Phase shift from a coral to a corallimorph-dominated reef associated with a shipwreck on Palmyra atoll
Thierry M. Work, G.S. Aeby, J.E. Maragos
2008, PLoS ONE (3)
Coral reefs can undergo relatively rapid changes in the dominant biota, a phenomenon referred to as phase shift. Various reasons have been proposed to explain this phenomenon including increased human disturbance, pollution, or changes in coral reef biota that serve a major ecological function such as depletion of grazers. However,...
Evidence for an eolian origin for the silt-enriched soil mantles on the glaciated uplands of eastern Upper Michigan, USA
R.J. Schaetzl, W.L. Loope
2008, Geomorphology (100) 285-295
We provide textural, geochemical, and mineralogical data on a thin, silty deposit that unconformably mantles glaciated uplands in the eastern Upper Peninsula of Michigan. Previous research on this deposit, which we hypothesize to be loess, is nonexistent. The uplands were islands or narrow peninsulas within one or more glacial lakes....
50,000 years of vegetation and climate history on the Colorado Plateau, Utah and Arizona, USA
Larry L. Coats, Kenneth L. Cole, Jim I. Mead
2008, Quaternary Research (70) 322-338
Sixty packrat middens were collected in Canyonlands and Grand Canyon National Parks, and these series include sites north of areas that produced previous detailed series from the Colorado Plateau. The exceptionally long time series obtained from each of three sites (> 48,000 14C yr BP to present) include some of the...
Identity and physiology of a new psychrophilic eukaryotic green alga, Chlorella sp., strain BI, isolated from a transitory pond near Bratina Island, Antarctica
R. M. Morgan-Kiss, A.G. Ivanov, S. Modla, K. Czymmek, N.P.A. Huner, J.C. Priscu, J.T. Lisle, T.E. Hanson
2008, Extremophiles (12) 701-711
Permanently low temperature environments are one of the most abundant microbial habitats on earth. As in most ecosystems, photosynthetic organisms drive primary production in low temperature food webs. Many of these phototrophic microorganisms are psychrophilic; however, functioning of the photosynthetic processes of these enigmatic psychrophiles (the 'photopsychrophiles') in cold environments...
Seasonal variation in size-dependent survival of juvenile Atlantic salmon (Salmo salar): Performance of multistate capture-mark-recapture models
B. H. Letcher, G.E. Horton
2008, Canadian Journal of Fisheries and Aquatic Sciences (65) 1649-1666
We estimated the magnitude and shape of size-dependent survival (SDS) across multiple sampling intervals for two cohorts of stream-dwelling Atlantic salmon (Salmo salar) juveniles using multistate capture-mark-recapture (CMR) models. Simulations designed to test the effectiveness of multistate models for detecting SDS in our system indicated that error in SDS estimates...
Evidence of infection by H5N2 highly pathogenic avian influenza viruses in healthy wild waterfowl
N. Gaidet, G. Cattoli, S. Hammoumi, S. H. Newman, W. Hagemeijer, John Y. Takekawa, J. Cappelle, T. Dodman, T. Joannis, P. Gil, I. Monne, A. Fusaro, I. Capua, S. Manu, P. Micheloni, U. Ottosson, J.H. Mshelbwala, J. Lubroth, J. Domenech, F. Monicat
2008, PLoS Pathogens (4)
The potential existence of a wild bird reservoir for highly pathogenic avian influenza (HPAI) has been recently questioned by the spread and the persisting circulation of H5N1 HPAI viruses, responsible for concurrent outbreaks in migratory and domestic birds over Asia, Europe, and Africa. During a large-scale surveillance programme over Eastern...
Microbial mass-dependent fractionation of chromium isotopes
E.R. Sikora, T.M. Johnson, T.D. Bullen
2008, Geochimica et Cosmochimica Acta (72) 3631-3641
Mass-dependent fractionation of Cr isotopes occurs during dissimilatory Cr(VI) reduction by Shewanella oneidensis strain MR-1. Cells suspended in a simple buffer solution, with various concentrations of lactate or formate added as electron donor, reduced 5 or 10 ??M Cr(VI) to Cr(III) over days to weeks. In all nine batch experiments,...
In situ arsenic removal in an alkaline clastic aquifer
A. H. Welch, K.G. Stollenwerk, A.P. Paul, D. K. Maurer, K. J. Halford
2008, Applied Geochemistry (23) 2477-2495
In situ removal of As from ground water used for water supply has been accomplished elsewhere in circum-neutral ground water containing high dissolved Fe(II) concentrations. The objective of this study was to evaluate in situ As ground-water treatment approaches in alkaline ground-water (pH > 8)...
Spatial patterns and movements of red king and Tanner crabs: Implications for the design of marine protected areas
S. James Taggart, Jennifer Mondragon, A.G. Andrews, J.K. Nielsen
2008, Marine Ecology Progress Series (365) 151-163
Most examples of positive population responses to marine protected areas (MPAs) have been documented for tropical reef species with very small home ranges; the utility of MPAs for commercially harvested temperate species that have large movement patterns remains poorly tested. We measured the distribution and abundance of red king Paralithodes...
Calculating wave-generated bottom orbital velocities from surface-wave parameters
P.L. Wiberg, C. R. Sherwood
2008, Computers & Geosciences (34) 1243-1262
Near-bed wave orbital velocities and shear stresses are important parameters in many sediment-transport and hydrodynamic models of the coastal ocean, estuaries, and lakes. Simple methods for estimating bottom orbital velocities from surface-wave statistics such as significant wave height and peak period often are inaccurate except in very shallow water. This...
Geolocation of man-made reservoirs across terrains of varying complexity using GIS
D.M. Mixon, D.A. Kinner, R.F. Stallard, J.P.M. Syvitski
2008, Computers & Geosciences (34) 1184-1197
The Reservoir Sedimentation Survey Information System (RESIS) is one of the world's most comprehensive databases of reservoir sedimentation rates, comprising nearly 6000 surveys for 1819 reservoirs across the continental United States. Sediment surveys in the database date from 1904 to 1999, though more than 95% of surveys were entered prior...
Assessing streamflow characteristics as limiting factors on benthic invertebrate assemblages in streams across the western United States
C.P. Konrad, A.M.D. Brasher, J. T. May
2008, Freshwater Biology (53) 1983-1998
1. Human use of land and water resources modifies many streamflow characteristics, which can have significant ecological consequences. Streamflow and invertebrate data collected at 111 sites in the western U.S.A. were analysed to identify streamflow characteristics (magnitude, frequency, duration, timing and variation) that are probably to limit characteristics of benthic...
Combining MODIS and Landsat imagery to estimate and map boreal forest cover loss
P. Potapov, Matthew C. Hansen, S.V. Stehman, Thomas R. Loveland, K. Pittman
2008, Remote Sensing of Environment (112) 3708-3719
Estimation of forest cover change is important for boreal forests, one of the most extensive forested biomes, due to its unique role in global timber stock, carbon sequestration and deposition, and high vulnerability to the effects of global climate change. We used time-series data from the MODerate Resolution Imaging Spectroradiometer...
Factors influencing leaf litter decomposition: An intersite decomposition experiment across China
G. Zhou, L. Guan, X. Wei, X. Tang, S. Liu, J. Liu, Dongxiao Zhang, J. Yan
2008, Plant and Soil (311) 61-72
The Long-Term Intersite Decomposition Experiment in China (hereafter referred to as LTIDE-China) was established in 2002 to study how substrate quality and macroclimate factors affect leaf litter decomposition. The LTIDE-China includes a wide variety of natural and managed ecosystems, consisting of 12 forest types (eight regional broadleaf forests, three needle-leaf...
Fish assemblages of the Casiquiare River, a corridor and zoogeographical filter for dispersal between the Orinoco and Amazon basins
K.O. Winemiller, H. Lopez-Fernandez, D.C. Taphorn, L.G. Nico, A.B. Duque
2008, Journal of Biogeography (35) 1551-1563
Aim: The aim of this study was to determine whether the Casiquiare River functions as a free dispersal corridor or as a partial barrier (i.e. filter) for the interchange of fish species of the Orinoco and Negro/Amazon basins using species assemblage patterns according to geographical location and environmental features. Location:...
Contrasting population trends of piscivorous seabirds in the Pribilof Islands: A 30-year perspective
G.V. Byrd, Joel A. Schmutz, H.M. Renner
2008, Deep-Sea Research Part II: Topical Studies in Oceanography (55) 1846-1855
The Pribilof Islands provide nesting habitat for one of the largest concentrations of piscivorous seabirds in the North Pacific region. Pribilof breeding populations of black-legged and red-legged kittiwakes (Rissa tridactyla and Rissa brevirostris), and common and thick-billed murres (Uria aalge and Uria lomvia) are supported by a highly productive marine...
Application of two tests of multivariate discordancy to fisheries data sets
M.A. Stapanian, P.M. Kocovsky, F.C. Garner
2008, Environmental Biology of Fishes (82) 325-339
The generalized (Mahalanobis) distance and multivariate kurtosis are two powerful tests of multivariate discordancies (outliers). Unlike the generalized distance test, the multivariate kurtosis test has not been applied as a test of discordancy to fisheries data heretofore. We applied both tests, along with published algorithms for identifying suspected causal variable(s)...
Photoreduction fuels biogeochemical cycling of iron in Spain's acid rivers
C.H. Gammons, D. A. Nimick, S.R. Parker, D.M. Snyder, R. Blaine McCleskey, R. Amils, S.R. Poulson
2008, Chemical Geology (252) 202-213
A number of investigations have shown that photoreduction of Fe(III) causes midday accumulations of dissolved Fe(II) in rivers and lakes, leading to large diel (24-h) fluctuations in the concentration and speciation of total dissolved iron. Less well appreciated is the importance of photoreduction in...
Humid tropical forest clearing from 2000 to 2005 quantified by using multitemporal and multiresolution remotely sensed data
Matthew C. Hansen, S.V. Stehman, Peter V. Potapov, Thomas R. Loveland, J.R.G. Townshend, R.S. DeFries, K.W. Pittman, B. Arunarwati, F. Stolle, M.K. Steininger, M. Carroll, C. DiMiceli
2008, Proceedings of the National Academy of Sciences of the United States of America (105) 9439-9444
Forest cover is an important input variable for assessing changes to carbon stocks, climate and hydrological systems, biodiversity richness, and other sustainability science disciplines. Despite incremental improvements in our ability to quantify rates of forest clearing, there is still no definitive understanding on global trends. Without timely and accurate forest...
A coupled model approach to reduce nonpoint-source pollution resulting from predicted urban growth: A case study in the Ambos Nogales watershed
L.M. Norman, D.P. Guertin, M. Feller
2008, Urban Geography (29) 496-516
The development of new approaches for understanding processes of urban development and their environmental effects, as well as strategies for sustainable management, is essential in expanding metropolitan areas. This study illustrates the potential of linking urban growth and watershed models to identify problem areas and support long-term watershed planning. Sediment...
A national reconnaissance for pharmaceuticals and other organic wastewater contaminants in the United States - II) Untreated drinking water sources
M. J. Focazio, D.W. Kolpin, K.K. Barnes, E. T. Furlong, M. T. Meyer, S.D. Zaugg, L. B. Barber, M.E. Thurman
2008, Science of the Total Environment (402) 201-216
Numerous studies have shown that a variety of manufactured and natural organic compounds such as pharmaceuticals, steroids, surfactants, flame retardants, fragrances, plasticizers and other chemicals often associated with wastewaters have been detected in the vicinity of municipal wastewater discharges and livestock agricultural facilities. To provide new data and insights about...
Real-time PCR detection and quantification of nine potential sources of fecal contamination by analysis of mitochondrial Cytochrome b targets
W. B. Schill, M.V. Mathes
2008, Environmental Science & Technology (42) 5229-5234
We designed and tested real-time PCR probe/primer sets to detect and quantify Cytochrome b sequences of mitochondrial DNA (mtDNA) from nine vertebrate species of pet (dog), farm (cow, chicken, sheep, horse, pig), wildlife (Canada goose, white-tailed deer), and human. Linear ranges of the assays were from 101 to 108 copies/??l....
Distribution and variability of redox zones controlling spatial variability of arsenic in the Mississippi River Valley alluvial aquifer, southeastern Arkansas
M.U. Sharif, R.K. Davis, K.F. Steele, B. Kim, P.D. Hays, T.M. Kresse, J.A. Fazio
2008, Journal of Contaminant Hydrology (99) 49-67
Twenty one of 118 irrigation water wells in the shallow (25-30??m thick) Mississippi River Valley alluvial aquifer in the Bayou Bartholomew watershed, southeastern Arkansas had arsenic (As) concentrations (< 0.5 to 77????g/L) exceeding 10????g/L. Sediment and groundwater samples were collected and analyzed from the sites of the highest, median, and...
Magnetic monitoring of earth and space
Jeffrey J. Love
2008, Physics Today (61) 31-37
For centuries, navigators of the world’s oceans have been familiar with an effect of Earth’s magnetic field: It imparts a directional preference to the needle of a compass. Although in some settings magnetic orientation remains important, the modern science of geomagnetismhas emerged from its romantic nautical origins and developed into a subject of great depth and...
Analytical and numerical analyses of an unconfined aquifer test considering unsaturated zone characteristics
A.F. Moench
2008, Water Resources Research (44)
A 7-d, constant rate aquifer test conducted by University of Waterloo researchers at Canadian Forces Base Borden in Ontario, Canada, is useful for advancing understanding of fluid flow processes in response to pumping from an unconfined aquifer. Measured data include not only drawdown in the saturated zone but also volumetric...
