Images

Photographs from Wild Turkeys (Meleagris gallopavo) found dead in Wisconsin, USA.  (A) The liver contains many multifocal to coalescing bullseye-shaped foci of necrosis (arrows). The ventriculus (*) is labeled for orientation. (B) The paired ceca (*) are ectatic with thickened walls.

Photomicrographs from Wild Turkeys (Meleagris gallopavo) found dead in Wisconsin, USA.  (A) In the liver, hepatocytes were replaced by macrophages, lymphocytes, and plasma cells (lower left) with occasional multinucleated giant cells (arrows). H&E stain.  (B) The cecum contains a fibrinonecrotic membrane effacing the mucosa (arrow).

Lauren Privette holds a large ice block from a frozen lake at Treehaven education center in northern Wisconsin.

Field team member Laura Hubbard shows off a sample in the field after pickup from the wastewater facility.

Five clear glass bottles contain samples of dry plankton, ranging in color from brown to dark green. Plankton samples were collected from different monthly collections in Lake Mendota, Wisconsin. The color gradient highlights how plankton communities can rapidly change over the course of spring to summer.

Justin Hegarty (Reflo Sustainable Water Solutions) and Dr. Tony Parolari (Marquette University) discussing the design of a bioswale at the Green Tech Station on Milwaukee’s north side.

This rat snake is a preserved museum specimen with snake fungal disease that was collected in Tennessee in 1973. The photo was taken at the USGS National Wildlife Health Center in 2017 as part of a study.

Entrance to the USDA Forest Products Laboratory building in Madison, Wisconsin, home of the Upper Midwest Water Science Center Wisconsin office and the Mercury Research Laboratory.

A restored section of Underwood Creek at Wauwatosa, Wisconsin. https://waterdata.usgs.gov/monitoring-location/04087088/

USGS scientists electrofishing with a backpack shocker at Underwood Creek at Wauwatosa, Wisconsin. https://waterdata.usgs.gov/monitoring-location/04087088/.

USGS scientist holding a milting rainbow trout caught as part of an assessment of fish passage in Underwood Creek at Wauwatosa, Wisconsin, just downstream of I-41/US 45. https://waterdata.usgs.gov/monitoring-location/04087088/

Rainbow trout caught in net in Underwood Creek at Wauwatosa, Wisconsin. https://waterdata.usgs.gov/monitoring-location/04087088/

USGS scientist holding a white sucker fish caught in Underwood Creek at Wauwatosa, Wisconsin. https://waterdata.usgs.gov/monitoring-location/04087088/

USGS scientist holding a male central stoneroller caught in Underwood Creek at Wauwatosa, Wisconsin. https://waterdata.usgs.gov/monitoring-location/04087088/. This fish is native to Wisconsin; the tubercles (bumps) on its head indicate that it is spawning.

USGS scientist Sarah Janssen preparing the multicollector inductively coupled plasma mass spectrometer for mercury isotope measurements at the M3 Research Laboratory.

USGS scientist Grace Armstrong sampling plankton on Lake Mendota in Madison, Wisconsin.

MC-ICP-MS used for mercury stable isotope analyses.

Nippon mercury analyzer for sediments and fish.

Photomicrographs from a big brown bat (Eptesicus fuscus) from Wisconsin, USA. H&E stain. (A) Low magnification of a cross section through the nares showing nasal cavity (*), oral mucosa (arrowhead), and haired skin (arrow). (B) Higher magnification showing a normal hair follicle (arrow) surrounded by sebaceous glands.

Graduate student, Grace Armstrong, performing mercury uptake studies in plankton at Mercury Research Laboratory, Middleton, Wisconsin.

Photo of helicopter with geophysical equipment loop deployed below it via slingload. Technician for scale. In January 2021 a helicopter carried an airborne electromagnetic induction sensor over parts of northeastern Wisconsin as part of a USGS study to map the aquifers in the region.