Using surface velocities to calculate ice thickness and bed topography: A case study at Columbia Glacier, Alaska, USA
R.W. McNabb, R. Hock, Shad O’Neel, Lowell A. Rasmussen, Y. Ahn, M. Braun, H. Conway, S. Herreid, I. Joughin, W.T. Pfeffer, B.E. Smith, M. Truffer
2012, Journal of Glaciology (58) 1151-1164
Information about glacier volume and ice thickness distribution is essential for many glaciological applications, but direct measurements of ice thickness can be difficult and costly. We present a new method that calculates ice thickness via an estimate of ice flux. We solve the familiar continuity equation between adjacent flowlines, which...
Interactions between methylmercury and selenomethionine injected into mallard eggs
J.D. Klimstra, J.L. Yee, G. H. Heinz, D. J. Hoffman, K.R. Stebbins
2012, Environmental Toxicology and Chemistry (31) 579-584
Methylmercury chloride and seleno-L-methionine were injected separately or in combinations into mallard eggs (Anas platyrhynchos), and embryo mortality and teratogenic effects (deformities) were modeled using a logistic regression model. Methylmercury was injected at doses that resulted in concentrations of 0, 0.2, 0.4, 0.8, and 1.6 µg/g Hg in the...
Chronic hydrocarbon exposure of harlequin ducks in areas affected by the Selendang Ayu oil spill at Unalaska Island, Alaska
Paul L. Flint, J.L. Schamber, K.A. Trust, A.K. Miles, J.D. Henderson, B.W. Wilson
2012, Environmental Toxicology and Chemistry (31) 2828-2831
We evaluated chronic exposure of harlequin ducks (Histrionicus histrionicus) to hydrocarbons associated with the 2004 M/V Selendang Ayu oil spill at Unalaska Island, Alaska. We measured levels of hepatic 7-ethoxyresorufin-O-deethylase activity (EROD) in liver biopsy samples as an indicator of hydrocarbon exposure in three oiled bays and one reference bay in...
High shrew diversity on Alaska's Seward Peninsula: Community assembly and environmental change
Andrew G. Hope
2012, Northwestern Naturalist (93) 101-110
In September 2010, 6 species of shrews (genus: Sorex) were collected at a single locality on the Seward Peninsula of Alaska. Such high sympatric diversity within a single mammalian genus is seldom realized. This phenomenon at high latitudes highlights complex Arctic community dynamics that reflect significant turnover through time as...
Rapid movement of frozen debris-lobes: implications for permafrost degradation and slope instability in the south-central Brooks Range, Alaska
R.P. Daanen, G. Grosse, M.M. Darrow, T. D. Hamilton, Benjamin M. Jones
2012, Natural Hazards and Earth System Sciences (12) 1521-1537
We present the results of a reconnaissance investigation of unusual debris mass-movement features on permafrost slopes that pose a potential infrastructure hazard in the south-central Brooks Range, Alaska. For the purpose of this paper, we describe these features as frozen debris-lobes. We focus on the characterisation of frozen debris-lobes as...
Food availability and offspring sex in a monogamous seabird: insights from an experimental approach
Thomas Merkling, Sarah Leclaire, Etienne Danchin, Emeline Lhuillier, Richard H. Wagner, Joel White, Scott A. Hatch, Pierrick Blanchard
2012, Behavioral Ecology (23) 751-758
Sex allocation theory predicts that parents should favor offspring of the sex that provides the greatest fitness return. Despite growing evidence suggesting that vertebrates are able to overcome the constraint of chromosomal sex determination, the general pattern remains equivocal, indicating a need for experimental investigations. We used an experimental feeding...
Listening to Glaciers: Passive hydroacoustics near marine-terminating glaciers
E.C. Pettit, J.A. Nystuen, Shad O’Neel
2012, Oceanography (25) 104-105
The catastrophic breakup of the Larsen B Ice Shelf in the Weddell Sea in 2002 paints a vivid portrait of the effects of glacier-climate interactions. This event, along with other unexpected episodes of rapid mass loss from marine-terminating glaciers (i.e., tidewater glaciers, outlet glaciers, ice streams, ice shelves) sparked intensified...
Vegetation shifts observed in arctic tundra 17 years after fire
Kirsten Barrett, Adrian V. Rocha, Martine Janet van de Weg, Gaius Shaver
2012, Remote Sensing Letters (3) 729-736
With anticipated climate change, tundra fires are expected to occur more frequently in the future, but data on the long-term effects of fire on tundra vegetation composition are scarce. This study addresses changes in vegetation structure that have persisted for 17 years after a tundra fire on the North Slope...
Tectonic influences on the preservation of marine terraces: Old and new evidence from Santa Catalina Island, California
R. Randall Schumann, Scott A. Minor, Daniel R. Muhs, Lindsey T. Groves, John P. McGeehin
2012, Geomorphology (179) 208-224
The California Channel Islands contain some of the best geologic records of past climate and sea-level changes, recorded in uplifted, fossil-bearing marine terrace deposits. Among the eight California Channel Islands and the nearby Palos Verdes Hills, only Santa Catalina Island does not exhibit prominent emergent marine terraces, though the same...
Influences on Bythotrephes longimanus life-history characteristics in the Great Lakes
Steven A. Pothoven, Henry A. Vanderploeg, David M. Warner, Jeffrey S. Schaeffer, Stuart A. Ludsin, Randall M. Claramunt, Thomas F. Nalepa
2012, Journal of Great Lakes Research (38) 134-141
We compared Bythotrephes population demographics and dynamics to predator (planktivorous fish) and prey (small-bodied crustacean zooplankton) densities at a site sampled through the growing season in Lakes Michigan, Huron, and Erie. Although seasonal average densities of Bythotrephes were similar across lakes (222/m2 Erie, 247/m2 Huron, 162/m2 Michigan), temporal trends in...
Montana Valley and Foothill Prairies Ecoregion: Chapter 6 in Status and trends of land change in the Western United States--1973 to 2000
Janis L. Taylor
2012, Professional Paper 1794-A-6
The Montana Valley and Foothill Prairies Ecoregion comprises numerous intermountain valleys and low-elevation foothill prairies spread across the western half of Montana, on both sides of the Continental Divide (Omernik, 1987; U.S. Environmental Protection Agency, 1997). The ecoregion, which covers approximately 64,658 km2 (24,965 mi2), includes the Flathead Valley and...
Northern Rockies Ecoregion: Chapter 7 in Status and trends of land change in the Western United States--1973 to 2000
Janis L. Taylor
2012, Professional Paper 1794-A-7
The Northern Rockies Ecoregion (Omernik, 1987; U.S. Environmental Protection Agency, 1997) covers approximately 162,746 km2 (63,200 mi2), primarily in Idaho but also including areas in western Montana and northeastern Washington (fig. 1). Canada forms the northern border of the ecoregion. To the west it is bordered by the Columbia Plateau...
Middle Rockies Ecoregion: Chapter 5 in Status and trends of land change in the Western United States--1973 to 2000
Janis L. Taylor
2012, Professional Paper 1794-A-5
The Middle Rockies Ecoregion—characterized by steep, high-elevation mountain ranges and intermountain valleys—is a disjunct ecoregion composed of three distinct geographic areas: the Greater Yellowstone area in northwest Wyoming, southwest Montana, and eastern Idaho; the Bighorn Mountains in north-central Wyoming and south-central Montana; and the Black Hills in western South Dakota...
Canadian Rockies Ecoregion: Chapter 4 in Status and trends of land change in the Western United States--1973 to 2000
Janis L. Taylor
2012, Professional Paper 1794-A-4
The Canadian Rockies Ecoregion covers approximately 18,494 km2 (7,141 mi2) in northwestern Montana (Omernik, 1987; U.S. Environmental Protection Agency, 1997). The east side of the ecoregion is bordered by the Montana Valley and Foothill Prairies Ecoregion, which also forms a large part of the western border of the ecoregion. In...
Willamette Valley Ecoregion: Chapter 3 in Status and trends of land change in the Western United States--1973 to 2000
Tamara S. Wilson, Daniel G. Sorenson
2012, Professional Paper 1794-A-3
The Willamette Valley Ecoregion (as defined by Omernik, 1987; U.S. Environmental Protection Agency, 1997) covers approximately 14,458 km² (5,582 mi2), making it one of the smallest ecoregions in the conterminous United States. The long, alluvial Willamette Valley, which stretches north to south more than 193 km and ranges from 32...
Carbon dioxide and methane emissions from the Yukon River system
Robert G. Striegl, Mark M. Dornblaser, Cory P. McDonald, Jennifer R. Rover, Edward G. Stets
2012, Global Biogeochemical Cycles (26)
Carbon dioxide (CO2) and methane (CH4) emissions are important, but poorly quantified, components of riverine carbon (C) budgets. This is largely because the data needed for gas flux calculations are sparse and are spatially and temporally variable. Additionally, the importance of C gas emissions relative to lateral C exports is...
Extreme weather and experience influence reproduction in an endangered bird
Brian E. Reichert, Christopher E. Cattau, Robert J. Fletcher Jr., William L. Kendall, Wiley M. Kitchens
2012, Ecology (93) 2580-2589
Extreme weather events, such as droughts and heat waves, are expected to become more severe and more frequent in the coming years, and understanding their impacts on demographic rates is of increasing interest to both evolutionary ecologists and conservation practitioners. An individual's breeding probability can be a sensitive indicator...
Population status and habitat associations of the King Rail in the midwestern United States
Jason R. Bolenbaugh, Tom Cooper, Ryan S. Brady, Karen L. Willard, David G. Krementz
2012, Waterbirds (35) 535-545
The migratory population of the King Rail (Rallus elegans) has declined dramatically during the past 50 years, emphasizing the need to document the distribution and status of this species to help guide conservation efforts. In an effort to guide King Rail breeding habitat protection and restoration, a landscape suitability index...
Spatial and temporal patterns of surface water quality and ichthyotoxicity in urban and rural river basins in Texas
Matthew M. VanLandeghem, Matthew D. Meyer, Stephen B. Cox, Bibek Sharma, Reynaldo Patino
2012, Water Research (20) 6638-6651
The Double Mountain Fork Brazos River (Texas, USA) consists of North (NF) and South Forks (SF). The NF receives urban runoff and twice-reclaimed wastewater effluent, whereas the SF flows through primarily rural areas. The objective of this study was to determine and compare associations between standard water quality variables and...
Solute and geothermal flux monitoring using electrical conductivity in the Madison, Firehole, and Gibbon Rivers, Yellowstone National Park
R. Blaine McCleskey, Laura Clor, Jacob B. Lowenstern, William C. Evans, D. Kirk Nordstrom, Henry Heasler, Mark Huebner
2012, Applied Geochemistry (27) 2370-2381
The thermal output from the Yellowstone magma chamber can be estimated from the Cl flux in the major rivers in Yellowstone National Park; and by utilizing continuous discharge and electrical conductivity measurements the Cl flux can be calculated. The relationship between electrical conductivity and concentrations of Cl and other geothermal...
A Bayesian spawning habitat suitability model for American shad in southeastern United States rivers
Joseph E. Hightower, Julianne E. Harris, Joshua K. Raabe, Prescott Brownell, C. Ashton Drew
2012, Journal of Fish and Wildlife Management (3) 184-198
Habitat suitability index models for American shad Alosa sapidissima were developed by Stier and Crance in 1985. These models, which were based on a combination of published information and expert opinion, are often used to make decisions about hydropower dam operations and fish passage. The purpose of this study was to develop...
A simple method for in situ monitoring of water temperature in substrates used by spawning salmonids
Christian E. Zimmerman, James E. Finn
2012, Journal of Fish and Wildlife Management (3) 288-295
Interstitial water temperature within spawning habitats of salmonids may differ from surface-water temperature depending on intragravel flow paths, geomorphic setting, or presence of groundwater. Because survival and developmental timing of salmon are partly controlled by temperature, monitoring temperature within gravels used by spawning salmonids is required to adequately describe the...
Groundwater depletion and sustainability of irrigation in the US High Plains and Central Valley
Bridget R. Scanlon, Claudia C. Faunt, Laurent Longuevergne, Robert C. Reedy, William M. Alley, Virginia L. McGuire, Peter B. McMahon
2012, Proceedings of the National Academy of Sciences (109) 9320-9325
Aquifer overexploitation could significantly impact crop production in the United States because 60% of irrigation relies on groundwater. Groundwater depletion in the irrigated High Plains and California Central Valley accounts for ∼50% of groundwater depletion in the United States since 1900. A newly developed High Plains recharge map shows that...
Estimating landscape carrying capacity through maximum clique analysis
Therese Donovan, Greg Warrington, W. Scott Schwenk, Jeffrey H. Dinitz
2012, Ecological Applications (22) 2265-2276
Habitat suitability (HS) maps are widely used tools in wildlife science and establish a link between wildlife populations and landscape pattern. Although HS maps spatially depict the distribution of optimal resources for a species, they do not reveal the population size a landscape is capable of supporting--information that is often...
Evaluating the negative effect of benthic egg predators on bloater recruitment in northern Lake Michigan
David B. Bunnell, Justin G. Mychek-Londer, James S. Diana, Wendylee Stott, Charles P. Madenjian
2012, Report
As the only extant deepwater cisco in Lake Michigan, bloater is currently at record low levels of abundance. Several mechanisms to regulate their recruitment have been proposed, including skewed sex ratios, predation on their larvae by adult alewife, and climatic factors during early life history stages, but none has...
