Predicting the locations of naturally fishless lakes
Emily Gaenzle Schilling, C.S. Loftin, K.E. Degoosh, Alexander D. Huryn, K.E. Webster
2008, Freshwater Biology (53) 1021-1035
1. Fish have been introduced into many previously fishless lakes throughout North America over the past 100+ years. It is difficult to determine the historical distribution of fishless lakes, however, because these introductions have not always been well-documented. 2. Due to its glacial history and low human population density, the...
Factors influencing nesting success of king eiders on northern Alaska's Coastal Plain
R.L. Bentzen, A.N. Powell, R.S. Suydam
2008, Journal of Wildlife Management (72) 1781-1789
King eider (Somateria spectabilis) populations have declined markedly in recent decades for unknown reasons. Nest survival is one component of recruitment, and a female's chance of reproductive success increases with her ability to choose an appropriate nesting strategy. We estimated variation in daily nest survival of king eiders at 2...
Implications of postseismic gravity change following the great 2004 Sumatra-Andaman earthquake from the regional harmonic analysis of GRACE intersatellite tracking data
S.-C. Han, J. Sauber, S.B. Luthcke, C. Ji, F. F. Pollitz.
2008, Journal of Geophysical Research B: Solid Earth (113)
We report Gravity Recovery and Climate Experiment (GRACE) satellite observations of coseismic displacements and postseismic transients from the great Sumatra-Andaman Islands (thrust event; Mw ???9.2) earthquake in December 2004. Instead of using global spherical harmonic solutions of monthly gravity fields, we estimated the gravity changes directly using intersatellite range-rate data...
Physical properties of sediments from Keathley Canyon and Atwater Valley, JIP Gulf of Mexico gas hydrate drilling program
William J. Winters, Brandon Dugan, Timothy S. Collett
2008, Marine and Petroleum Geology (25) 896-905
Physical property measurements and consolidation behavior are different between sediments from Atwater Valley and Keathley Canyon in the northern Gulf of Mexico. Void ratio and bulk density of Atwater Valley sediment from a seafloor mound (holes ATM1 and ATM2) show little effective stress (or depth) dependence to 27 meters below seafloor...
Radar imaging of winter seismic survey activity in the National Petroleum Reserve-Alaska
Benjamin M. Jones, Russ Rykhus, Z. Lu, C.D. Arp, D.J. Selkowitz
2008, Polar Record (44) 227-231
During the spring of 2006, Radarsat-1 synthetic aperture radar (SAR) imagery was acquired on a continual basis for the Teshekpuk Lake Special Area (TLSA), in the northeast portion of the National Petroleum Reserve, Alaska (NPR-A) in order to monitor lake ice melting processes. During data processing, it was discovered that...
Relative importance of natural disturbances and habitat degradation on snail kite population dynamics
J. Martin, W.M. Kitchens, Christopher E. Cattau, M.K. Oli
2008, Endangered Species Research (6) 25-39
Natural disturbances and habitat degradation are major factors influencing the dynamics and persistence of many wildlife populations, yet few large-scale studies have explored the relative influence of these factors on the dynamics and persistence of animal populations. We used longterm demographic data and matrix population models to examine the potential...
Conservation genetics of Lake Superior brook trout: Issues, questions, and directions
C.C. Wilson, W. Stott, L. Miller, S. D’Amelio, Martin J. Jennings, A.M. Cooper
2008, Conference Paper, North American Journal of Fisheries Management
Parallel efforts by several genetic research groups have tackled common themes relating to management concerns about and recent rehabilitation opportunities for coaster brook trout Salvelinus fontinalis in Lake Superior. The questions that have been addressed include the evolutionary and genetic status of coaster brook trout, the degree of relatedness among...
Surface drift prediction in the Adriatic Sea using hyper-ensemble statistics on atmospheric, ocean and wave models: Uncertainties and probability distribution areas
M. Rixen, E. Ferreira-Coelho, R. Signell
2008, Journal of Marine Systems (69) 86-98
Despite numerous and regular improvements in underlying models, surface drift prediction in the ocean remains a challenging task because of our yet limited understanding of all processes involved. Hence, deterministic approaches to the problem are often limited by empirical assumptions on underlying physics. Multi-model hyper-ensemble forecasts, which exploit the power...
Determination of methane concentrations in water in equilibrium with sI methane hydrate in the absence of a vapor phase by in situ Raman spectroscopy
W. Lu, I.-M. Chou, R.C. Burruss
2008, Geochimica et Cosmochimica Acta (72) 412-422
Most submarine gas hydrates are located within the two-phase equilibrium region of hydrate and interstitial water with pressures (P) ranging from 8 to 60 MPa and temperatures (T) from 275 to 293 K. However, current measurements of solubilities of methane in equilibrium with hydrate in the absence of a vapor...
Use of sinkhole and specific capacity distributions to assess vertical gradients in a karst aquifer
K.J. McCoy, M.D. Kozar
2008, Environmental Geology (54) 921-935
The carbonate-rock aquifer in the Great Valley, West Virginia, USA, was evaluated using a database of 687 sinkholes and 350 specific capacity tests to assess structural, lithologic, and topographic influences on the groundwater flow system. The enhanced permeability of the aquifer is characterized in part by the many sinkholes, springs,...
Estimation of the bottleneck size in Florida panthers
M. Culver, P.W. Hedrick, K. Murphy, S. O'Brien, M.G. Hornocker
2008, Animal Conservation (11) 104-110
We have estimated the extent of genetic variation in museum (1890s) and contemporary (1980s) samples of Florida panthers Puma concolor coryi for both nuclear loci and mtDNA. The microsatellite heterozygosity in the contemporary sample was only 0.325 that in the museum samples although our sample size and number of loci...
Application of multiple isotopic and geochemical tracers for investigation of recharge, salinization, and residence time of water in the Souss-Massa aquifer, southwest of Morocco
L. Bouchaou, J.L. Michelot, A. Vengosh, Y. Hsissou, M. Qurtobi, C.B. Gaye, T.D. Bullen, G.M. Zuppi
2008, Journal of Hydrology (352) 267-287
Groundwater and surface water in Souss-Massa basin in the west-southern part of Morocco is characterized by a large variation in salinity, up to levels of 37 g L-1. The high salinity coupled with groundwater level decline pose serious problems for current irrigation and domestic water supplies as well as future...
Increased terrestrial to ocean sediment and carbon fluxes in the northern Chesapeake Bay associated with twentieth century land alteration
C. Saenger, T. M. Cronin, D. Willard, J. Halka, R. Kerhin
2008, Estuaries and Coasts (31) 492-500
We calculated Chesapeake Bay (CB) sediment and carbon fluxes before and after major anthropogenic land clearance using robust monitoring, modeling and sedimentary data. Four distinct fluxes in the estuarine system were considered including (1) the flux of eroded material from the watershed to streams, (2) the flux of suspended sediment...
Ocean forecasting in terrain-following coordinates: Formulation and skill assessment of the Regional Ocean Modeling System
D.B. Haidvogel, H. Arango, W.P. Budgell, B.D. Cornuelle, E. Curchitser, Lorenzo E. Di, K. Fennel, W.R. Geyer, A.J. Hermann, L. Lanerolle, J. Levin, J.C. McWilliams, A.J. Miller, A.M. Moore, T.M. Powell, A.F. Shchepetkin, C. R. Sherwood, R. P. Signell, J.C. Warner, J. Wilkin
2008, Journal of Computational Physics (227) 3595-3624
Systematic improvements in algorithmic design of regional ocean circulation models have led to significant enhancement in simulation ability across a wide range of space/time scales and marine system types. As an example, we briefly review the Regional Ocean Modeling System, a member of a general class of three-dimensional, free-surface, terrain-following...
Prioritizing conservation effort through the use of biological soil crusts as ecosystem function indicators in an arid region
M. A. Bowker, M. E. Miller, J. Belnap, T.D. Sisk, N.C. Johnson
2008, Conservation Biology (22) 1533-1543
Conservation prioritization usually focuses on conservation of rare species or biodiversity, rather than ecological processes. This is partially due to a lack of informative indicators of ecosystem function. Biological soil crusts (BSCs) trap and retain soil and water resources in arid ecosystems and function as major carbon and nitrogen fixers;...
Detection rates of the MODIS active fire product in the United States
T. J. Hawbaker, V. C. Radeloff, A.D. Syphard, Z. Zhu, S. I. Stewart
2008, Remote Sensing of Environment (112) 2656-2664
MODIS active fire data offer new information about global fire patterns. However, uncertainties in detection rates can render satellite-derived fire statistics difficult to interpret. We evaluated the MODIS 1??km daily active fire product to quantify detection rates for both Terra and Aqua MODIS sensors, examined how cloud cover and fire...
Simulation of fluid, heat transport to estimate desert stream infiltration
J.T. Kulongoski, J. A. Izbicki
2008, Ground Water (46) 462-474
In semiarid regions, the contribution of infiltration from intermittent streamflow to ground water recharge may be quantified by comparing simulations of fluid and heat transport beneath stream channels to observed ground temperatures. In addition to quantifying natural recharge, streamflow infiltration estimates provide a means to characterize the physical properties of...
Coastal typology: An integrative "neutral" technique for coastal zone characterization and analysis
R. W. Buddemeier, S. V. Smith, D.P. Swaney, C.J. Crossland, B.A. Maxwell
2008, Estuarine, Coastal and Shelf Science (77) 197-205
Typology, the 'study or systematic classification of types that have characteristics or traits in common', has become a commonly used term and technique in coastal zone studies over the past two decades. At least part of this is due to adoption by the first Land-Ocean Interactions in the Coastal Zone...
Identifying mangrove species and their surrounding land use and land cover classes using object-oriented approach with a lacunarity spatial measure
S.W. Myint, C.P. Giri, L. Wang, Z. Zhu, S.C. Gillete
2008, GIScience and Remote Sensing (45) 188-208
Accurate and reliable information on the spatial distribution of mangrove species is needed for a wide variety of applications, including sustainable management of mangrove forests, conservation and reserve planning, ecological and biogeographical studies, and invasive species management. Remotely sensed data have been used for such purposes with mixed results. Our...
Using accelerated life testing procedures to compare the relative sensitivity of rainbow trout and the federally listed threatened bull trout to three commonly used rangeland herbicides (picloram, 2,4-D, and clopyralid)
J.F. Fairchild, A. Allert, L.S. Sappington, K.J. Nelson, J. Valle
2008, Environmental Toxicology and Chemistry (27) 623-630
We conducted 96-h static acute toxicity studies to evaluate the relative sensitivity of juveniles of the threatened bull trout (Salvelinus confluentus) and the standard cold-water surrogate rainbow trout (Onchorhyncus mykiss) to three rangeland herbicides commonly used for controlling invasive weeds in the northwestern United States. Relative species sensitivity was compared...
Transient deterministic shallow landslide modeling: Requirements for susceptibility and hazard assessments in a GIS framework
J. W. Godt, R.L. Baum, W. Z. Savage, D. Salciarini, W.H. Schulz, E. L. Harp
2008, Engineering Geology (102) 214-226
Application of transient deterministic shallow landslide models over broad regions for hazard and susceptibility assessments requires information on rainfall, topography and the distribution and properties of hillside materials. We survey techniques for generating the spatial and temporal input data for such models and present an example using a transient deterministic...
Depth distribution dynamics of the sculpin community in Lake Michigan
C.P. Madenjian, D.B. Bunnell
2008, Transactions of the American Fisheries Society (137) 1346-1357
Using data from our annual lakewide bottom trawl survey of Lake Michigan, we calculated the mean depths of capture for deepwater sculpin Myoxocephalus thompsonii and slimy sculpin Cottus cognatus for each combination of transect (Frankfort, Ludington, Saugatuck, and Manistique in Michigan, Waukegan in Illinois, and Port Washington and Sturgeon Bay...
Representing general theoretical concepts in structural equation models: The role of composite variables
J.B. Grace, K.A. Bollen
2008, Environmental and Ecological Statistics (15) 191-213
Structural equation modeling (SEM) holds the promise of providing natural scientists the capacity to evaluate complex multivariate hypotheses about ecological systems. Building on its predecessors, path analysis and factor analysis, SEM allows for the incorporation of both observed and unobserved (latent) variables into theoretically-based probabilistic models. In this paper we...
Anatomy of the Chesapeake Bay impact structure revealed by seismic imaging, Delmarva Peninsula, Virginia, USA
R. D. Catchings, D.S. Powars, G. S. Gohn, J. Wright Horton Jr., M. R. Goldman, J.A. Hole
2008, Journal of Geophysical Research B: Solid Earth (113)
A 30-km-long, radial seismic reflection and refraction survey completed across the northern part of the late Eocene Chesapeake Bay impact structure (CBIS) on the Delmarva Peninsula, Virginia, USA, confirms that the CBIS is a complex central-peak crater. We used a tomographic P wave velocity model and low-fold reflection images, constrained...
Geophysical data integration, stochastic simulation and significance analysis of groundwater responses using ANOVA in the Chicot Aquifer system, Louisiana, USA
A. Rahman, F.T.-C. Tsai, C.D. White, D.A. Carlson, C. S. Willson
2008, Hydrogeology Journal (16) 749-764
Data integration is challenging where there are different levels of support between primary and secondary data that need to be correlated in various ways. A geostatistical method is described, which integrates the hydraulic conductivity (K) measurements and electrical resistivity data to better estimate the K distribution in the Upper Chicot...
