Scientist Emeritus Dave Krabbenhoft collecting water sample at edge of Green Lake, Minnesota (Kandiyohi County).
David P Krabbenhoft
David Krabbenhoft is a Scientist Emeritus with the Upper Midwest Water Science Center.
David Krabbenhoft received his Ph.D. from the University of Wisconsin-Madison in 1988 and has been a research scientist with the U.S. Geological Survey since. He has general research interests are in biogeochemistry and hydrogeology of aquatic ecosystems. Dave began working on environmental mercury cycling, transformations, and fluxes in aquatic ecosystems with the Mercury in Temperate Lakes project in 1988; since then, the topic has consumed his professional life. In 1994, Dave established the USGS’s Mercury Research Laboratory, which includes a team of multi-disciplinary mercury investigators and a state-of-the-art analytical facility strictly dedicated to low-level speciation analysis of mercury. In 1995 he initiated the multi-agency Aquatic Cycling of Mercury in the Everglades (ACME) project, which is still ongoing. More recently, Dave has been a Primary Investigator on the internationally conducted Mercury Experiment To Assess Atmospheric Loadings in Canada and the US (METAALICUS) project, which is a novel effort to examine the ecosystem-level response to loading an entire watershed with mercury. Currently, Dave’s research team is active on projects that span environments as far ranging as the Pacific Ocean to freshwater systems in Alaska to Florida, and from California to New England. In recent years, the Mercury Research Team entered into the realm of atmospheric research by constructing and deployed the USGS Mobile Atmospheric Mercury Lab, which has the capability for rapid deployment and advanced study of mercury in the atmosphere. Since 1990, he has authored or coauthored over 100 papers on mercury in the environment. In August 2006, Dave served as the Co-Chair for the 8th International Conference on Mercury as a Global Pollutant.
Science and Products
Long-Term Monitoring Reveals How Water and Biota in Remote Lakes Respond Differently to Changes in Atmospheric Deposition of Mercury
A comparison of regional mercury atmospheric deposition data with water, yellow perch, and dragonfly larvae samples from lakes in Voyageurs National Park indicates that decreases in mercury emissions resulted in mercury reduction in water from these remote lakes, but mercury declines in biota were significant in only one of three lakes, likely because resident biota integrate exposure over much...
Areas of Concern: Development of St. Louis River AOC Remedial Targets for Mercury
The St. Louis River Area of Concern (SLRAOC) was designated in 1987 owing to the presence of a variety of legacy pollutants, including mercury. Elevated fish-mercury levels lead fish consumption advisories by both Minnesota and Wisconsin, which resulted in Beneficial Use Impairments (BUIs).
How are Mercury Sources Determined?
USGS scientists use innovative isotopic identification methods to determine mercury sources in air, water, sediments, and wildlife.
Food Web Changes Dampen Expected Reductions in Lake Trout Mercury Levels in Lake Michigan—Invasive Species Play Major Role
Combined analyses of mercury, nitrogen, and carbon isotopes in archived lake trout ( Salvelinus namaycush ) tissues and sediment cores in Lake Michigan from 1978 to 2012 indicated that lake trout mercury concentrations mirrored declines in mercury sources prior to the arrival of invasive species that changed mercury transfer through the food and dampened the expected decreases in mercury...
Mercury Isotope Ratios used to Determine Sources of Mercury to Fish in Northeast U.S. Streams
Mercury isotope analyses were used to distinguish different sources of mercury to fish in 23 streams along a forested-rural to urban-industrial land-use gradient in the Northeastern United States. The use of mercury isotope measurements in fish tissue allow for distinguishing different sources of mercury that are bioaccumulating into the food web. Mercury isotope signatures in fish in forested...
Mercury studies
The USGS Mercury Research Lab is a national leader in advancing mercury research and science, specializing in low-level mercury speciation and isotope analysis and mercury-source fingerprinting. The MRL leads national cutting-edge collaborative studies, including state-of-the-art sample analysis, methods development for field and lab procedures, and data interpretation and dissemination.
North American and European Atmospheric Mercury Declines Explained by Local and Regional Emission Reductions
Recent findings from a consortium of university, State, and U.S. Geological Survey (USGS) scientists indicate that declining atmospheric concentrations of mercury (Hg) can be explained by the phaseout of mercury in many commercial products and by reduced emissions from utilities over the past two decades.
New Tool to Track Sources and Exposure Pathways of Mercury in the Environment — Application for Predatory Fish in the Great Lakes
The US Geological Survey (USGS) and collaborators at the University of Wisconsin-Madison have developed a new tool for attributing (fingerprinting) mercury sources to the Great Lakes. This new fingerprinting tool helps resource managers understand which mitigation strategies will be most effective for reducing mercury loading and exposure to fish and wildlife.
Complex Response to Decline in Atmospheric Deposition of Mercury
U.S. Geological Survey (USGS) scientists found that mercury concentrations in shallow waters and methylmercury (MeHg) concentrations in fish in four lakes in Voyageurs National Park, Minnesota, were not consistent with decreases in the wet atmospheric deposition of mercury recorded at nearby monitoring stations for over a decade. Methylmercury is a toxic form of mercury (Hg) that accumulates and...
Mercury cycling, bioaccumulation, and risk across western North America: a landscape scale synthesis linking long-term datasets
Mercury (Hg) is a serious environmental problem that is impacting ecological and human health on a global scale. However, local and regional processes are largely responsible for producing methylmercury, which drives ecological risk. This is particularly true in western North America where the combination of diverse landscapes, habitat types, climates, and Hg sources may disproportionally impact t
Environmental Mercury Cycling and Global Change
Rising global temperatures and changing human actions will significantly affect the environmental distribution of mercury worldwide, according to a recent article in Science by U.S. Geological Survey (USGS) and Harvard University scientists. Higher temperatures and weaker air circulation patterns from climate change will likely have significant impacts on the atmospheric lifetime and patterns of...
Collecting water sample at edge of Green Lake, Minnesota (Kandiyohi County)
Scientist Emeritus Dave Krabbenhoft collecting water sample at edge of Green Lake, Minnesota (Kandiyohi County).
Zebra Mussels on shore of Green Lake, Minnesota (Kandiyohi County)
Close up of the Green Lake, Minnesota (Kandiyohi County) shoreline showing zebra mussels washed up on shore, October 2021
Close up of the Green Lake, Minnesota (Kandiyohi County) shoreline showing zebra mussels washed up on shore, October 2021
Panoramic view of sampling site in Everglades
Panoramic view of USGS employees at a sampling site in Florida Everglades.
Panoramic view of USGS employees at a sampling site in Florida Everglades.
Mercury research team collecting fish in Everglades
USGS Mercury research team collecting fish in Everglades National Park, Florida.
USGS Mercury research team collecting fish in Everglades National Park, Florida.
Filtration of water in the field at Everglades
Scientists filtering water in the field at Everglades National Park, Florida.
Scientists filtering water in the field at Everglades National Park, Florida.
Methylmercury photodecomposition experiment on the roof of building
Methylmercury photodecomposition experiment on the roof of USGS building in Middleton, WI.
Methylmercury photodecomposition experiment on the roof of USGS building in Middleton, WI.
Panoramic view of scientists in boat on Hells Canyon Reservoir
Panoramic view of scientists in boat on Hells Canyon Reservoir, Idaho
Panoramic view of scientists in boat on Hells Canyon Reservoir, Idaho
Particulate matter captured on a quartz fiber filter
Particulate matter captured on a quartz fiber filter at the Mercury Research Laboratory.
Particulate matter captured on a quartz fiber filter at the Mercury Research Laboratory.
Native birds resting on marker buoys in Brownlee Reservoir, Idaho
Native birds resting on marker buoys in Brownlee Reservoir, Idaho.
Native birds resting on marker buoys in Brownlee Reservoir, Idaho.
Draining overlying water from sedimentation sampler
Draining overlying water from sedimentation sampler at Brownlee Reservoir, Idaho.
Draining overlying water from sedimentation sampler at Brownlee Reservoir, Idaho.
Scenic landscape from Hells Canyon Reservoir, Idaho
Scenic landscape from Hells Canyon Reservoir, Idaho
Scenic landscape from Hells Canyon Reservoir, Idaho
Burning coal to provide energy contributes mercury to the atmosphere
Burning coal to provide energy contributes mercury to the atmosphere
Burning coal to provide energy contributes mercury to the atmosphere
USGS Mobile Atmospheric Mercury Laboratory
The USGS Mobile Atmospheric Mercury Laboratory has onboard instrumentation to measure aerosol concentrations and to continuously monitor mercury speciation and concentrations, air quality, automated wet deposition collection, and meteorological conditions.
The USGS Mobile Atmospheric Mercury Laboratory has onboard instrumentation to measure aerosol concentrations and to continuously monitor mercury speciation and concentrations, air quality, automated wet deposition collection, and meteorological conditions.
Studies at Voyageurs National Park Revealed Trends in Mercury
Voyageurs National Park (VNP), a pristine setting with abundant lakes, wetlands, and streams situated on granitic bedrock, is located near northern Minnesota's border with Canada. Long-term studies at VNP have revealed trends in mercury concentration in precipitation, surface water, and fish.
Voyageurs National Park (VNP), a pristine setting with abundant lakes, wetlands, and streams situated on granitic bedrock, is located near northern Minnesota's border with Canada. Long-term studies at VNP have revealed trends in mercury concentration in precipitation, surface water, and fish.
Science and Products
Long-Term Monitoring Reveals How Water and Biota in Remote Lakes Respond Differently to Changes in Atmospheric Deposition of Mercury
A comparison of regional mercury atmospheric deposition data with water, yellow perch, and dragonfly larvae samples from lakes in Voyageurs National Park indicates that decreases in mercury emissions resulted in mercury reduction in water from these remote lakes, but mercury declines in biota were significant in only one of three lakes, likely because resident biota integrate exposure over much...
Areas of Concern: Development of St. Louis River AOC Remedial Targets for Mercury
The St. Louis River Area of Concern (SLRAOC) was designated in 1987 owing to the presence of a variety of legacy pollutants, including mercury. Elevated fish-mercury levels lead fish consumption advisories by both Minnesota and Wisconsin, which resulted in Beneficial Use Impairments (BUIs).
How are Mercury Sources Determined?
USGS scientists use innovative isotopic identification methods to determine mercury sources in air, water, sediments, and wildlife.
Food Web Changes Dampen Expected Reductions in Lake Trout Mercury Levels in Lake Michigan—Invasive Species Play Major Role
Combined analyses of mercury, nitrogen, and carbon isotopes in archived lake trout ( Salvelinus namaycush ) tissues and sediment cores in Lake Michigan from 1978 to 2012 indicated that lake trout mercury concentrations mirrored declines in mercury sources prior to the arrival of invasive species that changed mercury transfer through the food and dampened the expected decreases in mercury...
Mercury Isotope Ratios used to Determine Sources of Mercury to Fish in Northeast U.S. Streams
Mercury isotope analyses were used to distinguish different sources of mercury to fish in 23 streams along a forested-rural to urban-industrial land-use gradient in the Northeastern United States. The use of mercury isotope measurements in fish tissue allow for distinguishing different sources of mercury that are bioaccumulating into the food web. Mercury isotope signatures in fish in forested...
Mercury studies
The USGS Mercury Research Lab is a national leader in advancing mercury research and science, specializing in low-level mercury speciation and isotope analysis and mercury-source fingerprinting. The MRL leads national cutting-edge collaborative studies, including state-of-the-art sample analysis, methods development for field and lab procedures, and data interpretation and dissemination.
North American and European Atmospheric Mercury Declines Explained by Local and Regional Emission Reductions
Recent findings from a consortium of university, State, and U.S. Geological Survey (USGS) scientists indicate that declining atmospheric concentrations of mercury (Hg) can be explained by the phaseout of mercury in many commercial products and by reduced emissions from utilities over the past two decades.
New Tool to Track Sources and Exposure Pathways of Mercury in the Environment — Application for Predatory Fish in the Great Lakes
The US Geological Survey (USGS) and collaborators at the University of Wisconsin-Madison have developed a new tool for attributing (fingerprinting) mercury sources to the Great Lakes. This new fingerprinting tool helps resource managers understand which mitigation strategies will be most effective for reducing mercury loading and exposure to fish and wildlife.
Complex Response to Decline in Atmospheric Deposition of Mercury
U.S. Geological Survey (USGS) scientists found that mercury concentrations in shallow waters and methylmercury (MeHg) concentrations in fish in four lakes in Voyageurs National Park, Minnesota, were not consistent with decreases in the wet atmospheric deposition of mercury recorded at nearby monitoring stations for over a decade. Methylmercury is a toxic form of mercury (Hg) that accumulates and...
Mercury cycling, bioaccumulation, and risk across western North America: a landscape scale synthesis linking long-term datasets
Mercury (Hg) is a serious environmental problem that is impacting ecological and human health on a global scale. However, local and regional processes are largely responsible for producing methylmercury, which drives ecological risk. This is particularly true in western North America where the combination of diverse landscapes, habitat types, climates, and Hg sources may disproportionally impact t
Environmental Mercury Cycling and Global Change
Rising global temperatures and changing human actions will significantly affect the environmental distribution of mercury worldwide, according to a recent article in Science by U.S. Geological Survey (USGS) and Harvard University scientists. Higher temperatures and weaker air circulation patterns from climate change will likely have significant impacts on the atmospheric lifetime and patterns of...
Collecting water sample at edge of Green Lake, Minnesota (Kandiyohi County)
Scientist Emeritus Dave Krabbenhoft collecting water sample at edge of Green Lake, Minnesota (Kandiyohi County).
Scientist Emeritus Dave Krabbenhoft collecting water sample at edge of Green Lake, Minnesota (Kandiyohi County).
Zebra Mussels on shore of Green Lake, Minnesota (Kandiyohi County)
Close up of the Green Lake, Minnesota (Kandiyohi County) shoreline showing zebra mussels washed up on shore, October 2021
Close up of the Green Lake, Minnesota (Kandiyohi County) shoreline showing zebra mussels washed up on shore, October 2021
Panoramic view of sampling site in Everglades
Panoramic view of USGS employees at a sampling site in Florida Everglades.
Panoramic view of USGS employees at a sampling site in Florida Everglades.
Mercury research team collecting fish in Everglades
USGS Mercury research team collecting fish in Everglades National Park, Florida.
USGS Mercury research team collecting fish in Everglades National Park, Florida.
Filtration of water in the field at Everglades
Scientists filtering water in the field at Everglades National Park, Florida.
Scientists filtering water in the field at Everglades National Park, Florida.
Methylmercury photodecomposition experiment on the roof of building
Methylmercury photodecomposition experiment on the roof of USGS building in Middleton, WI.
Methylmercury photodecomposition experiment on the roof of USGS building in Middleton, WI.
Panoramic view of scientists in boat on Hells Canyon Reservoir
Panoramic view of scientists in boat on Hells Canyon Reservoir, Idaho
Panoramic view of scientists in boat on Hells Canyon Reservoir, Idaho
Particulate matter captured on a quartz fiber filter
Particulate matter captured on a quartz fiber filter at the Mercury Research Laboratory.
Particulate matter captured on a quartz fiber filter at the Mercury Research Laboratory.
Native birds resting on marker buoys in Brownlee Reservoir, Idaho
Native birds resting on marker buoys in Brownlee Reservoir, Idaho.
Native birds resting on marker buoys in Brownlee Reservoir, Idaho.
Draining overlying water from sedimentation sampler
Draining overlying water from sedimentation sampler at Brownlee Reservoir, Idaho.
Draining overlying water from sedimentation sampler at Brownlee Reservoir, Idaho.
Scenic landscape from Hells Canyon Reservoir, Idaho
Scenic landscape from Hells Canyon Reservoir, Idaho
Scenic landscape from Hells Canyon Reservoir, Idaho
Burning coal to provide energy contributes mercury to the atmosphere
Burning coal to provide energy contributes mercury to the atmosphere
Burning coal to provide energy contributes mercury to the atmosphere
USGS Mobile Atmospheric Mercury Laboratory
The USGS Mobile Atmospheric Mercury Laboratory has onboard instrumentation to measure aerosol concentrations and to continuously monitor mercury speciation and concentrations, air quality, automated wet deposition collection, and meteorological conditions.
The USGS Mobile Atmospheric Mercury Laboratory has onboard instrumentation to measure aerosol concentrations and to continuously monitor mercury speciation and concentrations, air quality, automated wet deposition collection, and meteorological conditions.
Studies at Voyageurs National Park Revealed Trends in Mercury
Voyageurs National Park (VNP), a pristine setting with abundant lakes, wetlands, and streams situated on granitic bedrock, is located near northern Minnesota's border with Canada. Long-term studies at VNP have revealed trends in mercury concentration in precipitation, surface water, and fish.
Voyageurs National Park (VNP), a pristine setting with abundant lakes, wetlands, and streams situated on granitic bedrock, is located near northern Minnesota's border with Canada. Long-term studies at VNP have revealed trends in mercury concentration in precipitation, surface water, and fish.