Images

Bank erosion along an upstream reach of the Kinnickinnic River, October 2018.

Scientists collecting water samples for mercury isotope analysis in the Mobile River, Alabama.

Two single-frequency ADVMs mounted to Durand bridge.

Two white-tailed bucks (deer) looking at the camera at Lake of the Ozarks, Missouri.

USGS scientist removing attached algae from a defined surface area on one of multiple rocks collected in riffles at a stream site.

Close-up view of defined area of a rock cobble (middle) where attached algae and other material were removed with a brush. Rocks from multiple locations at a site are composited into a single sample representing the stream site.

USGS scientist collecting one of five subsamples of aquatic invertebrates from a stream riffle by removing invertebrates from a defined area and collecting them with a Surber net. Each subsample is transferred to a bucket for compositing into a single sample for the site.

Close up-view of defined area of the stream bottom where attached invertebrates are removed with a brush and washed into the Surber net; where possible, a hand rake is also used to dislodge organisms from shallow depths.

After collection, invertebrates are washed through a series of sieves where large debris can be removed before being placed in the sample bottle.

Panoramic view of scientists in boat on Hells Canyon Reservoir, Idaho

Scenic view while preparing to launch boats at Anderson Ranch, at the Anderson Reservoir, Idaho.

Flow-through sensor for measurement of three different optical signals.

Human-specific virus filtration units with 10-micron nominal pore size string-wound pre-filter and dead-end ultrafilter after a five-day composite sampling event with the Menomonee River in background. Menomonee River at 16^th St. in Milwaukee, Wisconsin.

Chromophoric (colored) Dissolved Organic Matter (CDOM) (left) and Tryptophan (right) sensors.

Photograph of a 24-bottle automatic sampler to collect water samples for optical properties of water and microbiological analyses.

Ultrafilters are used to concentrate pathogens from large-volume surface water samples. Plastic autoclaved bottles used for human-associated indicator bacteria analysis. Glass bottle used for DOC, simultaneous fluorescence and absorbance, and pharmaceutical compound analysis.

Prefilter and Ultrafilter assembly from Menomonee River at 16th St., Milwaukee, WI.

Particulate matter captured on a quartz fiber filter at the Mercury Research Laboratory.

Native birds resting on marker buoys in Brownlee Reservoir, Idaho.

Draining overlying water from sedimentation sampler at Brownlee Reservoir, Idaho.

Conduit associated with stream gage at Menomonee at 16th Street in Milwaukee (04087142).