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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: 2891

Population demographics and genetic diversity in remnant and translocated populations of sea otters

The effects of small population size on genetic diversity and subsequent population recovery are theoretically predicted, but few empirical data are available to describe those relations. We use data from four remnant and three translocated sea otter ( Enhydra lutris) populations to examine relations among magnitude and duration of minimum population size, population growth rates, and genetic vari
Authors
James L. Bodkin, Brenda E. Ballachey, M. A. Cronin, K.T. Scribner

At-sea distribution of Spectacled Eiders: A 120-year-old mystery resolved

The at-sea distribution of the threatened Spectacled Eider (Somateria fischeri) has remained largely undocumented. We identified migration corridors, staging and molting areas, and wintering areas of adult Spectacled Eiders using implanted satellite-transmitters in birds from each of the three extant breeding grounds (North Slope and Yukon-Kuskokwim Delta in Alaska and arctic Russia). Based on tra
Authors
Margaret R. Petersen, William W. Larned, David C. Douglas

Community reorganization in the Gulf of Alaska following ocean climate regime shift

A shift in ocean climate during the late 1970s triggered a reorganization of community structure in the Gulf of Alaska ecosystem, as evidenced in changing catch composition on long-term (1953 to 1997) small-mesh trawl surveys. Forage species such as pandalid shrimp and capelin declined because of recruitment failure and predation, and populations have not yet recovered. Total trawl catch biomass d
Authors
P.J. Anderson, John F. Piatt

Genetic structure of the world's polar bear populations

We studied genetic structure in polar bear (Ursus maritimus) populations by typing a sample of 473 individuals spanning the species distribution at 16 highly variable microsatellite loci. No genetic discontinuities were found that would be consistent with evolutionarily significant periods of isolation between groups. Direct comparison of movement data and genetic data from the Canadian Arctic rev
Authors
David Paetkau, Steven C. Amstrup, E.W. Born, W. Calvert, A.E. Derocher, G.W. Garner, F. Messier, I. Stirling, M.K. Taylor, O. Wiig, C. Strobeck

Subcutaneous implantation of satellite transmitters with percutaneous antennae into male polar bears (Ursus maritimus)

Male polar bears (Ursus maritimus) have not been successfully instrumented with satellite transmitters because they readily shed collar-mounted transmitters. Seven male polar bears were captured on the pack ice off the northern coast of Alaska and surgically implanted with satellite transmitters with percutaneous antennae into the subcutaneous space of the dorsal cervical region. Transmitters fail
Authors
Daniel M. Mulcahy, Gerald W. Garner

Measurements of Taku River, Alaska during Tulsequah Lake outburst floods

No abstract available.
Authors
Randy H. Host, Joseph M. Dorava

An aerial survey method to estimate sea otter abundance

Sea otters (Enhydra lutris) occur in shallow coastal habitats and can be highly visible on the sea surface. They generally rest in groups and their detection depends on factors that include sea conditions, viewing platform, observer technique and skill, distance, habitat and group size. While visible on the surface, they are difficult to see while diving and may dive in response to an approaching
Authors
James L. Bodkin, Mark S. Udevitz

Fluctuating asymmetry and genetic diversity in sea otters (Enhydra lutris)

No abstract available.
Authors
James L. Bodkin, Kimberly A. Kloecker, A. Burdin

Microsatellite diversity and conservation of a relic trout population: McCloud River redband trout

Rainbow trout native to the McCloud River, California, USA (Oncorhynchus mykiss stonei) are thought to represent a relic, nonanadromous trout adapted to harsh, fragmented environments. These fish, commonly named McCloud River ‘redband’ trout, survive in their most primitive form in a small, spring-fed stream, Sheepheaven Creek, in the upper McCloud River drainage. Turn-of-the-century fisheries rec
Authors
J.L. Nielsen, K.D. Crow, Monique C. Fountain

The needs of salmon and steelhead in balancing their conservation and use

Over the past 100 years, Pacific salmon Oncorhynchus spp. and steelhead trout O. mykiss populations in the Pacific Northwest have experienced dramatic declines as a result of human population growth and associated development of the region's natural resources. Any strategy to reverse those declines will depend on achieving consensus among a diverse group of stakeholders willing to (1) restore dama
Authors
Carl V. Burger

Vocalizations of the Kittlitz's Murrelet

We present the first documentation of Kittlitz's Murrelet (Brachyramphus brevirostris) vocalizations, based on recordings made in Glacier Bay, Alaska, in 1994. We identified two apparently related types of calls: groan and quack. The Kittlitz's Murrelet calls were markedly different from the most common calls of the congeneric Marbled Murrelet (Brachyramphus marmoratus), but shared characteristics
Authors
Thomas I. van Pelt, John F. Piatt, Gus B. Van Vliet