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: 42
Mercury Stable Isotope Assessment of Dragonflies and Fish Tissues across United States National Parks Mercury Stable Isotope Assessment of Dragonflies and Fish Tissues across United States National Parks
This dataset details mercury (Hg) stable isotope values in dragonflies and fish tissues collected across U.S. National Parks. Dragonfly samples were collected as part of the Dragonfly Mercury Project (https://geonarrative.usgs.gov/dmp/), a citizen science project focused on using dragonfly larvae as biosentinels for Hg bioaccumulation. Fish were collected as part of separate park-wide...
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...
Mercury Stable Isotope Assessment of Global Food Webs Mercury Stable Isotope Assessment of Global Food Webs
This dataset describes mercury (Hg) stable isotope values in fish dorsal muscle from different freshwater environments across the globe. Fish were collected at numerous field sites in North America, South and Central America, Africa, and Asia from 2006-2020. Sub-samples were provided by cooperators to the U.S. Geological Survey Mercury Research Laboratory and the University of Wisconsin...
Assessment of Mercury and Mercury Stable Isotopes in Sediments and Biota from Reservoirs and Remedial Zones within the Saint Louis River, Minnesota Assessment of Mercury and Mercury Stable Isotopes in Sediments and Biota from Reservoirs and Remedial Zones within the Saint Louis River, Minnesota
This data release includes mercury concentrations and mercury stable isotope measurements measured in sediments and biological tissues collected from the Saint Louis River located in Minnesota. Sediments and biota were collected by the U.S. Geological Survey, U.S. Environmental Protection Agency, U.S. Army Corps of Engineers, and federal contractors (Battelle) from 2017-2021. Collection...
Particulate mercury isotope results, fiber optic thermal survey data, and nearshore surface sediment results at the Bremerton Naval Complex, Washington, USA, 2020-21 Particulate mercury isotope results, fiber optic thermal survey data, and nearshore surface sediment results at the Bremerton Naval Complex, Washington, USA, 2020-21
This data release contains four data sets that support ongoing U.S. Geological Survey investigations, in cooperation with the U.S. Navy, at the Bremerton Naval Complex (BNC), Sinclair Inlet, Washington. Child item #1 includes reported concentrations of mercury isotopes in 28 samples of new (2018-19) or archived (2008-09) particulate samples from the BNC, surface sediment from Sinclair...
Chemical characterization of water, sediments, and fish from Water Conservation Areas and Canals of the Florida Everglades (USA), 2012 to 2019 Chemical characterization of water, sediments, and fish from Water Conservation Areas and Canals of the Florida Everglades (USA), 2012 to 2019
This dataset includes field and laboratory measurements of surface waters, pore waters, sediment, and fish from Water Conservation Areas and adjacent canals of the Florida Everglades (USA). Water, sediment, and fish samples were collected from Water Conservation Areas 1 (Arthur R. Marshall Loxahatchee National Wildlife Refuge), 2, and 3 and neighboring canals between 2012 and 2019. The...
African fish mercury burden and isotopic composition from archived museum specimens African fish mercury burden and isotopic composition from archived museum specimens
Fish collected for taxonomic and systematic purposes are often preserved and then archived in museum collections. Preserved fish are commonly first fixed in a formalin solution and then transferred to ethanol for long-term storage. The wet preservation method can potentially introduce mercury (Hg) contamination or unintentionally extract Hg from tissue. An experiment was designed to test...
Filter Total Items: 61
Climate-driven sulfate export in alpine watersheds may stimulate methylmercury production Climate-driven sulfate export in alpine watersheds may stimulate methylmercury production
Climate change is increasing sulfate export and changing wetland extent in mountain regions. These changes may increase microbially mediated production of the neurotoxic substance methylmercury due to enhanced sulfate metabolism in mountain environments. Here, we assess methylmercury concentrations and formation rates across high-elevation wetlands in the Colorado Rocky Mountains. We...
Authors
Hannah R. Miller, Charles T. Driscoll, Sarah E. Janssen, Eve-Lyn S. Hinckley
A comprehensive sulfate and DOM framework to assess methylmercury formation and risk in subtropical wetlands A comprehensive sulfate and DOM framework to assess methylmercury formation and risk in subtropical wetlands
Wetlands play a vital role in contaminant cycling and uptake. Understanding how sulfate (SO42‒) influences the conversion of inorganic mercury (Hg(II)) to toxic methylmercury (MeHg) is critical for predicting wetland responses to land use and climate change. Here, we sampled surface and pore waters across SO42‒ gradients in three freshwater Everglades wetlands to assess linkages between...
Authors
Brett A. Poulin, Michael T. Tate, Sarah E. Janssen, George R. Aiken, David P. Krabbenhoft
Seasonal stratification drives bioaccumulation of pelagic mercury sources in eutrophic lakes Seasonal stratification drives bioaccumulation of pelagic mercury sources in eutrophic lakes
Increased lake eutrophication, influenced by changing climate and land use, alters aquatic cycling and bioaccumulation of mercury (Hg). Additionally, seasonally dynamic lake circulation and plankton community composition can confound our ability to predict changes in biological Hg concentrations and sources. To assess temporal variation, we examined seasonal total Hg (THg) and...
Authors
Grace Jane Armstrong, Sarah Elizabeth Janssen, Ryan F. Lepak, Tylor Rosera, Benjamin D. Peterson, Samia T. Cushing, Michael T. Tate, James W. Hurley
Sulfate reduction drives elevated methylmercury formation in water column of eutrophic freshwater lake Sulfate reduction drives elevated methylmercury formation in water column of eutrophic freshwater lake
Mercury (Hg) contamination of aquatic food webs is controlled in part by the formation and accumulation of toxic and bioaccumulative methylmercury (MeHg). MeHg production is mediated by metabolically diverse microorganisms carrying the hgcAB gene pair, while the demethylation reaction is mediated by several biotic and abiotic processes. However, the relative importance of these two...
Authors
Benjamin D. Peterson, Sarah E. Janssen, Brett A. Poulin, Jacob M. Ogorek, Amber White, Elizabeth A. McDaniel, Robert A. Marick, Grace Jane Armstrong, Nicholas D. Scheel, Michael T. Tate, David P. Krabbenhoft, Katherine D. McMahon
Mercury speciation and stable isotopes in emperor penguins: First evidence for biochemical demethylation of methylmercury to mercury-dithiolate and mercury-tetraselenolate complexes Mercury speciation and stable isotopes in emperor penguins: First evidence for biochemical demethylation of methylmercury to mercury-dithiolate and mercury-tetraselenolate complexes
Apex marine predators, such as toothed whales and large petrels and albatrosses, ingest mercury (Hg) primarily in the form of methylmercury (MeHg) via prey consumption, which they detoxify as tiemannite (HgSe). One of the most intriguing current questions in Hg research is how more abundant lower trophic level predators detoxify MeHg, particularly in marine environments where tissue Hg...
Authors
Alain Manceau, Paco Bustamante, Etienne Richy, Yves Cherel, Sarah E. Janssen, Pieter Glatzel, Brett A. Poulin
New tools for a legacy problem: How isotope tracers inform area of concern actions in the St. Louis River in Lake Superior New tools for a legacy problem: How isotope tracers inform area of concern actions in the St. Louis River in Lake Superior
Numerous mercury (Hg) sources can contribute to biological burdens within the Great Lakes, including atmospheric deposition (e.g., precipitation), non-point source land runoff (e.g., watershed), and legacy contamination. Due to these different environmental entry points, it is often difficult to ascertain if legacy Hg contamination contributes to contemporary fish consumption advisories...
Authors
Sarah E. Janssen, Joel C. Hoffman, David P. Krabbenhoft
Using mercury and lead stable isotopes to assess mercury, lead, and trace metal source contributions to Great Salt Lake, Utah, USA Using mercury and lead stable isotopes to assess mercury, lead, and trace metal source contributions to Great Salt Lake, Utah, USA
Great Salt Lake is a critical habitat for migratory birds that is threatened by elevated metal concentrations, including mercury (Hg) and lead (Pb), and is subject to severe hydrologic changes, such as declining lake level. When assessing metal profiles recorded in Great Salt Lake sediment, a large data gap exists regarding the sources of metals within the system, which is complicated by...
Authors
Samuel Francisco Lopez, Sarah E. Janssen, Michael T. Tate, Diego P. Fernandez, Christopher R. Anderson, Grace Jane Armstrong, Thomas Charng-Shuen Wang, William P. Johnson
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
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: 42
Mercury Stable Isotope Assessment of Dragonflies and Fish Tissues across United States National Parks Mercury Stable Isotope Assessment of Dragonflies and Fish Tissues across United States National Parks
This dataset details mercury (Hg) stable isotope values in dragonflies and fish tissues collected across U.S. National Parks. Dragonfly samples were collected as part of the Dragonfly Mercury Project (https://geonarrative.usgs.gov/dmp/), a citizen science project focused on using dragonfly larvae as biosentinels for Hg bioaccumulation. Fish were collected as part of separate park-wide...
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...
Mercury Stable Isotope Assessment of Global Food Webs Mercury Stable Isotope Assessment of Global Food Webs
This dataset describes mercury (Hg) stable isotope values in fish dorsal muscle from different freshwater environments across the globe. Fish were collected at numerous field sites in North America, South and Central America, Africa, and Asia from 2006-2020. Sub-samples were provided by cooperators to the U.S. Geological Survey Mercury Research Laboratory and the University of Wisconsin...
Assessment of Mercury and Mercury Stable Isotopes in Sediments and Biota from Reservoirs and Remedial Zones within the Saint Louis River, Minnesota Assessment of Mercury and Mercury Stable Isotopes in Sediments and Biota from Reservoirs and Remedial Zones within the Saint Louis River, Minnesota
This data release includes mercury concentrations and mercury stable isotope measurements measured in sediments and biological tissues collected from the Saint Louis River located in Minnesota. Sediments and biota were collected by the U.S. Geological Survey, U.S. Environmental Protection Agency, U.S. Army Corps of Engineers, and federal contractors (Battelle) from 2017-2021. Collection...
Particulate mercury isotope results, fiber optic thermal survey data, and nearshore surface sediment results at the Bremerton Naval Complex, Washington, USA, 2020-21 Particulate mercury isotope results, fiber optic thermal survey data, and nearshore surface sediment results at the Bremerton Naval Complex, Washington, USA, 2020-21
This data release contains four data sets that support ongoing U.S. Geological Survey investigations, in cooperation with the U.S. Navy, at the Bremerton Naval Complex (BNC), Sinclair Inlet, Washington. Child item #1 includes reported concentrations of mercury isotopes in 28 samples of new (2018-19) or archived (2008-09) particulate samples from the BNC, surface sediment from Sinclair...
Chemical characterization of water, sediments, and fish from Water Conservation Areas and Canals of the Florida Everglades (USA), 2012 to 2019 Chemical characterization of water, sediments, and fish from Water Conservation Areas and Canals of the Florida Everglades (USA), 2012 to 2019
This dataset includes field and laboratory measurements of surface waters, pore waters, sediment, and fish from Water Conservation Areas and adjacent canals of the Florida Everglades (USA). Water, sediment, and fish samples were collected from Water Conservation Areas 1 (Arthur R. Marshall Loxahatchee National Wildlife Refuge), 2, and 3 and neighboring canals between 2012 and 2019. The...
African fish mercury burden and isotopic composition from archived museum specimens African fish mercury burden and isotopic composition from archived museum specimens
Fish collected for taxonomic and systematic purposes are often preserved and then archived in museum collections. Preserved fish are commonly first fixed in a formalin solution and then transferred to ethanol for long-term storage. The wet preservation method can potentially introduce mercury (Hg) contamination or unintentionally extract Hg from tissue. An experiment was designed to test...
Filter Total Items: 61
Climate-driven sulfate export in alpine watersheds may stimulate methylmercury production Climate-driven sulfate export in alpine watersheds may stimulate methylmercury production
Climate change is increasing sulfate export and changing wetland extent in mountain regions. These changes may increase microbially mediated production of the neurotoxic substance methylmercury due to enhanced sulfate metabolism in mountain environments. Here, we assess methylmercury concentrations and formation rates across high-elevation wetlands in the Colorado Rocky Mountains. We...
Authors
Hannah R. Miller, Charles T. Driscoll, Sarah E. Janssen, Eve-Lyn S. Hinckley
A comprehensive sulfate and DOM framework to assess methylmercury formation and risk in subtropical wetlands A comprehensive sulfate and DOM framework to assess methylmercury formation and risk in subtropical wetlands
Wetlands play a vital role in contaminant cycling and uptake. Understanding how sulfate (SO42‒) influences the conversion of inorganic mercury (Hg(II)) to toxic methylmercury (MeHg) is critical for predicting wetland responses to land use and climate change. Here, we sampled surface and pore waters across SO42‒ gradients in three freshwater Everglades wetlands to assess linkages between...
Authors
Brett A. Poulin, Michael T. Tate, Sarah E. Janssen, George R. Aiken, David P. Krabbenhoft
Seasonal stratification drives bioaccumulation of pelagic mercury sources in eutrophic lakes Seasonal stratification drives bioaccumulation of pelagic mercury sources in eutrophic lakes
Increased lake eutrophication, influenced by changing climate and land use, alters aquatic cycling and bioaccumulation of mercury (Hg). Additionally, seasonally dynamic lake circulation and plankton community composition can confound our ability to predict changes in biological Hg concentrations and sources. To assess temporal variation, we examined seasonal total Hg (THg) and...
Authors
Grace Jane Armstrong, Sarah Elizabeth Janssen, Ryan F. Lepak, Tylor Rosera, Benjamin D. Peterson, Samia T. Cushing, Michael T. Tate, James W. Hurley
Sulfate reduction drives elevated methylmercury formation in water column of eutrophic freshwater lake Sulfate reduction drives elevated methylmercury formation in water column of eutrophic freshwater lake
Mercury (Hg) contamination of aquatic food webs is controlled in part by the formation and accumulation of toxic and bioaccumulative methylmercury (MeHg). MeHg production is mediated by metabolically diverse microorganisms carrying the hgcAB gene pair, while the demethylation reaction is mediated by several biotic and abiotic processes. However, the relative importance of these two...
Authors
Benjamin D. Peterson, Sarah E. Janssen, Brett A. Poulin, Jacob M. Ogorek, Amber White, Elizabeth A. McDaniel, Robert A. Marick, Grace Jane Armstrong, Nicholas D. Scheel, Michael T. Tate, David P. Krabbenhoft, Katherine D. McMahon
Mercury speciation and stable isotopes in emperor penguins: First evidence for biochemical demethylation of methylmercury to mercury-dithiolate and mercury-tetraselenolate complexes Mercury speciation and stable isotopes in emperor penguins: First evidence for biochemical demethylation of methylmercury to mercury-dithiolate and mercury-tetraselenolate complexes
Apex marine predators, such as toothed whales and large petrels and albatrosses, ingest mercury (Hg) primarily in the form of methylmercury (MeHg) via prey consumption, which they detoxify as tiemannite (HgSe). One of the most intriguing current questions in Hg research is how more abundant lower trophic level predators detoxify MeHg, particularly in marine environments where tissue Hg...
Authors
Alain Manceau, Paco Bustamante, Etienne Richy, Yves Cherel, Sarah E. Janssen, Pieter Glatzel, Brett A. Poulin
New tools for a legacy problem: How isotope tracers inform area of concern actions in the St. Louis River in Lake Superior New tools for a legacy problem: How isotope tracers inform area of concern actions in the St. Louis River in Lake Superior
Numerous mercury (Hg) sources can contribute to biological burdens within the Great Lakes, including atmospheric deposition (e.g., precipitation), non-point source land runoff (e.g., watershed), and legacy contamination. Due to these different environmental entry points, it is often difficult to ascertain if legacy Hg contamination contributes to contemporary fish consumption advisories...
Authors
Sarah E. Janssen, Joel C. Hoffman, David P. Krabbenhoft
Using mercury and lead stable isotopes to assess mercury, lead, and trace metal source contributions to Great Salt Lake, Utah, USA Using mercury and lead stable isotopes to assess mercury, lead, and trace metal source contributions to Great Salt Lake, Utah, USA
Great Salt Lake is a critical habitat for migratory birds that is threatened by elevated metal concentrations, including mercury (Hg) and lead (Pb), and is subject to severe hydrologic changes, such as declining lake level. When assessing metal profiles recorded in Great Salt Lake sediment, a large data gap exists regarding the sources of metals within the system, which is complicated by...
Authors
Samuel Francisco Lopez, Sarah E. Janssen, Michael T. Tate, Diego P. Fernandez, Christopher R. Anderson, Grace Jane Armstrong, Thomas Charng-Shuen Wang, William P. Johnson
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
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
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