Loss of volatile hydrocarbons from an LNAPL oil source
Mary Jo Baedecker, Robert P. Eganhouse, Barbara A. Bekins, Geoffrey N. Delin
2011, Journal of Contaminant Hydrology (126) 140-152
The light nonaqueous phase liquid (LNAPL) oil pool in an aquifer that resulted from a pipeline spill near Bemidji, Minnesota, was analyzed for volatile hydrocarbons (VHCs) to determine if the composition of the oil remains constant over time. Oil samples were obtained from wells at five locations in the oil...
Precision of two methods for estimating age from burbot otoliths
W.H. Edwards, M.A. Stapanian, A.T. Stoneman
2011, Journal of Applied Ichthyology (27) 43-48
Lower reproductive success and older age structure are associated with many burbot (Lota lota L.) populations that are declining or of conservation concern. Therefore, reliable methods for estimating the age of burbot are critical for effective assessment and management. In Lake Erie, burbot populations have declined in recent years due...
Simulation of branched serial first-order decay of atrazine and metabolites in adapted and nonadapted soils
R. M. Webb, Mark W. Sandstrom, L.J. Krutz, D. L. Shaner
2011, Environmental Toxicology and Chemistry (30) 1973-1981
In the present study a branched serial first‐order decay (BSFOD) model is presented and used to derive transformation rates describing the decay of a common herbicide, atrazine, and its metabolites observed in unsaturated soils adapted to previous atrazine applications and in soils with no history of atrazine applications. Calibration of...
The bioinvasion of Guam: inferring geographic origin, pace, pattern and process of an invasive lizard (Carlia) in the Pacific using multi-locus genomic data
C.C. Austin, E.N. Rittmeyer, L.A. Oliver, J.O. Andermann, G.R. Zug, G.H. Rodda, N.D. Jackson
2011, Biological Invasions (13) 1951-1967
Invasive species often have dramatic negative effects that lead to the deterioration and loss of biodiversity frequently coupled with the burden of expensive biocontrol programs and subversion of socioeconomic stability. The fauna and flora of oceanic islands are particularly susceptible to invasive species and the increase of global movements of...
The role of model dynamics in ensemble Kalman filter performance for chaotic systems
G.-H.C. Ng, D. McLaughlin, D. Entekhabi, A. Ahanin
2011, Tellus, Series A: Dynamic Meteorology and Oceanography (63) 958-977
The ensemble Kalman filter (EnKF) is susceptible to losing track of observations, or ‘diverging’, when applied to large chaotic systems such as atmospheric and ocean models. Past studies have demonstrated the adverse impact of sampling error during the filter’s update step. We examine how system dynamics affect EnKF performance, and...
Factors controlling the early stages of viral haemorrhagic septicaemia epizootics: Low exposure levels, virus amplification and fish-to-fish transmission
P.K. Hershberger, J.L. Gregg, C.A. Grady, L.M. Hart, S.R. Roon, J. R. Winton
2011, Journal of Fish Diseases (34) 893-899
Viral haemorrhagic septicaemia virus, Genogroup IVa (VHSV), was highly infectious to Pacific herring, Clupea pallasii (Valenciennes), even at exposure doses occurring below the threshold of sensitivity for a standard viral plaque assay; however, further progression of the disease to a population‐level epizootic required viral amplification and effective fish‐to‐fish transmission. Among groups of...
Groupers on the edge: Shelf edge spawning habitat in and around marine reserves of the northeastern Gulf of Mexico
Felicia C. Coleman, Kathryn M. Scanlon, Christopher C. Koenig
2011, Professional Geographer (63) 456-474
The northeastern Gulf of Mexico contains some of the most diverse and productive marine habitat in the United States. Much of this habitat, located on the shelf edge in depths of 50 to 120 m, supports spawning for many economically important species, including groupers. Here, we couple acoustic surveys with...
Patterns in young-of-year smallmouth bass microhabitat use in multiple stream segments with contrasting land uses
S.K. Brewer
2011, Fisheries Management and Ecology (18) 506-512
Young‐of‐the‐year (YOY) smallmouth bass, Micropterus dolomieu Lacepéde, were evaluated in streams from eight catchments with two contrasting land uses to determine their use of microhabitats under a variety of stream conditions. Step‐wise discriminant function analyses revealed patterns of habitat use by discriminating used from available microhabitat conditions. Velocity was significant in 88%...
Native and exotic plants of fragments of sagebrush steppe produced by geomorphic processes versus land use
N. Huntly, R. Bangert, S.E. Hanser
2011, Plant Ecology (212) 1549-1561
Habitat fragmentation and invasion by exotic species are regarded as major threats to the biodiversity of many ecosystems. We surveyed the plant communities of two types of remnant sagebrush-steppe fragments from nearby areas on the Snake River Plain of southeastern Idaho, USA. One type resulted from land use (conversion to...
Where the wild things are: Predicting hotspots of seabird aggregations in the California Current System
N. Nur, J. Jahncke, M.P. Herzog, J. Howar, K.D. Hyrenbach, J.E. Zamon, D. G. Ainley, J. A. Wiens, K. Morgan, L.T. Balance, D. Stralberg
2011, Ecological Applications (21) 2241-2257
Marine Protected Areas (MPAs) provide an important tool for conservation of marine ecosystems. To be most effective, these areas should be strategically located in a manner that supports ecosystem function. To inform marine spatial planning and support strategic establishment of MPAs within the California Current System, we identified areas predicted...
Variations in eruption style during the 1931A.D. eruption of Aniakchak volcano, Alaska
R.S. Nicholson, J.E. Gardner, C.A. Neal
2011, Journal of Volcanology and Geothermal Research (207) 69-82
The 1931 A.D. eruption of Aniakchak volcano, Alaska, progressed from subplinian to effusive eruptive style and from trachydacite to basaltic andesite composition from multiple vent locations. Eyewitness accounts and new studies of deposit stratigraphy provide a combined narrative of eruptive events. Additional field, compositional, grain size, componentry, density, and grain morphology...
Comparing laser-based open- and closed-path gas analyzers to measure methane fluxes using the eddy covariance method
Matteo Detto, Joseph Verfaillie, Frank Anderson, Liukang Xu, Dennis Baldocchi
2011, Agricultural and Forest Meteorology (151) 1312-1324
Closed- and open-path methane gas analyzers are used in eddy covariance systems to compare three potential methane emitting ecosystems in the Sacramento-San Joaquin Delta (CA, USA): a rice field, a peatland pasture and a restored wetland. The study points out similarities and differences of the systems in field experiments and...
Population viability analysis to identify management priorities for reintroduced elk in the Cumberland Mountains, Tennessee
J.L. Kindall, L.I. Muller, J. D. Clark, J.L. Lupardus, J.L. Murrow
2011, Journal of Wildlife Management (75) 1745-1752
We used an individual-based population model to perform a viability analysis to simulate population growth (λ) of 167 elk (Cervus elaphus manitobensis; 71 male and 96 female) released in the Cumberland Mountains, Tennessee, to estimate sustainability (i.e., λ > 1.0) and identify the most appropriate options for managing elk restoration. We transported...
A comparison of methods to assess long-term changes in Sonoran Desert vegetation
S.M. Munson, R. H. Webb, J.A. Hubbard
2011, Journal of Arid Environments (75) 1228-1231
Knowledge about the condition of vegetation cover and composition is critical for assessing the structure and function of ecosystems. To effectively quantify the impacts of a rapidly changing environment, methods to track long-term trends of vegetation must be precise, repeatable, and time- and cost-efficient. Measuring vegetation cover and composition in...
Flow regime, temperature, and biotic interactions drive differential declines of trout species under climate change
S.J. Wenger, D.J. Isaak, C.H. Luce, H.M. Neville, K.D. Fausch, J. B. Dunham, D.C. Dauwalter, M.K. Young, M.M. Elsner, B.E. Rieman, A.F. Hamlet, J.E. Williams
2011, Proceedings of the National Academy of Sciences of the United States of America (108) 14175-14180
Broad-scale studies of climate change effects on freshwater species have focused mainly on temperature, ignoring critical drivers such as flow regime and biotic interactions. We use downscaled outputs from general circulation models coupled with a hydrologic model to forecast the effects of altered flows and increased temperatures on four interacting...
Bed morphology, flow structure, and sediment transport at the outlet of Lake Huron and in the upper St. Clair River
J. A. Czuba, J.L. Best, K. A. Oberg, D.R. Parsons, P.R. Jackson, M.H. Garcia, P. Ashmore
2011, Journal of Great Lakes Research (37) 480-493
An integrated multibeam echo sounder and acoustic Doppler current profiler field survey was conducted in July 2008 to investigate the morphodynamics of the St. Clair River at the outlet of Lake Huron. The principal morphological features of the upper St. Clair River included flow-transverse bedforms that appear weakly mobile, erosive bedforms in cohesive muds, thin non-cohesive veneers of...
Epistemic uncertainty in California-wide synthetic seismicity simulations
F. F. Pollitz
2011, Bulletin of the Seismological Society of America (101) 2481-2498
The generation of seismicity catalogs on synthetic fault networks holds the promise of providing key inputs into probabilistic seismic-hazard analysis, for example, the coefficient of variation, mean recurrence time as a function of magnitude, the probability of fault-to-fault ruptures, and conditional probabilities for foreshock-mainshock triggering. I employ a seismicity simulator...
Evaluation of influence of sediment on the sensitivity of a unionid mussel (Lampsilis siliquoidea) to ammonia in 28-day water exposures
N. Wang, R.A. Consbrock, C.G. Ingersoll, M.C. Barnhart
2011, Environmental Toxicology and Chemistry (30) 2270-2276
A draft update of the U.S. Environmental Protection Agency ambient water quality criteria (AWQC) for ammonia substantially lowers the ammonia AWQC, primarily due to the inclusion of toxicity data for freshwater mussels. However, most of the mussel data used in the updated AWQC were generated from water-only exposures and limited...
High-precision measurement of variations in calcium isotope ratios in urine by multiple collector inductively coupled plasma mass spectrometry
J.L.L. Morgan, G.W. Gordon, R.C. Arrua, J.L. Skulan, A.D. Anbar, T.D. Bullen
2011, Analytical Chemistry (83) 6956-6962
We describe a new chemical separation method to isolate Ca from other matrix elements in biological samples, developed with the long-term goal of making high-precision measurement of natural stable Ca isotope variations a clinically applicable tool to assess bone mineral balance. A new two-column procedure utilizing HBr achieves the purity...
Characteristics of foraging sites and protein status in wintering muskoxen: insights from isotopes of nitrogen
David D. Gustine, Perry S. Barboza, James P. Lawler, Stephen M. Arthur, Brad S. Shults, Kate Persons, Layne G. Adams
2011, Oikos (120) 1546-1556
Identifying links between nutritional condition of individuals and population trajectories greatly enhances our understanding of the ecology, conservation, and management of wildlife. For northern ungulates, the potential impacts of a changing climate to populations are predicted to be nutritionally mediated through an increase in the severity and variance in winter...
Genetic variation in westslope cutthroat trout Oncorhynchus clarkii lewisi: Implications for conservation
D.P. Drinan, S.T. Kalinowski, N.V. Vu, B.B. Shepard, C.C. Muhlfeld, M. R. Campbell
2011, Conservation Genetics (12) 1513-1523
Twenty-five populations of westslope cutthroat trout from throughout their native range were genotyped at 20 microsatellite loci to describe the genetic structure of westslope cutthroat trout. The most genetic diversity (heterozygosity, allelic richness, and private alleles) existed in populations from the Snake River drainage, while populations from the Missouri River...
40Ar* loss in experimentally deformed muscovite and biotite with implications for 40Ar/39Ar geochronology of naturally deformed rocks
M. Cosca, H. Stunitz, A.-L. Bourgeix, J.P. Lee
2011, Geochimica et Cosmochimica Acta (75) 7759-7778
The effects of deformation on radiogenic argon (40Ar∗) retentivity in mica are described from high pressure experiments performed on rock samples of peraluminous granite containing euhedral muscovite and biotite. Cylindrical cores, ∼15 mm in length and 6.25 mm in diameter, were drilled from granite collected from the South Armorican Massif in...
USGS remote sensing coordination for the 2010 Haiti earthquake
Kenneth A. Duda, Brenda Jones
2011, Photogrammetric Engineering and Remote Sensing (77) 899-908
In response to the devastating 12 January 2010, earthquake in Haiti, the US Geological Survey (USGS) provided essential coordinating services for remote sensing activities. Communication was rapidly established between the widely distributed response teams and data providers to define imaging requirements and sensor tasking opportunities. Data acquired from a variety...
Mars: the evolutionary history of the northern lowlands based on crater counting and geologic mapping
S.C. Werner, K. L. Tanaka, J.A. Skinner Jr.
2011, Planetary and Space Science (59) 1143-1165
The geologic history of planetary surfaces is most effectively determined by joining geologic mapping and crater counting which provides an iterative, qualitative and quantitative method for defining relative ages and absolute model ages. Based on this approach, we present spatial and temporal details regarding the evolution of the Martian northern...
Predicting breeding habitat for amphibians: A spatiotemporal analysis across Yellowstone National Park
Paul E. Bartelt, Alisa L. Gallant, Robert W. Klaver, C.K. Wright, Debra A. Patla, Charles R. Peterson
2011, Ecological Applications (21) 2530-2547
The ability to predict amphibian breeding across landscapes is important for informing land management decisions and helping biologists better understand and remediate factors contributing to declines in amphibian populations. We built geospatial models of likely breeding habitats for each of four amphibian species that breed in Yellowstone National Park (YNP)....
