Microscopic photograph of the cyanobacteria Dolichospermum circinale cells in curved filaments. This photograph is typical of the photographs in the field and laboratory guide to help identify cyanobacteria under microscopes. Figure 40 from USGSOpen-File Report 2015–1164.
Images
![Microscopic photograph of the cyanobacteria Dolichospermum circinale cells in curved filaments](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/thumbnails/image/figure_40_cyanobacteria_dolichospermum_circinale_usgs_ofr20151164_ann_st_amand_l.jpg?itok=8fauaXIL)
Microscopic photograph of the cyanobacteria Dolichospermum circinale cells in curved filaments. This photograph is typical of the photographs in the field and laboratory guide to help identify cyanobacteria under microscopes. Figure 40 from USGSOpen-File Report 2015–1164.
Dusty conditions prior to road treatment on the auto tour loop at Loess Bluffs National Wildlife Refuge in July 2014. Loess Bluffs was the site of a large-scale field test of two dust suppressant products, with monitoring of product performance and environmental safety.
Dusty conditions prior to road treatment on the auto tour loop at Loess Bluffs National Wildlife Refuge in July 2014. Loess Bluffs was the site of a large-scale field test of two dust suppressant products, with monitoring of product performance and environmental safety.
![USGS scientists collecting a water sample from a well at the USGS Bemidji Research Site](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/thumbnails/image/bemidji_water_quality_sampling_july_field_session_69.jpg?itok=D_h67N-t)
U.S. Geological Survey (USGS) scientists collecting a groundwater sample from a well at the USGS Bemidji Crude-Oil Spill Research Site, Minnesota. The scientists monitored in real time the dissolved oxygen, pH, specific conductance, and temperature of the water as the well is pumped so they can know when to collect representative sample.
U.S. Geological Survey (USGS) scientists collecting a groundwater sample from a well at the USGS Bemidji Crude-Oil Spill Research Site, Minnesota. The scientists monitored in real time the dissolved oxygen, pH, specific conductance, and temperature of the water as the well is pumped so they can know when to collect representative sample.
![Close up of the cyanobacteria Dolichospermum lemmermannii in a harmful algal bloom](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/thumbnails/image/figure_4_cyanobacteria_dolichospermum_lemmermannii_usgs_ofr20151164_ann_st_amand_l.jpg?itok=W1_hcfTv)
Close up of the cyanobacteria Dolichospermum lemmermannii in a harmful algal bloom
Close up of the cyanobacteria Dolichospermum lemmermannii in a harmful algal bloom
Experimental setup for small-scale transport test designed to assess the effectiveness of the "colmation layer" at the bottom sediments of Ashumet Pond (Cape Cod, Massachusetts) for filtering out cyanobacteria and viruses.
Experimental setup for small-scale transport test designed to assess the effectiveness of the "colmation layer" at the bottom sediments of Ashumet Pond (Cape Cod, Massachusetts) for filtering out cyanobacteria and viruses.
![USGS scientists collecting water-quality samples from shallow groundwater under Ashumet Pond](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/thumbnails/image/groundwater_sampling_under_ashumet_pond_img_1006_0.jpg?itok=ATLDVmdX)
U.S. Geological Survey (USGS) scientists collecting water-quality samples from shallow groundwater under Ashumet Pond, Cape Cod, Massachusetts.
U.S. Geological Survey (USGS) scientists collecting water-quality samples from shallow groundwater under Ashumet Pond, Cape Cod, Massachusetts.
![Crude-oil recovery system implemented at the Bemidji, Minnesota, research site](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/thumbnails/image/bemidji_crude_oil_recovery_system_l.png?itok=5fBVIqCW)
Crude-oil recovery system implemented at the Bemidji, Minnesota, research site, 1999 to 2003. The crude-oil in the unsaturated zone above the water table contained a mixture of crude oil, air, and water in the sediment pore spaces (Delin and Herkelrath, 2014).
Crude-oil recovery system implemented at the Bemidji, Minnesota, research site, 1999 to 2003. The crude-oil in the unsaturated zone above the water table contained a mixture of crude oil, air, and water in the sediment pore spaces (Delin and Herkelrath, 2014).
U.S. Geological Survey (USGS) scientist collects periphyton samples from Nantahala river near Hewitt, North Carolina
U.S. Geological Survey (USGS) scientist collects periphyton samples from Nantahala river near Hewitt, North Carolina
![US Geological Survey scientist measuring dissolved oxygen in a stream water sample.](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/thumbnails/image/wc_do_measurement_wvhf-04-061714_l.jpg?itok=BnJwToS2)
U.S. Geological Survey (USGS) scientist measuring dissolved oxygen in a stream water sample. The scientist is part of a USGS team of scientists that are investigating the potential environmental effects of activities at an oil and gas wastewater injection facility in West Virginia.
U.S. Geological Survey (USGS) scientist measuring dissolved oxygen in a stream water sample. The scientist is part of a USGS team of scientists that are investigating the potential environmental effects of activities at an oil and gas wastewater injection facility in West Virginia.
Scientist holding an adult Pacific lamprey collected at Bonneville Dam. The dam is on the Columbia River between the states of Oregon and Washington.
Scientist holding an adult Pacific lamprey collected at Bonneville Dam. The dam is on the Columbia River between the states of Oregon and Washington.
![USGS scientist collecting water samples on a wastewater disposal facility](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/thumbnails/image/sampling_at_disposal_facility_wvhf-06-061814_16.jpg?itok=cMcARf9C)
U.S.
![A view of the New River from the New River Gorge Bridge, West Virgina](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/thumbnails/image/new_river_view_wolf_creek_p_6_17_14_l.jpg?itok=fWnAr0GE)
A view of the New River from the New River Gorge Bridge, West Virgina. Wolf Creek is a tributary of the New River. Photo: Denise M. Akob, USGS.
A view of the New River from the New River Gorge Bridge, West Virgina. Wolf Creek is a tributary of the New River. Photo: Denise M. Akob, USGS.
A U.S. Geological Survey (USGS) scientist recording water-quality parameters (pH, temperature, and specific conductance) during the purging of a domestic well that was sampled for radon at a site north of Jersey Shore, Pennsylvania.
A U.S. Geological Survey (USGS) scientist recording water-quality parameters (pH, temperature, and specific conductance) during the purging of a domestic well that was sampled for radon at a site north of Jersey Shore, Pennsylvania.
Installing nest boxes at Clarks Marsh, Michigan, for a study of avian exposure and effects of Perfluoroalkyl substances (PFASs). Clarks Marsh, is on the south side of the former Wurtsmith Air Force Base in Oscoda Township, Michigan.
Installing nest boxes at Clarks Marsh, Michigan, for a study of avian exposure and effects of Perfluoroalkyl substances (PFASs). Clarks Marsh, is on the south side of the former Wurtsmith Air Force Base in Oscoda Township, Michigan.
Sunset view looking northwest from Fishermans Cove, across Ashumet Pond, Cape Cod, Massachusetts. The small sticks and flags in the lake are a sampling grid.
Sunset view looking northwest from Fishermans Cove, across Ashumet Pond, Cape Cod, Massachusetts. The small sticks and flags in the lake are a sampling grid.
![man wearing a life jacket holding a dip net](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/thumbnails/image/Colleting%20dragonfly%20larvae.jpeg?itok=9S82aYRg)
Between 2009 and 2018, scientists conducted a national scale assessment of mercury accumulation in the National Park System using dragonfly larvae as biosentinels (species that accumulate a pollutant in their tissues as an index of exposure to other organisms without significant adverse effects to the biosentinel) through a citizen science network called the Dragonf
Between 2009 and 2018, scientists conducted a national scale assessment of mercury accumulation in the National Park System using dragonfly larvae as biosentinels (species that accumulate a pollutant in their tissues as an index of exposure to other organisms without significant adverse effects to the biosentinel) through a citizen science network called the Dragonf
![USGS scientist collecting a water-quality sample from Zollner Creek, Oregon](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/thumbnails/image/zollner_creek_oregon_sampling_img_3169.jpg?itok=OUBUGTwn)
USGS Scientist Collecting a Water-Quality Sample from Zollner Creek, Oregon, for the Analysis of Dissolved Pesticides
linkU.S. Geological Survey (USGS) hydrologic technician Dan Polette collecting a water-quality sample from Zollner Creek, Oregon for a national-scale investigation of the environmental occurrence of neonicotinoid insecticides in agricultural and urban settings.
USGS Scientist Collecting a Water-Quality Sample from Zollner Creek, Oregon, for the Analysis of Dissolved Pesticides
linkU.S. Geological Survey (USGS) hydrologic technician Dan Polette collecting a water-quality sample from Zollner Creek, Oregon for a national-scale investigation of the environmental occurrence of neonicotinoid insecticides in agricultural and urban settings.
![U.S. Geological Survey (USGS) scientist collecting water-quality samples from the Enoree River, South Carolina](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/thumbnails/image/collecting_water_quality_sample_enoree_river_site_p1010244_l.jpg?itok=4YYRCFXW)
USGS scientist collecting water-quality samples from the Enoree River, SC
USGS scientist collecting water-quality samples from the Enoree River, SC
![USGS scientist processing water-quality samples collected from the Enoree River, South Carolina](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/thumbnails/image/processing_water_quality_samples_enoree_river_site_p1010243_l.jpg?itok=kH95kE_T)
USGS scientist processing water-quality samples. She is surrounded by lots of equipment
USGS scientist processing water-quality samples. She is surrounded by lots of equipment
American kestrel egg experiment
American kestrel egg experiment
![USGS scientists collecting mycrocystin samples from Enoree River at Pelham, South Carolina](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/thumbnails/image/p1010152_crop_enoree_river_sc_l.jpg?itok=JcxpJGiX)
USGS scientists collecting microcystin samples from the Enoree River at Pelham, South Carolina
USGS scientists collecting microcystin samples from the Enoree River at Pelham, South Carolina