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2011

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Articles 271 - 300 of 403

Full-Text Articles in Oceanography and Atmospheric Sciences and Meteorology

Oceanographic Center Overview, Nova Southeastern University Jan 2011

Oceanographic Center Overview, Nova Southeastern University

Halmos College of Natural Sciences and Oceanography Course Catalogs

No abstract provided.


A Financial Impact Assessment Of Ld 1725: Stream Crossings Presentation, New England Environmental Finance Center Jan 2011

A Financial Impact Assessment Of Ld 1725: Stream Crossings Presentation, New England Environmental Finance Center

Economics and Finance

This report looks at the potential financial impact of LD 1725 on the estimated 30,000 stream crossings in the State of Maine that would be affected by the law. Our research for this report included the analysis of nearly 2000 stream crossings and the data collection necessary for the development of extensive stream crossing replacement cost models. We found that the 1.2 bankfull requirements in LD 1725 would result in a 75% ‐ 250% increase in structure widths for stream crossing projects across the state. An upsize of this magnitude would increase the cost of replacing stream crossings statewide by …


Mercury And Selenium Bioaccumulation In The Stromatolite Community Of The Great Salt Lake, Utah, Usa, Wayne A. Wurtsbaugh Jan 2011

Mercury And Selenium Bioaccumulation In The Stromatolite Community Of The Great Salt Lake, Utah, Usa, Wayne A. Wurtsbaugh

Watershed Sciences Faculty Publications

No abstract provided.


Phosphorus Release From Bottom Sediments At Lake Wister, Oklahoma, Summer 2010, B.E. Haggard, J.T. Scott Jan 2011

Phosphorus Release From Bottom Sediments At Lake Wister, Oklahoma, Summer 2010, B.E. Haggard, J.T. Scott

Arkansas Water Resources Center Technical Reports

A previous reservoir model of Lake Wister, Oklahoma suggested that internal P sources were dominant, and that a watershed management plan need not be developed to address external sources. The objectives of this study were to collect intact sediment cores from three sites at Lake Wister and measure sediment O₂ demand (SOD) and soluble reactive P (SRP) release to the overlying water during lab incubations under quiescent conditions. The measured SOD rates were between 9.9 and 22.6 mg m⁻² hr⁻¹ on average across the three sites, where the shallow headwaters site had the least SOD. The SRP release rates were …


Farmer Perceptions Of Sustainable Agriculture Practices And Drought Risk Reduction In Nebraska, Usa, Cody L. Knutson, Tonya Haigh, Michael J. Hayes, Melissa Widhalm, J. Nothwehr, M. Kleinschmidt, L. Graf Jan 2011

Farmer Perceptions Of Sustainable Agriculture Practices And Drought Risk Reduction In Nebraska, Usa, Cody L. Knutson, Tonya Haigh, Michael J. Hayes, Melissa Widhalm, J. Nothwehr, M. Kleinschmidt, L. Graf

National Drought Mitigation Center: Faculty Publications

Social factors, such as farming methods, have an impact on farm vulnerability to drought, but have received little research or policy attention. Some researchers and advocates have argued that sustainable agriculture systems are less vulnerable to climate risk than conventional systems because sustainable agriculture requires producers to have skills promoting adaptability. In this paper, we investigate producers’ perceptions on the use of sustainable agriculture in reducing drought risk, and what they believe would help them better adapt to drought. We surveyed and interviewed farmer members of two sustainable agriculture organizations in Nebraska, USA, during a multi-year drought period from 1999 …


The Global Drought Monitor Portal, Michael J. Brewer, Richard R. Heim Jr. Jan 2011

The Global Drought Monitor Portal, Michael J. Brewer, Richard R. Heim Jr.

National Drought Mitigation Center: Faculty Publications

Drought monitoring, assessment, response, mitigation, adaptation, and early warning systems have been created in a number of countries around the world, and some regional and continental efforts have been successful. However, the creation of a Global Drought Early Warning System (GDEWS) remains elusive. A GDEWS incorporates forecasting and research improvements, in addition to monitoring, impact, planning, mitigation and adaptation and recovery information. At a series of workshops in 2010, the U.S. National Integrated Drought Information System (NIDIS) agreed to take the first step toward a GDEWS, the formation of a Global Drought Monitoring Portal (GDMP). This effort currently covers three …


Colorado's Large Snow Events' Impact On Tree Ring Growth And Dillon Reservoir, Katrina Leona Marzetta Jan 2011

Colorado's Large Snow Events' Impact On Tree Ring Growth And Dillon Reservoir, Katrina Leona Marzetta

Electronic Theses and Dissertations

Meteorological observations from 1894 through 2010 suggest that 17 historically large snow events occurred in the mountains of Colorado within Denver's water supply region. Of these 16 events, 14 can be identified in precipitation sensitive tree ring records as positive climatic pointer years. If these storms were to occur today, they would have the potential to fill reservoirs in Denver Water's supply system, even after years of sustained drought. These "drought busters" have the potential to refill Dillon Reservoir by increasing average yearly inflow up to 146% of the previous year's inflow. Such drought busters can help Denver recover from …


Modification Of Turbulence At The Air-Sea Interface Due To The Presence Of Surfactants And Implications For Gas Exchange. Part Ii: Numerical Simulations, Silvia Matt, Atsushi Fujimara, Alexander Soloviev, Shin Hyung Rhee Jan 2011

Modification Of Turbulence At The Air-Sea Interface Due To The Presence Of Surfactants And Implications For Gas Exchange. Part Ii: Numerical Simulations, Silvia Matt, Atsushi Fujimara, Alexander Soloviev, Shin Hyung Rhee

Marine & Environmental Sciences Faculty Books and Book Chapters

We conducted high-resolution non-hydrostatic numerical simulations to study the effect of surfactants on near-surface turbulence. Laboratory experiments at the UM RSMAS ASIST facility presented in a companion paper report a reduction of turbulence below the air-sea interface and an increase of the surface drift velocity in the presence of surfactants. We implement the effect of surfactants as a rheological, viscoelastic boundary condition at the surface. Our numerical experiments are consistent with the results of the laboratory experiments. We also simulated the effect of surfactants on the temperature difference across the thermal molecular sublayer (cool skin) and on gas transfer velocity. …


Sailfish Habitat Utilization And Vertical Movements In The Southern Gulf Of Mexico And Florida Straits, David W. Kerstetter, Shannon Michael Bayse, Jenny Fenton, John E. Graves Jan 2011

Sailfish Habitat Utilization And Vertical Movements In The Southern Gulf Of Mexico And Florida Straits, David W. Kerstetter, Shannon Michael Bayse, Jenny Fenton, John E. Graves

Marine & Environmental Sciences Faculty Articles

Pop-up satellite archival tags (PSATs) were deployed on 19 sailfish Istiophorus platypterus captured in the southern Gulf of Mexico and Florida Straits between 2005 and 2007 on commercial pelagic longline gear (n = 18) and recreational rod-and-reel gear (n = 1). The data from three tags indicated mortality events and were excluded from subsequent analyses. All PSATs were programmed to collect pressure (depth), temperature, and light-level data for 10 d at approximately 90-s intervals. These transmitted point data subsequently allowed the reconstruction of vertical movement patterns. The remaining 16 PSAT data sets indicate that sailfish are primarily associated …


State Of The Climate In 2010, Jessica Blunden, Derek S. Arndt, Molly O. Baringer Jan 2011

State Of The Climate In 2010, Jessica Blunden, Derek S. Arndt, Molly O. Baringer

United States Department of Commerce: Staff Publications

Several large-scale climate patterns influenced climate conditions and weather patterns across the globe during 2010. The transition from a warm El Niño phase at the beginning of the year to a cool La Niña phase by July contributed to many notable events, ranging from record wetness across much of Australia to historically low Eastern Pacific basin and near-record high North Atlantic basin hurricane activity. The remaining five main hurricane basins experienced below- to well-below-normal tropical cyclone activity. The negative phase of the Arctic Oscillation was a major driver of Northern Hemisphere temperature patterns during 2009/10 winter and again in late …


Estimating Age From Recapture Data: Integrating Incremental Growth Measures With Ancillary Data To Infer Age-At-Length, Mitchell J. Eaton, William A. Link Jan 2011

Estimating Age From Recapture Data: Integrating Incremental Growth Measures With Ancillary Data To Infer Age-At-Length, Mitchell J. Eaton, William A. Link

United States Geological Survey: Staff Publications

Estimating the age of individuals in wild populations can be of fundamental importance for answering ecological questions, modeling population demographics, and managing exploited or threatened species. Significant effort has been devoted to determining age through the use of growth annuli, secondary physical characteristics related to age, and growth models. Many species, however, either do not exhibit physical characteristics useful for independent age validation or are too rare to justify sacrificing a large number of individuals to establish the relationship between size and age. Length-at-age models are well represented in the fisheries and other wildlife management literature. Many of these models …


Characteristics Of Suspended And Streambed Sediment Within Constructed Chutes And The Main Channel At Upper Hamburg And Glovers Point Bends, Missouri River, Nebraska, 2008, Brenda K. Woodward, David L. Rus Jan 2011

Characteristics Of Suspended And Streambed Sediment Within Constructed Chutes And The Main Channel At Upper Hamburg And Glovers Point Bends, Missouri River, Nebraska, 2008, Brenda K. Woodward, David L. Rus

United States Geological Survey: Water Reports and Publications

The Umited States Army Corps of Engineers, Omaha District, as part of the Missouri River Bank Stabilization and Navigation Mitigation Project, has constructed 17 off-channel chutes along the channelized Missouri River, downstream from Sioux City, Iowa, to increase habitat diversity. To better understand characteristics of suspended and streambed sediment within these constructed chutes, the United States Geological Survey (USGS) investigated specific aspects of chute design and function in relation to sediment characteristics including: (1) effects of inlet structures; (2) changes occurring between the inlet and the outlet of a chute; (3) effects of chutes on sediment characteristics in the main …


Sediment Samples And Channel-Geometry Data, Lower Platte River Watershed, Nebraska, 2010, Nathaniel J. Schaepe, Jason S. Alexander Jan 2011

Sediment Samples And Channel-Geometry Data, Lower Platte River Watershed, Nebraska, 2010, Nathaniel J. Schaepe, Jason S. Alexander

United States Geological Survey: Water Reports and Publications

The relation between channel width and stream physical habitat in the lower Platte River in eastern Nebraska was studied as part of the lower Platte River Cumulative Impact Study. The purpose of this component was to document the grain-size distribution of sediment deposited as specific types of physical features, such as sandbars, banks, and stream beds within different hydraulic habitats, within the lower Platte River system. In so doing, the major sources of sediment for sandbar creation downstream are described. Sediment samples were collected from 11 reaches of the lower Platte River from Silver Creek, Nebraska, to the mouth of …


Helicopter Electromagnetic And Magnetic Geophysical Survey Data, Swedeburg And Sprague Study Areas, Eastern Nebraska, May 2009, B. D. Smith, J. D. Abraham, J. C. Cannia, B. J. Minsley, L. B. Ball, Gregory V. Steele, M. Deszcz-Pan Jan 2011

Helicopter Electromagnetic And Magnetic Geophysical Survey Data, Swedeburg And Sprague Study Areas, Eastern Nebraska, May 2009, B. D. Smith, J. D. Abraham, J. C. Cannia, B. J. Minsley, L. B. Ball, Gregory V. Steele, M. Deszcz-Pan

United States Geological Survey: Water Reports and Publications

This report is a release of digital data from a helicopter electromagnetic and magnetic survey conducted by Fugro Airborne Surveys in areas of eastern Nebraska as part of a joint hydrologic study by the Lower Platte North and Lower Platte South Natural Resources Districts, and the Umited States Geological Survey (USGS). The survey flight lines covered 1,418.6 line km (882 line mile). The survey was flown from April 22 to May 2, 2009. The objective of the contracted survey was to improve the understanding of the relation between surface water and groundwater systems critical to developing groundwater models used in …


Selected Approaches To Estimate Water-Budget Components Of The High Plains, 1940 Through 1949 And 2000 Through 2009, Jennifer S. Stanton, Sharon L. Qi, Derek W. Ryter, Sarah E. Falk, Natalie A. Houston, Steven M. Peterson, Stephen M. Westenbroek, Scott C. Christenson Jan 2011

Selected Approaches To Estimate Water-Budget Components Of The High Plains, 1940 Through 1949 And 2000 Through 2009, Jennifer S. Stanton, Sharon L. Qi, Derek W. Ryter, Sarah E. Falk, Natalie A. Houston, Steven M. Peterson, Stephen M. Westenbroek, Scott C. Christenson

United States Geological Survey: Water Reports and Publications

The High Plains aquifer, underlying almost 112 million acres in the central United States, is one of the largest aquifers in the Nation. It is the primary water supply for drinking water, irrigation, animal production, and industry in the region. Expansion of irrigated agriculture throughout the past 60 years has helped make the High Plains one of the most productive agricultural regions in the Nation. Extensive withdrawals of groundwater for irrigation have caused water-level declines in many parts of the aquifer and increased concerns about the long-term sustainability of the aquifer.

Quantification of water-budget components is a prerequisite for effective …


The Role Of Demographic Compensation Theory In Incidental Take Assessments For Endangered Species, Conor P. Mcgowan, Mark R. Ryan, Michael C. Runge, Joshua J. Millspaugh, Jean Fitts Cochrane Jan 2011

The Role Of Demographic Compensation Theory In Incidental Take Assessments For Endangered Species, Conor P. Mcgowan, Mark R. Ryan, Michael C. Runge, Joshua J. Millspaugh, Jean Fitts Cochrane

United States Geological Survey: Staff Publications

Many endangered species laws provide exceptions to legislated prohibitions through incidental take provisions as long as take is the result of unintended consequences of an otherwise legal activity. These allowances presumably invoke the theory of demographic compensation, commonly applied to harvested species, by allowing limited harm as long as the probability of the species’ survival or recovery is not reduced appreciably. Demographic compensation requires some density-dependent limits on survival or reproduction in a species’ annual cycle that can be alleviated through incidental take. Using a population model for piping plovers in the Great Plains, we found that when the population …


Selenium In Birds, Harry M. Ohlendorf, Gary H. Heinz Jan 2011

Selenium In Birds, Harry M. Ohlendorf, Gary H. Heinz

United States Geological Survey: Staff Publications

Selenium (Se) is a metalloid trace element that birds and other wildlife need in small amounts for good health. The main purpose of this chapter is to interpret tissue concentrations of Se. However, because food is the main source of Se accumulation for birds and other wildlife, and because dietary concentrations for effects on bird reproduction have been reported, we also provide interpretive information on Se in the diet.

Se deficiencies in domestic poultry and livestock occur in some parts of the world and must be corrected by additions of Se to the diet. However, the range of dietary concentrations …


History Of Wildlife Toxicology And The Interpretation Of Contaminant Concentrations In Tissues, Barnett A. Rattner, Anton M. Scheuhammer, John E. Ellott Jan 2011

History Of Wildlife Toxicology And The Interpretation Of Contaminant Concentrations In Tissues, Barnett A. Rattner, Anton M. Scheuhammer, John E. Ellott

United States Geological Survey: Staff Publications

The detection and interpretation of contaminants in tissues of wildlife belongs to the field of toxicology, a scientific discipline with a long, intriguing, and illustrious history (reviewed by Hayes 1991, Gallo 2001, Gilbert and Hayes 2006, Wax 2006). We review its history briefly, to provide a context for understanding the use of tissue residues in toxicology, and to explain how their use has developed over time. Because so much work has been conducted on mercury, and dioxins and polychlorinated biphenyls (PCBs), separate case histories are included that describe the evolution of the use of tissue concentrations to assess exposure and …


Droughtscape, Winter 2011, Kelly Smith Jan 2011

Droughtscape, Winter 2011, Kelly Smith

DroughtScape: Quarterly Newsletter of the National Drought Mitigation Center (2007–2023)

Register for the U.S. Drought Monitor Forum

La Niña Brings Southeast, Southwest Drought

International Efforts

Drought Returns in 2010

Impacts Emerge “Before” Summer Drought in East

October-December Quarterly Impacts Summary

Climate Adaptation for Local Government

NDMC Elicits Missouri River Basin Recollections

Woudenberg Coordinates Educational Booklet


Changes In Water Levels And Storage In The High Plains Aquifer, Predevelopment To 2009, Virginia L. Mcguire Jan 2011

Changes In Water Levels And Storage In The High Plains Aquifer, Predevelopment To 2009, Virginia L. Mcguire

United States Geological Survey: Water Reports and Publications

The High Plains aquifer underlies 111.8 million acres (175,000 square miles) in parts of eight States—Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming. The area overlying the High Plains aquifer is one of the primary agricultural regions in the Nation. Water-level declines began in parts of the High Plains aquifer soon after the onset of substantial irrigation with groundwater from the aquifer (about 1950 and termed "predevelopment" in this fact sheet). By 1980, water levels in the High Plains aquifer in parts of Texas, Oklahoma, and southwestern Kansas had declined more than 100 feet (ft) (Luckey and …


Hydrostratigraphic Interpretation Of Test-Hole And Geophysical Data, Upper Loup River Basin, Nebraska, 2008-10, Christopher M. Hobza, Theodore H. Asch, Paul A. Bedrosian Jan 2011

Hydrostratigraphic Interpretation Of Test-Hole And Geophysical Data, Upper Loup River Basin, Nebraska, 2008-10, Christopher M. Hobza, Theodore H. Asch, Paul A. Bedrosian

United States Geological Survey: Water Reports and Publications

Nebraska's Upper Loup Natural Resources District is currently (2011) participating in the Elkhorn-Loup Model to understand the effect of various groundwater-management scenarios on surface-water resources. During Phase 1 of the Elkhorn-Loup Model, a lack of subsurface geological information in the Upper Loup Natural Resources District, hereafter referred to as the upper Loup study area, was identified as a gap in current knowledge that needed to be addressed. To improve the understanding of the hydrogeology of the upper Loup study area, the United States Geological Survey, in cooperation with the Upper Loup Natural Resources District and the University of Nebraska Conservation …


Summer 2011, Nova Southeastern University Jan 2011

Summer 2011, Nova Southeastern University

Currents

No abstract provided.


Ecological Design Of Marine Construction For Socio-Economic Benefits: Ecosystem Integration Of A Pipeline In Coral Reef Area, Sylvain Pioch, Philippe Saussola, Kirk Kilfoyle, Richard E. Spieler Jan 2011

Ecological Design Of Marine Construction For Socio-Economic Benefits: Ecosystem Integration Of A Pipeline In Coral Reef Area, Sylvain Pioch, Philippe Saussola, Kirk Kilfoyle, Richard E. Spieler

Marine & Environmental Sciences Faculty Articles

It is critical to understand that an ecosystem integration of construction requires a close Engineering/Biology partnership to meet socio-economic benefits in management goals. Biologists are not typically trained or licensed for the requisite engineering involved in construction. Likewise, non-biologists designing habitat often can lead to egregious results. For example, unintentionally constructing the wrong habitat, i.e., refuge for predators in a nursery area, or habitat that facilitates the spread of non-desirable species can increase, rather than ameliorate, the impact of construction. In recent years, Pioch and co-workers (unpublished) developed an alternative to the “classic” engineering approach to marine construction. This new …


The Rise And Fall Of Lake Bonneville Between 45 And 10.5 Ka, L.V. Benson, S.P. Lund, J.P. Smoot, D.E. Rhode, R.J. Spencer, K.L. Verosub, L.A. Louderback, C.A. Johnson, R.O. Rye, R.M. Negrini Jan 2011

The Rise And Fall Of Lake Bonneville Between 45 And 10.5 Ka, L.V. Benson, S.P. Lund, J.P. Smoot, D.E. Rhode, R.J. Spencer, K.L. Verosub, L.A. Louderback, C.A. Johnson, R.O. Rye, R.M. Negrini

United States Geological Survey: Staff Publications

A sediment core taken from the western edge of the Bonneville Basin has provided high-resolution proxy records of relative lake-size change for the period 45.1-10.5 calendar ka (hereafter ka). Age control was provided by a paleomagnetic secular variation (PSV)-based age model for Blue Lake core BL04-4. Continuous records of δ18O and total inorganic carbon (TIC) generally match an earlier lake-level envelope based on outcrops and geomorphic features, but with differences in the timing of some hydrologic events/states. The Stansbury Oscillation was found to consist of two oscillations centered on 25 and 24 ka. Lake Bonneville appears to have …


Sampling Methods For Acropora Corals, Other Benthic Coral Reef Organisms, And Marine Debris In The Florida Keys: Field Protocol Manual For 2011-2012 Assessments, Steven Miller, Leanne M. Rutten, Mark Chiappone Jan 2011

Sampling Methods For Acropora Corals, Other Benthic Coral Reef Organisms, And Marine Debris In The Florida Keys: Field Protocol Manual For 2011-2012 Assessments, Steven Miller, Leanne M. Rutten, Mark Chiappone

Marine & Environmental Sciences Faculty Reports

The 2011-2012 sampling of Acropora corals, other coral reef benthic invertebrates, and marine debris in the Florida Keys National Marine Sanctuary (FKNMS) is being undertaken as a spatially intensive effort to provide updated population distribution and abundance information. The particular focus of surveys in the Florida Keys, as well as in the U.S. Caribbean (Puerto Rico and the U.S.V.I.), concerns the habitat distribution, colony density, size, condition, and population abundance of Acropora corals. Surveys in the Florida Keys also include assessments of urchins, mollusks, anemones, corallimorpharians, and marine debris. These additional assessments are relatively fast and easy to perform. Annual …


Essential Fish Habitat Project Status Report, Jodi L. Pirtle, Christopher D. Wilson, Chris Rooper, Thomas C. Weber Jan 2011

Essential Fish Habitat Project Status Report, Jodi L. Pirtle, Christopher D. Wilson, Chris Rooper, Thomas C. Weber

Center for Coastal and Ocean Mapping

: Groundfish that associate with rugged seafloor types are difficult to assess with bottom-trawl sampling gear. Simrad ME70 multibeam echosounder (MBES) data and video imagery were collected to characterize trawlable and untrawlable areas, and to ultimately improve efforts to determine habitat-specific groundfish biomass. The data were collected during two acoustic-trawl surveys of the Gulf of Alaska (GOA) during 2011 and 2012 by NOAA Alaska Fisheries Science Center (AFSC) researchers. MBES data were collected continuously along the trackline, which included parallel transects (1-20 nmi spacing) and fine-scale survey locations in 2011. Video data were collected at camera stations using a drop …


Influence Of Karst Landscape On Planetary Boundary Layer Atmosphere: A Weather Research And Forecasting (Wrf) Model–Based Investigation, Ronnie Leeper, Rezaul Mamood, Arturo I. Quintanar Jan 2011

Influence Of Karst Landscape On Planetary Boundary Layer Atmosphere: A Weather Research And Forecasting (Wrf) Model–Based Investigation, Ronnie Leeper, Rezaul Mamood, Arturo I. Quintanar

High Plains Regional Climate Center: Staff Publications

Karst hydrology provides a unique set of surface and subsurface hydrological components that affect soil moisture variability. Over karst topography, surface moisture moves rapidly below ground via sink holes, vertical shafts, and sinking streams, reducing surface runoff and moisture infiltration into the soil. In addition, subsurface cave blockage or rapid snowmelt over karst can lead to surface flooding. Moreover, regions dominated by karst may exhibit either drier or wetter soils when compared to nonkarst landscape. However, because of the lack of both observational soil moisture datasets to initialize simulations and regional land surface models (LSMs) that include explicit karst hydrological …


Assessment And Characterization Of Physical Habitat, Water Quality, And Biotic Assemblages Of The Tyronza River, Arkansas, N. J. Wentz, N. D. Henderson, A. D. Christian Jan 2011

Assessment And Characterization Of Physical Habitat, Water Quality, And Biotic Assemblages Of The Tyronza River, Arkansas, N. J. Wentz, N. D. Henderson, A. D. Christian

Journal of the Arkansas Academy of Science

Few studies within the last few decades have addressed water quality and biotic assemblages within Arkansas’s large channel-altered deltaic rivers. The Tyronza River is located in northeast Arkansas and its watershed has a heavy agricultural presence that drastically affects habitat quality. Meanwhile, the Tyronza River hosts one of the more recent documented range extensions of the federally endangered fat pocketbook mussel [Potamilus capax (Green, 1832)]. The purpose of this study was to assess physical habitat, water quality, and biotic assemblages of the Tyronza River using the Arkansas Department of Environmental Quality’s (ADEQ) regional biometrics. Water samples were collected at 9 …


Lakes As Buffers Of Stream Dissolved Organic Matter (Dom) Variability: Temporal Patterns Of Dom Characteristics In Mountain Stream-Lake Systems, K. J. Goodman, Michelle A. Baker, Wayne A. Wurtsbaugh Jan 2011

Lakes As Buffers Of Stream Dissolved Organic Matter (Dom) Variability: Temporal Patterns Of Dom Characteristics In Mountain Stream-Lake Systems, K. J. Goodman, Michelle A. Baker, Wayne A. Wurtsbaugh

Watershed Sciences Faculty Publications

Lakes within fluvial networks may affect dissolved organic matter (DOM) dynamics in streams by dampening spring DOM snowmelt flushing responses and/or by increasing summer DOM production. We assessed the temporal variability of dissolved organic carbon (DOC) concentration and DOM characteristics (specific ultraviolet absorbance (SUVA254); DOC:dissolved organic nitrogen (DOC:DON)), as well as DOC export in seven paired lake inflows and outflows in the Sawtooth Mountain lake district, Idaho. We hypothesized that lakes would decrease stream DOM temporal variability and increase DOM export as a result of autotrophic production. We correlated DOM variability with landscape factors to evaluate potential drivers of DOM …


Variability In Red Snapper Otolith Microchemistry Among Gulf Of Mexico Regions, Michelle Zapp Sluis Jan 2011

Variability In Red Snapper Otolith Microchemistry Among Gulf Of Mexico Regions, Michelle Zapp Sluis

LSU Doctoral Dissertations

Red snapper, Lutjanus campechanus, has been an economically important reef fish in the Gulf of Mexico (Gulf) for over 150 years and is currently overfished. Catch statistics and demographic differences have lead to the population being categorized into eastern and western substocks divided by the Mississippi River, but data is recombined to set a Gulf-wide annual catch limit. The two objectives of this study were to apply otolith nursery chemical signatures to estimate red snapper mixing dynamics in the western Gulf, and to determine if signatures based upon trace metals associated with oil and gas platforms could discriminate between region …