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Articles 631 - 660 of 861

Full-Text Articles in Oceanography and Atmospheric Sciences and Meteorology

Barcoding Bushmeat: Molecular Identification Of Central African And South American Harvested Vertebrates, Mitchell J. Eaton, Greta L. Meyers, Sergios-Orestis Kolokotronis, Matthew S. Leslie, Andrew P. Martin, George Amato Jan 2010

Barcoding Bushmeat: Molecular Identification Of Central African And South American Harvested Vertebrates, Mitchell J. Eaton, Greta L. Meyers, Sergios-Orestis Kolokotronis, Matthew S. Leslie, Andrew P. Martin, George Amato

United States Geological Survey: Staff Publications

The creation and use of a globally available database of DNA sequences from a standardized gene region has been proposed as a tool for species identification, assessing genetic diversity and monitoring the legal and illegal trade in wildlife species. Here, we contribute to the Barcode of Life Data System and test whether a short region of the mitochondrial cytochrome c oxidase subunit 1 (COX1) gene would reliably distinguish among a suite of commonly hunted African and South American mammal and reptile species. We used universal primers to generate reference barcode sequences of 645 bp for 23 species from five vertebrate …


The Role Of African Dust In The Formation Of Quaternary Soils On Mallorca, Spain And Implications For The Genesis Of Red Mediterranean Soils, Daniel R. Muhs, James Budahn, Anna Avila, Gary Skipp, Joshua Freeman, Deanna Patterson Jan 2010

The Role Of African Dust In The Formation Of Quaternary Soils On Mallorca, Spain And Implications For The Genesis Of Red Mediterranean Soils, Daniel R. Muhs, James Budahn, Anna Avila, Gary Skipp, Joshua Freeman, Deanna Patterson

United States Geological Survey: Staff Publications

African dust additions explain the origin of terra rossa soils that are common on the carbonate-platform island of Mallorca, Spain. Mineralogical and geochemical analyses indicate that Quaternary carbonate eolianites on Mallorca have a very high purity, usually composed of more than 90% carbonate minerals (calcite, dolomite, and aragonite). In contrast, terra rossa soils developed on these eolianites have lower carbonate contents and contain higher concentrations of quartz and other silicates. Analyses of immobile trace elements indicate that the non-carbonate fractions of the eolianites have distinctive Zr/Hf, La/Yb, Cr/Sc and Th/Ta values that differ from the superjacent terra rossa soils. These …


Assessing The Potential For Luminescence Dating Of Basalts, S. Tsukamoto, G. A.T. Duller, A. G. Wintle, Daniel R. Muhs Jan 2010

Assessing The Potential For Luminescence Dating Of Basalts, S. Tsukamoto, G. A.T. Duller, A. G. Wintle, Daniel R. Muhs

United States Geological Survey: Staff Publications

The possibility of dating basalt using luminescence was tested on four samples with independent age control from Cima volcanic !eld, California, with the ultimate aim of assessing whether the technique could be used to date sediments on the surface of Mars. Previous analysis of these samples had demonstrated that the infrared stimulated luminescence (IRSL) signal is most suitable for dating as it showed the lowest fading rate among various luminescence signals. In this study, changes in equivalent dose as a function of preheat are described. The ages for the two youngest Cima samples agree with the independent ages based on …


The Emerging Role Of Lidar Remote Sensing In Coastal Research And Resource Management Full Access, John C. Brock, Samuel J. Purkis Oct 2009

The Emerging Role Of Lidar Remote Sensing In Coastal Research And Resource Management Full Access, John C. Brock, Samuel J. Purkis

Marine & Environmental Sciences Faculty Articles

Knowledge of coastal elevation is an essential requirement for resource management and scientific research. Recognizing the vast potential of lidar remote sensing in coastal studies, this Special Issue includes a collection of articles intended to represent the state-of-the-art for lidar investigations of nearshore submerged and emergent ecosystems, coastal morphodynamics, and hazards due to sea-level rise and severe storms. Some current applications for lidar remote sensing described in this Special Issue include bluegreen wavelength lidar used for submarine coastal benthic environments such as coral reef ecosystems, airborne lidar used for shoreline mapping and coastal change detection, and temporal waveform-resolving lidar used …


Constraints On The Utility Of Mno2 Cartridge Method For The Extraction Of Radionuclides: A Case Study Using 234Th, M. Baskaran, P. W. Swarzenski, B. A. Biddanda Apr 2009

Constraints On The Utility Of Mno2 Cartridge Method For The Extraction Of Radionuclides: A Case Study Using 234Th, M. Baskaran, P. W. Swarzenski, B. A. Biddanda

Environmental Science and Geology Faculty Research Publications

Large volume (102–103 L) seawater samples are routinely processed to investigate the partitioning of particle reactive radionuclides and Ra between solution and size-fractionated suspended particulate matter. One of the most frequently used methods to preconcentrate these nuclides from such large volumes involves extraction onto three filter cartridges (a prefilter for particulate species and two MnO2-coated filters for dissolved species) connected in series. This method assumes that the extraction efficiency is uniform for both MnO2-coated cartridges, that no dissolved species are removed by the prefilter, and that any adsorbed radionuclides are not desorbed from …


Structured Decision Making As A Conceptual Framework To Identify Thresholds For Conservation And Management, Julien Martin, Michael C. Runge, James D. Nichols, Bruce C. Lubow, William L. Kendall Jan 2009

Structured Decision Making As A Conceptual Framework To Identify Thresholds For Conservation And Management, Julien Martin, Michael C. Runge, James D. Nichols, Bruce C. Lubow, William L. Kendall

United States Geological Survey: Staff Publications

Thresholds and their relevance to conservation have become a major topic of discussion in the ecological literature. Unfortunately, in many cases the lack of a clear conceptual framework for thinking about thresholds may have led to confusion in attempts to apply the concept of thresholds to conservation decisions. Here, we advocate a framework for thinking about thresholds in terms of a structured decision making process. The purpose of this framework is to promote a logical and transparent process for making informed decisions for conservation.

Specification of such a framework leads naturally to consideration of definitions and roles of different kinds …


Structured Decision Making As A Conceptual Framework To Identify Thresholds For Conservation And Management, Julien Martin, Michael C. Runge, James D. Nichols, Bruce C. Lubow, William L. Kendall2 Jan 2009

Structured Decision Making As A Conceptual Framework To Identify Thresholds For Conservation And Management, Julien Martin, Michael C. Runge, James D. Nichols, Bruce C. Lubow, William L. Kendall2

United States Geological Survey: Staff Publications

Threshold and their relevance to conservation have become a major topic of discussion in the ecological literature. Unfortunately, in many cases the lack of a clear conceptual framework for thinking about thresholds in terms of a structured decision making process. The purpose of this framework is to promote a logical and transparent process for making informed decisions for conservation.

Specification of such a framework leads naturally to consideration of definitions and roles of different kinds of thresholds in the process. We distinguish among three categories of thresholds. Ecological thresholds are values of system state variables at which small changes bring …


Behavior And Reproductive Success Of Rock Sandpipers Breeding On The Yukon-Kuskokwim River Delta, Alaska, Matthew Johnson, Jesse R. Conklin, Branden L. Johnson, Brian J. Mccaffery, Susan M. Haig, Jeffrey R. Walters Jan 2009

Behavior And Reproductive Success Of Rock Sandpipers Breeding On The Yukon-Kuskokwim River Delta, Alaska, Matthew Johnson, Jesse R. Conklin, Branden L. Johnson, Brian J. Mccaffery, Susan M. Haig, Jeffrey R. Walters

United States Geological Survey: Staff Publications

We studied Rock Sandpiper (Calidris ptilocnemis) breeding behavior and monitored reproductive success from 1998 to 2005 on the Yukon-Kuskokwim River Delta, Alaska, USA. We banded 24 adults and monitored 45 nests. Annual return rate of adults ranged between 67 and 100%. Six pairs of Rock Sandpipers bred at our study site for ≥ 2 years, and among these we did not observe mate change (i.e., when both members of a pair returned and each mated with a new individual). Nests were typically initiated by mid-May and 53% of females laid second clutches if first clutches were lost through …


The Neoglacial Landscape And Human History Of Glacier Bay, Glacier Bay National Park And Preserve, Southeast Alaska, Usa, Cathy Connor, Greg Streveler, Austin Post, Daniel Monteith, Wanye Howell Jan 2009

The Neoglacial Landscape And Human History Of Glacier Bay, Glacier Bay National Park And Preserve, Southeast Alaska, Usa, Cathy Connor, Greg Streveler, Austin Post, Daniel Monteith, Wanye Howell

United States Geological Survey: Staff Publications

The Neoglacial landscape of the Huna Tlingit homeland in Glacier Bay is recreated through new interpretations of the lower Bay’s fjordal geomorphology, late Quaternary geology and its ethnographic landscape. Geological interpretation is enhanced by 38 radiocarbon dates compiled from published and unpublished sources, as well as 15 newly dated samples. Neoglacial changes in ice positions, outwash and lake extents are reconstructed for c. 5500–200 cal. yr ago, and portrayed as a set of three landscapes at 1600–1000, 500–300 and 300–200 cal. yr ago. This history reveals episodic ice advance towards the Bay mouth, transforming it from a fjordal seascape into …


A Robust, Multisite Holocene History Of Drift Ice Off Northern Iceland: Implications For North Atlantic Climate, John T. Andrews, Dennis A. Darby, Dennis Eberle, Anne E. Jennings, Matthias Moros, Astrid Ogilvie Jan 2009

A Robust, Multisite Holocene History Of Drift Ice Off Northern Iceland: Implications For North Atlantic Climate, John T. Andrews, Dennis A. Darby, Dennis Eberle, Anne E. Jennings, Matthias Moros, Astrid Ogilvie

OES Faculty Publications

An important indicator of Holocene climate change is provided by evidence for variations in the extent of drift ice. A proxy for drift ice in Iceland waters is provided by the presence of quartz. Quantitative xray diffraction analysis of the < 2 mm sediment fraction was undertaken on 16 cores from around Iceland. The quartz weight (wt.)% estimates from each core were integrated into 250-yr intervals between −0.05 and 11.7 cal. ka BP. Median quartz wt.% varied between 0.2 and 3.4 and maximum values ranged between 2.8 and 11.8 wt.%. High values were attained in the early Holocene and minimum values were reached 6–7 cal. ka BP. Quartz wt.% then rose steadily during the late Holocene. Our data exhibit no correlation with counts on haematite-stained quartz (HSQ) grains from VM129-191 west of Ireland casting doubt on the ice-transport origin. A pilot study on the provenance of Fe oxide grains in two cores that cover the last 1.3 and 6.1 cal. ka BP indicated a large fraction of the grains between 1 and 6 cal. ka BP were from either Icelandic or presently unsampled sources. However, there was a dramatic increase in Canadian and Russian sources from the Arctic Ocean ~1 cal. ka BP. These data may indicate the beginning of an Arctic Oscillation-like climate mode.


On The Interpretation Of Caribbean Paleo-Temperature Reconstructions During The Younger Dryas, Xiuquan Wan, Ping Chang, R. Saravanan, Rong Zhang, Matthew W. Schmidt Jan 2009

On The Interpretation Of Caribbean Paleo-Temperature Reconstructions During The Younger Dryas, Xiuquan Wan, Ping Chang, R. Saravanan, Rong Zhang, Matthew W. Schmidt

OES Faculty Publications

A conundrum exists regarding whether the sea-surface temperatures decreased or increased over the southern Caribbean and the western Tropical Atlantic region during the Younger Dryas when the North Atlantic cooled substantially and the Atlantic thermohaline circulation was weakened significantly. Despite the proximity of core locations, some proxy reconstructions record a surface cooling, while others indicate a warming. We suggest that this seemingly paradoxical finding may, at least partially, be attributed to the competing physical processes that result in opposing signs of temperature change in the region in response to weakened North Atlantic meridional overturning circulation. Our coupled ocean-atmosphere model experiments …


Toxicity Of Polybrominated Diphenyl Ethers (De-71) In Chicken (Gallus Gallus), Mallard (Anas Platyrhynchos), And American Kestrel (Falco Sparverius) Embryos And Hatchlings, Moira A. Mckernan, Barnett A. Rattner, Robert C. Hales, Mary Ann Ottinger Jan 2009

Toxicity Of Polybrominated Diphenyl Ethers (De-71) In Chicken (Gallus Gallus), Mallard (Anas Platyrhynchos), And American Kestrel (Falco Sparverius) Embryos And Hatchlings, Moira A. Mckernan, Barnett A. Rattner, Robert C. Hales, Mary Ann Ottinger

United States Geological Survey: Staff Publications

Embryonic survival, pipping and hatching success, and sublethal biochemical, endocrine, and histological endpoints were examined in hatchling chickens (Gallus gallus), mallards (Anas platyrhynchos), and American kestrels (Falco sparverius) following air cell administration of a pentabrominated diphenyl ether (penta-BDE; DE-71) mixture (0.01–20 µg/g egg) or polychlorinated biphenyl (PCB) congener 126 (3,3’,4,4’,5-pentachlorobiphenyl; 0.002 µg/g egg). The penta-BDE decreased pipping and hatching success at concentrations of 10 and 20 µg/g egg in kestrels but had no effect on survival endpoints in chickens or mallards. Sublethal effects in hatchling chickens included ethoxyresorufin-O-dealkylase (EROD) induction and histological …


Atmospheric Soluble Dust Records From A Tibetan Ice Core: Possible Climate Proxies And Teleconnection With The Pacific Decadal Oscillation, B. Grigholm, P. A. Mayewski, S. Kang, Y. Zhang, Susan Kaspari, S. B. Sneed, Q. Zhang Jan 2009

Atmospheric Soluble Dust Records From A Tibetan Ice Core: Possible Climate Proxies And Teleconnection With The Pacific Decadal Oscillation, B. Grigholm, P. A. Mayewski, S. Kang, Y. Zhang, Susan Kaspari, S. B. Sneed, Q. Zhang

Geological Sciences Faculty Scholarship

In autumn 2005, a joint expedition between the University of Maine and the Institute of Tibetan Plateau Research recovered three ice cores from Guoqu Glacier (33°34′37.8″N, 91°10′35.3″E, 5720 m above sea level) on the northern side of Mt. Geladaindong, central Tibetan Plateau. Isotopes (δ18O), major soluble ions (Na+, K+, Mg2+, Ca2+, Cl, NO3, SO42−), and radionuclide (β‐activity) measurements from one of the cores revealed a 70‐year record (1935–2005). Statistical analysis of major ion time series suggests that atmospheric soluble …


Possible Sources Of Archaeological Maize Found In Chaco Canyon And Aztec Ruin, New Mexico, Larry Benson, J. R. Stein, H. E. Taylor Jan 2009

Possible Sources Of Archaeological Maize Found In Chaco Canyon And Aztec Ruin, New Mexico, Larry Benson, J. R. Stein, H. E. Taylor

United States Geological Survey: Staff Publications

Maize played a major role in Chaco’s interaction with outlying communities in the southern Colorado Plateau. This paper seeks to determine where archaeological corn cobs brought to Chaco Canyon were grown. Strontium-isotope and trace-metal ratios of 180 soil-water and 18 surface-water sites in the Southern Colorado Plateau have revealed possible source areas for some of 37 archaeological corn cobs from Chaco Canyon and 10 archaeological corn cobs from Aztec Ruin, New Mexico. The most probable source areas for cobs that predate the middle-12th-century drought include several Upper Rio Chaco sites (not including Chaco Canyon). There are many potential source areas …


A Robust, Multisite Holocene History Of Drift Ice Off Northern Iceland: Implications For North Atlantic Climate, John T. Andrews, Dennis Darby, Dennis Eberle, Anne E. Jennings, Matthias Moros, Astrid Ogilvie Jan 2009

A Robust, Multisite Holocene History Of Drift Ice Off Northern Iceland: Implications For North Atlantic Climate, John T. Andrews, Dennis Darby, Dennis Eberle, Anne E. Jennings, Matthias Moros, Astrid Ogilvie

United States Geological Survey: Staff Publications

An important indicator of Holocene climate change is provided by evidence for variations in the extent of drift ice. A proxy for drift ice in Iceland waters is provided by the presence of quartz. Quantitative xray diffraction analysis of the < 2 mm sediment fraction was undertaken on 16 cores from around Iceland. The quartz weight (wt.)% estimates from each core were integrated into 250-yr intervals between −0.05 and 11.7 cal. ka BP. Median quartz wt.% varied between 0.2 and 3.4 and maximum values ranged between 2.8 and 11.8 wt.%. High values were attained in the early Holocene and minimum values were reached 6–7 cal. ka BP. Quartz wt.% then rose steadily during the late Holocene. Our data exhibit no correlation with counts on haematite-stained quartz (HSQ) grains from VM129-191 west of Ireland casting doubt on the ice-transport origin. A pilot study on the provenance of Fe oxide grains in two cores that cover the last 1.3 and 6.1 cal. ka BP indicated a large fraction of the grains between 1 and 6 cal. ka BP were from either Icelandic or presently unsampled sources. However, there was a dramatic increase in Canadian and Russian sources from the Arctic Ocean ~1 cal. ka BP. These data may indicate the beginning of an Arctic Oscillation-like climate mode.


History Of Wildlife Toxicology, Barnett A. Rattner Jan 2009

History Of Wildlife Toxicology, Barnett A. Rattner

United States Geological Survey: Staff Publications

The field of wildlife toxicology can be traced to

the late nineteenth and early twentieth centuries. Initial

reports included unintentional poisoning of birds from

ingestion of spent lead shot and predator control agents,

alkali poisoning of waterbirds, and die-offs from maritime

oil spills. With the advent of synthetic pesticides in the

1930s and 1940s, effects of DDT and other pesticides were

investigated in free-ranging and captive wildlife. In

response to research findings in the US and UK, and the

publication of Silent Spring in 1962, public debate on the

hazards of pollutants arose and national contaminant

monitoring programs were initiated. …


Climate Trends Of The North American Prairie Pothole Region 1906–2000, Bruce Millett, W. Carter Johnson, Glenn Guntenspergen Jan 2009

Climate Trends Of The North American Prairie Pothole Region 1906–2000, Bruce Millett, W. Carter Johnson, Glenn Guntenspergen

United States Geological Survey: Staff Publications

The Prairie Pothole Region (PPR) is unique to North America. Its millions of wetlands and abundant ecosystem goods and services are highly sensitive to wide variations of temperature and precipitation in time and space characteristic of a strongly continental climate. Precipitation and temperature gradients across the PPR are orthogonal to each other. Precipitation nearly triples from west to east from approximately 300 mm/year to 900 mm/year, while mean annual temperature ranges from approximately 1°C in the north to nearly 10°C in the south. Twentieth-century weather records for 18 PPR weather stations representing 6 ecoregions revealed several trends. The climate generally …


Climate Trends Of The North American Prairie Pothole Region 1906–2000, Bruce Millett, W. Carter Johnson, Glenn R. Guntenspergen Jan 2009

Climate Trends Of The North American Prairie Pothole Region 1906–2000, Bruce Millett, W. Carter Johnson, Glenn R. Guntenspergen

United States Geological Survey: Staff Publications

The Prairie Pothole Region (PPR) is unique to North America. Its millions of wetlands and abundant ecosystem goods and services are highly sensitive to wide variations of temperature and precipitation in time and space characteristic of a strongly continental climate. Precipitation and temperature gradients across the PPR are orthogonal to each other. Precipitation nearly triples from west to east from approximately 300 mm/year to 900 mm/year, while mean annual temperature ranges from approximately 1◦C in the north to nearly 10◦C in the south. Twentieth-century weather records for 18 PPR weather stations representing 6 ecoregions revealed several trends. The climate generally …


Geology And Hydrology Of Karst In West-Central And North-Central Florida, Lee J. Florea Aug 2008

Geology And Hydrology Of Karst In West-Central And North-Central Florida, Lee J. Florea

Earth, Environmental, and Atmospheric Sciences Faculty Publications

The state of Florida is blessed with the highest density of large springs in North America and hundreds of smaller springs where the water from limestone aquifers returns to the surface (Scott et al., 2004). Spectacular underwater caves supply water to these springs. Lesser known are the equally fantastic air-filled caves of Florida and South Georgia (Florea, 2006; Lane, 1986). This paper features these underwater and airfilled caves, explores the impact of changes in sea level on karst in this near-coastal environment, and establishes several geologic and hydrologic characteristics that distinguish karst in the limestones of the southeast from karst …


The Mayan Ice Cap: Glacial Geology And Paleoclimate Of The Northern Guatemalan Highlands, Alex Joseph Roy Aug 2008

The Mayan Ice Cap: Glacial Geology And Paleoclimate Of The Northern Guatemalan Highlands, Alex Joseph Roy

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Sierra de los Cuchumatanes region of the northern Guatemalan highlands supported a large plateau ice cap with an area of -40 km2 along with a group of 5 cirque glaciers -1 to 2 km2 during the local last glacial maximum (LLGM). A comprehensive mapping reconstruction of the northern Guatemalan highlands is presented here, including glacial geology and an estimate of maximum ice limits from physical evidence and computer modeling. The glacial geologic map was produced via field mapping with global positioning system (GPS) surveying combined with aerial stereo photographic and topographic map analysis. This new field work on moraine …


California Drought, An Update April 2008, Baryohay Davidoff, Fawzi Karajeh, Dean Reynolds, Eric Senter, John Woodling Apr 2008

California Drought, An Update April 2008, Baryohay Davidoff, Fawzi Karajeh, Dean Reynolds, Eric Senter, John Woodling

United States Geological Survey: Staff Publications

TABLE OF CONTENTS

CHAPTER 1. RECENT HYDROLOGIC CONDITIONS AND IMPACTS

Introduction....................................................... 1

Water Year 2007 .................................................. 1

Drought in the Colorado River Basin ..................................................... 5

Drought and Dry Conditions in the Early 2000s .................................... 7

The 2001 Klamath Basin Drought Emergency ............................... 11

CHAPTER 2. PROGRAMMATIC AND INSTITUTIONAL UPDATES

The San Francisco Bay-Sacramento/San Joaquin River Delta.................................................................. 15

The Colorado River .................................................................... 16

State Financial Assistance to Local Agencies.................................... 17

Urban Water Management Planning ................................................... 20

Water Transfers .............................................................................. 20

Small Water Systems and Drought Preparedness ................................. 21


The Influence Of Metal Exposure History And Ultraviolet-B Radiation On Benthic Communities In Colorado Rocky Mountain Streams, Robert E. Zuellig, Donna R. Kashian, Marjorie L. Brooks, Peter M. Kiffney, William H. Clements Mar 2008

The Influence Of Metal Exposure History And Ultraviolet-B Radiation On Benthic Communities In Colorado Rocky Mountain Streams, Robert E. Zuellig, Donna R. Kashian, Marjorie L. Brooks, Peter M. Kiffney, William H. Clements

Environmental Science and Geology Faculty Research Publications

Interest in understanding the influence of ultraviolet-B (UVB; 280–320 nm) radiation in aquatic ecosystems has increased since the early 1990s. Pollution from historic mining operations coupled with physicochemical characteristics of Rocky Mountain streams that increase exposure of benthic communities to UVB provided an opportunity to examine how UVB interacted with heavy metal contamination to structure stream communities. We integrated a series of UVB addition experiments done in stream microcosms with a large-scale UVB shading experiment to test the hypothesis that effects of UVB were greater on benthic communities from metal-polluted streams than from reference streams. Microcosm experiments involved short-term exposure …


Visualization Of Groundwater Flow Within Touching-Vu And Matrix Porosity In An Eogenetic Karst Aquifer, Lee J. Florea, Kevin J. Cunningham, Stephen Altobelli Jan 2008

Visualization Of Groundwater Flow Within Touching-Vu And Matrix Porosity In An Eogenetic Karst Aquifer, Lee J. Florea, Kevin J. Cunningham, Stephen Altobelli

Earth, Environmental, and Atmospheric Sciences Faculty Publications

In this study, we use an innovative, non-invasive technology, nuclear magnetic resonance imaging (NMRI), to visualize the direction and magnitude of groundwater flow in field samples of late Pleistocene limestone of the Biscayne aquifer. Specific goals of the first set of NMRI experiments are to map the advective velocity of water flowing at two rates of specific discharge (0.00025 and 0.00013 m/s) through a 10-cm-diameter cylindrical, epoxy-resin model. The model interior accurately reproduces a well-connected maze of ichnologically influenced, centimeter-scale, touching-vug macroporosity common within preferred flow zones in parts of the Biscayne aquifer. A second set of NMRI experiments investigates …


Biogenic Porosity And Its Lattice Boltzmann Method Permeability In The Karst Biscayne Aquifer, Kevin Cunningham, Mike Sukop, Haibo Huang, Pedro Alvarez, Allen Curran, Michael Waker, Lee J. Florea, Robert Renken, Joann F. Dixon Jan 2008

Biogenic Porosity And Its Lattice Boltzmann Method Permeability In The Karst Biscayne Aquifer, Kevin Cunningham, Mike Sukop, Haibo Huang, Pedro Alvarez, Allen Curran, Michael Waker, Lee J. Florea, Robert Renken, Joann F. Dixon

Earth, Environmental, and Atmospheric Sciences Faculty Publications

No abstract provided.


Focus Group On Karst Hydrology - Conceptual Models, Aquifer Characterization, And Numerical Modeling, Martin Sauter, Lee J. Florea, Others Jan 2008

Focus Group On Karst Hydrology - Conceptual Models, Aquifer Characterization, And Numerical Modeling, Martin Sauter, Lee J. Florea, Others

Earth, Environmental, and Atmospheric Sciences Faculty Publications

No abstract provided.


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 …


Development And Evaluation Of Geochemical Methods For The Sourcing Of Archaeological Maize, L.V. Benson, H. E. Taylor, K.A. Peterson, B.D. Shattuck, C.A. Ramotnik, J.R. Stein Jan 2008

Development And Evaluation Of Geochemical Methods For The Sourcing Of Archaeological Maize, L.V. Benson, H. E. Taylor, K.A. Peterson, B.D. Shattuck, C.A. Ramotnik, J.R. Stein

United States Geological Survey: Staff Publications

Strontium (Sr)-isotope values on bone from deer mice pairs from 12 field sites in the Chaco Canyon area, New Mexico, were compared with isotope values of synthetic soil waters from the same fields. The data indicate that mice obtain Sr from near-surface sources and that soil samples collected at depths ranging from 25 to 95 cm contain Sr that is more accessible to the deep roots of maize; thus, synthetic soil solutions provide better data for the sourcing of archaeological maize. However, the Sr-isotope composition of mice may be more valuable in sourcing archaeological remains of animals such as rabbit, …


Tools And Technology Article: Estimation And Correction Of Visibility Bias In Aerial Surveys Of Wintering Ducks, Aaron T. Pearse, Patrick D. Gerard, Stephen J. Dinsmore, Richard M. Kaminski, Kenneth J. Reinecke Jan 2008

Tools And Technology Article: Estimation And Correction Of Visibility Bias In Aerial Surveys Of Wintering Ducks, Aaron T. Pearse, Patrick D. Gerard, Stephen J. Dinsmore, Richard M. Kaminski, Kenneth J. Reinecke

United States Geological Survey: Staff Publications

Incomplete detection of all individuals leading to negative bias in abundance estimates is a pervasive source of error in aerial surveys of wildlife, and correcting that bias is a critical step in improving surveys. We conducted experiments using duck decoys as surrogates for live ducks to estimate bias associated with surveys of wintering ducks in Mississippi, USA. We found detection of decoy groups was related to wedand cover type (open vs. forested), group size (1-100 decoys), and interaction of these variables. Observers who detected decoy groups reported counts that averaged 78% of the decoys actually present, and this counting bias …


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 …


Relations Between And Among Contaminant Concentrations And Biomarkers In Black Bass (Micropterus Spp.) And Common Carp (Cyprinus Carpio) From Large U.S. Rivers, 1995–2004, Jo Ellen Hinck, Christopher J. Schmitt, Mark R. Ellersieck, Donald E. Tillitt Jan 2008

Relations Between And Among Contaminant Concentrations And Biomarkers In Black Bass (Micropterus Spp.) And Common Carp (Cyprinus Carpio) From Large U.S. Rivers, 1995–2004, Jo Ellen Hinck, Christopher J. Schmitt, Mark R. Ellersieck, Donald E. Tillitt

United States Geological Survey: Staff Publications

Environmental contaminant and biomarker monitoring data from major U.S. river basins were summarized for black bass (Micropterus spp.) and common carp (Cyprinus carpio) sampled over a nine year period. Cumulative frequency distributions revealed taxon differences for many organochlorine residue concentrations, elemental contaminant concentrations, and biomarkers, but few gender differences were evident for chemical concentrations. Concentrations of dacthal, pentachloroanisole, p,p'-DDE, endosulfan sulfate, barium, cadmium, copper, manganese, lead, selenium, vanadium, and zinc were greater in carp than bass, but concentrations of mercury and magnesium were greater in bass. Gender differences were evident in bass for mercury and in carp …