Whole-ecosystem study shows rapid fish-mercury response to changes in mercury deposition
R.C. Harris, J.W.M. Rudd, M. Amyot, Christopher L. Babiarz, K.G. Beaty, P.J. Blanchfield, R.A. Bodaly, B.A. Branfireun, C.C. Gilmour, J.A. Graydon, A. Heyes, H. Hintelmann, J.P. Hurley, C.A. Kelly, David P. Krabbenhoft, S.E. Lindberg, R.P. Mason, M.J. Paterson, C.L. Podemski, A. Robinson, K.A. Sandilands, G.R. Southworthn, Louis, Michael T. Tate
2007, Proceedings of the National Academy of Sciences of the United States of America (104) 16586-16591
Methylmercury contamination of fisheries from centuries of industrial atmospheric emissions negatively impacts humans and wild-life worldwide. The response of fish methylmercury concentrations to changes in mercury deposition has been difficult to establish because sediments/soils contain large pools of historical contamination, and many factors in addition to deposition affect fish mercury....
A stand-replacing fire history in upper montane forests of the southern Rocky Mountains
E.Q. Margolis, T.W. Swetnam, Craig D. Allen
2007, Canadian Journal of Forest Research (37) 2227-2241
Dendroecological techniques were applied to reconstruct stand-replacing fire history in upper montane forests in northern New Mexico and southern Colorado. Fourteen stand-replacing fires were dated to 8 unique fire years (1842–1901) using four lines of evidence at each of 12 sites within the upper Rio Grande Basin. The four lines...
Random forests for classification in ecology
D.R. Cutler, T.C. Edwards Jr., K.H. Beard, A. Cutler, K.T. Hess, J. Gibson, J.J. Lawler
2007, Ecology (88) 2783-2792
Classification procedures are some of the most widely used statistical methods in ecology. Random forests (RF) is a new and powerful statistical classifier that is well established in other disciplines but is relatively unknown in ecology. Advantages of RF compared to other statistical classifiers include (1) very high classification accuracy;...
Responses of California Brown Pelicans to disturbances at a large Oregon roost
Sadie K. Wright, D.D. Roby, R.G. Anthony
2007, Waterbirds (30) 479-487
Numbers of California Brown Pelicans (Pelecanus occidentalis californicus) along the coast of Oregon and Washington have increased sharply in recent years. We identified East Sand Island in the Columbia River estuary as the site of the largest pelican roost within this region. Numbers of pelicans roosting on East Sand Island...
Observations of magnetite dissolution in poorly drained soils
D.A. Grimley, N.K. Arruda
2007, Soil Science (172) 968-982
Dissolution of strongly magnetic minerals is a common and relatively rapid phenomenon in poorly drained soils of the central United States, resulting in low magnetic susceptibility (MS). Low Eh reducing conditions are primarily responsible for magnetic mineral dissolution; a process likely mediated by iron-reducing bacteria in the presence of soil...
Correlations between Cassini VIMS spectra and RADAR SAR images: Implications for Titan's surface composition and the character of the Huygens Probe Landing Site
Laurence A. Soderblom, Randolph L. Kirk, Jonathan I. Lunine, Jeffrey A. Anderson, Kevin H. Baines, Jason W. Barnes, Janet M. Barrett, Robert H. Brown, Bonnie J. Buratti, Roger N. Clark, Dale P. Cruikshank, Charles Elachi, Michael A. Janssen, Ralf Jaumann, Erich Karkoschka, Stéphane Le Mouélic, Rosaly Lopes, Ralph D. Lorenz, Thomas B. McCord, Philip D. Nicholson, Jani Radebaugh, Bashar Rizk, Christophe Sotin, Ellen R. Stofan, Tracie L. Sucharski, Martin G. Tomasko, Stephen D. Wall
2007, Planetary and Space Science (55) 2025-2036
Titan's vast equatorial fields of RADAR-dark longitudinal dunes seen in Cassini RADAR synthetic aperture images correlate with one of two dark surface units discriminated as “brown” and “blue” in Visible and Infrared Mapping Spectrometer (VIMS) color composites of short-wavelength infrared spectral cubes (RGB as 2.0, 1.6, 1.3 μm). In such composites...
Adequacy of satellite derived rainfall data for stream flow modeling
G. Artan, Hussein Gadain, Jodie Smith, Kwasi Asante, C.J. Bandaragoda, J. P. Verdin
2007, Natural Hazards (43) 167-185
Floods are the most common and widespread climate-related hazard on Earth. Flood forecasting can reduce the death toll associated with floods. Satellites offer effective and economical means for calculating areal rainfall estimates in sparsely gauged regions. However, satellite-based rainfall estimates have had limited use in flood forecasting and hydrologic stream...
Coexistence of twisted and untwisted crystals: An impurity/structural order model with implications for agate patterns
J. Comer, P. Ortoleva
2007, American Mineralogist (92) 1952-1957
Coexistence of twisted and untwisted crystals is explained via a model that accounts for the coupling of the entropic and energetic effects of impurities and a supra-lattice-scale structural order parameter. It is shown that twisted impure crystals can be in equilibrium with untwisted purer ones. The model explains how coexistence...
Quantification of changes in metal loading from storm runoff, Merse River (Tuscany, Italy)
Briant A. Kimball, F. Bianchi, Katherine Walton-Day, Robert L. Runkel, M. Nannucci, A. Salvadori
2007, Mine Water and the Environment (26) 209-216
The Merse River in Tuscany is affected by mine drainage and the weathering of mine wastes along several kilometres of its catchment. The metal loading to the stream was quantified by defining detailed profiles of discharge and concentration, using tracer-dilution and synoptic-sampling techniques. During the course of a field experiment...
A rangewide population genetic study of trumpeter swans
S.J. Oyler-McCance, F.A. Ransler, L.K. Berkman, T.W. Quinn
2007, Conservation Genetics (8) 1339-1353
For management purposes, the range of naturally occurring trumpeter swans (Cygnus buccinator) has been divided into two populations, the Pacific Coast Population (PP) and the Rocky Mountain Population (RMP). Little is known about the distribution of genetic variation across the species' range despite increasing pressure to make difficult management decisions...
Rarity and diversity in forest ant assemblages of Great Smoky Mountains National Park
J.-P. Lessard, R.R. Dunn, C.R. Parker, N.J. Sanders
2007, Conference Paper, Southeastern Naturalist
We report on a systematic survey of the ant fauna occurring in hardwood forests in the Great Smoky Mountains National Park. At 22-mixed hardwood sites, we collected leaf-litter ant species using Winkler samplers. At eight of those sites, we also collected ants using pitfall and Malaise traps. In total, we...
Effect of daily oscillation in temperature and increased suspended sediment on growth and smolting in juvenile chinook salmon, Oncorhynchus tshawytscha
J. M. Shrimpton, Joseph D. Zydlewski, J.W. Heath
2007, Aquaculture (273) 269-276
We examined the effect of temperature oscillation and increased suspended sediment concentration on growth and smolting in juvenile ocean-type chinook salmon (Oncorhynchus tshawytscha). Fish were ponded on February 26; each treatment group had three replicates of 250 fish. Mean temperatures for the entire experiment were 12.3????C for all tanks with...
Body size affects the predatory interactions between introduced American Bullfrogs (Rana catesbeiana) and native anurans in China: An experimental study
Y. Wang, Z. Guo, C.A. Pearl, Y. Li
2007, Journal of Herpetology (41) 514-520
Introduced American Bullfrogs (Rana catesbeiana) have established breeding populations in several provinces in China since their introduction in 1959. Although Bullfrogs are viewed as a potentially important predator of Chinese native anurans, their impacts in the field are difficult to quantify. We used two experiments to examine factors likely to...
Impacts of the 2004 Indian ocean tsunami on the southwest coasts of Sri Lanka
Robert A. Morton, John A. Goff, Scott L. Nichol
2007, Conference Paper, Coastal Sediments '07 - Proceedings of 6th International Symposium on Coastal Engineering and Science of Coastal Sediment Processes
The 2004 Indian Ocean tsunami caused major landscape changes along the southwest coasts of Sri Lanka that were controlled by the flow, natural topography and bathymetry, and anthropogenic modifications of the terrain. Landscape changes included substantial beach erosion and scouring of return-flow channels near the beach, and deposition of sand...
Exploring rippled scour depressions offshore Huntington Beach, CA
Eleyne L. Phillips, Curt D. Storlazzi, Peter Dartnell, Brian D. Edwards
2007, Conference Paper, Coastal Sediments '07 - Proceedings of 6th International Symposium on Coastal Engineering and Science of Coastal Sediment Processes
Morphological model computations based on uniform (non-graded) sediment revealed an unrealistically strong scour of the sea floor in the immediate vicinity to the west of Maasvlakte 2. By means of a state-of-the-art graded sediment transport model the effect of natural armouring and sorting of bed material on...
Transport and degradation of chlorofluorocarbons (CFCs) in the pyritic Rabis Creek aquifer, Denmark
K. Hinsby, Anker L. Højberg, P. Engesgaard, K.H. Jensen, F. Larsen, Niel Plummer, Eurybiades Busenberg
2007, Water Resources Research (43)
Vertical profiles of the chlorofluorocarbons CFC‐11, CFC‐12, and CFC‐113 penetrating aerobic and anaerobic parts of a shallow sandy aquifer show that the CFC gases are degraded in the <1 m thick transition zone from aerobic to anaerobic groundwater in a pyritic sand aquifer at Rabis Creek, Denmark. Two‐dimensional solute transport...
Composition of pore water in lake sediments, research site "B", Osage County, Oklahoma: Implications for lake water quality and benthic organisms
Robert A. Zielinski, William N. Herkelrath, James K. Otton
2007, Applied Geochemistry (22) 2177-2192
Shallow ground water at US Geological Survey research site B in northeastern Oklahoma is contaminated with NaCl-rich brine from past and present oil production operations. Contaminated ground water provides a potential source of salts, metals, and hydrocarbons to sediment and water of adjacent Skiatook Lake. A former brine storage pit...
Near-fault peak ground velocity from earthquake and laboratory data
Art McGarr, Joe B. Fletcher
2007, Bulletin of the Seismological Society of America (97) 1502-1510
We test the hypothesis that peak ground velocity (PGV) has an upper bound independent of earthquake magnitude and that this bound is controlled primarily by the strength of the seismogenic crust. The highest PGVs, ranging up to several meters per second, have been measured at sites within a few kilometers...
Effects of two sediment types on the fluorescence yield of two Hawaiian scleractinian corals
G.A. Piniak
2007, Marine Environmental Research (64) 456-468
This study used non-invasive pulse-amplitude modulated (PAM) fluorometry to measure the maximum fluorescence yield (Fv/Fm) of two Hawaiian scleractinian coral species exposed to short-term sedimentation stress. Beach sand or harbor mud was applied to coral fragments in a flow-through aquarium system for 0-45 h, and changes in Fv/Fm were measured...
Geochemical and geophysical examination of submarine groundwater discharge and associated nutrient loading estimates into Lynch Cove, Hood Canal, WA
P.W. Swarzenski, F. W. Simonds, A.J. Paulson, S. Kruse, C. Reich
2007, Environmental Science & Technology (41) 7022-7029
Geochemical tracer data (i.e., 222Rn and four naturally occurring Ra isotopes), electromagnetic (EM) seepage meter results, and high-resolution, stationary electrical resistivity images were used to examine the bi-directional (i.e., submarine groundwater discharge and recharge) exchange of a coastal aquifer with seawater. Our study site for these experiments was Lynch Cove,...
Dissolved organic carbon in Alaskan boreal forest: Sources, chemical characteristics, and biodegradability
Kimberly P. Wickland, Jason C. Neff, George R. Aiken
2007, Ecosystems (10) 1323-1340
The fate of terrestrially-derived dissolved organic carbon (DOC) is important to carbon (C) cycling in both terrestrial and aquatic environments, and recent evidence suggests that climate warming is influencing DOC dynamics in northern ecosystems. To understand what determines the fate of terrestrial DOC, it is essential to quantify the chemical...
Revisiting evolutionary dead ends in sockeye salmon ( Oncorhynchus nerka) life history
S.A. Pavey, T.R. Hamon, J.L. Nielsen
2007, Canadian Journal of Fisheries and Aquatic Sciences (64) 1199-1208
This study challenges recent hypotheses about sockeye salmon (Oncorhynchus nerka) colonization based on life history and broadens the pathways that investigators should consider when studying sockeye colonization of novel habitats. Most sockeye populations exhibit lake-type life histories. Riverine populations are thought to be more likely to stray from their natal...
Dietary and spatial overlap between sympatric ursids relative to salmon use
Jennifer K. Fortin, Sean D. Farley, Karyn D. Rode, Charles T. Robbins
2007, Ursus (18) 19-29
We hypothesized that there would be minimal dietary overlap between sympatric brown bears (Ursus arctos) and American black bears (U. americanus) relative to salmon (Oncorhynchus spp.) utilization when alternative foods (e.g., fruits) are abundant. To maximize the chance that we would reject this hypothesis, we examined the diets of brown and black...
Modeling dune response using measured and equilibrium bathymetric profiles
Laura A. Fauver, David M. Thompson, Asbury H. Sallenger Jr.
2007, Conference Paper, Coastal Sediments '07 - Proceedings of 6th International Symposium on Coastal Engineering and Science of Coastal Sediment Processes
Coastal engineers typically use numerical models such as SBEACH to predict coastal change due to extreme storms. SBEACH model inputs include pre-storm profiles, wave heights and periods, and water levels. This study focuses on the sensitivity of SBEACH to the details of pre-storm bathymetry. The SBEACH model is tested with...
Near-infrared spectral mapping of Titan's mountains and channels
Jason W. Barnes, Jani Radebaugh, Robert H. Brown, Steve Wall, Laurence A. Soderblom, Jonathan I. Lunine, Devon M. Burr, Christophe Sotin, Stephane Le Mouelic, Sebastien Rodriguez, Bonnie J. Buratti, Roger N. Clark, Kevin H. Baines, Ralf Jaumann, Philip D. Nicholson, Randolph L. Kirk, Rosaly Lopes, Ralph D. Lorenz, Ken Mitchell, Charles A. Wood
2007, Journal of Geophysical Research E: Planets (112)
We investigate the spectral reflectance properties of channels and mountain ranges on Titan using data from Cassini's Visual and Infrared Mapping Spectrometer (VIMS) obtained during the T9 encounter (26 December 2005). We identify the location of channels and mountains using synthetic aperture radar maps obtained from Cassini's RADAR instrument during...
