Statistical analysis of water-quality data containing multiple detection limits II: S-language software for nonparametric distribution modeling and hypothesis testing
L. Lee, D. Helsel
2007, Computers & Geosciences (33) 696-704
Analysis of low concentrations of trace contaminants in environmental media often results in left-censored data that are below some limit of analytical precision. Interpretation of values becomes complicated when there are multiple detection limits in the data-perhaps as a result of changing analytical precision over time. Parametric and semi-parametric methods,...
Seabird behavior as an indicator of food supplies: Sensitivity across the breeding season
A.M.A. Harding, John F. Piatt, Joel A. Schmutz
2007, Marine Ecology Progress Series (352) 269-274
We used empirical data on the time allocation of common murres Uria aalge in relation to measures of local prey density to examine whether adults provisioning chicks are more sensitive to changes in prey density than birds that are incubating eggs. We hypothesized that seasonal differences in food requirements of...
Generating an image of dispersive energy by frequency decomposition and slant stacking
J. Xia, Y. Xu, R. D. Miller
2007, Pure and Applied Geophysics (164) 941-956
We present a new algorithm for calculating an image of dispersive energy in the frequency-velocity (f-v) domain. The frequency decomposition is first applied to a shot gather in the offset-time domain to stretch impulsive data into pseudo-vibroseis data or frequency-swept data. Because there is a deterministic relationship between frequency and...
A comparison of shoreline seines with fyke nets for sampling littoral fish communities in floodplain lakes
S.J. Clark, J.R. Jackson, S.E. Lochmann
2007, North American Journal of Fisheries Management (27) 676-680
We compared shoreline seines with fyke nets in terms of their ability to sample fish species in the littoral zone of 22 floodplain lakes of the White River, Arkansas. Lakes ranged in size from less than 0.5 to 51.0 ha. Most contained large amounts of coarse woody debris within the...
Escape tectonics and the extrusion of Alaska: Past, present, and future
T.F. Redfield, D.W. Scholl, P.G. Fitzgerald, M. E. Beck Jr.
2007, Geology (35) 1039-1042
The North Pacific Rim is a tectonically active plate boundary zone parts of which may be characterized as a laterally moving orogenic stream. Crustal blocks are transported along large-magnitude strike-slip faults in western Canada and central Alaska toward the Aleutian-Bering Sea subduction zones. Throughout much of the Cenozoic, at and...
Conservation value of Mount Rushmore National Memorial's forest
Amy J. Symstad, Michael R. Bynum
2007, Natural Areas Journal (27) 293-301
Justifying the maintenance of small natural areas requires understanding their contribution to the conservation of specific natural resources. Mount Rushmore National Memorial (MORU) is a small portion of the Black Hills of western South Dakota and eastern Wyoming. Because it has been protected from logging since the late 1930s, it...
Robust 24 ± 6 ka 40Ar/39Ar age of a low-potassium tholeiitic basalt in the Lassen region of NE California
Brent D. Turrin, L.J. Patrick Muffler, Michael A. Clynne, Duane E. Champion
2007, Quaternary Research (68) 96-110
40Ar/39Ar ages on the Hat Creek Basalt (HCB) and stratigraphically related lava flows show that latest Pleistocene tholeiitic basalt with very low K2O can be dated reliably. The HCB underlies ∼ 15 ka glacial gravel and overlies four andesite and basaltic andesite lava flows that yield 40Ar/39Ar ages of 38 ± 7 ka (Cinder Butte; 1.65%...
Physical limits on ground motion at Yucca Mountain
D.J. Andrews, Thomas C. Hanks, J.W. Whitney
2007, Bulletin of the Seismological Society of America (97) 1771-1792
Physical limits on possible maximum ground motion at Yucca Mountain, Nevada, the designated site of a high-level radioactive waste repository, are set by the shear stress available in the seismogenic depth of the crust and by limits on stress change that can propagate through the medium. We find in dynamic...
Stress does not inhibit induced vitellogenesis in juvenile rainbow trout
A.R. Schwindt, G.W. Feist, C.B. Schreck
2007, Environmental Biology of Fishes (80) 453-463
Vitellogenin (Vtg) is a widely used biomarker for xenoestrogen exposure in male fishes. In female fishes Vtg can be negatively affected by stress independent of declines in estrogen. However, few data are available on the effect of stress in male fish abnormally producing Vtg, such as when exposed to xenoestrogens....
Coordinated analyses of orbital and spirit rover data to characterize surface materials on the cratered plains of Gusev Crater, Mars
K.A. Lichtenberg, R. E. Arvidson, F. Poulet, R.V. Morris, A. Knudson, J.F. Bell, G. Bellucci, J.-P. Bibring, W. H. Farrand, J. R. Johnson, D. W. Ming, P.C. Pinet, A.D. Rogers, S. W. Squyres
2007, Journal of Geophysical Research E: Planets (112)
Comparison of the Mars Exploration Rover Spirit's Pancam (0.4 to 1.0 ??m) and Mars Express Observatoire pour la Mineralogie l'Eau, les Glaces et l'Activite?? (OMEGA) (0.4 to 2.5 ??m) spectral reflectance data over Spirit's traverses shows that Gusev cratered plains are dominated by nanophase ferric-oxide-rich dust covering weakly altered basaltic...
Barrier island vulnerability to breaching: a case study on Dauphin Island, Alabama
Mark Hansen, Asbury H. Sallenger Jr.
2007, Conference Paper, Coastal Sediments '07 - Proceedings of 6th International Symposium on Coastal Engineering and Science of Coastal Sediment Processes
Breaching of barrier islands can adversely impact society by severing infrastructure, destroying private properties, and altering water quality in back bays and estuaries. This study provides a scheme that assesses the relative vulnerability of a barrier island to breach during storms. Dauphin Island, Alabama was selected for this study because...
Hypoxia tolerance of two centrarchid sunfishes and an introduced cichlid from karstic Everglades wetlands of southern Florida, U.S.A.
P. J. Schofield, W.F. Loftus, M.E. Brown
2007, Journal of Fish Biology (71) 87-99
In this study, the hypoxia tolerance of three Everglades fishes, two native centrarchids (Lepomis gulosus and Lepomis marginatus) and a recently introduced cichlid (Hemichromis letourneuxi), were documented. Aquatic surface respiration (ASR) thresholds were lowest for H. letourneuxi, followed by L. gulosus, then L. marginatus. The ASR thresholds for L. marginatus...
Radiometric calibration status of Landsat-7 and Landsat-5
J. A. Barsi, B. L. Markham, D. L. Helder, G. Chander
2007, Conference Paper, Proceedings of SPIE - The International Society for Optical Engineering
Launched in April 1999, Landsat-7 ETM+ continues to acquire data globally. The Scan Line Corrector in failure in 2003 has affected ground coverage and the recent switch to Bumper Mode operations in April 2007 has degraded the internal geometric accuracy of the data, but the radiometry has been unaffected. The...
Intersex (Testicular Oocytes) in smallmouth bass from the Potomac River and selected nearby drainages
Vicki S. Blazer, Luke R. Iwanowicz, Deborah D. Iwanowicz, David R. Smith, John A. Young, J.D. Hedrick, S.W. Foster, S.J. Reeser
2007, Journal of Aquatic Animal Health (19) 242-253
Intersex, or the presence of characteristics of both sexes, in fishes that are normally gonochoristic has been used as an indicator of exposure to estrogenic compounds. In 2003, during health assessments conducted in response to kills and a high prevalence of skin lesions observed in smallmouth bass Micropterus dolomieu in...
Geoarchaeology of stratified paleoindian deposits at the Big Eddy site, Southwest Missouri, U.S.A
E.R. Hajic, R.D. Mandel, J.H. Ray, N.H. Lopinot
2007, Geoarchaeology (22) 891-934
The Big Eddy site (23CE426) in the Sac River valley of southwest Missouri is a rare recorded example of distinctly stratified Early through Late Paleoindian cultural deposits. Early point types recovered from the site include Gainey, Sedgwick, Dalton (fluted and unfluted), San Patrice, Wilson, and Packard. The Paleoindian record at...
Infection by a black spot-causing species of Uvulifer and associated opercular alterations in fishes from a high-desert stream in Wyoming
M.C. Quist, M.R. Bower, W.A. Hubert
2007, Diseases of Aquatic Organisms (78) 129-136
Black spot is a common disease syndrome of freshwater fishes. This study provides information on the rank of density of the black spot agent and opercular bone alterations associated with at least one digenean, Uvulifer sp., infecting native and non-native catostomids and cyprinids of the Upper Colorado River Basin. We...
Climate and floods still govern California levee breaks
J.L. Florsheim, M. D. Dettinger
2007, Geophysical Research Letters (34)
Even in heavily engineered river systems, climate still governs flood variability and thus still drives many levee breaks and geomorphic changes. We assemble a 155-year record of levee breaks for a major California river system to find that breaks occurred in 25% of years during the 20th Century. A relation...
Supplemental water releases for fisheries restoration in a Brazilian floodplain River: A conceptual model
Alexandre L. Godinho, B. Kynard, C.B. Martinez
2007, River Research and Applications (23) 947-962
Highly productive floodplain rivers in Brazil and elsewhere provide livelihood and recreational fishing for millions of people around the world, but damming and controlled water discharge are a threat to these valuable ecosystems. Supplemental water releases (SWRs) at a dam are increasingly used for restoring fisheries productivity in many floodplain...
Velafrons coahuilensis, a new labeosaurine haddrosaurid (Dinosauria: Ornithopoda) from the Late Campanian Cerro del Pueblo formation, Coahuila, Mexico
Terry A. Gates, Scott D. Sampson, Carlos R. Delgado de Jesus, Lindsay E. Zanno, David Eberth, Rene Hernandez-Rivera, Martha C. Aguillon-Martinez, James I. Kirkland
2007, Journal of Vertebrate Paleontology (27) 917-930
A new lambeosaurine hadrosaurid, Velafrons coahuilensis, is described as the first lambeosaurine from the Cerro del Pueblo Formation of Coahuila, Mexico, and the first lambeosaurine genus to be named from North America in more than 70 years. Although the holotype specimen is a juvenile individual—as evidenced by its incomplete crest development...
Quantifying fluid and bed dynamics for characterizing benthic physical habitat in large rivers
D. Gaeuman, R. B. Jacobson
2007, Journal of Applied Ichthyology (23) 359-364
Sturgeon use benthic habitats in and adjacent to main channels where environmental conditions can include bedload sediment transport and high near-bed flow velocities. Bed velocity measurements obtained with acoustic Doppler instruments provide a means to assess the concentration and velocity of sediment moving near the streambed, and are thus indicative...
Effects of river discharge on abundance and instantaneous growth of age-0 carpsuckers in the Oconee River, Georgia, USA
Ronald C. Peterson, Cecil A. Jennings
2007, River Research and Applications (23) 1016-1025
The Oconee River in middle Georgia, U.S.A., has been regulated by the Sinclair Dam since 1953. Since then, the habitat of the lower Oconee River has been altered and the river has become more incised. The altered environmental conditions of the Oconee River may limit the success of various fish...
Effects of flow fluctuations on the spawning habitat of a riverine fish
T.B. Grabowski, J. Jeffery Isely
2007, Southeastern Naturalist (6) 471-478
Shallow-water, lithophilic spawning fishes are among the most vulnerable to anthropogenic fluctuations in water levels. We monitored water levels and environmental conditions at the nest sites of Moxostoma robustum (Robust Redhorse) on a main-channel gravel bar in the Savannah River, GA-SC During the course of the 2005 spawning season, over...
Risk assessment of water quality in three North Carolina, USA, streams supporting federally endangered freshwater mussels (Unionidae)
S. Ward, T. Augspurger, F.J. Dwyer, C. Kane, C.G. Ingersoll
2007, Environmental Toxicology and Chemistry (26) 2075-2085
Water quality data were collected from three drainages supporting the endangered Carolina heelsplitter (Lasmigona decorata) and dwarf wedgemussel (Alasmidonta heterodon) to determine the potential for impaired water quality to limit the recovery of these freshwater mussels in North Carolina, USA. Total recoverable copper, total residual chlorine, and total ammonia nitrogen...
Survival and breeding advantages of larger Black Brant (Branta bernicla nigricans) goslings: Within- and among-cohort variation
J.S. Sedinger, N.D. Chelgren
2007, The Auk (124) 1281-1293
We examined the relationship between mass late in the first summer and survival and return to the natal breeding colony for 12 cohorts (1986-1997) of female Black Brant (Branta bernicla nigricans). We used Cormack-Jolly-Seber methods and the program MARK to analyze capture-recapture data. Models included two kinds of residuals from...
Smallmouth bass and largemouth bass predation on juvenile Chinook salmon and other salmonids in the Lake Washington basin
R.A. Tabor, B.A. Footen, K.L. Fresh, M.T. Celedonia, F. Mejia, D.L. Low, L. Park
2007, North American Journal of Fisheries Management (27) 1174-1188
We assessed the impact of predation by smallmouth bass Micropterus dolomieu and largemouth bass M. salmoides on juveniles of federally listed Chinook salmon Oncorhynchus tshawytscha and other anadromous salmonid populations in the Lake Washington system. Bass were collected with boat electrofishing equipment in the south end of Lake Washington (February-June)...
