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....
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...
Field-derived relationships for flow velocity and resistance in high-gradient streams
F. Comiti, L. Mao, A. Wilcox, E.E. Wohl, M.A. Lenzi
2007, Journal of Hydrology (340) 48-62
We measured velocity and channel geometry in 10 reaches (bed gradient = 0.08-0.21) of a predominantly step-pool channel, the Rio Cordon, Italy, over a range of discharges (3-80% of the bankfull discharge). The resulting data were used to compute flow resistance. At-a-station hydraulic geometry relations indicate that in most reaches,...
Effects of intraborehole flow on groundwater age distribution
B.A. Zinn, Leonard F. Konikow
2007, Hydrogeology Journal (15) 633-643
Environmental tracers are used to estimate groundwater ages and travel times, but the strongly heterogeneous nature of many subsurface environments can cause mixing between waters of highly disparate ages, adding additional complexity to the age-estimation process. Mixing may be exacerbated by the presence of wells because long open intervals or...
In situ hydrogen consumption kinetics as an indicator of subsurface microbial activity
S.H. Harris, Richard L. Smith, Joseph M. Suflita
2007, FEMS Microbiology Ecology (60) 220-228
There are few methods available for broadly assessing microbial community metabolism directly within a groundwater environment. In this study, hydrogen consumption rates were estimated from in situ injection/withdrawal tests conducted in two geochemically varying, contaminated aquifers as an approach towards developing such a method. The hydrogen consumption first-order rates varied...
Reproductive responses of male fathead minnows exposed to wastewater treatment plant effluent, effluent treated with XAD8 resin, and an environmentally relevant mixture of alkylphenol compounds
Larry B. Barber, Kathy Lee, Deborah L. Swackhamer, Heiko L. Schoenfuss
2007, Aquatic Toxicology (82) 36-46
On-site, continuous-flow experiments were conducted during August and October 2002 at a major metropolitan wastewater treatment plant (WWTP) to determine if effluent exposure induced endocrine disruption as manifested in the reproductive competence of sexually mature male fathead minnows (Pimephales promelas). The fathead minnows were exposed in parallel experiments to WWTP...
Free zinc ion and dissolved orthophosphate effects on phytoplankton from Coeur d'Alene Lake, Idaho
James S. Kuwabara, Brent R. Topping, Paul F. Woods, James L. Carter
2007, Environmental Science & Technology (41) 2811-2817
Coeur d'Alene Lake in northern Idaho is fed by two major rivers: the Coeur d'Alene River from the east and the St. Joe River from the south, with the Spokane River as its outlet to the north. This phosphorus-limited lake has been subjected to decades of mining (primarily for zinc...
Formation of tellurium nanocrystals during anaerobic growth of bacteria that use Te oxyanions as respiratory electron acceptors
Shaun M. Baesman, Thomas D. Bullen, J. Dewald, Donghui Zhang, S. Curran, F.S. Islam, T.J. Beveridge, Ronald S. Oremland
2007, Applied and Environmental Microbiology (73) 2135-2143
Certain toxic elements support the metabolism of diverse prokaryotes by serving as respiratory electron acceptors for growth. Here, we demonstrate that two anaerobes previously shown to be capable of respiring oxyanions of selenium also achieve growth by reduction of either tellurate [Te(VI)] or tellurite [Te(IV)] to elemental...
Anthropogenic contaminants as tracers in an urbanizing karst aquifer
B. Mahler, N. Massei
2007, Journal of Contaminant Hydrology (91) 81-106
Karst aquifers are uniquely vulnerable to contamination. In the Barton Springs segment of the karstic Edwards aquifer (Texas, U.S.A.), urban contaminants such as pesticides and volatile organic compounds frequently are detected in spring base flow. To determine whether contaminant concentrations change in response to storms, and if they therefore might...
Biotransformation of caffeine, cotinine, and nicotine in stream sediments: Implications for use as wastewater indicators
Paul M. Bradley, Larry B. Barber, Dana W. Kolpin, Peter B. McMahon, Francis H. Chapelle
2007, Environmental Toxicology and Chemistry (26) 1116-1121
Microbially catalyzed cleavage of the imadazole ring of caffeine was observed in stream sediments collected upstream and downstream of municipal wastewater treatment plants (WWTP) in three geographically separate stream systems. Microbial demethylation of the N-methyl component of cotinine and its metabolic precursor, nicotine, also was observed in these sediments. These...
Mars reconnaissance orbiter's high resolution imaging science experiment (HiRISE)
Alfred S. McEwen, Eric M. Eliason, James W. Bergstrom, Nathan T. Bridges, Candice J. Hansen, W. Alan Delamere, John A. Grant, Virginia C. Gulick, Kenneth E. Herkenhoff, Laszlo P. Keszthelyi, Randolph L. Kirk, Michael T. Mellon, Steven W. Squyres, Nicolas Thomas, Catherine M. Weitz
2007, Journal of Geophysical Research E: Planets (112)
The HiRISE camera features a 0.5 m diameter primary mirror, 12 m effective focal length, and a focal plane system that can acquire images containing up to 28 Gb (gigabits) of data in as little as 6 seconds. HiRISE will provide detailed images (0.25 to 1.3 m/pixel) covering ∼1% of...
Late Quaternary paleoenvironments of an ephemeral wetland in North Dakota, USA: Relative interactions of ground-water hydrology and climate change
C.H. Yansa, W.E. Dean, E.C. Murphy
2007, Journal of Paleolimnology (38) 441-457
This study of fossils (pollen, plant macrofossils, stomata and fish) and sediments (lithostratigraphy and geochemistry) from the Wendel site in North Dakota, USA, emphasizes the importance of considering ground-water hydrology when deciphering paleoclimate signals from lakes in postglacial landscapes. The Wendel site was a paleolake from about 11,500 14C yr...
Restoring coastal wetlands that were ditched for mosquito control: a preliminary assessment of hydro-leveling as a restoration technique
Thomas J. Smith III, Ginger Tiling, Pamela S. Leasure
2007, Journal of Coastal Conservation (11) 67-74
The wetlands surrounding Tampa Bay, Florida were extensively ditched for mosquito control in the 1950s. Spoil from ditch construction was placed adjacent to the wetlands ditches creating mound-like features (spoil-mounds). These mounds represent a loss of 14% of the wetland area in Tampa Bay. Spoil mounds interfere with tidal flow...
Widespread natural perchlorate in unsaturated zones of the southwest United States
Balaji Rao, Todd A. Anderson, Greta J. Orris, Ken A. Rainwater, Srinath Rajagopalan, Renee M. Sandvig, Bridget R. Scanlon, David A. Stonestrom, Michelle Ann Walvoord, W Andrew Jackson
2007, Environmental Science & Technology (41) 4522-4528
A substantial reservoir (up to 1 kg ha-1) of natural perchlorate is present in diverse unsaturated zones of the arid and semi-arid southwestern United States. The perchlorate co-occurs with meteoric chloride that has accumulated in these soils throughout the Holocene [0...
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...
Anaerobic biodegradation and hydrogeochemical controls on natural attenuation of trichloroethene in an inland forested wetland
M.M. Lorah, L.J. Dyer, D.R. Burris
2007, Bioremediation Journal (11) 85-102
Anaerobic biodegradation was conducted in a forested wetland where a plume of trichloroethylene discharges from a sand aquifer through organic-rich wetland and stream-bottom sediments. The rapid response of the wetland hydrology to precipitation events altered groundwater flow and geochemistry during wet conditions in the spring compared to the drier conditions...
Hydrodynamics of coalbed methane reservoirs in the Black Warrior Basin: Key to understanding reservoir performance and environmental issues
J.C. Pashin
2007, Applied Geochemistry (22) 2257-2272
The Black Warrior Basin of the southeastern United States hosts one of the world's most prolific and long-lived coalbed methane plays, and the wealth of experience in this basin provides insight into the relationships among basin hydrology, production performance, and environmental issues. Along the southeast margin of the basin, meteoric...
Concentrations of metals in water, sediment, biofilm, benthic macroinvertebrates, and fish in the Boulder River watershed, Montana, and the role of colloids in metal uptake
Aida Farag, David A. Nimick, Briant A. Kimball, Stanley E. Church, David D. Harper, William G. Brumbaugh
2007, Archives of Environmental Contamination and Toxicology (52) 397-409
To characterize the partitioning of metals in a stream ecosystem, concentrations of trace metals including As, Cd, Cu, Pb, and Zn were measured in water, colloids, sediment, biofilm (also referred to as aufwuchs), macroinvertebrates, and fish collected from the Boulder River watershed, Montana. Median concentrations of Cd, Cu, and...
Use of carboxylated microspheres to assess transport potential of Cryptosporidium parvum oocysts at the Russian River water supply facility, Sonoma County, California
David W. Metge, Ronald W. Harvey, Robert Anders, Donald O. Rosenberry, Donald Seymour, Jay Jasperse
2007, Geomicrobiology Journal (24) 231-245
<div...
Detection, attribution, and sensitivity of trends toward earlier streamflow in the Sierra Nevada
E.P. Maurer, I.T. Stewart, Celine Bonfils, P. B. Duffy, D. Cayan
2007, Journal of Geophysical Research D: Atmospheres (112)
Observed changes in the timing of snowmelt dominated streamflow in the western United States are often linked to anthropogenic or other external causes. We assess whether observed streamflow timing changes can be statistically attributed to external forcing, or whether they still lie within the bounds of natural (internal) variability for...
Hydrology and water quality in two mountain basins of the northeastern US: Assessing baseline conditions and effects of ski area development
B. Wemple, J. Shanley, J. Denner, D. Ross, K. Mills
2007, Conference Paper, Hydrological Processes
Mountain regions throughout the world face intense development pressures associated with recreational and tourism uses. Despite these pressures, much of the research on bio-geophysical impacts of humans in mountain regions has focused on the effects of natural resource extraction. This paper describes findings from the first 3 years of a...
Effect of bedrock permeability on subsurface stormflow and the water balance of a trenched hillslope at the Panola Mountain Research Watershed, Georgia, USA
Meerveld H. J. Tromp-van H. J., N.E. Peters, Jeffery J. McDonnell
2007, Hydrological Processes (21) 750-769
The effect of bedrock permeability on subsurface stormflow initiation and the hillslope water balance is poorly understood. Previous hillslope hydrological studies at the Panola Mountain Research Watershed (PMRW), Georgia, USA, have assumed that the bedrock underlying the trenched hillslope is effectively impermeable. This paper presents a series of sprinkling experiments...
Simple predictions of maximum transport rate in unsaturated soil and rock
John R. Nimmo
2007, Water Resources Research (43)
In contrast with the extreme variability expected for water and contaminant fluxes in the unsaturated zone, evidence from 64 field tests of preferential flow indicates that the maximum transport speed Vmax, adjusted for episodicity of infiltration, deviates little from a geometric mean of 13 m/d. A model based on constant‐speed travel...
Radium-226 accumulation in Florida freshwater mussels
M. Brenner, J.M. Smoak, D.A. Leeper, M. Streubert, S.M. Baker
2007, Limnology and Oceanography (52) 1614-1623
Selected lakes in Hillsborough County, Florida have been hydrologically augmented with groundwater to offset stage declines caused by excessive pumping of the Floridan Aquifer. Augmentation water can be relatively rich in 226Ra (>5 decays per minute [dpm] L-1). We measured 226Ra activities in shells and soft tissues of adult bivalve...
The influence of river regulation and land use on floodplain forest regeneration in the semi-arid upper Colorado River Basin, USA
K. Northcott, D.C. Andersen, D.J. Cooper
2007, River Research and Applications (23) 565-577
Flow regulation effects on floodplain forests in the semi-arid western United States are moderately well understood, whereas effects associated with changes in floodplain land use are poorly documented. We mapped land cover patterns from recent aerial photos and applied a classification scheme to mainstem alluvial floodplains in 10 subjectively selected...
