The Asian clam Corbicula fluminea as a biomonitor of trace element contamination: Accounting for different sources of variation using an hierarchical linear model
W. A. Shoults-Wilson, J.T. Peterson, J. M. Unrine, J. Rickard, M.C. Black
2009, Environmental Toxicology and Chemistry (28) 2224-2232
In the present study, specimens of the invasive clam, Corbicula fluminea, were collected above and below possible sources of potentially toxic trace elements (As, Cd, Cr, Cu, Hg, Pb, and Zn) in the Altamaha River system (Georgia, USA). Bioaccumulation of these elements was quantified, along with environmental (water and sediment)...
The changing global carbon cycle: Linking plant-soil carbon dynamics to global consequences
F. S. Chapin III, J. McFarland, David A. McGuire, E.S. Euskirchen, Roger W. Ruess, K. Kielland
2009, Journal of Ecology (97) 840-850
Most current climate-carbon cycle models that include the terrestrial carbon (C) cycle are based on a model developed 40 years ago by Woodwell & Whittaker (1968) and omit advances in biogeochemical understanding since that time. Their model treats net C emissions from ecosystems as the balance between net primary production...
Contrasting residence times and fluxes of water and sulfate in two small forested watersheds in Virginia, USA
J.K. Böhlke, R. L. Michel
2009, Science of the Total Environment (407) 4363-4377
Watershed mass balances for solutes of atmospheric origin may be complicated by the residence times of water and solutes at various time scales. In two small forested headwater catchments in the Appalachian Mountains of Virginia, USA, mean annual export rates of SO4= differ by a factor of 2, and seasonal variations...
Movements by adult cutthroat trout in a lotic system: Implications for watershed-scale management
T.B. Sanderson, W.A. Hubert
2009, Fisheries Management and Ecology (16) 329-336
Movements by adult cutthroat trout, Oncorhynchus clarkii (Richardson), were assessed from autumn to summer in the Salt River watershed, Wyoming-Idaho, USA by radio telemetry. Adult cutthroat trout were captured during September and October 2005 in the main stem of the Salt River, surgically implanted with radio transmitters, and tracked through...
Multiple spring migration strategies in a population of Pacific Common Eiders
Margaret R. Petersen
2009, Condor (111) 59-70
Spring migration strategies vary within and among species. Examination of this variability extends our understanding of life histories and has implications for conservation. I used satellite transmitters to determine migration strategies and evaluate factors influencing the timing of spring migration of Pacific Common Eiders (Somateria mollissima v-nigrum) that nest along...
A new method for high-resolution characterization of hydraulic conductivity
Gaisheng Liu, J.J. Butler Jr., Geoffrey C. Bohling, Ed Reboulet, Steve Knobbe, D.W. Hyndman
2009, Water Resources Research (45)
A new probe has been developed for high-resolution characterization of hydraulic conductivity (K) in shallow unconsolidated formations. The probe was recently applied at the Macrodispersion Experiment (MADE) site in Mississippi where K was rapidly characterized at a resolution as fine as 0.015 m, which has not previously been possible. Eleven...
A method to assess longitudinal riverine connectivity in tropical streams dominated by migratory biota
K.E. Crook, C. M. Pringle, Mary C. Freeman
2009, Aquatic Conservation: Marine and Freshwater Ecosystems (19) 714-723
1. One way in which dams affect ecosystem function is by altering the distribution and abundance of aquatic species. 2. Previous studies indicate that migratory shrimps have significant effects on ecosystem processes in Puerto Rican streams, but are vulnerable to impediments to upstream or downstream passage, such as dams and...
Seasonal habitat selection by lake trout (Salvelinus namaycush) in a small Canadian shield lake: Constraints imposed by winter conditions
P.J. Blanchfield, L.S. Tate, J.M. Plumb, M.-L. Acolas, K.G. Beaty
2009, Aquatic Ecology (43) 777-787
The need for cold, well-oxygenated waters significantly reduces the habitat available for lake trout (Salvelinus namaycush) during stratification of small temperate lakes. We examined the spatial and pelagic distribution of lake trout over two consecutive summers and winters and tested whether winter increased habitat availability and access to littoral regions...
High-quality unsaturated zone hydraulic property data for hydrologic applications
Kimberlie Perkins, John R. Nimmo
2009, Water Resources Research (45)
In hydrologic studies, especially those using dynamic unsaturated zone moisture modeling, calculations based on property transfer models informed by hydraulic property databases are often used in lieu of measured data from the site of interest. Reliance on database-informed predicted values has become increasingly common with the use of neural networks....
San Andreas fault geometry at Desert Hot Springs, California, and its effects on earthquake hazards and groundwater
R. D. Catchings, M. J. Rymer, M. R. Goldman, G. Gandhok
2009, Bulletin of the Seismological Society of America (99) 2190-2207
The Mission Creek and Banning faults are two of the principal strands of the San Andreas fault zone in the northern Coachella Valley of southern California. Structural characteristics of the faults affect both regional earthquake hazards and local groundwater resources. We use seismic, gravity, and geological data to characterize the...
Continental-scale patterns in soil geochemistry and mineralogy: results from two transects across the United States and Canada
L. G. Woodruff, W.F. Cannon, D. D. Eberl, D. B. Smith, J.E. Kilburn, J.D. Horton, R. G. Garrett, R.A. Klassen
2009, Applied Geochemistry (24) 1369-1381
In 2004, the US Geological Survey (USGS) and the Geological Survey of Canada (GSC) initiated a pilot study that involved collection of more than 1500 soil samples from 221 sites along two continental transects across Canada and the United States. The pilot study was designed to test and refine protocols...
Morphological variability of the planktonic foraminifer Neogloboquadrina pachyderma from ACEX cores: Implications for late pleistocene circulation in the Arctic Ocean
F. Eynaud, T. M. Cronin, S.A. Smith, S. Zaragosi, J. Mavel, Y. Mary, V. Mas, C. Pujol
2009, Micropaleontology (55) 101-116
Planktonic foraminifera populations were studied throughout the top 25 meters of the IODP ACEX 302 Hole 4C from the central Arctic Ocean at a resolution varying from 5cm (at the top of the record) to 10cm. Planktonic foraminifera occur in high absolute abundances only in the uppermost fifty centimetres and...
Influences of wind-wave exposure on the distribution and density of recruit reef fishes at Kure and Pearl and Hermes Atolls, Northwestern Hawaiian Islands
E.E. DeMartini, B.J. Zgliczynski, R.C. Boland, A. M. Friedlander
2009, Environmental Biology of Fishes (85) 319-332
This paper describes the results of a field survey designed to test the prediction that the density of benthic juveniles of shallow-reef fishes is greater on wind-wave "exposed" sectors of a pair of isolated oceanic atolls (Kure, Pearl and Hermes) at the far northwestern end of the Hawaiian Islands, an...
Geoelectrical measurement and modeling of biogeochemical breakthrough behavior during microbial activity
L.D. Slater, Frederick D. Day-Lewis, D. Ntarlagiannis, M. O'Brien, N. Yee
2009, Geophysical Research Letters (36)
We recorded bulk electrical conductivity (σb) along a soil column during microbially-mediated selenite oxyanion reduction. Effluent fluid electrical conductivity and early time σb were modeled according to classic advective-dispersive transport of the nutrient medium. However, σb along the column exhibited strongly bimodal breakthrough which cannot be explained by changes in the electrical conductivity of...
Obtaining parsimonious hydraulic conductivity fields using head and transport observations: A Bayesian geostatistical parameter estimation approach
Michael N. Fienen, R. Hunt, D. Krabbenhoft, T. Clemo
2009, Water Resources Research (45)
Flow path delineation is a valuable tool for interpreting the subsurface hydrogeochemical environment. Different types of data, such as groundwater flow and transport, inform different aspects of hydrogeologic parameter values (hydraulic conductivity in this case) which, in turn, determine flow paths. This work combines flow and transport information to estimate...
New evidence for a magmatic influence on the origin of Valles Marineris, Mars
J. M. Dohm, J.-P. Williams, R. C. Anderson, J. Ruiz, P.C. McGuire, G. Komatsu, A.F. Davila, J.C. Ferris, D. Schulze-Makuch, V.R. Baker, W. V. Boynton, A.G. Fairen, T.M. Hare, H. Miyamoto, K. L. Tanaka, S.J. Wheelock
2009, Journal of Volcanology and Geothermal Research (185) 12-27
In this paper, we show that the complex geological evolution of Valles Marineris, Mars, has been highly influenced by the manifestation of magmatism (e.g., possible plume activity). This is based on a diversity of evidence, reported here, for the central part, Melas Chasma, and nearby regions, including uplift, loss of...
Deformation band clusters on Mars and implications for subsurface fluid flow
Chris Okubo, Richard A. Schultz, Marjorie A. Chan, Goro Komatsu, the HiRISE TEam
2009, Geological Society of America Bulletin (121) 474-482
High-resolution imagery reveals unprecedented lines of evidence for the presence of deformation band clusters in layered sedimentary deposits in the equatorial region of Mars. Deformation bands are a class of geologic structural discontinuity that is a precursor to faults in clastic rocks and soils. Clusters of deformation bands, consisting of...
The last glacial maximum
P.U. Clark, A. S. Dyke, J.D. Shakun, A.E. Carlson, J. Clark, B. Wohlfarth, J.X. Mitrovica, S. W. Hostetler, A.M. McCabe
2009, Science (325) 710-714
We used 5704 14C, 10Be, and 3He ages that span the interval from 10,000 to 50,000 years ago (10 to 50 ka) to constrain the timing of the Last Glacial Maximum (LGM) in terms of global ice-sheet and mountain-glacier extent. Growth of the ice sheets to their maximum positions occurred...
Taxonomy of quaternary deep-sea ostracods from the Western North Atlantic ocean
Moriaki Yasuhara, H. Okahashi, T. M. Cronin
2009, Palaeontology (52) 879-931
Late Quaternary sediments from Ocean Drilling Program (ODP) Hole 1055B, Carolina Slope, western North Atlantic (32??47.041??? N, 76??17.179??? W; 1798m water depth) were examined for deep-sea ostracod taxonomy. A total of 13933 specimens were picked from 207 samples and c. 120 species were identified. Among them, 87 species were included...
Gas hydrate drilling transect across northern Cascadia margin - IODP Expedition 311
M. Riedel, Timothy S. Collett, M.J. Malone
2009, Geological Society Special Publication 11-19
A transect of four sites (U1325, U1326, U1327 and U1329) across the northern Cascadia margin was established during Integrated Ocean Drilling Program Expedition 311 to study the occurrence and formation of gas hydrate in accretionary complexes. In addition to the transect sites, a fifth site (U1328) was established at a...
Selenium and trace element mobility affected by periodic displacement of stratification in the Great Salt Lake, Utah
K. Beisner, D. L. Naftz, W.P. Johnson, X. Diaz
2009, Science of the Total Environment (407) 5263-5273
The Great Salt Lake (GSL) is a unique ecosystem in which trace element activity cannot be characterized by standard geochemical parameters due to the high salinity. Movement of selenium and other trace elements present in the lake bed sediments of GSL may occur due to periodic stratification displacement events or...
Flood frequency analysis for nonstationary annual peak records in an urban drainage basin
G. Villarini, J. A. Smith, F. Serinaldi, J. Bales, P.D. Bates, W.F. Krajewski
2009, Advances in Water Resources (32) 1255-1266
Flood frequency analysis in urban watersheds is complicated by nonstationarities of annual peak records associated with land use change and evolving urban stormwater infrastructure. In this study, a framework for flood frequency analysis is developed based on the Generalized Additive Models for Location, Scale and Shape parameters (GAMLSS), a tool...
Do summer temperatures trigger spring maturation in pacific lamprey, Entosphenus tridentatus?
B.J. Clemens, S. Van De Wetering, J. Kaufman, R.A. Holt, C.B. Schreck
2009, Ecology of Freshwater Fish (18) 418-426
Pacific lamprey, Entosphenus tridentatus, return to streams and use somatic energy to fuel maturation. Body size decreases, the lamprey mature, spawn, and then die. We predicted that warm, summer temperatures (>20 ??C) would accentuate shrinkage in body size, and expedite sexual maturation and subsequent death. We compared fish reared in...
Hydrologic and biogeochemical controls of river subsurface solutes under agriculturally enhanced ground water flow
R.A. Wildman Jr., Joseph L. Domagalski, J. G. Hering
2009, Journal of Environmental Quality (38) 1830-1840
The relative influences of hydrologic processes and biogeochemistry on the transport and retention of minor solutes were compared in the riverbed of the lower Merced River (California, USA). The subsurface of this reach receives ground water discharge and surface water infiltration due to an altered hydraulic setting resulting from agricultural...
Mercury bioaccumulation and risk to three waterbird foraging guilds is influenced by foraging ecology and breeding stage
Collin A. Eagles-Smith, Joshua T. Ackerman, S.E.W. de la Cruz, John Y. Takekawa
2009, Environmental Pollution (157) 1993-2002
We evaluated mercury (Hg) in five waterbird species representing three foraging guilds in San Francisco Bay, CA. Fish-eating birds (Forster's and Caspian terns) had the highest Hg concentrations in thier tissues, but concentrations in an invertebrate-foraging shorebird (black-necked stilt) were also elevated. Foraging habitat was important for Hg exposure as...
