Arsenic attenuation by oxidized aquifer sediments in Bangladesh
Kenneth G. Stollenwerk, George N. Breit, Alan H. Welch, James C. Yount, John W. Whitney, Andrea L. Foster, M.N. Uddin, R.K. Majumder, N. Ahmed
2007, Science of the Total Environment (379) 133-150
Recognition of arsenic (As) contamination of shallow fluvio-deltaic aquifers in the Bengal Basin has resulted in increasing exploitation of groundwater from deeper aquifers that generally contain low concentrations of dissolved As. Pumping-induced infiltration of high-As groundwater could eventually cause As concentrations in these aquifers to increase. This study investigates the...
Red-shouldered hawk occupancy surveys in central Minnesota, USA
C. Henneman, M.A. McLeod, D. E. Andersen
2007, Journal of Wildlife Management (71) 526-533
Forest-dwelling raptors are often difficult to detect because many species occur at low density or are secretive. Broadcasting conspecific vocalizations can increase the probability of detecting forest-dwelling raptors and has been shown to be an effective method for locating raptors and assessing their relative abundance. Recent advances in statistical techniques...
Aerial population estimates of wild horses (Equus caballus) in the adobe town and salt wells creek herd management areas using an integrated simultaneous double-count and sightability bias correction technique
Bruce C. Lubow, Jason I. Ransom
2007, Open-File Report 2007-1274
An aerial survey technique combining simultaneous double-count and sightability bias correction methodologies was used to estimate the population of wild horses inhabiting Adobe Town and Salt Wells Creek Herd Management Areas, Wyoming. Based on 5 surveys over 4 years, we conclude that the technique produced estimates consistent with the known...
Multiple-methods investigation of recharge at a humid-region fractured rock site, Pennsylvania, USA
C.S. Heppner, J. R. Nimmo, G.J. Folmar, W.J. Gburek, D. W. Risser
2007, Hydrogeology Journal (15) 915-927
Lysimeter-percolate and well-hydrograph analyses were combined to evaluate recharge for the Masser Recharge Site (central Pennsylvania, USA). In humid regions, aquifer recharge through an unconfined low-porosity fractured-rock aquifer can cause large magnitude water-table fluctuations over short time scales. The unsaturated hydraulic characteristics of the subsurface porous...
Close temporal correspondence between geomagnetic anomalies and earthquakes during the 2002-2003 eruption of Etna volcano
G. Currenti, Negro C. Del, M. Johnston, Y. Sasai
2007, Journal of Geophysical Research B: Solid Earth (112)
The early stages of the 2002-2003 lateral eruption at Mount Etna were accompanied by slow changes (over some hours) and some rapid step offsets in the local magnetic field. At five monitoring locations, the total magnetic field intensity has been measured using continuously operating Overhauser magnetometers at a sampling rate...
A model for estimating passive integrated transponder (PIT) tag antenna efficiencies for interval-specific emigration rates
G.E. Horton, T.L. Dubreuil, B. H. Letcher
2007, Transactions of the American Fisheries Society (136) 1165-1176
Our goal was to understand movement and its interaction with survival for populations of stream salmonids at long-term study sites in the northeastern United States by employing passive integrated transponder (PIT) tags and associated technology. Although our PIT tag antenna arrays spanned the stream channel (at most flows) and were...
Diamondoid hydrocarbons as a molecular proxy for thermal maturity and oil cracking: Geochemical models from hydrous pyrolysis
Z. Wei, J.M. Moldowan, S. Zhang, R. Hill, D.M. Jarvie, Hongfang Wang, F. Song, F. Fago
2007, Organic Geochemistry (38) 227-249
A series of isothermal hydrous pyrolysis experiments was performed on immature sedimentary rocks and peats of different lithology and organic source input to explore the generation of diamondoids during the thermal maturation of sediments. Oil generation curves indicate that peak oil yields occur between 340 and 360 ??C, followed by...
Understanding the genetic effects of recent habitat fragmentation in the context of evolutionary history: Phylogeography and landscape genetics of a southern California endemic Jerusalem cricket (Orthoptera: Stenopelmatidae: Stenopelmatus)
Amy G. Vandergast, A.J. Bohonak, D.B. Weissman, Robert N. Fisher
2007, Molecular Ecology (16) 977-992
Habitat loss and fragmentation due to urbanization are the most pervasive threats to biodiversity in southern California. Loss of habitat and fragmentation can lower migration rates and genetic connectivity among remaining populations of native species, reducing genetic variability and increasing extinction risk. However, it may be difficult to separate the...
Predicting Secchi disk depth from average beam attenuation in a deep, ultra-clear lake
G.L. Larson, R.L. Hoffman, B.R. Hargreaves, R.W. Collier
2007, Hydrobiologia (574) 141-148
We addressed potential sources of error in estimating the water clarity of mountain lakes by investigating the use of beam transmissometer measurements to estimate Secchi disk depth. The optical properties Secchi disk depth (SD) and beam transmissometer attenuation (BA) were measured in Crater Lake (Crater Lake National Park, Oregon, USA)...
Sub-sampling genetic data to estimate black bear population size: A case study
C.A. Tredick, M.R. Vaughan, D.F. Stauffer, S.L. Simek, T. Eason
2007, Ursus (18) 179-188
Costs for genetic analysis of hair samples collected for individual identification of bears average approximately US$50 [2004] per sample. This can easily exceed budgetary allowances for large-scale studies or studies of high-density bear populations. We used 2 genetic datasets from 2 areas in the southeastern United States to explore how...
Multi-channel resistivity investigations of the freshwater-saltwater interface: A new tool to study an old problem
P.W. Swarzenski, S. Kruse, C. Reich, W.V. Swarzenski
2007, Conference Paper
It has been well established that fresh or brackish groundwater can exist both near and far from shore in many coastal and marine environments. The often permeable nature of marine sediments and the underlying bedrock provides abundant pathways for submarine groundwater discharge. While submarine groundwater discharge as a coastal hydrogeological...
Abundance of diurnal raptors in relation to prairie dog colonies: Implications for bird-aircraft strike hazard
J.W. Merriman, C. W. Boal, T.L. Bashore, P.J. Zwank, D.B. Wester
2007, Journal of Wildlife Management (71) 811-815
Some diurnal raptors are frequently observed at prairie dog (Cynomys sp.) colonies. As a result, some military installations have conducted prairie dog control activities to reduce the bird-aircraft strike hazard (BASH) potential of low-flying aircraft. To evaluate the validity of this management strategy, we assessed raptor associations with prairie dog...
Landscape correlates along mourning dove call-count routes in Mississippi
R.D. Elmore, F. J. Vilella, P.D. Gerard
2007, Journal of Wildlife Management (71) 422-427
Mourning dove (Zenaida macroura) call-count surveys in Mississippi, USA, suggest declining populations. We used available mourning dove call-count data to evaluate long-term mourning dove habitat relationships. Dove routes were located in the Mississippi Alluvial Valley, Deep Loess Province, Mid Coastal Plain, and Hilly Coastal Plain physiographic provinces of Mississippi. We...
Geoelectrical evidence of bicontinuum transport in groundwater
K. Singha, Frederick D. Day-Lewis, John W. Lane Jr.
2007, Geophysical Research Letters (34)
Bicontinuum models and rate-limited mass transfer (RLMT) explain complex transport behavior (e.g., long tailing and rebound) in heterogeneous geologic media, but experimental verification is problematic because geochemical samples represent the mobile component of the pore space. Here, we present geophysical evidence of RLMT at the field scale during an aquifer-storage...
Determining metal assimilation efficiency in aquatic invertebrates using enriched stable metal isotope tracers
Marie Noele Croteau, Samuel N. Luoma, B. Pellet
2007, Aquatic Toxicology (83) 116-125
We employ a novel approach that combines pulse-chase feeding and multi-labelled stable isotopes to determine gut passage time (GPT), gut retention time (GRT), food ingestion rate (IR) and assimilation efficiency (AE) of three trace elements for a freshwater gastropod. Lettuce isotopically enriched in 53Cr, 65Cu and 106Cd was fed for 2 h to Lymnaea stagnalis....
Porphyry copper deposit tract definition - A global analysis comparing geologic map scales
G. L. Raines, K.A. Connors, L.B. Chorlton
2007, Natural Resources Research (16) 191-198
Geologic maps are a fundamental data source used to define mineral-resource potential tracts for the first step of a mineral resource assessment. Further, it is generally believed that the scale of the geologic map is a critical consideration. Previously published research has demonstrated that the U.S. Geological Survey porphyry tracts...
Abundance and impacts of fallow deer leks at Point Reyes National Seashore
G. M. Fellers, M.S. Osbourn
2007, California Fish and Game (93) 149-160
Fallow deer, Dama dama, were released at Point Reyes National Seashore in the 1940s. A population of about 860 of these non-native deer are now well-established within the park. Fallow deer have an unusual mating system. During the fall, males establish areas known as leks where they display to potential...
Dynamics of newly established elk populations
G.A. Sargeant, M.W. Oehler Sr.
2007, Journal of Wildlife Management (71) 1141-1148
The dynamics of newly established elk (Cervus elaphus) populations can provide insights about maximum sustainable rates of reproduction, survival, and increase. However, data used to estimate rates of increase typically have been limited to counts and rarely have included complementary estimates of vital rates. Complexities of population dynamics cannot be...
Forensically important calliphoridae (diptera) associated with pig carrion in rural north-central Florida
Susan V. Gruner, D. H. Slone, J.L. Capinera
2007, Journal of Medical Entomology (44) 509-515
A study to determine the relative abundance and seasonality of forensically important blow flies (Diptera: Calliphoridae) in rural north-central Florida was conducted using pig carcasses (Sus scrofa L.) as models for human bodies. Seven species of Calliphoridae were collected: Lucilia coeruleiviridis (=Phoenicia) (Macquart), Cochliomyia macellaria (F.), Chrysomya rufifaces (Macquart), Phormia...
Characterizing dissolved Cu and Cd uptake in terms of the biotic ligand and biodynamics using enriched stable isotopes
Marie Noele Croteau, Samuel N. Luoma
2007, Environmental Science & Technology (41) 3140-3145
The biotic ligand model considers the biological and geochemical complexities that affect metal exposure. It relates toxicity to the fraction of physiological active sites impacted by reactive metal species. The biodynamic model is a complementary construct that predicts bioaccumulation and assumes that toxicity occurs when influx...
The rate and pattern of bed incision and bank adjustment on the Colorado River in Glen Canyon downstream from Glen Canyon Dam, 1956-2000
P.E. Grams, J. C. Schmidt, D.J. Topping
2007, Geological Society of America Bulletin (119) 556-575
Closure of Glen Canyon Dam in 1963 transformed the Colorado River by reducing the magnitude and duration of spring floods, increasing the magnitude of base flows, and trapping fine sediment delivered from the upper watershed. These changes caused the channel downstream in Glen Canyon to incise, armor, and narrow. This...
Structure-specific scalar intensity measures for near-source and ordinary earthquake ground motions
N. Luco, C.A. Cornell
2007, Earthquake Spectra (23) 357-392
Introduced in this paper are several alternative ground-motion intensity measures (IMs) that are intended for use in assessing the seismic performance of a structure at a site susceptible to near-source and/or ordinary ground motions. A comparison of such IMs is facilitated by defining the "efficiency" and "sufficiency" of an IM,...
Power to detect trend in short-term time series of bird abundance
W.E. Thogmartin, B. R. Gray, M. Gallagher, N. Young, J.J. Rohweder, M. G. Knutson
2007, Condor (109) 943-948
Avian point counts for population monitoring are often collected over a short timespan (e.g., 3-5 years). We examined whether power was adequate (power ???0.80) in short-duration studies to warrant the calculation of trend estimates. We modeled power to detect trends in abundance indices of eight bird species occurring across three...
Invasive species and coal bed methane development in the Powder River Basin, Wyoming
E. Bergquist, P. Evangelista, T.J. Stohlgren, N. Alley
2007, Environmental Monitoring and Assessment (128) 381-394
One of the fastest growing areas of natural gas production is coal bed methane (CBM) due to the large monetary returns and increased demand for energy from consumers. The Powder River Basin, Wyoming is one of the most rapidly expanding areas of CBM development with projections of the establishment of...
An age-structured population model for horseshoe crabs in the Delaware Bay area to assess harvest and egg availability for shorebirds
J. A. Sweka, D. R. Smith, M. J. Millard
2007, Estuaries and Coasts (30) 277-286
The objective of this simulation study was to create an age-structured population model for horseshoe crabs (Limulus polyphenols) in the Delaware Bay region using best available estimates of age-specific mortality and recent harvest levels. Density dependence was incorporated using a spatial model relating egg mortality with abundance of spawning females....
