Summer microhabitat use of fluvial bull trout in Eastern Oregon streams
R. Al-Chokhachy, P. Budy
2007, North American Journal of Fisheries Management (27) 1068-1081
The management and recovery of populations of bull trout Salvelinus confluentus requires a comprehensive understanding of habitat use across different systems, life stages, and life history forms. To address these needs, we collected microhabitat use and availability data in three fluvial populations of bull trout in eastern Oregon. We evaluated...
Genetic characterization of Common Eiders breeding in the Yukon-Kuskokwim Delta, Alaska
Sarah A. Sonsthagen, Sandra L. Talbot, Kevin G. McCracken
2007, The Condor (109) 878-893
We assessed population genetic subdivision among four colonies of Common Eiders (Somateria mollissima v-nigrum) breeding in the Yukon-Kuskokwim Delta (YKD), Alaska, using microsatellite genotypes and DNA sequences with differing modes of inheritance. Significant, albeit low, levels of genetic differentiation were observed between mainland populations and Kigigak Island for nuclear intron lamin A...
Pumping-induced drawdown and stream depletion in a leaky aquifer system
J.J. Butler Jr., X. Zhan, V.A. Zlotnik
2007, Ground Water (45) 178-186
The impact of ground water pumping on nearby streams is often estimated using analytic models of the interconnected stream-aquifer system. A common assumption of these models is that the pumped aquifer is underlain by an impermeable formation. A new semianalytic solution for drawdown and stream depletion has been developed that...
The instantaneous rate dependence in low temperature laboratory rock friction and rock deformation experiments
N.M. Beeler, T.E. Tullis, A. K. Kronenberg, L.A. Reinen
2007, Journal of Geophysical Research B: Solid Earth (112)
[1] Earthquake occurrence probabilities that account for stress transfer and time-dependent failure depend on the product of the effective normal stress and a lab-derived dimensionless coefficient a. This coefficient describes the instantaneous dependence of fault strength on deformation rate, and determines the duration of precursory slip....
A simulation-based approach for estimating premining water quality: Red Mountain Creek, Colorado
Robert L. Runkel, Briant A Kimball, Katherine Walton-Day, Philip L. Verplanck
2007, Applied Geochemistry (22) 1899-1918
Regulatory agencies are often charged with the task of setting site-specific numeric water quality standards for impaired streams. This task is particularly difficult for streams draining highly mineralized watersheds with past mining activity. Baseline water quality data obtained prior to mining are often non-existent and application of generic water quality...
Paleoearthquakes on the southern San Andreas Fault, Wrightwood, California, 3000 to 1500 B.C.: A new method for evaluating paleoseismic evidence and earthquake horizons
K.M. Scharer, R.J. Weldon II, T. E. Fumal, G. P. Biasi
2007, Bulletin of the Seismological Society of America (97) 1054-1093
We present evidence of 11–14 earthquakes that occurred between 3000 and 1500 b.c. on the San Andreas fault at the Wrightwood paleoseismic site. Earthquake evidence is presented in a novel form in which we rank (high, moderate, poor, or low) the quality of all...
Spectral element modelling of fault-plane reflections arising from fluid pressure distributions
M. Haney, R. Snieder, J.-P. Ampuero, R. Hofmann
2007, Geophysical Journal International (170) 933-951
The presence of fault-plane reflections in seismic images, besides indicating the locations of faults, offers a possible source of information on the properties of these poorly understood zones. To better understand the physical mechanism giving rise to fault-plane reflections in compacting sedimentary basins, we numerically model the full elastic wavefield...
Food web structure in exotic and native mangroves: A Hawaii-Puerto Rico comparison
A. W.J. Demopoulos, B. Fry, C. R. Smith
2007, Oecologia (153) 675-686
Plant invasions can fundamentally alter detrital inputs and the structure of detritus-based food webs. We examined the detrital pathways in mangrove food webs in native (Puerto Rican) and introduced (Hawaiian) Rhizophora mangle forests using a dual isotope approach and a mixing model. Based on trophic-level fractionation of 0-1??? for ??...
Numerical investigation of implementation of air-earth boundary by acoustic-elastic boundary approach
Y. Xu, J. Xia, R. D. Miller
2007, Geophysics (72)
The need for incorporating the traction-free condition at the air-earth boundary for finite-difference modeling of seismic wave propagation has been discussed widely. A new implementation has been developed for simulating elastic wave propagation in which the free-surface condition is replaced by an explicit acoustic-elastic boundary. Detailed comparisons of seismograms with...
Controls on the variability of net infiltration to desert sandstone
Victor M. Heilweil, Tim S. McKinney, Michael S. Zhdanov, Dennis E. Watt
2007, Water Resources Research (43)
As populations grow in arid climates and desert bedrock aquifers are increasingly targeted for future development, understanding and quantifying the spatial variability of net infiltration becomes critically important for accurately inventorying water resources and mapping contamination vulnerability. This paper presents a conceptual model of net infiltration to desert sandstone and...
Testing alternative ground water models using cross-validation and other methods
L. Foglia, S.W. Mehl, M. C. Hill, P. Perona, P. Burlando
2007, Ground Water (45) 627-641
Many methods can be used to test alternative ground water models. Of concern in this work are methods able to (1) rank alternative models (also called model discrimination) and (2) identify observations important to parameter estimates and predictions (equivalent to the purpose served by some types of sensitivity analysis). Some...
Origin of halite brine in the Onondaga Trough near Syracuse, New York State, USA: Modeling geochemistry and variable-density flow
Richard M. Yager, William M. Kappel, Niel Plummer
2007, Hydrogeology Journal (15) 1321-1339
Halite brine (saturation ranging from 45 to 80%) lies within glacial sediments that fill the Onondaga Trough, a bedrock valley deepened by Pleistocene glaciation near Syracuse, New York State, USA. The most concentrated brine occupies the northern end of the trough, about 10 km downgradient of the northern limit of...
Ecological gradients within a Pennsylvanian mire forest
William A. DiMichele, H. J. Falcon-Lang, W.J. Nelson, S.D. Elrick, P.R. Ames
2007, Geology (35) 415-418
Pennsylvanian coals represent remains of the earliest peat-forming rain forests, but there is no current consensus on forest ecology. Localized studies of fossil forests suggest intermixture of taxa (heterogeneity), while, in contrast, coal ball and palynological analyses imply the existence of pronounced ecological gradients. Here, we report the discovery of...
Butterfly responses to prairie restoration through fire and grazing
Jennifer A. Vogel, Diane M. Debinski, Rolf R. Koford, J.R. Miller
2007, Biological Conservation (140) 78-90
The development of land for modern agriculture has resulted in losses of native prairie habitat. The small, isolated patches of prairie habitat that remain are threatened by fire suppression, overgrazing, and invasion by non-native species. We evaluated the effects of three restoration practices (grazing only, burning only, and burning and...
Distribution and accumulation of mercury in tissues of captive-reared common loon (Gavia immer) chicks
K.P. Kenow, M.W. Meyer, R. K. Hines, W. H. Karasov
2007, Environmental Toxicology and Chemistry (26) 1047-1055
We determined the distribution and accumulation of Hg in tissues of common loon (Gavia immer) chicks maintained for up to 15 weeks on either a control diet with no added methylmercury chloride (MeHgCl) or one containing either 0.4 or 1.2 ??g Hg (as MeHgCl)/g wet-weight food. Total Hg and MeHg...
Dams, floodplain land use, and riparian forest conservation in the semiarid Upper Colorado River Basin, USA
D.C. Andersen, D.J. Cooper, K. Northcott
2007, Environmental Management (40) 453-475
Land and water resource development can independently eliminate riparian plant communities, including Fremont cottonwood forest (CF), a major contributor to ecosystem structure and functioning in semiarid portions of the American Southwest. We tested whether floodplain development was linked to river regulation in the Upper Colorado River Basin (UCRB) by relating...
Influence of light and temperature on Prochlorococcus ecotype distributions in the Atlantic Ocean
E.R. Zinser, Z.I. Johnson, A. Coe, E. Karaca, D. Veneziano, S.W. Chisholm
2007, Limnology and Oceanography (52) 2205-2220
In a focused analysis of Prochlorococcus population structure in the western North Atlantic, we found that the relative abundances of ecotypes varied significantly with depth and, at seasonally stratified locations, with degree of vertical mixing. More limited regional variation was observed (e.g., Sargasso Sea, Gulf Stream, continental slope, and equatorial...
Study of a prehistoric landslide using seismic reflection methods integrated with geological data in the Wasatch Mountains, Utah, USA
B.E. Tingey, J.H. McBride, T.J. Thompson, W. J. Stephenson, J.V. South, M. Bushman
2007, Engineering Geology (95) 1-29
An integration of geological and geophysical techniques characterizes the internal and basal structure of a landslide along the western margin of the Wasatch Mountains in northern Utah, USA. The study area is within a region of planned and continuing residential development. The Little Valley Landslide is a prehistoric landslide as...
MODIS imagery as a tool for synoptic water quality assessments in the southern California coastal ocean
N.P. Nezlin, P.M. DiGiacomo, B.H. Jones, K.M. Reifel, J.A. Warrick, S.C. Johnson, M.J. Mengel
2007, Conference Paper, Proceedings of SPIE - The International Society for Optical Engineering
The dynamics of rainstorm plumes in the coastal waters of southern California was studied during the Bight'03 Regional Water Quality Program surveys. Measurements of surface salinity and bacterial counts collected from research vessels were compared to MODIS-Aqua satellite imagery. The spectra of normalized water-leaving radiation (nLw) were different in plumes...
Role of hydrous iron oxide formation in attenuation and diel cycling of dissolved trace metals in a stream affected by acid rock drainage
Stephen R. Parker, Chris Gammons, Clain A. Jones, David A. Nimick
2007, Water, Air, & Soil Pollution (181) 247-263
Mining-impacted streams have been shown to undergo diel (24-h) fluctuations in concentrations of major and trace elements. Fisher Creek in south-central Montana, USA receives acid rock drainage (ARD) from natural and mining-related sources. A previous diel field study found substantial changes in dissolved metal concentrations at three sites with differing...
Use of a watershed model to characterize the fate and transport of fluometuron, a soil-applied cotton herbicide, in surface water
R.H. Coupe
2007, International Journal of Environmental Analytical Chemistry (87) 883-896
The Soil and Water Assessment Tool (SWAT) was used to characterize the fate and transport of fluometuron (a herbicide used on cotton) in the Bogue Phalia Basin in northwestern Mississippi, USA. SWAT is a basin-scale watershed model, able to simulate hydrological, chemical, and sediment transport processes. After adjustments to a...
Bypass system modification at Bonneville Dam on the Columbia River improved the survival of juvenile salmon
J.W. Ferguson, B.P. Sandford, R.E. Reagan, L.G. Gilbreath, E.B. Meyer, R.D. Ledgerwood, N.S. Adams
2007, Transactions of the American Fisheries Society (136) 1487-1510
From 1987 to 1992, we evaluated a fish bypass system at Bonneville Dam Powerhouse 2 on the Columbia River. The survival of subyearling Chinook salmon Oncorhynchus tshawytscha released into the system ranged from 0.774 to 0.911 and was significantly lower than the survival of test fish released into turbines and...
Minimizing noise in fiberglass aquaculture tanks: Noise reduction potential of various retrofits
J. Davidson, A.S. Frankel, W.T. Ellison, S. Summerfelt, A.N. Popper, P. Mazik, J. Bebak
2007, Aquacultural Engineering (37) 125-131
Equipment used in intensive aquaculture systems, such as pumps and blowers can produce underwater sound levels and frequencies within the range of fish hearing. The impacts of underwater noise on fish are not well known, but limited research suggests that subjecting fish to noise could result in impairment of the...
Population demographics of Hiodon tergisus (Mooneye) in the lower Tallapoosa River
C.T. Katechis, P.C. Sakaris, E.R. Irwin
2007, Southeastern Naturalist (6) 461-470
We describe age structure, growth, and fecundity of Hiodon tergisus (Mooneye) from the lower Tallapoosa River, AL. Mooneye (N = 49, 214-316 mm total length, 79-284 g) were aged using otoliths, and a von Bertalanffy growth model was derived for the species (L??? = 316, K = 0.285, to =...
Topography and geomorphology of the Huygens landing site on Titan
Laurence A. Soderblom, Martin G. Tomasko, Brent A. Archinal, Tammy L. Becker, Michael W. Bushroe, Debbie Cook, Lyn R. Doose, Donna M. Galuszka, Trent M. Hare, Elpitha Howington-Kraus, Erich Karkoschka, Randolph L. Kirk, Jonathan I. Lunine, Elisabeth A. McFarlane, Bonnie L. Redding, Bashar Rizk, Mark R. Rosiek, Charles See, Peter H. Smith
2007, Planetary and Space Science (55) 2015-2024
The Descent Imager/Spectral Radiometer (DISR) aboard the Huygens Probe took several hundred visible-light images with its three cameras on approach to the surface of Titan. Several sets of stereo image pairs were collected during the descent. The digital terrain models constructed from those images show rugged topography, in places approaching...
