jihong Liu, Chuan Hong, Fengxiu Ouyang
Simulated sea level rise in coastal peat oils stimulates mercury methylation Simulated sea level rise in coastal peat oils stimulates mercury methylation
Coastal wetlands are vulnerable to sea level rise with unknown consequences for mercury (Hg) cycling, particularly the potential for exacerbating neurotoxic methylmercury (MeHg) production and bioaccumulation in food webs. Here, the effect of sea level rise on MeHg formation in the Florida Everglades was evaluated by incubating peat cores from a freshwater wetland for 0–20 days in the...
Authors
Bryce A. Cook, Benjamin D. Peterson, Jacob M. Ogorek, Sarah E. Janssen, Brett A. Poulin
Non-USGS Publications**
Janssen, S.E.; Johnson, M.W.; Blum, J.D.; Barkay, T.; Reinfelder, J.R., Separation of monomethylmercury from estuarine sediments for mercury isotope analysis. Chemical Geology 2015
Janssen, S.E.; Schaefer, J.K.; Barkay, T.; Reinfelder, J.R. Fractionation of mercury stable isotopes during microbial methylmercury production in pure culture. Environ. Sci. Technol. 2016
Lloyd, N.; Janssen, S.E.; Reinfelder J.R.; Barkay, T., Exposure to mercury selects for antibiotic resistance in Fundulus heteroclitus gut microbiome, Current Microbiology, 2016
**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
Filter Total Items: 41
Walleye (Sander vitreus), Yellow Perch (Perca flavescens) and Surface Water Mercury Concentrations in Minnesota Lakes Walleye (Sander vitreus), Yellow Perch (Perca flavescens) and Surface Water Mercury Concentrations in Minnesota Lakes
Water quality and fish tissue samples were collected and measured for mercury concentrations in a total of 23 small to medium size lakes in Minnesota to assess the impact that zebra mussel (Dreissena polymorpha) invasion had on mercury bioaccumulation. Water samples were collected in October and November of 2021 from 22 lakes and analyzed for total mercury, methylmercury, dissolved...
Great Lakes Sediment Surveillance Program: Mercury Concentrations and Mercury Stable Isotopes in Sediments of the Laurentian Great Lakes Great Lakes Sediment Surveillance Program: Mercury Concentrations and Mercury Stable Isotopes in Sediments of the Laurentian Great Lakes
As part of the larger Great Lakes Sediment Surveillance Program (GLSSP), the U.S. Geological Survey Mercury Research Laboratory (MRL) partnered with the U.S. Environmental Protection Agency and the University of Minnesota-Duluth to assess contaminant concentrations within surface sediments and sediment cores from the Laurentian Great Lakes. Sediments were assessed for mercury...
Measurements of mercury stable isotopes during planktonic uptake and photochemical demethylation of methylmercury Measurements of mercury stable isotopes during planktonic uptake and photochemical demethylation of methylmercury
Laboratory experiments were performed between 2019 and 2020 to examine how dissolved organic matter (DOM) and phytoplankton (Raphidocelis subcapitata) cells alter mercury (Hg) uptake and isotope fractionation. Experiments were performed at ambient Hg to thiol ratios using natural organic matter isolates received from collaborators at the University of California-Davis. Two types of...
Mercury Stable Isotope Measurements in Water and Suspended Particulate Matter from Snake River Tributaries in Idaho and Oregon, USA Mercury Stable Isotope Measurements in Water and Suspended Particulate Matter from Snake River Tributaries in Idaho and Oregon, USA
This study was designed to examine mercury (Hg) stable isotope values in filtered water and suspended particulate matter from tributaries to the Snake River located in Oregon and Idaho. Water samples were collected from 21 tributary sites representing a range of watershed land use types (e.g., agriculture, forest, etc.) within the Snake River Basin. In 2018, water samples were collected...
Hydrological, Chemical, and Biological Characterization of the Snake River and Associated Tributaries and Irrigation Drains from River Mile 448 to 346, 2022 Hydrological, Chemical, and Biological Characterization of the Snake River and Associated Tributaries and Irrigation Drains from River Mile 448 to 346, 2022
This dataset includes field hydrologic measurements and laboratory analyses of surface and pore waters, sediments, benthic plants/biofilms, and biota along the Middle Snake River upgradient of the Hells Canyon Complex. The study region for this work focuses on a section of the Snake River heavily utilized for agriculture, with complex systems of irrigation diversion and return drainage...
Mercury stable isotopes in biota, sediment, groundwater, and waste piles, Clear Lake area, Lake County, California, 2019-2022 Mercury stable isotopes in biota, sediment, groundwater, and waste piles, Clear Lake area, Lake County, California, 2019-2022
Samples were collected from Clear Lake, California from 2019-2022 by the U.S. Geological Survey (USGS) California Water Science Center, the USGS Forest and Rangeland Ecosystem Science Center (FRESC), the US Environmental Protection Agency, and EA Engineering Science and Technology Inc. to assess the extent and cycling of legacy mercury (Hg) contamination from Sulphur Bank Mine. Samples...
Filter Total Items: 51
Increased mercury concentrations in walleye and yellow perch in lakes invaded by zebra mussels Increased mercury concentrations in walleye and yellow perch in lakes invaded by zebra mussels
Zebra mussels (Dreissena polymorpha) are invasive species that alter ecosystems and food webs with the potential to affect aquatic mercury cycling and bioaccumulation in fishes, although the effect of zebra mussels on fish tissue mercury has not been tested in inland lakes. We assessed differences in fish tissue mercury concentrations and food webs in Minnesota lakes with and without...
Authors
Naomi S. Blinick, Denver Link, Tyler D. Ahrenstoroff, Bethany J. Bethke, Abram B. Fleishman, Sarah E. Janssen, David P. Krabbenhoft, Jenna K.R. Nelson, Heidi M. Rantala, Claire L. Rude, Gretchen J.A. Hansen
Riparian methylmercury production increases riverine mercury flux and food web concentrations Riparian methylmercury production increases riverine mercury flux and food web concentrations
The production and uptake of toxic methylmercury (MeHg) impacts aquatic ecosystems globally. Rivers can be dynamic and difficult systems to study for MeHg production and bioaccumulation, hence identifying sources of MeHg to these systems is both challenging and important for resource management within rivers and main-stem reservoirs. Riparian zones, which are known biogeochemical...
Authors
Virginia Krause, Austin K. Baldwin, Benjamin D. Peterson, David P. Krabbenhoft, Sarah E. Janssen, James Willacker, Collin A. Eagles-Smith, Brett A. Poulin
Adaptable plasmonic membrane sensors for fast and reliable detection of trace low micrometer microplastics in lake water Adaptable plasmonic membrane sensors for fast and reliable detection of trace low micrometer microplastics in lake water
In freshwater environments, low-micrometer microplastics (LMMPs) have captured significant attention due to their prevalence and toxicity. Yet, rapid detection of LMMPs (1–10 μm) at the single-particle level within complex freshwater matrices remains a hurdle. We developed an adaptable plasmonic membrane sensor for fast detection of individual LMMPs in eutrophic lake waters. The...
Authors
Ziyan Wu, Sarah E. Janssen, Michael T. Tate, Hoaran Wei, Mohan Qin
Mesopelagic diet as pathway of high mercury levels in body feathers of the endangered Black-capped Petrel (Diablotin) Pterodroma hasitata Mesopelagic diet as pathway of high mercury levels in body feathers of the endangered Black-capped Petrel (Diablotin) Pterodroma hasitata
The Diablotin or Black-capped Petrel Pterodroma hasitata is an endangered gadfly petrel found in the western North Atlantic, Caribbean Sea, and northern Gulf of Mexico. An estimated ~2000 pairs nest at five known sites on Hispaniola, Greater Antilles, although only 120 nests have been located to date. We collected breast feathers and feces from breeding adults in the Dominican Republic...
Authors
Yvan G. Satgé, Sarah E. Janssen, Gemma Clucas, Ernst Rupp, J. Brian Patteson, Patrick G.R. Jodice
Hair mercury isotopes, a noninvasive biomarker for dietary methylmercury exposure and biological uptake Hair mercury isotopes, a noninvasive biomarker for dietary methylmercury exposure and biological uptake
Background. Fish and rice are the main dietary sources of methylmercury (MeHg); however, rice does not contain the same beneficial nutrients as fish, and these differences can impact the observed health effects of MeHg. Hence, it is important to validate a biomarker, which can distinguish among dietary MeHg sources. Methods. Mercury (Hg) stable isotopes were analyzed in hair samples from
Authors
Sarah E Rothenburg, Susan A Korrick, Donald Harrington, Sally W Thurston, Sarah E. Janssen, Michael T. Tate, YanFen Nong, Hua Nong, Jihong Liu, Chuan Hong, Fengxiu Ouyang
Simulated sea level rise in coastal peat oils stimulates mercury methylation Simulated sea level rise in coastal peat oils stimulates mercury methylation
Coastal wetlands are vulnerable to sea level rise with unknown consequences for mercury (Hg) cycling, particularly the potential for exacerbating neurotoxic methylmercury (MeHg) production and bioaccumulation in food webs. Here, the effect of sea level rise on MeHg formation in the Florida Everglades was evaluated by incubating peat cores from a freshwater wetland for 0–20 days in the...
Authors
Bryce A. Cook, Benjamin D. Peterson, Jacob M. Ogorek, Sarah E. Janssen, Brett A. Poulin
Non-USGS Publications**
Janssen, S.E.; Johnson, M.W.; Blum, J.D.; Barkay, T.; Reinfelder, J.R., Separation of monomethylmercury from estuarine sediments for mercury isotope analysis. Chemical Geology 2015
Janssen, S.E.; Schaefer, J.K.; Barkay, T.; Reinfelder, J.R. Fractionation of mercury stable isotopes during microbial methylmercury production in pure culture. Environ. Sci. Technol. 2016
Lloyd, N.; Janssen, S.E.; Reinfelder J.R.; Barkay, T., Exposure to mercury selects for antibiotic resistance in Fundulus heteroclitus gut microbiome, Current Microbiology, 2016
**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.