The U.S. Geological Survey laboratory for the analysis of per- and polyfluoroalkyl substances (PFAS) uses cutting-edge techniques to analyze environmental samples including tissues, plasma, water, and soils to undertake and support research projects across the country.
Disease and Contaminants
Avian Influenza in the United States
USGS scientists across the country are assessing how the movement of migratory waterfowl impacts the spread of avian influenza.
Waste not, want not: How USGS capabilities enhance COVID-19 wastewater surveillance
Checking wastewater for infectious disease is an important tool to prevent new infectious disease outbreaks
Lead Poisoning in Bald and Golden Eagles
Groundbreaking study finds nearly 50 percent of birds sampled showed evidence of repeated exposure to lead.
USGS Response to White-Nose Syndrome in Bats
The USGS has been a leading contributor to the interagency response to white-nose syndrome since 2008, when millions of bats died from this devastating disease.
Evaluating Impacts of Stormwater and Road Runoff on Salmon and Aquatic Ecosystems
How can automobiles pose a threat to our aquatic ecosystems?
The health of animals, humans, and the environment are closely connected. The effects of diseases, pathogens, contaminants, and toxins are global and profound, often resulting in economic and agricultural impacts, declines in wildlife populations, and ecological disturbance. The USGS works to advance wildlife health science for the benefit of animals, humans, and the environment.
Diseases and Pathogens
![The cyanobacteria Gleotrichia shown under a microscope from a water sample collected at Ek Lake Trail](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/side_image/public/thumbnails/image/Image_10.png?itok=ivjatwTv)
Viruses, bacteria, fungi, and parasites are a normal part of any ecosystem. But viruses, along with some bacteria, fungi, and parasites, can also be pathogens, meaning they cause disease in humans, plants, and wildlife. The fungus Pseudogymnoascus destructans causes the deadly white-nose syndrome in hibernating bats. A tiny protein particle known as a prion causes the fatal brain disease Chronic Wasting Disease in deer. The H5N1 virus causes avian influenza in birds. These diseases can devastate wildlife populations and have serious conservation and management consequences. The health of people is also connected to the health of wildlife and our shared environment. Some diseases, known as zoonotic diseases, can jump from animals to humans. According to the Centers for Disease Control and Prevention, 60% of known infectious diseases in people can be spread from animals, and three out of every four new or emerging infectious diseases in people come from animals. Other diseases can jump from wild animals to domestic animals.
USGS is a leader in wildlife disease research and surveillance. The USGS monitors the presence of pathogens and diseases in animals and the environment, develops tools for their detection, identifies whether environmental factors influence their spread, and studies the health risks that they pose. Our scientists are at the table with public and animal health agencies as they tackle diseases that affect mammals, fish, reptiles, and more, developing advanced tools for diagnosis, surveillance, risk assessment, and control.
Contaminants and Toxins
Contaminants and toxins represent another potential threat to the health of humans and wildlife, and in their shared environment. People use chemical-based products every day, and these chemicals enter the environment from treated wastewater, industrial processes, runoff from urban and agricultural land surfaces, and more. Pesticides, pharmaceuticals, and per-and polyfluoroalkyl substances (PFAS) are just a few examples of the many contaminants that make their way into our Nation’s waterways each day. Contaminants may be found at high levels and cause immediate effects or occur lower levels and only cause problems after long-term exposure, and sometimes the chemicals are at low enough levels that they do not by themselves create a health risk.
The environment also contains natural toxins. For example, algal blooms often contain cyanobacteria and other microorganisms which can produce natural toxins that harm people, pets, and wildlife when they occur at high enough levels in water resources used for recreation and drinking water. Harmful algal blooms (HABs) occur when environmental conditions are favorable, such as when water temperatures are unusually warm, but human activities can also contribute to their occurrence, for example when fertilizers used on lawns and crops run off into waterways.
USGS scientists develop and use advanced techniques and tools to quantify the presence of contaminants and toxins in the environment, determine when, where, and how exposure occurs, forecast future occurrence, and assess their effects all the way up the food chain.
Supporting the Health of Our Wildlife, Lands, and Waters
The USGS is a leader in developing research solutions to address the deadliest wildlife diseases, detect pathogens in the environment, and monitor for the presence of dangerous chemicals and toxins.
Fish and Wildlife Disease
Zoonotic Diseases
Plant Diseases
Pathogens
Emerging Contaminants
Toxins & Harmful Algal Blooms
Threat Detection and Rapid Response
USGS science focuses on quickly detecting, characterizing, and responding to potential hazards and biological threats, including infectious diseases like chronic wasting disease and avian influenza and other pathogens like waterborne bacteria.
The USGS is leading efforts to predict and forecast the risk of biological threats like infectious diseases and to ensure that these risks are detected early. This information helps federal, and state natural resource managers and public health professionals prepare for and respond to these threats. The USGS is developing a nationwide biosurveillance network to address ongoing and emerging needs through projects that improve threat detection, interagency communication, and early detection and rapid response decision making. Explore these activities below.
Environmental DNA
Environmental DNA (eDNA), or DNA that is released from an organism into the environment, can allow for rapid, cost-effective data collection on the distribution and abundance of a species. It can also be used to understand the distribution and prevalence of pathogens on land or in water.
![Collecting DNA in the Boise River (Boise, ID)](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/half_width/public/thumbnails/image/5027_.jpg?itok=NbIdikI3)
![Image: Gibbon River Falls, Yellowstone National Park](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/half_width/public/Gibbon_River_at_Yellowstone_NP__WY_9-2-2006.jpg?itok=GV0j0K6D)
Investigating Exposure to Lethal Threats
Sometimes, the effects of biological threats are immediate and abrupt, such as the sudden and sharp decline of a population, an event known as a “die-off”. In other cases, impacts are felt over time, such as when small amounts of a contaminant build up in the tissues of organisms and can cause long-term effects on plant, animal, and even human health. USGS scientists work in collaboration with partner agencies to investigate the exposure of plants and animals to lethal diseases, pathogens, contaminants, and the impacts of these threats on species.
![Arctic tern feeding a sand lance to her chick.](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/half_width/public/thumbnails/image/tern%26chickw-sandlance2_0.jpg?itok=BCCdVKU3)
![Dragonfly on tagline](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/half_width/public/thumbnails/image/HM2_Dragonfly%20On%20Tagline.jpg?itok=TYMckbnL)
Publications
Evaluating management alternatives for Wyoming elk feedgrounds in consideration of chronic wasting disease
Executive SummaryThe authors used decision and modeling analyses to evaluate management alternatives for a decision on whether to permit Cervus canadensis (elk) feeding on two sites on Bridger-Teton National Forest, Dell Creek and Forest Park. Supplemental feeding of elk could increase the transmission of chronic wasting disease (CWD) locally and disease spread regionally, potentially impacting el
Assessing the ecological risk of heavy metal sediment contamination from Port Everglades Florida USA
WHISPers—Providing situational awareness of wildlife disease threats to the Nation—A fact sheet for the biosurveillance community
Hawaiian forest bird conservation strategies for minimizing the risk of extinction: biological and biocultural considerations
Integrated science for the study of perfluoroalkyl and polyfluoroalkyl substances (PFAS) in the environment—A strategic science vision for the U.S. Geological Survey
Science
Q&A: Bird Flu - Ongoing Threat of Highly Pathogenic Avian Influenza (HPAI) in Alaska and North America
Avian Influenza Research
Harmful Algal Bloom Toxins in Alaska Seabirds
Application of a systems approach for management of chronic wasting disease
A National Assessment of Pesticide, PFAS, Microplastic, and Antibiotic Resistance Gene Exposures in White-Tailed Deer
Multimedia
![USGS Laboratory for the Analysis of Per- and Polyfluoroalkyl Substances (PFAS) U.S. Geological Survey. Laboratory for the Analysis of Per-and Polyfluoroalkyl Substances (PFAS)](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/media/images/EEC%20PFAS%20Lab%20Thumbnail.jpg?itok=h0P8IN3r)
The U.S. Geological Survey laboratory for the analysis of per- and polyfluoroalkyl substances (PFAS) uses cutting-edge techniques to analyze environmental samples including tissues, plasma, water, and soils to undertake and support research projects across the country.
PubTalk-03/2023: Coral Reef in Crisis - Science to Guide Reef Restoration for Ecosystem Recovery
linkCoral Reef in Crisis - Science to Guide Reef Restoration for Ecosystem Recovery
By Ilsa Kuffner, Research Marine Biologist
USGS St. Petersburg Coastal & Marine Science Center
Learn About:
PubTalk-03/2023: Coral Reef in Crisis - Science to Guide Reef Restoration for Ecosystem Recovery
linkCoral Reef in Crisis - Science to Guide Reef Restoration for Ecosystem Recovery
By Ilsa Kuffner, Research Marine Biologist
USGS St. Petersburg Coastal & Marine Science Center
Learn About:
Behind the Headlines of a Wildlife Disease Die-off
The how and why of wildlife disease investigation
By Dr. Kimberli Miller, Wildlife Disease Specialist
USGS National Wildlife Health Center
Behind the Headlines of a Wildlife Disease Die-off
The how and why of wildlife disease investigation
By Dr. Kimberli Miller, Wildlife Disease Specialist
USGS National Wildlife Health Center
USGS volunteer Liliana uses a syringe to draw an eDNA sample from a rock pool along the Puka Stream. The eDNA sampled by USGS field crews informs research on invasive mosquito population dynamics.
USGS volunteer Liliana uses a syringe to draw an eDNA sample from a rock pool along the Puka Stream. The eDNA sampled by USGS field crews informs research on invasive mosquito population dynamics.
Kili Kawaiaea and Liliana Tobar sampling eDNA from a rock pool along the Puka Stream.
Kili Kawaiaea and Liliana Tobar sampling eDNA from a rock pool along the Puka Stream.
A biologist measures the length of a brook trout as part of a study on environmental DNA (eDNA).
A biologist measures the length of a brook trout as part of a study on environmental DNA (eDNA).
![Disease and Contaminates Affecting Wildlife and the Environment Image: Prairie Pothole Dragonfly](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/NOROCK_2_EnergyMinerals.jpg?itok=tufehnGD)
Slide show with examples of disease and contaminates affecting wildlife and the environment
Slide show with examples of disease and contaminates affecting wildlife and the environment
![Scientist wading in river with an orange inflatable boat](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/media/images/RoseauRiverWildlifeManagementArea.jpg?itok=lh153YSH)
Field assistant Kathryn Johncock wades in a wetland while filtering for infectious avian influenza virus at the Roseau River Wildlife Management Area, Roseau, Minnesota.
Field assistant Kathryn Johncock wades in a wetland while filtering for infectious avian influenza virus at the Roseau River Wildlife Management Area, Roseau, Minnesota.
![Environmental Health Program Energy Lifecycle Integrated science Team Activities USGS scientists collecting water-quality samples from observation wells](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/thumbnails/image/bemidji_water_sampling_2011_21_l.jpg?itok=H9hwjk-w)
News
USGS partners with Havasupai Tribe to identify potential contaminant exposure pathways from Grand Canyon uranium mining
Pesticides are likely impacting invertebrate life essential to our nation’s streams
Monitoring Change at the Lower Darby Creek Area Superfund Site
The publications listed below are a sampling of USGS science on this topic and do not represent an exhaustive list.
The science listed below is a sampling of USGS science on this topic and do not represent an exhaustive list.
Pesticide Fate Research Group (PFRG)
Avian Influenza
Effect of Chronic Neonicotinoid Insecticide Exposure upon Monarch Development
Risk of Adult Mosquito Control Pesticides to Imperiled Butterflies
Beak Deformities in Landbirds
Ecology of Wildlife Disease
Ecology of Plague
Ecological Investigations of White-Nose Syndrome in Bats
Aquatic Ecology and Contaminants
Ecology of Insect-eating Bats
The data listed below are a sampling of USGS science on this topic and do not represent an exhaustive list.
The multimedia listed below are a sampling of USGS science on this topic and do not represent an exhaustive list.
The news below is a sampling of USGS science on this topic and do not represent an exhaustive list.
The FAQs below are a sampling of USGS science on this topic and do not represent an exhaustive list.
The health of animals, humans, and the environment are closely connected. The effects of diseases, pathogens, contaminants, and toxins are global and profound, often resulting in economic and agricultural impacts, declines in wildlife populations, and ecological disturbance. The USGS works to advance wildlife health science for the benefit of animals, humans, and the environment.
Diseases and Pathogens
![The cyanobacteria Gleotrichia shown under a microscope from a water sample collected at Ek Lake Trail](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/side_image/public/thumbnails/image/Image_10.png?itok=ivjatwTv)
Viruses, bacteria, fungi, and parasites are a normal part of any ecosystem. But viruses, along with some bacteria, fungi, and parasites, can also be pathogens, meaning they cause disease in humans, plants, and wildlife. The fungus Pseudogymnoascus destructans causes the deadly white-nose syndrome in hibernating bats. A tiny protein particle known as a prion causes the fatal brain disease Chronic Wasting Disease in deer. The H5N1 virus causes avian influenza in birds. These diseases can devastate wildlife populations and have serious conservation and management consequences. The health of people is also connected to the health of wildlife and our shared environment. Some diseases, known as zoonotic diseases, can jump from animals to humans. According to the Centers for Disease Control and Prevention, 60% of known infectious diseases in people can be spread from animals, and three out of every four new or emerging infectious diseases in people come from animals. Other diseases can jump from wild animals to domestic animals.
USGS is a leader in wildlife disease research and surveillance. The USGS monitors the presence of pathogens and diseases in animals and the environment, develops tools for their detection, identifies whether environmental factors influence their spread, and studies the health risks that they pose. Our scientists are at the table with public and animal health agencies as they tackle diseases that affect mammals, fish, reptiles, and more, developing advanced tools for diagnosis, surveillance, risk assessment, and control.
Contaminants and Toxins
Contaminants and toxins represent another potential threat to the health of humans and wildlife, and in their shared environment. People use chemical-based products every day, and these chemicals enter the environment from treated wastewater, industrial processes, runoff from urban and agricultural land surfaces, and more. Pesticides, pharmaceuticals, and per-and polyfluoroalkyl substances (PFAS) are just a few examples of the many contaminants that make their way into our Nation’s waterways each day. Contaminants may be found at high levels and cause immediate effects or occur lower levels and only cause problems after long-term exposure, and sometimes the chemicals are at low enough levels that they do not by themselves create a health risk.
The environment also contains natural toxins. For example, algal blooms often contain cyanobacteria and other microorganisms which can produce natural toxins that harm people, pets, and wildlife when they occur at high enough levels in water resources used for recreation and drinking water. Harmful algal blooms (HABs) occur when environmental conditions are favorable, such as when water temperatures are unusually warm, but human activities can also contribute to their occurrence, for example when fertilizers used on lawns and crops run off into waterways.
USGS scientists develop and use advanced techniques and tools to quantify the presence of contaminants and toxins in the environment, determine when, where, and how exposure occurs, forecast future occurrence, and assess their effects all the way up the food chain.
Supporting the Health of Our Wildlife, Lands, and Waters
The USGS is a leader in developing research solutions to address the deadliest wildlife diseases, detect pathogens in the environment, and monitor for the presence of dangerous chemicals and toxins.
Fish and Wildlife Disease
Zoonotic Diseases
Plant Diseases
Pathogens
Emerging Contaminants
Toxins & Harmful Algal Blooms
Threat Detection and Rapid Response
USGS science focuses on quickly detecting, characterizing, and responding to potential hazards and biological threats, including infectious diseases like chronic wasting disease and avian influenza and other pathogens like waterborne bacteria.
The USGS is leading efforts to predict and forecast the risk of biological threats like infectious diseases and to ensure that these risks are detected early. This information helps federal, and state natural resource managers and public health professionals prepare for and respond to these threats. The USGS is developing a nationwide biosurveillance network to address ongoing and emerging needs through projects that improve threat detection, interagency communication, and early detection and rapid response decision making. Explore these activities below.
Environmental DNA
Environmental DNA (eDNA), or DNA that is released from an organism into the environment, can allow for rapid, cost-effective data collection on the distribution and abundance of a species. It can also be used to understand the distribution and prevalence of pathogens on land or in water.
![Collecting DNA in the Boise River (Boise, ID)](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/half_width/public/thumbnails/image/5027_.jpg?itok=NbIdikI3)
![Image: Gibbon River Falls, Yellowstone National Park](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/half_width/public/Gibbon_River_at_Yellowstone_NP__WY_9-2-2006.jpg?itok=GV0j0K6D)
Investigating Exposure to Lethal Threats
Sometimes, the effects of biological threats are immediate and abrupt, such as the sudden and sharp decline of a population, an event known as a “die-off”. In other cases, impacts are felt over time, such as when small amounts of a contaminant build up in the tissues of organisms and can cause long-term effects on plant, animal, and even human health. USGS scientists work in collaboration with partner agencies to investigate the exposure of plants and animals to lethal diseases, pathogens, contaminants, and the impacts of these threats on species.
![Arctic tern feeding a sand lance to her chick.](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/half_width/public/thumbnails/image/tern%26chickw-sandlance2_0.jpg?itok=BCCdVKU3)
![Dragonfly on tagline](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/half_width/public/thumbnails/image/HM2_Dragonfly%20On%20Tagline.jpg?itok=TYMckbnL)
Publications
Evaluating management alternatives for Wyoming elk feedgrounds in consideration of chronic wasting disease
Executive SummaryThe authors used decision and modeling analyses to evaluate management alternatives for a decision on whether to permit Cervus canadensis (elk) feeding on two sites on Bridger-Teton National Forest, Dell Creek and Forest Park. Supplemental feeding of elk could increase the transmission of chronic wasting disease (CWD) locally and disease spread regionally, potentially impacting el
Assessing the ecological risk of heavy metal sediment contamination from Port Everglades Florida USA
WHISPers—Providing situational awareness of wildlife disease threats to the Nation—A fact sheet for the biosurveillance community
Hawaiian forest bird conservation strategies for minimizing the risk of extinction: biological and biocultural considerations
Integrated science for the study of perfluoroalkyl and polyfluoroalkyl substances (PFAS) in the environment—A strategic science vision for the U.S. Geological Survey
Science
Q&A: Bird Flu - Ongoing Threat of Highly Pathogenic Avian Influenza (HPAI) in Alaska and North America
Avian Influenza Research
Harmful Algal Bloom Toxins in Alaska Seabirds
Application of a systems approach for management of chronic wasting disease
A National Assessment of Pesticide, PFAS, Microplastic, and Antibiotic Resistance Gene Exposures in White-Tailed Deer
Multimedia
![USGS Laboratory for the Analysis of Per- and Polyfluoroalkyl Substances (PFAS) U.S. Geological Survey. Laboratory for the Analysis of Per-and Polyfluoroalkyl Substances (PFAS)](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/media/images/EEC%20PFAS%20Lab%20Thumbnail.jpg?itok=h0P8IN3r)
The U.S. Geological Survey laboratory for the analysis of per- and polyfluoroalkyl substances (PFAS) uses cutting-edge techniques to analyze environmental samples including tissues, plasma, water, and soils to undertake and support research projects across the country.
The U.S. Geological Survey laboratory for the analysis of per- and polyfluoroalkyl substances (PFAS) uses cutting-edge techniques to analyze environmental samples including tissues, plasma, water, and soils to undertake and support research projects across the country.
PubTalk-03/2023: Coral Reef in Crisis - Science to Guide Reef Restoration for Ecosystem Recovery
linkCoral Reef in Crisis - Science to Guide Reef Restoration for Ecosystem Recovery
By Ilsa Kuffner, Research Marine Biologist
USGS St. Petersburg Coastal & Marine Science Center
Learn About:
PubTalk-03/2023: Coral Reef in Crisis - Science to Guide Reef Restoration for Ecosystem Recovery
linkCoral Reef in Crisis - Science to Guide Reef Restoration for Ecosystem Recovery
By Ilsa Kuffner, Research Marine Biologist
USGS St. Petersburg Coastal & Marine Science Center
Learn About:
Behind the Headlines of a Wildlife Disease Die-off
The how and why of wildlife disease investigation
By Dr. Kimberli Miller, Wildlife Disease Specialist
USGS National Wildlife Health Center
Behind the Headlines of a Wildlife Disease Die-off
The how and why of wildlife disease investigation
By Dr. Kimberli Miller, Wildlife Disease Specialist
USGS National Wildlife Health Center
USGS volunteer Liliana uses a syringe to draw an eDNA sample from a rock pool along the Puka Stream. The eDNA sampled by USGS field crews informs research on invasive mosquito population dynamics.
USGS volunteer Liliana uses a syringe to draw an eDNA sample from a rock pool along the Puka Stream. The eDNA sampled by USGS field crews informs research on invasive mosquito population dynamics.
Kili Kawaiaea and Liliana Tobar sampling eDNA from a rock pool along the Puka Stream.
Kili Kawaiaea and Liliana Tobar sampling eDNA from a rock pool along the Puka Stream.
A biologist measures the length of a brook trout as part of a study on environmental DNA (eDNA).
A biologist measures the length of a brook trout as part of a study on environmental DNA (eDNA).
![Disease and Contaminates Affecting Wildlife and the Environment Image: Prairie Pothole Dragonfly](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/NOROCK_2_EnergyMinerals.jpg?itok=tufehnGD)
Slide show with examples of disease and contaminates affecting wildlife and the environment
Slide show with examples of disease and contaminates affecting wildlife and the environment
![Scientist wading in river with an orange inflatable boat](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/media/images/RoseauRiverWildlifeManagementArea.jpg?itok=lh153YSH)
Field assistant Kathryn Johncock wades in a wetland while filtering for infectious avian influenza virus at the Roseau River Wildlife Management Area, Roseau, Minnesota.
Field assistant Kathryn Johncock wades in a wetland while filtering for infectious avian influenza virus at the Roseau River Wildlife Management Area, Roseau, Minnesota.
![Environmental Health Program Energy Lifecycle Integrated science Team Activities USGS scientists collecting water-quality samples from observation wells](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/thumbnails/image/bemidji_water_sampling_2011_21_l.jpg?itok=H9hwjk-w)
News
USGS partners with Havasupai Tribe to identify potential contaminant exposure pathways from Grand Canyon uranium mining
Pesticides are likely impacting invertebrate life essential to our nation’s streams
Monitoring Change at the Lower Darby Creek Area Superfund Site
The publications listed below are a sampling of USGS science on this topic and do not represent an exhaustive list.
The science listed below is a sampling of USGS science on this topic and do not represent an exhaustive list.
Pesticide Fate Research Group (PFRG)
Avian Influenza
Effect of Chronic Neonicotinoid Insecticide Exposure upon Monarch Development
Risk of Adult Mosquito Control Pesticides to Imperiled Butterflies
Beak Deformities in Landbirds
Ecology of Wildlife Disease
Ecology of Plague
Ecological Investigations of White-Nose Syndrome in Bats
Aquatic Ecology and Contaminants
Ecology of Insect-eating Bats
The data listed below are a sampling of USGS science on this topic and do not represent an exhaustive list.
The multimedia listed below are a sampling of USGS science on this topic and do not represent an exhaustive list.
The news below is a sampling of USGS science on this topic and do not represent an exhaustive list.
The FAQs below are a sampling of USGS science on this topic and do not represent an exhaustive list.