Mercury Active
Mercury in the Environment
Science used to highlight a dangerous issue
Got Mercury?
The fish in your stream might just tell you where it came from
Mercury is a potent neurotoxin that can affect the human nervous system. Eating fish contaminated with mercury can cause serious harm to people and wildlife.
BACKGROUND
Mercury is a potent neurotoxin that can accumulate in fish to levels of concern for human health and the health of fish-eating wildlife. Mercury contamination of fish is the primary reason for issuing fish consumption advisories, which exist in every State in the Nation. Much of the mercury in the environment originates from combustion of coal and can travel long distances in the atmosphere before being deposited on the land surface. As a result, mercury can bioaccumulate in fish in areas with no obvious source of mercury pollution.1
Mercury is the leading cause of impairment in the Nation's estuaries and lakes and was cited in nearly 80 percent of all reported fish-consumption advisories.2 The geographic extent of mercury advisories covers more than 10 million acres of lakes and more than 400,000 stream miles.3
The fact sheet Mercury Contamination of Aquatic Ecosystems answers many of the basic questions about mercury. For a deeper dive into the topic, download the USGS Circular 1395, highlighted below.
FACTS ABOUT MERCURY
- Highly toxic to the nervous system
- Persistent in the environment
- Bioaccumulates (higher concentrations in tissues of aquatic plants and animals than in water)
- Biomagnifies (higher concentrations at increasingly higher levels in the food chain)
- Numerous chemical forms in air, water, sediment, and biota
UNDERSTANDING THE MERCURY CYCLE
Mercury contamination is global and affects many waters that have no obvious mercury source. This is because mercury emissions generally disperse widely in the atmosphere before being deposited to the earth's surface. Mercury is emitted by natural sources, such as volcanoes, geothermal springs, geologic deposits, and the ocean. Human-related sources primarily include coal combustion, waste incineration, industrial uses, and mining. During the last 150 years, human activities have more than doubled natural amounts of mercury in the atmosphere.4
In natural waters, inorganic mercury is generally not a health concern. The real issue is methylmercury, an organic form that is highly toxic to the nervous system. Methylmercury is produced from inorganic mercury by methylation, a microbial process that is controlled by certain bacteria and enhanced by chemical and environmental variables, such as the presence of organic matter and the absence of oxygen. More than 95 percent of all mercury in fish is methylmercury, and this form of mercury biomagnifies to high concentrations at the top of food chains.5
RELATED USGS RESEARCH
- Mercury in the Environment
- USGS Mercury Research Laboratory
- Mercury in Aquatic Ecosystems
- Mercury Statistics and Information
ADDITIONAL RESOURCES
U.S. Environmental Protection Agency
Use the links below to access web pages describing additional USGS research on mercury and associated topics
Use the links below to explore multimedia items associated with USGS research on mercury and water quality.
Access USGS reports and publications on mercury and water quality. For more publications on mercury, search the USGS Publications Warehouse. Look here for help using the Pubs Warehouse.
Mercury contamination of aquatic ecosystems
Mercury and methylmercury dynamics in the hyporheic zone of an Oregon stream
Mercury in fishes from 21 national parks in the Western United States: inter- and intra-park variation in concentrations and ecological risk
Mercury and methylmercury stream concentrations in a Coastal Plain watershed: A multi-scale simulation analysis
Optimizing stream water mercury sampling for calculation of fish bioaccumulation factors
Intra- and inter-basin mercury comparisons: Importance of basin scale and time-weighted methylmercury estimates
Mercury trends in fish from rivers and lakes in the United States, 1969-2005
Hydrological mobilization of mercury and dissolved organic carbon in a snow-dominated, forested watershed: Conceptualization and modeling
Mercury in fish, bed sediment, and water from streams across the United States, 1998-2005
Characterizing dry deposition of mercury in urban runoff
Mercury in stream ecosystems -- New studies initiated by the U.S. Geological Survey
A national pilot study of mercury contamination of aquatic ecosystems along multiple gradients" Bioaccumulation in fish
Use the links below to find news stories on USGS research on mercury and water quality.
Isotopic tracers in fish in Northeast provide clue to mercury sources
Isotopes of mercury in fish can indicate the source of that mercury, reports a new study from the USGS Regional Stream Quality Assessment.
- Overview
Mercury is a potent neurotoxin that can affect the human nervous system. Eating fish contaminated with mercury can cause serious harm to people and wildlife.
BACKGROUND
Mercury is a potent neurotoxin that can accumulate in fish to levels of concern for human health and the health of fish-eating wildlife. Mercury contamination of fish is the primary reason for issuing fish consumption advisories, which exist in every State in the Nation. Much of the mercury in the environment originates from combustion of coal and can travel long distances in the atmosphere before being deposited on the land surface. As a result, mercury can bioaccumulate in fish in areas with no obvious source of mercury pollution.1
Mercury is the leading cause of impairment in the Nation's estuaries and lakes and was cited in nearly 80 percent of all reported fish-consumption advisories.2 The geographic extent of mercury advisories covers more than 10 million acres of lakes and more than 400,000 stream miles.3
The fact sheet Mercury Contamination of Aquatic Ecosystems answers many of the basic questions about mercury. For a deeper dive into the topic, download the USGS Circular 1395, highlighted below.
FACTS ABOUT MERCURY
- Highly toxic to the nervous system
- Persistent in the environment
- Bioaccumulates (higher concentrations in tissues of aquatic plants and animals than in water)
- Biomagnifies (higher concentrations at increasingly higher levels in the food chain)
- Numerous chemical forms in air, water, sediment, and biota
UNDERSTANDING THE MERCURY CYCLE
Mercury contamination is global and affects many waters that have no obvious mercury source. This is because mercury emissions generally disperse widely in the atmosphere before being deposited to the earth's surface. Mercury is emitted by natural sources, such as volcanoes, geothermal springs, geologic deposits, and the ocean. Human-related sources primarily include coal combustion, waste incineration, industrial uses, and mining. During the last 150 years, human activities have more than doubled natural amounts of mercury in the atmosphere.4
In natural waters, inorganic mercury is generally not a health concern. The real issue is methylmercury, an organic form that is highly toxic to the nervous system. Methylmercury is produced from inorganic mercury by methylation, a microbial process that is controlled by certain bacteria and enhanced by chemical and environmental variables, such as the presence of organic matter and the absence of oxygen. More than 95 percent of all mercury in fish is methylmercury, and this form of mercury biomagnifies to high concentrations at the top of food chains.5
RELATED USGS RESEARCH
- Mercury in the Environment
- USGS Mercury Research Laboratory
- Mercury in Aquatic Ecosystems
- Mercury Statistics and Information
ADDITIONAL RESOURCES
U.S. Environmental Protection Agency
- Science
Use the links below to access web pages describing additional USGS research on mercury and associated topics
- Multimedia
Use the links below to explore multimedia items associated with USGS research on mercury and water quality.
- Publications
Access USGS reports and publications on mercury and water quality. For more publications on mercury, search the USGS Publications Warehouse. Look here for help using the Pubs Warehouse.
Mercury contamination of aquatic ecosystems
Mercury has been well known as an environmental pollutant for several decades. As early as the 1950's it was established that emissions of mercury to the environment could have serious effects on human health. These early studies demonstrated that fish and other wildlife from various ecosystems commonly attain mercury levels of toxicological concern when directly affected by mercury-containing emiAuthorsDavid P. Krabbenhoft, David A. RickertFilter Total Items: 23Mercury and methylmercury dynamics in the hyporheic zone of an Oregon stream
The role of the hyporheic zone in mercury (Hg) cycling has received limited attention despite the biogeochemically active nature of this zone and, thus, its potential to influence Hg behavior in streams. An assessment of Hg geochemistry in the hyporheic zone of a coarse-grained island in the Coast Fork Willamette River in Oregon, USA, illustrates the spatially dynamic nature of this region of theAuthorsStephen R. Hinkle, Kenneth E. Bencala, Dennis A. Wentz, David P. KrabbenhoftMercury in fishes from 21 national parks in the Western United States: inter- and intra-park variation in concentrations and ecological risk
Mercury (Hg) is a global contaminant and human activities have increased atmospheric Hg concentrations 3- to 5-fold during the past 150 years. This increased release into the atmosphere has resulted in elevated loadings to aquatic habitats where biogeochemical processes promote the microbial conversion of inorganic Hg to methylmercury, the bioavailable form of Hg. The physicochemical properties ofAuthorsCollin A. Eagles-Smith, James J. Willacker, Colleen M. Flanagan PritzMercury and methylmercury stream concentrations in a Coastal Plain watershed: A multi-scale simulation analysis
Mercury is a ubiquitous global environmental toxicant responsible for most US fish advisories. Processes governing mercury concentrations in rivers and streams are not well understood, particularly at multiple spatial scales. We investigate how insights gained from reach-scale mercury data and model simulations can be applied at broader watershed scales using a spatially and temporally explicit waAuthorsChristopher D. Knightes, Heather E. Golden, Celeste A. Journey, Gary M. Davis, Paul Conrads, Mark Marvin-DiPasquale, Mark E. Brigham, Paul M. BradleyOptimizing stream water mercury sampling for calculation of fish bioaccumulation factors
Mercury (Hg) bioaccumulation factors (BAFs) for game fishes are widely employed for monitoring, assessment, and regulatory purposes. Mercury BAFs are calculated as the fish Hg concentration (Hgfish) divided by the water Hg concentration (Hgwater) and, consequently, are sensitive to sampling and analysis artifacts for fish and water. We evaluated the influence of water sample timing, filtration, anAuthorsKaren Riva-Murray, Paul M. Bradley, Celeste A. Journey, Mark E. Brigham, Barbara C. Scudder Eikenberry, Christopher Knightes, Daniel T. ButtonIntra- and inter-basin mercury comparisons: Importance of basin scale and time-weighted methylmercury estimates
To assess inter-comparability of fluvial mercury (Hg) observations at substantially different scales, Hg concentrations, yields, and bivariate-relations were evaluated at nested-basin locations in the Edisto River, South Carolina and Hudson River, New York. Differences between scales were observed for filtered methylmercury (FMeHg) in the Edisto (attributed to wetland coverage differences) but notAuthorsPaul M. Bradley, Celeste A. Journey, Mark E. Bringham, Douglas A. Burns, Daniel T. Button, Karen Riva-MurrayMercury trends in fish from rivers and lakes in the United States, 1969-2005
A national dataset on concentrations of mercury in fish, compiled mainly from state and federal monitoring programs, was used to evaluate trends in mercury (Hg) in fish from US rivers and lakes. Trends were analyzed on data aggregated by site and by state, using samples of the same fish species and tissue type, and using fish of similar lengths. Site-based trends were evaluated from 1969 to 2005,AuthorsA.T. Chalmers, D.M. Argue, D.A. Gay, M. E. Brigham, C. J. Schmitt, D. L. LorenzHydrological mobilization of mercury and dissolved organic carbon in a snow-dominated, forested watershed: Conceptualization and modeling
The mobilization of mercury and dissolved organic carbon (DOC) during snowmelt often accounts for a major fraction of the annual loads. We studied the role of hydrological connectivity of riparian wetlands and upland/wetland transition zones to surface waters on the mobilization of Hg and DOC in Fishing Brook, a headwater of the Adirondack Mountains, New York. Stream water total mercury (THg) concAuthorsJ. Schelker, Douglas A. Burns, M. Weiler, H. LaudonMercury in fish, bed sediment, and water from streams across the United States, 1998-2005
Mercury (Hg) was examined in top-predator fish, bed sediment, and water from streams that spanned regional and national gradients of Hg source strength and other factors thought to influence methylmercury (MeHg) bioaccumulation. Sampled settings include stream basins that were agricultural, urbanized, undeveloped (forested, grassland, shrubland, and wetland land cover), and mined (for gold and Hg)AuthorsBarbara C. Scudder, Lia C. Chasar, Dennis A. Wentz, Nancy J. Bauch, Mark E. Brigham, Patrick W. Moran, David P. KrabbenhoftCharacterizing dry deposition of mercury in urban runoff
Stormwater runoff from urban surfaces often contains elevated levels of toxic metals. When discharged directly into water bodies, these pollutants degrade water quality and impact aquatic life and human health. In this study, the composition of impervious surface runoff and associated rainfall was investigated for several storm events at an urban site in Orlando, Florida. Total mercury in runoff cAuthorsM. Fulkerson, F.N. Nnadi, L.S. ChasarMercury in stream ecosystems -- New studies initiated by the U.S. Geological Survey
Mercury can adversely affect humans and wildlife through consumption of contaminated fish, particularly by sensitive individuals, such as children and women of childbearing age. Mercury is currently the leading cause of impairment in the Nation’s estuaries and lakes and was cited in nearly 80 percent of fish-consumption advisories (2,242 of 2,838) reported by states in 2000. The geographic extentAuthorsMark E. Brigham, David P. Krabbenhoft, Pixie A. HamiltonA national pilot study of mercury contamination of aquatic ecosystems along multiple gradients" Bioaccumulation in fish
Water, sediment, and fish were sampled in the summer and fall of 1998 at 106 sites from 20 U.S. watershed basins to examine relations of mercury (Hg) and methylmercury (MeHg) in aquatic ecosystems. Bioaccumulation of Hg in fish from these basins was evaluated in relation to species, Hg and MeHg in surficial sediment and water, and watershed characteristics. Bioaccumulation was strongly (positivelyAuthorsWilliam G. Brumbaugh, David P. Krabbenhoft, Dennis R. Helsel, James G. Wiener, Kathy R. Echols - News
Use the links below to find news stories on USGS research on mercury and water quality.
Isotopic tracers in fish in Northeast provide clue to mercury sources
Isotopes of mercury in fish can indicate the source of that mercury, reports a new study from the USGS Regional Stream Quality Assessment.