Publications
USGS research activities relevant to Alaska have yielded more than 9400 historical publications. This page features some of the most recent newsworthy research findings.
Filter Total Items: 3111
The use of sea ice habitat by female polar bears in the Beaufort Sea The use of sea ice habitat by female polar bears in the Beaufort Sea
Polar bears (Ursus maritimus) depend on ice-covered seas to satisfy life history requirements. Modern threats to polar bears include oil spills in the marine environment and changes in ice composition resulting from climate change. Managers need practical models that explain the distribution of bears in order to assess the impacts of these threats. We used stepwise procedures to create...
Authors
George M. Durner, Steven C. Amstrup, Ryan M. Nielson, Trent McDonald
Detecting denning polar bears with forward looking infra-red imagery (FLIR) Detecting denning polar bears with forward looking infra-red imagery (FLIR)
Polar bears give birth in snow dens in mid winter, and remain in dens until early spring. Survival and development of neonates is dependent on the stable environment within the maternal den. Petroleum related activities currently span approximately 200 km of the Alaskan Beaufort Sea coastal area. New and proposed developments are expected to dramatically expand the area influenced by...
Authors
Steven C. Amstrup, Geoff Weston-York, T. L. McDonald, R. Neilsen, Kristin S. Simac, George M. Durner
Unlocking the secrets of Lake Clark sockeye salmon Unlocking the secrets of Lake Clark sockeye salmon
Sockeye salmon are a cornerstone species in many Alaska watersheds. Each summer, adults lay eggs in rocky nests called “redds,” and they die soon after. In spring, their fry emerge from gravels and then rear in a nearby freshwater lake for one year or more before migrating as smolt to the sea. During this smolt phase, an olfactory map of their route is imprinted on their memories...
Authors
Carol Ann Woody
Bear-human interactions at Glacier Bay National Park and Preserve: Conflict risk assessment Bear-human interactions at Glacier Bay National Park and Preserve: Conflict risk assessment
Many bear-human conflicts have occurred in Alaska parks and refuges, resulting in area closures, property damage, human injury, and loss of life. Human activity in bear country has also had negative and substantial consequences for bears: disruption of their natural activity patterns, displacement from important habitats, injury, and death. It is unfortunate for both people and bears...
Authors
Tom S. Smith, Terry D. DeBruyn, Tania Lewis, Rusty Yerxa, Steven T. Partridge
Lake Clark sockeye salmon population assessment Lake Clark sockeye salmon population assessment
Radio telemetry was used to identify and map sockeye salmon spawning habitats in glacially influenced Lake Clark, Kvichak River watershed, Alaska. Two hundred eighty-two adult sockeye salmon were radio tagged and tracked to spawning grounds. Thirty-five spawning areas were identified, including 18 previously unidentified. Comparison of radio telemetry data with past aerial population...
Authors
Carol Ann Woody, Kristina M. Ramstad, Daniel Young, G. Kevin Sage, Fred W. Allendorf
[Book Review] Biology of marine birds [Book Review] Biology of marine birds
A text devoted to the biology and ecology of marine birds has not been published in the last 15 years. Although a number of more taxa-specific texts have been produced during that period, there has not been a single publication that attempted to review our knowledge of all the major seabird orders since the works of Nelson (1979), Croxall (1987), and Furness and Monaghan (1987)...
Authors
Patrick G.R. Jodice, Daniel D. Roby, Michelle Antolos, Donald E. Lyons, Daniel Rizzolo, Sadie K. Wright, Cynthia D. Anderson, Scott K. Anderson, S. Kim Nelson, Adrian E. Gall, Liv Wennerberg
Metamorphism within the Chugach accretionary complex on southern Baranof Island, southeastern Alaska Metamorphism within the Chugach accretionary complex on southern Baranof Island, southeastern Alaska
On Baranof Island, southeastern Alaska, we identify four metamorphic events that affect rocks associated with the Chugach accretionary complex. This study focuses on the M1 and M4 metamorphic events. Mesozoic schists, gneisses, and migmatitic gneisses exposed near the Kasnyku pluton on central Baranof Island represent the M1 metamorphic rocks. These rocks underwent amphibolite facies...
Authors
Cathy L. Zumsteg, Glen R. Himmelberg, Susan M. Karl, Peter J. Haeussler
Surgical implantation of transmitters into fish Surgical implantation of transmitters into fish
Although the Animal Welfare Act does not cover poikilotherms, individual institutions and policies and legal requirements other than the Animal Welfare Act (e.g., the US Public Health Service and the Interagency Research Animal Committee's Principles for the Utilization and Care of Vertebrate Animals Used in Testing, Research, and Training) require the review of projects involving fish...
Authors
Daniel M. Mulcahy
Large woody debris and flow resistance in step-pool channels, Cascade Range, Washington Large woody debris and flow resistance in step-pool channels, Cascade Range, Washington
Total flow resistance, measured as Darcy-Weisbach f, in 20 step-pool channels with large woody debris (LWD) in Washington, ranged from 5 to 380 during summer low flows. Step risers in the study streams consist of either (1) large and relatively immobile woody debris, bedrock, or roots that form fixed, or “forced,” steps, or (2) smaller and relatively mobile wood or clasts, or a mixture...
Authors
Janet H. Curran, Ellen E. Wohl
Using the bootstrap and fast Fourier transform to estimate confidence intervals of 2D kernel densities Using the bootstrap and fast Fourier transform to estimate confidence intervals of 2D kernel densities
No abstract available.
Authors
John W. Kern, Trent L. McDonald, Steven C. Amstrup, George M. Durner, Wallace P. Erickson
Demography of Dall's sheep in northwestern Alaska Demography of Dall's sheep in northwestern Alaska
Dall’s sheep in northwestern Alaska declined in the early 1990s following the severe 1989-90 and 1990-91 winters. In the Baird Mountains of Noatak National Preserve, estimates of adult sheep declined by 50% from 800 in 1989 to under 400 in 1991. Population counts remained low throughout 1991 to 1996, reaching a minimum of 244 adult sheep in 1996. Few lambs were observed during annual...
Authors
Christopher Kleckner, Mark S. Udevitz, Layne G. Adams, Brad S. Shults
Polar bear aerial survey in the eastern Chukchi Sea: A pilot study Polar bear aerial survey in the eastern Chukchi Sea: A pilot study
Alaska has two polar bear populations: the Southern Beaufort Sea population, shared with Canada, and the Chukchi/Bering Seas population, shared with Russia. Currently a reliable population estimate for the Chukchi/Bering Seas population does not exist. Land-based aerial and mark-recapture population surveys may not be possible in the Chukchi Sea because variable ice conditions, the...
Authors
Thomas J. Evans, Anthony S. Fischbach, Scott L. Schliebe, Bryan Manly, Susanne B. Kalxdorff, Geoff S. York