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: 2885
The evolutionary history of steelhead (Oncorhynchus mykiss) along the US Pacific Coast: Developing a conservation strategy using genetic diversity
Changes in genetic variation across a species range may indicate patterns of population structure resulting from past ecological and demographic events that are otherwise difficult to infer and thus provide insight into evolutionary development. Genetic data is used, drawn from 11 microsatellite loci amplified from anadromous steelhead (Oncorhynchus mykiss) sampled throughout its range in the east
Authors
J.L. Nielsen
The epipelagic fish community of Beaufort Sea coastal waters, Alaska
A three-year study of epipelagic fishes inhabiting Beaufort Sea coastal waters in Alaska documented spatial and temporal patterns in fish distribution and abundance and examined their relationships to thermohaline features during summer. Significant interannual, seasonal, and geographical differences in surface water temperatures and salinities were observed. In 1990, sea ice was absent and marine
Authors
L. E. Jarvela, Lyman K. Thorsteinson
Surgical and immediate postrelease mortality of harlequin ducks (Histrionicus histrionicus) implanted with abdominal radio transmitters with percutaneous antennae
Radiotelemetry is an essential tool in the study of free-ranging bird populations, and a variety of transmitter-attachment methods have been developed. A promising new method is abdominal implantation of a transmitter with a percutaneous antenna. Researchers using this technique should be concerned about and aware of mortality during surgery and during the immediate postrelease period (the 14-day
Authors
Daniel M. Mulcahy, Daniel Esler
Working group on future trends
This working group did not divide into subgroups, and its report consists of a unified document in a format somewhat different than those of the other working groups. The group considered four major topics: (1) projected "new" contaminants of future concern; (2) future trends with contaminants currently known to be issues for marine mammals; (3) future needs to improve and insure consistency of sa
Authors
Implications of climate change for Alaska's seabirds
Seabirds are prominent and highly visible components of marine ecosystems that will be affected by global climate change. The Bering Sea region is particularly important to seabirds; populations there are larger and more diverse than in any similar region in North America—over 90% of seabirds breeding in the continental United States are found in this region. Seabirds, so named because they spend
Authors
Rosa Meehan, G. Vernon Byrd, George J. Divoky, John F. Piatt
Seasonal shorebird use of intertidal habitats in Cook Inlet, Alaska
Seasonal shorebird use of intertidal habitats of Cook Inlet, Alaska, was studied from February 1997 to February 1999 using aerial surveys as the principal method of assessment. On-ground studies were conducted to validate aerial survey results and to assess shorebird use of vegetated habitats, especially during the breeding season. Twenty-eight species of shorebirds were recorded using the area, r
Authors
Robert E. Gill, T. Lee Tibbitts
Sand lance as cornerstone prey for predator populations
Sand lance (Ammodytes) constitute a major prey for at least some populations of over 100 species of consumer, including 40 species of birds, 12 species of marine mammals, 45 species of fishes, and some invertebrates. Variation in the availability of sand lance (and other forage fishes) can have major effects on the breeding success and survival of their predators. Commercial fishing and other pres
Authors
Mary F. Willson, Robert H. Armstrong, Martin D. Robards, John F. Piatt
Sand lance: A review of biology and predator relations and annotated bibliography
Six species of sand lance (Ammodytes) in temperate and boreal regions are currently recognized. Sand lance can occupy a wide range of environmental conditions, but all appear to be dormant predominantly in winter, and one species is in summer also. They lack a swim bladder and spend much of their time buried in specific substrates. Copepods are the primary food. Spawning usually occurs in fall or
Comparison of aerial survey procedures for estimating polar bear density: Results of pilot studies in northern Alaska
The U.S. Marine Mammal Protection Act (MMPA) and International Agreement on the Conservation of Polar Bears mandate that boundaries and sizes of polar bear (Ursus maritimus) populations be known so they can be managed at optimum sustainable levels. However, data to estimate polar bear numbers for the Chukchi/Bering Sea and Beaufort Sea populations in Alaska are limited. We evaluated aerial line tr
Authors
Lyman L. McDonald, Gerald W. Garner
Modeling variability in replicated surveys at aggregation sites
Surveys of aggregation sites can provide unbiased estimates of annual trends in population size if the proportion of the population counted at these sites does not vary systematically among years. However, counts at these sites tend to be highly variable and resulting trend estimates typically have poor precision. I developed an index based on a simple parametric model for counts of Pacific walrus
Authors
Mark S. Udevitz