Constancy of the relation between floc size and density in San Francisco Bay
N. K. Ganju, D. H. Schoellhamer, M.C. Murrell, J. W. Gartner, S.A. Wright
2007, Proceedings in Marine Science (8) 75-91
The size and density of fine-sediment aggregates, or flocs, govern their transport and depositional properties. While the mass and volume concentrations of flocs can be measured directly or by optical methods, they must be determined simultaneously to gain an accurate density measurement. Results are presented from a tidal cycle study in...
Characterization of the origin of coalbed gases in southeastern Illinois Basin by compound-specific carbon and hydrogen stable isotope ratios
D. Strapoc, Maria Mastalerz, C. Eble, A. Schimmelmann
2007, Organic Geochemistry (38) 267-287
Coalbed gases and waters from exploratory and production gas wells in the southeastern Illinois Basin were sampled to assess geochemically the origin of coalbed gases, with an emphasis on the Springfield and Seelyville Coal Members that are commercially targeted for coalbed methane production in Indiana. On-line analyses of hydrocarbon gases...
Previously undocumented two-year freshwater residency of juvenile coho salmon in Prairie Creek, California
E. Bell, W.G. Duffy
2007, Transactions of the American Fisheries Society (136) 966-970
Over 2,000 juvenile coho salmon Oncorhynchus kisutch were tagged with passive integrated transponder (PIT) tags during the fall of 1998 and 1999 in Prairie Creek, California, as part of a study on individual winter growth rates and movement of juvenile coho salmon. During this study, age-2 out-migrants were incidentally observed....
Geochemical evidence for African dust inputs to soils of western Atlantic islands: Barbados, the Bahamas, and Florida
D.R. Muhs, J. R. Budahn, J.M. Prospero, S.N. Carey
2007, Journal of Geophysical Research F: Earth Surface (112)
We studied soils on high-purity limestones of Quaternary age on the western Atlantic Ocean islands of Barbados, the Florida Keys, and the Bahamas. Potential soil parent materials in this region, external to the carbonate substrate, include volcanic ash from the island of St. Vincent (near Barbados), volcanic ash from the...
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...
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...
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...
An outbreak of type C botulism in Herring Gulls (Larus argentatus) in Southeastern Sweden
A. Neimanis, D. Gavier-Widen, F. Leighton, T. Bollinger, Tonie E. Rocke, T. Morner
2007, Journal of Wildlife Diseases (43) 327-336
From 2000 to 2004, over 10,000 seabirds, primarily Herring Gulls (Larus argentatus), died from an undetermined cause in the Blekinge archipelago in southeastern Sweden. In June 2004, 24 affected Herring Gulls were examined clinically, killed humanely, and 23 were examined by necropsy. Seven and 10 unaffected Herring Gulls collected from...
Chinook salmon use of spawning patches: Relative roles of habitat quality, size, and connectivity
D.J. Isaak, R.F. Thurow, B.E. Rieman, J. B. Dunham
2007, Ecological Applications (17) 352-364
Declines in many native fish populations have led to reassessments of management goals and shifted priorities from consumptive uses to species preservation. As management has shifted, relevant environmental characteristics have evolved from traditional metrics that described local habitat quality to characterizations of habitat size and connectivity. Despite the implications this...
Diverse dinosaur-dominated ichnofaunas from the Potomac Group (Lower Cretaceous) Maryland
Ray Stanford, Martin G. Lockley, Robert E. Weems
2007, Ichnos: An International Journal for Plant and Animal Traces (14) 155-173
Until recently fossil footprints were virtually unknown from the Cretaceous of the eastern United States. The discovery of about 300 footprints in iron-rich siliciclastic facies of the Patuxent Formation (Potomac Group) of Aptian age is undoubtedly one of the most significant Early Cretaceous track discoveries since the Paluxy track discoveries...
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...
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...
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 ??...
Temporal trends in concentrations of DBCP and nitrate in groundwater in the eastern San Joaquin Valley, California, USA
K.R. Burow, N. M. Dubrovsky, James L. Shelton
2007, Hydrogeology Journal (15) 991-1007
Temporal monitoring of the pesticide 1,2-dibromo-3-chloropropane (DBCP) and nitrate and indicators of mean groundwater age were used to evaluate the transport and fate of agricultural chemicals in groundwater and to predict the long-term effects in the regional aquifer system in the eastern San Joaquin Valley, California. Twenty monitoring wells were...
Sensitivity of estuarine turbidity maximum to settling velocity, tidal mixing, and sediment supply
J.C. Warner, C. R. Sherwood, W.R. Geyer
Maa J.P.Y.Sanford L.P.Schoellhamer D.H., editor(s)
2007, Proceedings in Marine Science (8) 355-376
Estuarine turbidity maximum, numerical modeling, settling velocity, stratification The spatial and temporal distribution of suspended material in an Estuarine Turbidity Maxima (ETM) is primarily controlled by particle settling velocity, tidal mixing, shear-stress thresholds for resuspension, and sediment supply. We vary these parameters in numerical experiments of an idealized two-dimensional (x-z)...
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...
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...
The impact of time and field conditions on brown bear (Ursus arctos) faecal DNA amplification
M.A. Murphy, K.C. Kendall, A. Robinson, L.P. Waits
2007, Conservation Genetics (8) 1219-1224
To establish longevity of faecal DNA samples under varying summer field conditions, we collected 53 faeces from captive brown bears (Ursus arctos) on a restricted vegetation diet. Each faeces was divided, and one half was placed on a warm, dry field site while the other half was placed on a...
Rapid assessment of postfire plant invasions in coniferous forests of the western United States
J.P. Freeman, T.J. Stohlgren, M.E. Hunter, Philip N. Omi, E.J. Martinson, G.W. Chong, C. S. Brown
2007, Ecological Applications (17) 1656-1665
Fire is a natural part of most forest ecosystems in the western United States, but its effects on nonnative plant invasion have only recently been studied. Also, forest managers are engaging in fuel reduction projects to lessen fire severity, often without considering potential negative ecological consequences such as nonnative plant...
Reactivation of a cryptobiotic stream ecosystem in the McMurdo Dry Valleys, Antarctica: A long-term geomorphological experiment
Diane M. McKnight, C. M. Tate, E.D. Andrews, D.K. Niyogi, K. Cozzetto, K. Welch, W.B. Lyons, D.G. Capone
2007, Geomorphology (89) 186-204
The McMurdo Dry Valleys of Antarctica contain many glacial meltwater streams that flow for 6 to 12??weeks during the austral summer and link the glaciers to the lakes on the valley floors. Dry valley streams gain solutes longitudinally through weathering reactions and microbial processes occurring in the hyporheic zone. Some...
Aqueous exposure to 4-nonylphenol and 17β-estradiol increases stress sensitivity and disrupts ion regulatory ability of juvenile atlantic salmon
Darrren T. Lerner, Bjorn Thrandur Bjornsson, Stephen D. McCormick
2007, Environmental Toxicology and Chemistry (26) 1433-1440
Population declines of wild Atlantic salmon have been attributed to an array of anthropogenic disturbances, including dams, commercial and recreational fishing, habitat loss, and pollution. Environmental contaminants in particular, can act as environmental stressors on fish, typically causing disruption of ion homeostasis due to their close association with the aquatic...
Atmospheric bromine flux from the coastal Abu Dhabi sabkhat: A ground-water mass-balance investigation
W.W. Wood, W. E. Sanford
2007, Geophysical Research Letters (34)
A solute mass-balance study of ground water of the 3000 km2 coastal sabkhat (salt flats) of the Emirate of Abu Dhabi, United Arab Emirates, documents an annual bromide loss of approximately 255 metric tons (0.0032 Gmoles), or 85 kg/km2. This value is an order of magnitude greater than previously published...
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...
Identifying sources of nitrogen to Hanalei Bay, Kauai, utilizing the nitrogen isotope signature of macroalgae
E. Derse, K.L. Knee, Scott D. Wankel, Carol Kendall, Carl J. Berg Jr., A. Paytan
2007, Environmental Science & Technology (41) 5217-5223
Sewage effluent, storm runoff, discharge from polluted rivers, and inputs of groundwater have all been suggested as potential sources of land derived nutrients into Hanalei Bay, Kauai. We determined the nitrogen isotopic signatures (δ15N) of different nitrate sources to Hanalei Bay...
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...
