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: 3087
Proximate composition, energetic value, and relative abundance of prey fish from the inshore eastern Bering Sea: Implications for piscivorous predators Proximate composition, energetic value, and relative abundance of prey fish from the inshore eastern Bering Sea: Implications for piscivorous predators
Changing ocean conditions and subsequent shifts in forage fish communities have been linked to numerical declines of some piscivorous marine birds and mammals in the North Pacific. However, limited information about fish communities is available for some regions, including nearshore waters of the eastern Bering Sea, where many piscivores reside. We determined proximate composition and...
Authors
J.R. Ball, Daniel Esler, Joel A. Schmutz
Mass dynamics of wintering Pacific Black Brant: Body, adipose tissue, organ, and muscle masses vary with location Mass dynamics of wintering Pacific Black Brant: Body, adipose tissue, organ, and muscle masses vary with location
We compared body size and mass of the whole body, organs, adipose tissue, and muscles of adult Pacific Black Brant (Branta bernicla nigricans (Lawrence, 1846)) collected concurrently in Alaska and Baja California during the fall, winter, and spring of 2002–2003. Head and tarsal lengths of males were similar between sites and slightly larger for females in Alaska than in Baja California...
Authors
D.D. Mason, P.S. Barboza, David H. Ward
Post-den emergence behavior of polar bears (Ursus maritimus) in Northern Alaska Post-den emergence behavior of polar bears (Ursus maritimus) in Northern Alaska
We observed polar bear (Ursus maritimus) maternity den sites on Alaska’s North Slope in March 2002 and 2003 in an effort to describe bears’ post-den emergence behavior. During 40 sessions spanning 459 h, we observed 8 adults and 14 dependent cubs outside dens for 37.5 h (8.2% of total observation time). There was no significant difference between den emergence dates in 2002 (mean = 15...
Authors
T. S. Smith, Steven T. Partridge, Steven C. Amstrup, S. Schliebe
Early marine growth in relation to marine-stage survival rates for Alaska sockeye salmon (Oncorhynchus nerka) Early marine growth in relation to marine-stage survival rates for Alaska sockeye salmon (Oncorhynchus nerka)
We tested the hypothesis that larger juvenile sockeye salmon (Oncorhynchus nerka) in Bristol Bay, Alaska, have higher marine-stage survival rates than smaller juvenile salmon. We used scales from returning adults (33 years of data) and trawl samples of juveniles (n= 3572) collected along the eastern Bering Sea shelf during August through September 2000−02. The size of juvenile sockeye...
Authors
Edward V. Farley, J.M. Murphy, Milo D. Adkison, Lisa B. Eisner, J.H. Helle, J.H. Moss, Jennifer L. Nielsen
The geophysical character of southern Alaska - Implications for crustal evolution The geophysical character of southern Alaska - Implications for crustal evolution
The southern Alaska continental margin has undergone a long and complicated history of plate convergence, subduction, accretion, and margin-parallel displacements. The crustal character of this continental margin is discernible through combined analysis of aeromagnetic and gravity data with key constraints from previous seismic interpretation. Regional magnetic data are particularly...
Authors
R. W. Saltus, T. L. Hudson, Frederic H. Wilson
Estimating the amount of eroded section in a partially exhumed basin from geophysical well logs: An example from the North Slope Estimating the amount of eroded section in a partially exhumed basin from geophysical well logs: An example from the North Slope
The reconstruction of burial and thermal histories of partially exhumed basins requires an estimation of the amount of erosion that has occurred since the time of maximum burial. We have developed a method for estimating eroded thickness by using porosity-depth trends derived from borehole sonic logs of wells in the Colville Basin of northern Alaska. Porosity-depth functions defined from...
Authors
W. Matthew Burns, Daniel O. Hayba, Elisabeth L. Rowan, David W. Houseknecht
Upper triassic continental margin strata of the central alaska range: Implications for paleogeographic reconstruction Upper triassic continental margin strata of the central alaska range: Implications for paleogeographic reconstruction
Remnants of a Late Triassic continental margin and ocean basin are scattered across central and southern Alaska. Little is known about the fundamental nature of the margin because most remnants have not been studied in detail and a protracted period of terrane accretion and margin-parallel translation has disrupted original stratigraphic and structural relationships. Three new conodont...
Authors
A.B. Till, A. G. Harris, B. R. Wardlaw, M. Mullen
Using a bioenergetic model to assess growth reduction from catch-and-release fishing and hooking injury in rainbow trout, Oncorhynchus mykiss Using a bioenergetic model to assess growth reduction from catch-and-release fishing and hooking injury in rainbow trout, Oncorhynchus mykiss
A bioenergetic model was used to predict the potential effects of feeding cessation caused by catch-and-release capture and a reduction in feeding efficiency from hooking injuries on rainbow trout, Oncorhynchus mykiss (Walbaum), growth in southwest Alaska, USA. Simulations indicated that a 1-day feeding cessation for a rainbow trout captured one to two times during summer months resulted...
Authors
Julie M. Meka, F.J. Margraf
Assessment of marine-derived nutrients in the Copper River Delta, Alaska, using natural abundance of the stable isotopes of nitrogen, sulfur, and carbon Assessment of marine-derived nutrients in the Copper River Delta, Alaska, using natural abundance of the stable isotopes of nitrogen, sulfur, and carbon
We performed nitrogen, sulfur, and carbon stable isotope analysis (SIA) on maturing and juvenile anadromous sockeye and coho salmon, and periphyton in two Copper River delta watersheds of Alaska to trace salmonderived nutrients during 2003–2004. Maturing salmon were isotopically enriched relative to alternate freshwater N, S, and C sources as expected, with differences consistent with...
Authors
Thomas C. Kline, Carol Ann Woody, Mary Anne Bishop, Sean P. Powers, E. Eric Knudsen
North to Alaska: Evidence for conveyor belt transport of Dungeness crab larvae along the west coast of the United States and Canada North to Alaska: Evidence for conveyor belt transport of Dungeness crab larvae along the west coast of the United States and Canada
We propose and evaluate the hypothesis that Dungeness crab (Cancer magister) larvae from the northwestern coast of the United States and Canada can be transported northward to southeastern Alaska. Larvae collected in southeastern Alaska during May and June 1997–2004 had abundances and stages that varied seasonally, interannually, and spatially. An unexpected presence of late-stage larvae...
Authors
W. Park, David C. Douglas, Thomas C. Shirley
Landward and eastward shift of Alaskan polar bear denning associated with recent sea ice changes Landward and eastward shift of Alaskan polar bear denning associated with recent sea ice changes
Polar bears (Ursus maritimus) in the northern Alaska region den in coastal areas and on offshore drifting ice. We evaluated changes in the distribution of polar bear maternal dens between 1985 and 2005, using satellite telemetry. We determined the distribution of maternal dens occupied by 89 satellite collared female polar bears between 137°W and 167°W longitude. The proportion of dens...
Authors
Anthony S. Fischbach, Steven C. Amstrup, David C. Douglas
Distribution of ground-nesting marine birds along shorelines in Glacier Bay, southeastern Alaska: An assessment related to potential disturbance by back-country users Distribution of ground-nesting marine birds along shorelines in Glacier Bay, southeastern Alaska: An assessment related to potential disturbance by back-country users
With the exception of a few large colonies, the distribution of ground-nesting marine birds in Glacier Bay National Park in southeastern Alaska is largely unknown. As visitor use increases in back-country areas of the park, there is growing concern over the potential impact of human activities on breeding birds. During the 2003–05 breeding seasons, the shoreline of Glacier Bay was...
Authors
Mayumi L. Arimitsu, John F. Piatt, Marc D. Romano