Images

This is a graphical abstract for a publication by the USGS and collaborators that examines the role of diet and food intake affecting polar bear population dynamics. Polar bears consume diets consisting of high proportions of marine mammal blubber that they access from the sea ice.

Figure comparing Synthetic Aperture Radar (SAR) satellite images of Pacific walruses on a terrestrial haulout near Point Lay, Alaska, as collected by four different SAR instruments possessing different spatial resolution capabilities (Sentinel-1, Radarsat-2, TerraSAR-X, and Capella Space).

Tributary of Kugururok River located in Noatak National Park and Preserve, Alaska with orange water. Recent observations from Arctic Alaska indicate that waters draining permafrost landscapes may be susceptible to iron and carbon mobilization following thaw.

Deposition on tributary of Salmon River located in Kobuk Valley National Park, Alaska. Recent observations from Arctic Alaska indicate that waters draining permafrost landscapes may be susceptible to iron and carbon mobilization following thaw.

Tributary of Salmon River located in Kobuk Valley National Park, Alaska. Recent observations from Arctic Alaska indicate that waters draining permafrost landscapes may be susceptible to iron and carbon mobilization following thaw.

Mainstem of Salmon River located in Kobuk Valley National Park, Alaska. Recent observations from Arctic Alaska indicate that waters draining permafrost landscapes may be susceptible to iron and carbon mobilization following thaw.

Tributary of Salmon River located in the Kobuk Valley National Park, Alaska. Recent observations from Arctic Alaska indicate that waters draining permafrost landscapes may be susceptible to iron and carbon mobilization following thaw.

Tyree Brown is holding a GPS, where he is navigating to the next survey point. Photo taken on Bird Ridge. In the background is Turnagain Arm, Alaska. Photo taken by Toshio Matsuoka

Tyree brown, smiling, stands on a rocky outcrop at Bird ridge, Alaska with mountains in the background. Photo by Toshio Matsuoka

Tyree brown is hiking up Bird Ridge with Turnagain Arm in the background. Photo taken by Toshio Matsuoka.

Tyree brown is recording a GPS point of a survey point in the middle of a mixed deciduous and evergreen forest on Bird Ridge, Alaska. The survey marker is the shiny metal disk on the tree on the right side of the frame. Photo by Toshio Matsuoka

Scientist checking a gold pan for gold and critical minerals in placer tailings on lower Chicken Creek near Flat, Alaska, in the Kuskokwim Mountains. A sample was collected from legacy gold placer tailings at this site and 7 others in the Flat mining district to determine the critical mineral contents of tailings from which only gold has been removed.

USGS crew measuring forest conditions following the Dixie Fire in 2021. Lassen Volcanic National Park. California. 

A bucket holds an assortment of forage-sized fishes from Lion Bay on the Beaufort Sea, Alaska. Species include saffron cod (Eleginus gracilis), Arctic cod (Boreogadus saida), fourhorn sculpin (Myoxocephalus quadricornis), and Arctic smelt (Osmerus mordax), among others.

Fourhorn sculpin, Beaufort Sea, Alaska. A fourhorn sculpin sits in a net pen underwater.

A saffron cod (left, Eleginus gracilis) and Arctic cod (right, Boreogadus saida) sit on a measuring board for comparison.

An assortment of forage sized fishes from the Beaufort Sea, Alaska lie on a measuring board.

An eroding and slumping shoreline adjacent to a fyke net fishing site in Lion Bay, Beaufort Sea, Alaska.

A Common Murre holding a capelin at a breeding colony on Gull Island, in Kachemak Bay, Alaska. Capelin are an important, energy rich forage fish for many marine predators.

Six slender eelblennys (Lumpenus fabricii) and two fourhorn sculpin (Myoxocephalus quadricornis) lie on a measuring board. Fish collected from Beaufort Sea, Alaska.

A Tufted Puffin carrying a bill load of capelin back to its chick on Gull Island, in Kachemak Bay, Alaska. Capelin are an important, energy rich forage fish for many marine predators.