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
Diminishing sea ice in the western Arctic Ocean Diminishing sea ice in the western Arctic Ocean
Since the advent of satellite passive microwave radiometry (1978), variations in sea ice extent and concentration have been carefully monitored from space. An estimated 7.4% decrease in sea ice extent has occurred in the last 25 yr (Johannessen et al. 2004), with recent record minima (e.g., Maslanik et al. 1999; Serreze et al. 2003) accounting for much of the decline. Comparisons between...
Authors
R. S. Stone, G. I. Belchansky, Sheldon Drobot, David C. Douglas
Sea otter research methods and tools Sea otter research methods and tools
Sea otters possess physical characteristics and life history attributes that provide both opportunity and constraint to their study. Because of their relatively limited diving ability they occur in nearshore marine habitats that are usually viewable from shore, allowing direct observation of most behaviors. Because sea otters live nearshore and forage on benthic invertebrates, foraging...
Authors
James L. Bodkin
Response of predators to Western Sandpiper nest exclosures Response of predators to Western Sandpiper nest exclosures
In 2001, predator exclosures were used to protect nests of the Western Sandpiper (Calidris mauri) in western Alaska. During the exclosure experiment, nest contents in exclosures had significantly higher daily survival rates than control nests, however, late in the study predators began to cue in on exclosures and predate the nest contents. An Arctic Fox (Alopex lagopus) dug under one...
Authors
Amanda C. Niehaus, Daniel R. Ruthrauff, Brian J. McCaffery
Subarctic, alpine nesting by Bairds Sandpipers Calidris bairdii Subarctic, alpine nesting by Bairds Sandpipers Calidris bairdii
Baird's Sandpipers Calidris bairdii were found nesting in alpine habitat in southwestern Alaska (60°48'N, 154°00'W), almost 250 km from the nearest known breeding site, and studied over three consecutive seasons, 1997-1999. The first birds arrived during the second week of May each spring with peak numbers recorded the third week of May. Most nests and newly hatched broods were found on...
Authors
Robert E. Gill, Pavel S. Tomkovich
Spatial variation in shorebird nest success: Implications for inference Spatial variation in shorebird nest success: Implications for inference
Estimates of nest success are widely applied in order to evaluate a multitude of theoretical and practical issues. Frequently, however, researchers fail to limit their inferences to the appropriate spatial scale. We evaluated small-scale variation in nest success of Western Sandpipers Calidris mauri during a four-year study on the Yukon-Kuskokwim Delta in western Alaska. We use these...
Authors
Brian J. McCaffery, Daniel R. Ruthrauff
Introduction [to Issue 3] Introduction [to Issue 3]
Artificial propagation of aquatic organisms is increasing globally and currently accounts for approximately 32% of total world fishery production (Vannuccini, 2004). Between 1970 and 2000, aquaculture production of salmonids has grown from less than 200,000 metric tons per year to over 1.5 million metric tons (Tacon, 2003). In 1995, the number of Atlantic salmon (Salmo salar) far...
Authors
Christian E. Zimmerman, Jennifer L. Nielsen
Persistent organic pollutants in Alaskan murre (Uria spp.) eggs: Geographical, species, and temporal comparisons Persistent organic pollutants in Alaskan murre (Uria spp.) eggs: Geographical, species, and temporal comparisons
Concentrations of persistent organic pollutants (POPs) in eggs of common and thick-billed murres (Uria aalge and U. lomvia) from five Alaskan nesting colonies were dominated by 4,4‘-DDE, total polychlorinated biphenyls (ΣPCBs; 46 congeners comprised mainly of PCB congeners 153, 118, 138, 99, and 151), hexachlorobenzene (HCB), β-hexachlorocyclohexane (β-HCH), and chlordane compounds (ΣCHL...
Authors
Stacy S. Vander Pol, Paul R. Becker, John R. Kucklick, Rebecca S. Pugh, David G. Roseneau, Kristin S. Simac
Spatiotemporal predictability of schooling and nonschooling prey of Pigeon Guillemots Spatiotemporal predictability of schooling and nonschooling prey of Pigeon Guillemots
Low spatiotemporal variability in the abundance of nonschooling prey might allow Pigeon Guillemots (Cepphus columba) to maintain the high chick provisioning rates that are characteristic of the species. We tested predictions of this hypothesis with data collected with beach seines and scuba and hydroacoustic surveys in Kachemak Bay, Alaska, during 1996–1999. Coefficients of variability...
Authors
Michael A. Litzow, John F. Piatt, Alisa A. Abookire, Suzann G. Speckman, Mayumi L. Arimitsu, Jared D. Figurski
A comparison of genetic ariation between an anadromous steelhead, Oncorhynchus mykiss, population and seven derived populations sequestered in freshwater for 70 years A comparison of genetic ariation between an anadromous steelhead, Oncorhynchus mykiss, population and seven derived populations sequestered in freshwater for 70 years
In 1926 cannery workers from the Wakefield Fisheries Plant at Little Port Walter in Southeast Alaska captured small trout, Oncorhynchus mykiss, from a portion of Sashin Creek populated with a wild steelhead (anadromous O. mykiss) run. They planted them into Sashin Lake which had been fishless to that time and separated from the lower stream by two large waterfalls that prevented upstream...
Authors
Frank Thrower, Charles Guthrie, Jennifer L. Nielsen, John Joyce
Reaction rim growth on olivine in silicic melts: Implications for magma mixing Reaction rim growth on olivine in silicic melts: Implications for magma mixing
Finely crystalline amphibole or pyroxene rims that form during reaction between silicic host melt and cognate olivine xenocrysts, newly introduced during magma mixing events, can provide information about the timing between mixing and volcanic eruptions. We investigated rim growth experimentally by placing forsteritic olivine in rhyolitic and rhyodacitic melts for times between 25 and...
Authors
Michelle L. Coombs, James E. Gardner
Determinants of reproductive costs in the long-lived Black-legged Kittiwake: A multiyear experiment Determinants of reproductive costs in the long-lived Black-legged Kittiwake: A multiyear experiment
We studied reproductive costs of Black-legged Kittiwakes (Rissa tridactyla) in Prince William Sound, Alaska (USA) by removing entire clutches from randomly selected nests over four successive years, and then contrasting survival and fecundity of adults from manipulated and unmanipulated nests in each subsequent year. To elucidate mechanisms that lead to the expression of reproductive...
Authors
Gregory H. Golet, Joel A. Schmutz, David B. Irons, James A. Estes
Ultra-high chlorine in submarine Kı̄lauea glasses: Evidence for direct assimilation of brine by magma Ultra-high chlorine in submarine Kı̄lauea glasses: Evidence for direct assimilation of brine by magma
Basaltic glass grains from the submarine south flank of Kı̄lauea, Hawai′i, have Cl concentrations of 0.01–1.68 wt%, the latter being the highest Cl content yet recorded for a Hawaiian glass. The high-Cl glass grains are products of brine assimilation by tholeiite magma. The glasses are grains in a sandstone clast from bedded breccias draping the southwestern margin of Kı̄lauea’s...
Authors
Michelle L. Coombs, Thomas W. Sisson, Jun-Ichi Kimura