Images

Summer photo of Salix reticulata in the USFWS Arctic National Wildlife Refuge, a forage species commonly consumed by barren-ground caribou. The bright red bulbs on the right leaf are not berries, but galls, likely caused by bacteria, fungi, or insects.

The dominant plant in the photo is Arctic sweet coltsfoot (Petasides frigidus), a forage species commonly consumed by barren-ground caribou during the summer in the USFWS Arctic National Wildlife Refuge.

Summer photo of diamond-leaf willow (Salix pulchra) in the USFWS Arctic National Wildlife Refuge, a forage species commonly consumed by barren-ground caribou. 

USGS Staff at the Unuk River Streamgage in Southeast Alaska. The Unuk River is the second smallest watershed in the transboundary study of Southeast Alaska, but has three large mining projects in development (Kerr-Sulplherets-Mitchell (KSM), Brucejack, and Eskay Creek)

Pacific walrus group hauled-out on sea ice in the Chukchi Sea. The photo was captured during a survey of the age structure of the population to evaluate population status. Observers assign each animal in a group to an age/sex category according to published criteria. USFWS Permit No. 33776D. 

Pacific walrus group hauled-out on sea ice in the Chukchi Sea. The photo was captured during a survey of the age structure of the population to evaluate population status. Observers assign each animal in a group to an age/sex category according to published criteria.  USFWS Permit No. 33776D.

A biologist samples lake trout (Salvelinus namaycush) tissues. This fish, captured in Chelle Lake within Wrangell-St. Elias National Park, is part of a study investigating the biomagnification of mercury through lake food webs. Mount Drum rises above the hills to the southeast. 

Scientists collecting a 1/5 yard composite sample in blue 5-gallon buckets from gold placer tailings to analyze for critical mineral contents in Clear Creek, in the Zane Hills north central Alaska.

An adult female Pacific walrus slides into the water as she assesses her surroundings.  The female is 15 years or older based on the length of the tusks.  USGS and the U.S.

Walrus groups hauled on sea ice as far as the eye can see in the Chukchi Sea.  USGS and the U.S.

Alarge, active, and noisy walrus group hauled on sea ice in the Chukchi Sea.  USGS and the U.S.

Amanda Herbert (foreground) and Ami Everett onboard the R/V Norseman II. Amanda and Ami are on top of the wheelhouse of the ship to observe groups of Pacific walrus hauled-out on sea ice. Observers assign each animal in a group to an age/sex category according to published criteria.

A dim light shines during the summer Arctic morning in the Chukchi Sea as groups of Pacific walruses rest.  USGS and the U.S.

From left: Joshua Carpenter (USGS volunteer), William Beatty (USGS research wildlife biologist), Caroline Cummings (USGS volunteer), Amanda Herbert (USGS biological science technician), and Ami Everett (USGS biological science technician) conducting Pacific walrus age structure surveys from the RV Norseman II.  The team observed walruses hau

From left:  Joshua Carpenter (USGS volunteer), Ami Everett (USGS biological science technician), Amanda Herbert (USGS biological science technician), and Caroline Cummings (USGS volunteer) conducting Pacific walrus age structure surveys from the RV Norseman II.

An adult female walrus with a one-year old offspring.  USGS and the U.S.

Pacific walrus group hauled-out on sea ice in the Chukchi Sea. The photo was captured during a survey of the age structure of the population to evaluate population status. Observers assign each animal in a group to an age/sex category according to published criteria. USFWS Permit No. 33776D. 

A rainbow emerges from an evening shower in the Chukchi Sea.  USGS and the U.S.

Orange streams are increasingly common in the Brooks Range of northern Alaska. The orange stream color reflects oxidized iron, but also often indicates elevated heavy metal concentrations. Our ongoing study aims to document these occurrences and the timing of their onset.

Orange streams are increasingly common in the Brooks Range of northern Alaska. The orange stream color reflects oxidized iron, but also often indicates elevated heavy metal concentrations. Our ongoing study aims to document these occurrences and the timing of their onset.

Orange streams are increasingly common in the Brooks Range of northern Alaska. The orange stream color reflects oxidized iron, but also often indicates elevated heavy metal concentrations. Our ongoing study aims to document these occurrences and the timing of their onset.