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United States Geological Survey: Staff Publications

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Articles 481 - 510 of 1026

Full-Text Articles in Earth Sciences

Comparative Study Of Transport Processes Of Nitrogen, Phosphorus, And Herbicides To Streams In Five Agricultural Basins, Usa, Joseph L. Domagalski, Scott Ator, Richard Coupe, Kathleen Mccarthy, David Lampe, Mark Sandstrom, Nancy Baker Jan 2008

Comparative Study Of Transport Processes Of Nitrogen, Phosphorus, And Herbicides To Streams In Five Agricultural Basins, Usa, Joseph L. Domagalski, Scott Ator, Richard Coupe, Kathleen Mccarthy, David Lampe, Mark Sandstrom, Nancy Baker

United States Geological Survey: Staff Publications

Agricultural chemical transport to surface water and the linkage to other hydrological compartments, principally ground water, was investigated at five watersheds in semiarid to humid climatic settings. Chemical transport was affected by storm water runoff , soil drainage, irrigation, and how streams were linked to shallow ground water systems. Irrigation practices and timing of chemical use greatly affected nutrient and pesticide transport in the semiarid basins. Irrigation with imported water tended to increase ground water and chemical transport, whereas the use of locally pumped irrigation water may eliminate connections between streams and ground water, resulting in lower annual loads. Drainage …

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Estimation Of Groundwater And Nutrient Fluxes To The Neuse River Estuary, North Carolina, Timothy B. Spruill, John F. Bratton Jan 2008

Estimation Of Groundwater And Nutrient Fluxes To The Neuse River Estuary, North Carolina, Timothy B. Spruill, John F. Bratton

United States Geological Survey: Staff Publications

A study was conducted between April 2004 and September 2005 to estimate groundwater and nutrient discharge to the Neuse River estuary in North Carolina. The largest groundwater fluxes were observed to occur generally within 20 m of the shoreline. Groundwater flux estimates based on seepage meter measurements ranged from 2.86×108 to 4.33×108 m3 annually and are comparable to estimates made using radon, a simple water-budget method, and estimates derived by using Darcy’s Law and previously published general aquifer characteristics of the area. The lower groundwater flux estimate (equal to about 9 m3 s-1), which …

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Introgression And Dispersal Among Spotted Owl (Strix Occidentalis) Subspecies, W. Chris Funk, Eric D. Forsman, Thomas D. Mullins, Susan M. Haig Jan 2008

Introgression And Dispersal Among Spotted Owl (Strix Occidentalis) Subspecies, W. Chris Funk, Eric D. Forsman, Thomas D. Mullins, Susan M. Haig

United States Geological Survey: Staff Publications

Population genetics plays an increasingly important role in the conservation and management of declining species, particularly for defining taxonomic units. Subspecies are recognized by several conservation organizations and countries and receive legal protection under the US Endangered Species Act (ESA). Two subspecies of spotted owls, northern (Strix occidentalis caurina) and Mexican (S. o. lucida) spotted owls, are ESA-listed as threatened, but the California (S. o. occidentalis) spotted owl is not listed. Thus, determining the boundaries of these subspecies is critical for effective enforcement of the ESA. We tested the validity of previously recognized spotted …

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Range-Wide Phylogeographic Analysis Of The Spotted Frog Complex (Rana Luteiventris And Rana Pretiosa) In Northwestern North America, W. Chris Funk, Christopher A. Pearl, Hope M. Draheim, Michael J. Adams, Thomas D. Mullins, Susan M. Haig Jan 2008

Range-Wide Phylogeographic Analysis Of The Spotted Frog Complex (Rana Luteiventris And Rana Pretiosa) In Northwestern North America, W. Chris Funk, Christopher A. Pearl, Hope M. Draheim, Michael J. Adams, Thomas D. Mullins, Susan M. Haig

United States Geological Survey: Staff Publications

The dynamic geological and climatic history of northwestern North America has made it a focal region for phylogeography. We conducted a range-wide phylogeographic analysis of the spotted frog complex (Rana luteiventris and Rana pretiosa) across its range in northwestern North America to understand its evolutionary history and the distribution of clades to inform conservation of R. pretiosa and Great Basin R. luteiventris, candidates for listing under the US Endangered Species Act. Mitochondrial DNA sequence data from a segment of the cytochrome b gene were obtained from 308 R. luteiventris and R. pretiosa from 96 sites. Phylogenetic analysis …

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Management And Conservation Note: Conserving Waste Rice For Wintering Waterfowl In The Mississippi Alluvial Valley, Jennifer P. Kross, Richard M. Kaminski, Aaron T. Pearse Jan 2008

Management And Conservation Note: Conserving Waste Rice For Wintering Waterfowl In The Mississippi Alluvial Valley, Jennifer P. Kross, Richard M. Kaminski, Aaron T. Pearse

United States Geological Survey: Staff Publications

The Mississippi Alluvial Valley (MAV), USA, is an internationally important migration and wintering region for North American waterfowl (Reinecke et al. 1989). The Lower Mississippi Valley Joint Venture (LMVJV) assumes food availability is the primary factor influencing carrying capacity of wintering waterfowl in this region (Reinecke and Loesch 1996). Because much of the MAV was converted from a seasonally flooded bottomland-hardwood ecosystem to a landscape dominated by agriculture, the LMVJV has incorporated estimates of the abundance of agricultural seeds such as rice into habitat conservation plans (Reinecke et al. 1988, Fredrickson et al. 2005). Biologists designed these plans to provide …

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Tools And Technology Article: Evaluation Of An Aerial Survey To Estimate Abundance Of Wintering Ducks In Mississippi, Aaron T. Pearse, Stephen J. Dinsmore, Richard M. Kaminski, Kenneth J. Reinecke Jan 2008

Tools And Technology Article: Evaluation Of An Aerial Survey To Estimate Abundance Of Wintering Ducks In Mississippi, Aaron T. Pearse, Stephen J. Dinsmore, Richard M. Kaminski, Kenneth J. Reinecke

United States Geological Survey: Staff Publications

Researchers have successfully designed aerial surveys that provided precise estimates of wintering populations of ducks over large physiographic regions, yet few conservation agencies have adopted these probability-based sampling designs for their surveys. We designed and evaluated an aerial survey to estimate abundance of wintering mallards (Anas platyrhynchos), dabbling ducks (tribe Anatini) other than mallards, diving ducks (tribes Aythini, Mergini, and Oxyurini), and total ducks in western Mississippi, USA. We used design-based sampling of fixed width transects to estimate population indices (/), and we used model-based methods to correct population indices for visibility bias and estimate population abundance (N) for 14 …

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Apparent Tolerance Of Turkey Vultures (Cathartes Aura) To The Non-Steroidal Anti-Inflammatory Drug Diclofenac, Barnett A. Rattner, Maria A. Whitehead, Grace Gasper, Carol U. Meteyer, William A. Link, Mark A. Taggart, Andrew A. Meharg, Oliver H. Pattee, Deborah J. Pain Jan 2008

Apparent Tolerance Of Turkey Vultures (Cathartes Aura) To The Non-Steroidal Anti-Inflammatory Drug Diclofenac, Barnett A. Rattner, Maria A. Whitehead, Grace Gasper, Carol U. Meteyer, William A. Link, Mark A. Taggart, Andrew A. Meharg, Oliver H. Pattee, Deborah J. Pain

United States Geological Survey: Staff Publications

The nonsteroidal anti-inflammatory drug diclofenac is extremely toxic to Old World Gyps vultures (median lethal dose ~0.1–0.2 mg/kg), evoking visceral gout, renal necrosis, and mortality within a few days of exposure. Unintentional secondary poisoning of vultures that fed upon carcasses of diclofenac-treated livestock decimated populations in the Indian subcontinent. Because of the widespread use of diclofenac and other cyclooxygenase-2 inhibiting drugs, a toxicological study was undertaken in turkey vultures (Cathartes aura) as an initial step in examining sensitivity of New World scavenging birds. Two trials were conducted entailing oral gavage of diclofenac at doses ranging from 0.08 to …

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Influence Of Fipronil Compounds And Rice-Cultivation Land-Use Intensity On Macroinvertebrate Communities In Streams Of Southwestern Louisiana, Usa, Scott V. Mize, Stephen D. Porter, Dennis K. Demcheck Jan 2008

Influence Of Fipronil Compounds And Rice-Cultivation Land-Use Intensity On Macroinvertebrate Communities In Streams Of Southwestern Louisiana, Usa, Scott V. Mize, Stephen D. Porter, Dennis K. Demcheck

United States Geological Survey: Staff Publications

Laboratory tests of fipronil and its degradation products have revealed acute lethal toxicity at very low concentrations (LC50) of <0.5 μg/L to selected aquatic macroinvertebrates. In streams draining basins with intensive rice cultivation in southwestern Louisiana, USA, concentrations of fipronil compounds were an order of magnitude larger than the LC50. The abundance (p=-0.64; p=0.015) and taxa richness (r2=0.515, p<0.005) of macroinvertebrate communities declined significantly with increases in concentrations of fipronil compounds and rice-cultivation land-use intensity. Macroinvertebrate community tolerance scores increased linearly (r2=0.442, p < 0.005) with increases in the percentage of rice cultivation in the basins, indicating increasingly degraded stream conditions. Similarly, macroinvertebrate community-tolerance scores increased rapidly as fipronil concentrations approached about 1 μg/L. Pesticide toxicity index determinations indicated that aquatic macroinvertebrates respond to a gradient of fipronil compounds in water although stream size and habitat cannot be ruled out as contributing influences.

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Comparison Of Total Mercury And Methylmercury Cycling At Five Sites Using The Small Watershed Approach, James B. Shanley, M. Alisa Mast, Donald H. Campbell, George R. Aiken, David P. Krabbenhoft, Randall J. Hunt, John F. Walker, Paul F. Schuster, Ann Chalmers, Brent T. Aulenbach, Norman E. Peters, Mark Marvin-Dipasquale, David W. Clow, Martin M. Shafer Jan 2008

Comparison Of Total Mercury And Methylmercury Cycling At Five Sites Using The Small Watershed Approach, James B. Shanley, M. Alisa Mast, Donald H. Campbell, George R. Aiken, David P. Krabbenhoft, Randall J. Hunt, John F. Walker, Paul F. Schuster, Ann Chalmers, Brent T. Aulenbach, Norman E. Peters, Mark Marvin-Dipasquale, David W. Clow, Martin M. Shafer

United States Geological Survey: Staff Publications

The small watershed approach is well-suited but underutilized in mercury research. We applied the small watershed approach to investigate total mercury (THg) and methylmercury (MeHg) dynamics in streamwater at the five diverse forested headwater catchments of the US Geological Survey Water, Energy, and Biogeochemical Budgets (WEBB) program. At all sites, baseflow THg was generally less than 1 ng L-1 and MeHg was less than 0.2 ng L-1. THg and MeHg concentrations increased with streamflow, so export was primarily episodic. At three sites, THg and MeHg concentration and export were dominated by the particulate fraction in association with …

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Influence Of Plankton Mercury Dynamics And Trophic Pathways On Mercury Concentrations Of Top Predator Fish Of A Mining-Impacted Reservoir, A. Robin Stewart, Michael K. Saiki, James S. Kuwabara, Charles N. Alpers, Mark Marvin-Dipasquale, David P. Krabbenhoft Jan 2008

Influence Of Plankton Mercury Dynamics And Trophic Pathways On Mercury Concentrations Of Top Predator Fish Of A Mining-Impacted Reservoir, A. Robin Stewart, Michael K. Saiki, James S. Kuwabara, Charles N. Alpers, Mark Marvin-Dipasquale, David P. Krabbenhoft

United States Geological Survey: Staff Publications

Physical and biogeochemical characteristics of the aquatic environment that affect growth dynamics of phytoplankton and the zooplankton communities that depend on them may also affect uptake of methylmercury (MeHg) into the pelagic food web of oligotrophic reservoirs. We evaluated changes in the quality and quantity of suspended particulate material, zooplankton taxonomy, and MeHg concentrations coincident with seasonal changes in water storage of a mining-impacted reservoir in northern California, USA. MeHg concentrations in bulk zooplankton increased from 4 ng·g–1 at low water to 77 ± 6.1 ng·g–1 at high water and were positively correlated with cladoceran biomass (r = …

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The Persistence Of Lead From Past Gasoline Emissions And Mining Drainage In A Large Riparian System: Evidence From Lead Isotopes In The Sacramento River, California, C. E. Dunlap, Charles N. Alpers, R. Bouse, H. E. Taylor, D. M. Unruh, A. R. Flegal Jan 2008

The Persistence Of Lead From Past Gasoline Emissions And Mining Drainage In A Large Riparian System: Evidence From Lead Isotopes In The Sacramento River, California, C. E. Dunlap, Charles N. Alpers, R. Bouse, H. E. Taylor, D. M. Unruh, A. R. Flegal

United States Geological Survey: Staff Publications

Lead concentrations and isotope ratios measured in river water colloids and streambed sediment samples along 426 km of the Sacramento River, California reveal that the influence of lead from the historical mining of massive sulfide deposits in the West Shasta Cu-mining district (at the headwaters of the Sacramento River) is confined to a 60 km stretch of river immediately downstream of that mining region, whereas inputs from past leaded gasoline emissions and historical hydraulic Au-mining in the Sierra Nevadan foothills are the dominant lead sources in the remaining 370 km of the river. Binary mixing calculations suggest that more than …

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Isotopic Evidence For The Diversity Of Late Quaternary Loess In Nebraska: Glaciogenic And Nonglaciogenic Sources, John N. Aleinikoff, Daniel R. Muhs, E. Arthur Bettis Iii, William C. Johnson, C. Mark Fanning, Rachel Benton Jan 2008

Isotopic Evidence For The Diversity Of Late Quaternary Loess In Nebraska: Glaciogenic And Nonglaciogenic Sources, John N. Aleinikoff, Daniel R. Muhs, E. Arthur Bettis Iii, William C. Johnson, C. Mark Fanning, Rachel Benton

United States Geological Survey: Staff Publications

Pb isotope compositions of detrital K-feldspars and U-Pb ages of detrital zircons are used as indicators for determining the sources of Peoria Loess deposited during the last glacial period (late Wisconsin, ca. 25–14 ka) in Nebraska and western Iowa. Our new data indicate that only loess adjacent to the Platte River has Pb isotopic characteristics suggesting derivation from this river. Most Peoria Loess in central Nebraska (up to 20 m thick) is non-glaciogenic, on the basis of Pb isotope ratios in K-feldspars and the presence of 34-Ma detrital zircons. These isotopic characteristics suggest derivation primarily from the Oligocene White River …

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Integrated Modelling Frameworks For Environmental Assessment And Decision Support, A. E. Rizzoli, G. Leavesley, J. C. Ascough Ii, R. M. Argent, I. N. Athanasiadis, V. Brilhante, F. H. A. Claeys, O. David, M. Donatelli, P. Gijsbers, D. Havlik, A. Kassahun, P. Krause, N. W. T. Quinn, H. Scholten, R. S. Sojda, F. Villa Jan 2008

Integrated Modelling Frameworks For Environmental Assessment And Decision Support, A. E. Rizzoli, G. Leavesley, J. C. Ascough Ii, R. M. Argent, I. N. Athanasiadis, V. Brilhante, F. H. A. Claeys, O. David, M. Donatelli, P. Gijsbers, D. Havlik, A. Kassahun, P. Krause, N. W. T. Quinn, H. Scholten, R. S. Sojda, F. Villa

United States Geological Survey: Staff Publications

As argued in Chapter 1, modern management of environmental resources defines problems from a holistic and integrated perspective, thereby imposing strong requirements on Environmental Decision Support Systems (EDSSs) and Integrated Assessment Tools (IATs). These systems and tools tend to be increasingly complex in terms of software architecture and computational power in order to cope with the type of problems they must solve. For instance, the discipline of Integrated Assessment (IA) needs tools that arc able to span a wide range of disciplines, from socio-economics to ecology to hydrology. Such tools must support a wide range of methodologies and techniques like …

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Human-Induced Changes In The Hydrology Of The Western United States, Tim P. Barnett, David W. Pierce, Hugo G. Hidalgo, Celine Bonfils, Benjamin D. Santer, Tapash Das, Govindasamy Bala, Andrew W. Wood, Toru Nozawa, Arthur A. Mirin, Daniel R. Cayan, Michael D. Dettinger Jan 2008

Human-Induced Changes In The Hydrology Of The Western United States, Tim P. Barnett, David W. Pierce, Hugo G. Hidalgo, Celine Bonfils, Benjamin D. Santer, Tapash Das, Govindasamy Bala, Andrew W. Wood, Toru Nozawa, Arthur A. Mirin, Daniel R. Cayan, Michael D. Dettinger

United States Geological Survey: Staff Publications

Observations have shown that the hydrological cycle of the western United States changed significantly over the last half of the 20th century. We present a regional, multivariable climate change detection and attribution study, using a high-resolution hydrologic model forced by global climate models, focusing on the changes that have already affected this primarily arid region with a large and growing population. The results show that up to 60% of the climate-related trends of river flow, winter air temperature, and snow pack between 1950 and 1999 are human-induced. These results are robust to perturbation of study variates and methods. They portend, …

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Bioaccumulation Of Pharmaceuticals And Other Anthropogenic Waste Indicators In Earthworms From Agricultural Soil Amended With Biosolid Or Swine Manure, Chad Kinney, Edward Furlong, Dana Kolpin, Mark Burkhardt, Steven Zaugg, Stephen Werner, Joseph Bossio, Mark Benotti Jan 2008

Bioaccumulation Of Pharmaceuticals And Other Anthropogenic Waste Indicators In Earthworms From Agricultural Soil Amended With Biosolid Or Swine Manure, Chad Kinney, Edward Furlong, Dana Kolpin, Mark Burkhardt, Steven Zaugg, Stephen Werner, Joseph Bossio, Mark Benotti

United States Geological Survey: Staff Publications

Analysis of earthworms offers potential for assessing the transfer of organic anthropogenic waste indicators (AWIs) derived from land-applied biosolid or manure to biota. Earthworms and soil samples were collected from three Midwest agricultural fields to measure the presence and potential for transfer of 77 AWIs from land-applied biosolids and livestock manure to earthworms. The sites consisted of a soybean field with no amendments of human or livestock waste (Site 1), a soybean field amended with biosolids from a municipal wastewater treatment plant (Site 2), and a cornfield amended with swine manure (Site 3). The biosolid applied to Site 2 contained …

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Metals Fate And Transport Modelling In Streams And Watersheds: State Of The Science And Usepa Workshop Review, B. S. Caruso, T. J. Cox, R. L. Runkel, M. L. Velleux, K. E. Bencala, D. K. Nordstrom, P. Y. Julien, B. A. Butler, Charles N. Alpers, A. Marion, K. S. Smith Jan 2008

Metals Fate And Transport Modelling In Streams And Watersheds: State Of The Science And Usepa Workshop Review, B. S. Caruso, T. J. Cox, R. L. Runkel, M. L. Velleux, K. E. Bencala, D. K. Nordstrom, P. Y. Julien, B. A. Butler, Charles N. Alpers, A. Marion, K. S. Smith

United States Geological Survey: Staff Publications

Metals pollution in surface waters from point and non-point sources (NPS) is a widespread problem in the United States and worldwide (Lofts et al., 2007; USEPA, 2007). In the western United States, metals associated with acid mine drainage (AMD) from hardrock mines in mountainous areas impact aquatic ecosystems and human health (USEPA, 1997a; Caruso and Ward, 1998; Church et al., 2007). Metals fate and transport modelling in streams and watersheds is sometimes needed for assessment and restoration of surface waters, including mining-impacted streams (Runkel and Kimball, 2002; Caruso, 2003; Velleux et al., 2006). The Water Quality Analysis …

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Post-Breeding Habitat Use By Adult Boreal Toads (Bufo Boreas) After Wildfire In Glacier National Park, Usa, C. Gregory Guscio, Blake R. Hossack, Lisa A. Eby, Paul Stephen Corn Dec 2007

Post-Breeding Habitat Use By Adult Boreal Toads (Bufo Boreas) After Wildfire In Glacier National Park, Usa, C. Gregory Guscio, Blake R. Hossack, Lisa A. Eby, Paul Stephen Corn

United States Geological Survey: Staff Publications

Effects of wildfire on amphibians are complex, and some species may benefit from the severe disturbance of stand-replacing fire. Boreal Toads (Bufo boreas boreas) in Glacier National Park, Montana, USA increased in occurrence after fires in 2001 and 2003. We used radio telemetry to track adult B. boreas in a mosaic of terrestrial habitats with different burn severities to better understand factors related to the post-fire pulse in breeding activity. Toads used severely burned habitats more than expected and partially burned habitats less than expected. No toads were relocated in unburned habitat, but little of the study area …

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Wildfire Effects On Water Temperature And Selection Of Breeding Sites By The Boreal Toad (Bufo Boreas) In Seasonal Wetlands, Blake R. Hossack, Paul Stephen Corn Dec 2007

Wildfire Effects On Water Temperature And Selection Of Breeding Sites By The Boreal Toad (Bufo Boreas) In Seasonal Wetlands, Blake R. Hossack, Paul Stephen Corn

United States Geological Survey: Staff Publications

Disturbances can significantly affect the thermal regime and community structure of wetlands. We investigated the effect of a wildfire on water temperature of seasonal, montane wetlands after documenting the colonization of recently burned wetlands by the Boreal Toad (Bufo boreas boreas). We compared the daily mean temperature, daily maximum temperature, and accumulated growing degree·days measured on the north shore of three classes of wetlands: unburned wetlands, burned wetlands that were colonized by breeding toads, and burned wetlands that were not colonized. We hypothesized that toads colonized burned wetlands because they were warmer than unburned wetlands and selected specific …

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Persistent Near-Bottom Aggregations Of Mesopelagic Animals Along The North Carolina And Virginia Continental Slopes, John V. Gartner Jr., Kenneth J. Sulak, Steve W. Ross, Ann Marie Necaise Nov 2007

Persistent Near-Bottom Aggregations Of Mesopelagic Animals Along The North Carolina And Virginia Continental Slopes, John V. Gartner Jr., Kenneth J. Sulak, Steve W. Ross, Ann Marie Necaise

United States Geological Survey: Staff Publications

Submersible observations during four missions over the North Carolina and Virginia continental slopes (184–900 m) documented the occurrence of large aggregations of mesopelagic Wshes and macronektonic invertebrates near or on the bottom. Aggregated mesopelagics formed a layer up to tens of meters deep positioned from a few centimeters to 20 m, usually <10 >m, above the substrate. Aggregations were numerically dominated by microvores, notably the myctophid Wsh Ceratoscopelus maderensis and the penaeid shrimp Sergestes arcticus. Consistently present but in relatively lower numbers, were mesopelagic predators, including the paralepidids Notolepis rissoi and Lestidium atlanticum, the eel Nemichthys scolopaceus, the …

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Saprolegniaceae Identified On Amphibian Eggs Throughout The Pacific Northwest, Usa, By Internal Transcribed Spacer Sequences And Phylogenetic Analysis, Jill E. Petrisko, Christopher A. Pearl, David S. Pilliod, Peter P. Sheridan, Charles F. Williams, Charles R. Peterson, R. Bruce Bury Nov 2007

Saprolegniaceae Identified On Amphibian Eggs Throughout The Pacific Northwest, Usa, By Internal Transcribed Spacer Sequences And Phylogenetic Analysis, Jill E. Petrisko, Christopher A. Pearl, David S. Pilliod, Peter P. Sheridan, Charles F. Williams, Charles R. Peterson, R. Bruce Bury

United States Geological Survey: Staff Publications

We assessed the diversity and phylogeny of Saprolegniaceae on amphibian eggs from the Pacific Northwest, with particular focus on Saprolegnia ferax, a species implicated in high egg mortality. We identified isolates from eggs of six amphibians with the internal transcribed spacer (ITS) and 5.8S gene regions and BLAST of the GenBank database. We identified 68 sequences as Saprolegniaceae and 43 sequences as true fungi from at least nine genera. Our phylogenetic analysis of the Saprolegniaceae included isolates within the genera Saprolegnia, Achlya and Leptolegnia. Our phylogeny grouped S. semihypogyna with Achlya rather than with the Saprolegnia reference …

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Demersal Fishes Associated With Lophelia Pertusa Coral And Hard-Substrate Biotopes On The Continental Slope, Northern Gulf Of Mexico, Kenneth J. Sulak, R. Allen Brooks, Kirsten E. Luke, April D. Norem, Michael Randall, Andrew J. Quaid, George E. Yeargin, Jana M. Miller, William M. Harden, John H. Caruso, Steve W. Ross Nov 2007

Demersal Fishes Associated With Lophelia Pertusa Coral And Hard-Substrate Biotopes On The Continental Slope, Northern Gulf Of Mexico, Kenneth J. Sulak, R. Allen Brooks, Kirsten E. Luke, April D. Norem, Michael Randall, Andrew J. Quaid, George E. Yeargin, Jana M. Miller, William M. Harden, John H. Caruso, Steve W. Ross

United States Geological Survey: Staff Publications

The demersal fish fauna of Lophelia pertusa (Linnaeus, 1758) coral reefs and associated hard-bottom biotopes was investigated at two depth horizons in the northern Gulf of Mexico using a manned submersible and remote sampling. The Viosca Knoll fauna consisted of at least 53 demersal fish species, 37 of which were documented by submersible video. On the 325 m horizon, dominant taxa determined from frame-by-frame video analysis included Stromateidae, Serranidae, Trachichthyidae, Congridae, Scorpaenidae, and Gadiformes. On the 500 m horizon, large mobile visual macrocarnivores of families Stromateidae and Serranidae dropped out, while a zeiform microcarnivore assumed importance on reef “Thicket” biotope, …

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Evaluation Of An Experimental Lidar For Surveying A Shallow, Braided, Sand-Bedded River, Paul J. Kinzel, C. Wayne Wright, Jonathan M. Nelson, Aaron R. Burman Jul 2007

Evaluation Of An Experimental Lidar For Surveying A Shallow, Braided, Sand-Bedded River, Paul J. Kinzel, C. Wayne Wright, Jonathan M. Nelson, Aaron R. Burman

United States Geological Survey: Staff Publications

Reaches of a shallow (<1.0 m), braided, sand-bedded river were surveyed in 2002 and 2005 with the National Aeronautics and Space Administration’s Experimental Advanced Airborne Research LiDAR (EAARL) and concurrently with conventional survey-grade, real-time kinematic, global positioning system technology. The laser pulses transmitted by the EAARL instrument and the return backscatter waveforms from exposed sand and submerged sand targets in the river were completely digitized and stored for postflight processing. The vertical mapping accuracy of the EAARL was evaluated by comparing the ellipsoidal heights computed from ranging measurements made using an EAARL terrestrial algorithm to nearby (<0.5 m apart) ground-truth ellipsoidal heights. After correcting for apparent systematic bias in the surveys, the root mean square error of these heights with the terrestrial algorithm in the 2002 survey was 0.11 m for the 26 measurements taken on exposed sand and 0.18 m for the 59 measurements taken on submerged sand. In the 2005 survey, the root mean square error was 0.18 m for 92 measurements taken on exposed sand and 0.24 m for 434 measurements on submerged sand. In submerged areas the waveforms were complicated by reflections from the surface, water column entrained turbidity, and potentially the riverbed. When applied to these waveforms, especially in depths greater than 0.4 m, the terrestrial algorithm calculated the range above the riverbed. A bathymetric algorithm has been developed to approximate the position of the riverbed in these convolved waveforms and preliminary results are encouraging.

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Evaluating Discontinuities In Complex Systems: Toward Quantitative Measures Of Resilience, Craig Stow, Craig R. Allen, Ahjond S. Garmestani Jun 2007

Evaluating Discontinuities In Complex Systems: Toward Quantitative Measures Of Resilience, Craig Stow, Craig R. Allen, Ahjond S. Garmestani

United States Geological Survey: Staff Publications

The textural discontinuity hypothesis (TDH) is based on the observation that animal body mass distributions exhibit discontinuities that may reflect the texture of the landscape available for exploitation. This idea has been extended to other complex systems, hinting that the identification and quantification of discontinuities in the distributions of appropriate variables may provide clues to emergent system properties such as resilience. We propose a discontinuity index, based on the vector norm of the full assemblage of observed discontinuities, as a means to quantify and compare this characteristic among systems. We also evaluate four methods to identify the number and location …

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Observer Bias In Anuran Call Surveys, Aaron Lotz, Craig R. Allen Apr 2007

Observer Bias In Anuran Call Surveys, Aaron Lotz, Craig R. Allen

United States Geological Survey: Staff Publications

Amphibian monitoring programs rarely question the quality of data obtained by observers and often ignore observer bias. In order to test for bias in amphibian call surveys, we sampled 29 clusters of wetlands from the Rainwater Basin, Nebraska, USA, totaling 228 functionally connected wetlands. Sampling consisted of 3-minute stops where volunteers recorded species heard and made digital recordings. Based on 627 samples, we examined 3 types of observer bias: omission, false inclusion (commission), and incorrect identification. Misidentification rates ranged from 4.2% to 18.3%. Relatively high and unquantified error rates can negatively affect the ability of monitoring programs to accurately detect …

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Frequency Of Sublethal Injury In A Deepwater Ophiuroid, Ophiacantha Bidentata, An Important Component Of Western Atlantic Lophelia Reef Communities, R. Allen Brooks, Martha S. Nizinski, Steve W. Ross, Kenneth J. Sulak Mar 2007

Frequency Of Sublethal Injury In A Deepwater Ophiuroid, Ophiacantha Bidentata, An Important Component Of Western Atlantic Lophelia Reef Communities, R. Allen Brooks, Martha S. Nizinski, Steve W. Ross, Kenneth J. Sulak

United States Geological Survey: Staff Publications

The occurrence and relative abundance of tissue (arm) regeneration in the ophiuroid, Ophiacantha bidentata (Retzius), was examined in individuals collected primarily among colonies of the deep-water coral Lophelia pertusa off the southeastern United States. Seven deep-water coral sites (384–756 m), located between Cape Lookout, NC, and Cape Canaveral, FL, were sampled in June 2004 using a manned submersible. The presence of regenerative tissue was evaluated by visual inspection of each individual ophiuroid, and the proportion of regenerating arms per individual was examined relative to size of individual, geographic location, and depth of collection. Ophiacantha bidentata, the dominant brittle star collected, …

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The Art And Science Of Weed Mapping, David T. Barnett, Thomas J. Stohlgren, Catherine S. Jarnevich, Geneva W. Chong, Jenny A. Ericson, Tracy R. Davern, Sara E. Simonson Feb 2007

The Art And Science Of Weed Mapping, David T. Barnett, Thomas J. Stohlgren, Catherine S. Jarnevich, Geneva W. Chong, Jenny A. Ericson, Tracy R. Davern, Sara E. Simonson

United States Geological Survey: Staff Publications

Land managers need cost-effective and informative tools for non-native plant species management. Many local, state, and federal agencies adopted mapping systems designed to collect comparable data for the early detection and monitoring of non-native species. We compared mapping information to statistically rigorous, plot-based methods to better understand the benefits and compatibility of the two techniques. Mapping non-native species locations provided a species list, associated species distributions, and infested area for subjectively selected survey sites. The value of this information may be compromised by crude estimates of cover and incomplete or biased estimations of species distributions. Incorporating plot-based assessments guided by …

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Peptidomic Analysis Of Skin Secretions Supports Separate Species Status For The Tailed Frogs, Ascaphus Truei And Ascaphus Montanus, J. Michael Conlon, Catherine R. Bevier, Laurent Coquet, Jérôme Leprince, Thierry Jouenne, Hubert Vaudry, Blake R. Hossack Jan 2007

Peptidomic Analysis Of Skin Secretions Supports Separate Species Status For The Tailed Frogs, Ascaphus Truei And Ascaphus Montanus, J. Michael Conlon, Catherine R. Bevier, Laurent Coquet, Jérôme Leprince, Thierry Jouenne, Hubert Vaudry, Blake R. Hossack

United States Geological Survey: Staff Publications

The tailed frog Ascaphus truei Stejneger, 1899 is the most primitive extant anuran and the sister taxon to the clade of all other living frogs. The species occupies two disjunct ranges in the Northwest region of North America: the Cascade Mountains and coastal area from British Columbia to Northern California, and an inland range in the northern Rocky Mountains and the Blue andWallowa mountains. A previous study led to the isolation of eight peptides with antimicrobial activity (termed the ascaphins) from skin secretions of A. truei from the coastal range. The present study has used peptidomic analysis to identify the …

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Return To The Wild: Translocation As A Tool In Conservation Of The Desert Tortoise (Gopherus Agassizii), Kimberleigh J. Field, C. Richard Tracy, Philip A. Medica, Ronald W. Marlow, Paul Stephen Corn Jan 2007

Return To The Wild: Translocation As A Tool In Conservation Of The Desert Tortoise (Gopherus Agassizii), Kimberleigh J. Field, C. Richard Tracy, Philip A. Medica, Ronald W. Marlow, Paul Stephen Corn

United States Geological Survey: Staff Publications

Translocation could be used as a tool in conservation of the threatened Mojave Desert Tortoise (Gopherus agassizii) by moving individuals from harm’s way and into areas where they could contribute to conservation of the species. Numerous factors may affect the success of translocations, including the conditions experienced by tortoises in holding facilities while awaiting translocation. The tortoises available for our translocation study had been provided supplemental water during their years spent in a captive holding facility, potentially inducing carelessness in water conservation. In addition to generally investigating the efficacy of translocation, we compared the effects of continuing with …

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Loess Deposits, Origins And Properties, Daniel R. Muhs Jan 2007

Loess Deposits, Origins And Properties, Daniel R. Muhs

United States Geological Survey: Staff Publications

Loess is an eolian (windblown) sediment that is an important archive of Quaternary climate changes. It may provide one of the most complete terrestrial records of interglacial–glacial cycles. Loess is unusual as a record of Quaternary climate change because it is one of the few sediments that is deposited directly from the atmosphere. Thus, it is a geologic deposit that contains a record of atmospheric circulation and can be used to reconstruct synoptic-scale paleoclimatology. Loess is also unusual in that it can be dated directly using ‘trapped electron’ or luminescence methods that require only the sediment itself. Commonly, loess deposits …

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Effects Of Sorbate Speciation On Sorption Of Selected Sulfonamides In Three Loamy Soils, Sudarshan Kurwadkar, Craig Adams, Michael Meyer, Dana Kolpin Jan 2007

Effects Of Sorbate Speciation On Sorption Of Selected Sulfonamides In Three Loamy Soils, Sudarshan Kurwadkar, Craig Adams, Michael Meyer, Dana Kolpin

United States Geological Survey: Staff Publications

Sorption of sulfamethazine (SMN) and sulfathiazole (STZ) was investigated in three soils, a North Carolina loamy sand, an Iowa sandy loam, and a Missouri loam, under various pH conditions. A significant increase in the sorption coefficient (KD) was observed in all three soils, as the sulfonamides converted from an anionic form at higher pH to a neutral/cationic form at lower pH. Above pH 7.5, sulfonamides exist primarily in anionic form and have higher aqueous solubility and no cationic character, thereby consequently leading to lower sorption to soils. The effect of speciation on sorption is not the same …

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