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Full-Text Articles in Physical Sciences and Mathematics

Sediment Transport And Channel Morphology Dynamics Of Highly Regulated Alluvial Rivers - A Case Study Of The Lowermost Mississippi River., Sanjeev Joshi Jan 2017

Sediment Transport And Channel Morphology Dynamics Of Highly Regulated Alluvial Rivers - A Case Study Of The Lowermost Mississippi River., Sanjeev Joshi

LSU Doctoral Dissertations

The Mississippi River delta is facing severe land loss. An urgent need exists to examine sediment transport and channel morphology dynamics along this highly engineered alluvial river that has shaped and will continue to shape its delta. This dissertation research focuses on investigating channel morphology dynamics and sediment transport in the recent three decades along a 327-km reach (from about 492 to 167 km upstream from the river’s outlet in the Gulf of Mexico) of the Lowermost Mississippi River (LmMR). The specific objectives of this research were to: 1) analyze riverbed adjustment, i.e., channel-bed aggradation or channel erosion at seven …


Condition Of Birds In Amazonian Rainforest Fragments And Second-Growth Forests, Angelica Maria Hernandez Palma Jan 2017

Condition Of Birds In Amazonian Rainforest Fragments And Second-Growth Forests, Angelica Maria Hernandez Palma

LSU Doctoral Dissertations

Deforestation modifies otherwise intact expanses of forest into small, isolated fragments. In addition to fragmentation, deforestation also creates abrupt forest edges and large areas of regenerating vegetation where land is abandoned after clearing. Understanding how changes in the landscape affect the physical condition of birds is crucial for managing populations in human-modified landscapes. Here I use the biomarkers feather growth rate and feather quality (ptilochronology), fluctuating asymmetry (FA), and stress hormones from feathers (CORT), to estimate the physical condition of Amazonian understory birds living in forest fragments, second-growth forests, and continuous forests. Feather CORT revealed how fragmentation disrupts interspecific interactions; …


Quantitative Oil Source-Fingerprinting Techniques And Their Application To Differentiating Crude Oil In Coastal Marsh Sediments, Buffy Marie Meyer Jan 2016

Quantitative Oil Source-Fingerprinting Techniques And Their Application To Differentiating Crude Oil In Coastal Marsh Sediments, Buffy Marie Meyer

LSU Doctoral Dissertations

Oil source-fingerprinting is an environmental forensics technique that uses analytical chemistry to determine the origin of oil residues in environmental samples by comparison to a known or suspected source oil. Currently, the only standardized method for oil source fingerprinting is a qualitative approach that is very effective in almost every oil spill response situation. However, the need for quantitative oil source-fingerprinting methods to complement the qualitative determinations is extremely desired. The research herein aims to utilize data generated by gas chromatography/mass spectrometry (GC/MS) methodologies to test two different quantitative techniques: diagnostic biomarker ratio analysis and chemometrics. The most common crude …


Biomass Gasification For Electricity Generation: An Integrated Approach For Development Of Forest Residue-Based Projects In Rural India, Anand Mishra Jan 2016

Biomass Gasification For Electricity Generation: An Integrated Approach For Development Of Forest Residue-Based Projects In Rural India, Anand Mishra

LSU Doctoral Dissertations

Biomass gasification is generally regarded as a promising technology for various advanced application in energy production. Biomass is the only carbon-based sustainable option among the renewable energy sources. This study is focused on fostering biomass gasification for electricity generation sector in India. The study addresses four broad aspects of biomass gasification for electricity generation - feedstock properties and gasification technology, policy and regulatory framework governing the sector, financial evaluation of electricity generation from biomass gasification, and feedstock supply. The study is divided in four chapters, each of which addresses one aspect of electricity generation through biomass gasification. Based on literature, …


Immune Gene Variation And Susceptibility To Upper Respiratory Tract Disease In Gopher Tortoises, Jean Pierre Elbers Jan 2016

Immune Gene Variation And Susceptibility To Upper Respiratory Tract Disease In Gopher Tortoises, Jean Pierre Elbers

LSU Doctoral Dissertations

The immune system defends the host from bacteria, fungi, parasites, and viruses. The immune system is partially under genetic control through immune response genes, such as those of the major histocompatibility complex (MHC) whose nucleotide variation influences the host’s ability to recognize foreign pathogens and can influence disease susceptibility. Populations of threatened species generally possess low levels of genetic variation, and genetically depauperate hosts may be at greater risk of infectious disease contributing to extirpations because they also possess low immunogenetic variation. My dissertation examines the relationship between immunogenetic variation and disease susceptibility and the factors that influence innate immune …


Ecological-Hydrological Feedback In Forested Wetlands, Scott Thomas Allen Jan 2016

Ecological-Hydrological Feedback In Forested Wetlands, Scott Thomas Allen

LSU Doctoral Dissertations

In forested wetlands, the biotic and abiotic consequences of water level variability is not well understood. The effects of flooding on carbon and water exchanges are important knowledge gaps where progress could benefit management of natural resources and predicting of changes in surface geophysical cycles. Two specific needs are a better understanding of (1) wetland tree responses to hydrologic variations, and (2) the effects of the forest and associated tree stressors on surface energy and water fluxes. Objectives were to determine effects of flooding on evaporation rates and energy dynamics, tree water use and growth responses to river-floodplain connectivity and …


Vegetation Influences Microbial Community Structure And Methane Emissions In Southeastern Louisiana Wetlands, Anthony Jason Rietl Jan 2016

Vegetation Influences Microbial Community Structure And Methane Emissions In Southeastern Louisiana Wetlands, Anthony Jason Rietl

LSU Doctoral Dissertations

Methane has a warming potential 28 times that of carbon dioxide and has been increasing in the Earth’s atmosphere since 1750. An understanding of the dynamics of methane emissions from natural sources is becoming increasingly important as we may need to mitigate emissions from these sources in the future to help reduce the effects of climate change. Wetlands are the single largest natural source of methane; however, little attention has been given to how plant species, biota, and interactions between above and belowground communities and microbial communities may affect methane emissions. First, microbial community structure and function was assessed for …


Temporal Dynamics Of Benthic Responses To Habitat Disturbance In Coastal Plain Headwaters Of Southwestern Louisiana, Catherine Elizabeth Murphy Jan 2016

Temporal Dynamics Of Benthic Responses To Habitat Disturbance In Coastal Plain Headwaters Of Southwestern Louisiana, Catherine Elizabeth Murphy

LSU Doctoral Dissertations

Weak biotic responses to habitat gradients within Northern Gulf of Mexico streams have been attributed to spatial and temporal variability. Landscape and in-stream habitat descriptions are presented for watersheds within Pleistocene terraces of the Coastal Plains geomorphic province of Louisiana, USA. Geologic influences on stream habitat were inferred by comparing multivariate ordinations on physicochemical measurements between terraces. Seasonal variability was assessed during a drought year (2011) and a typical water year (2013). Within coastal plains of Louisiana, stream condition was more similar within terraces than within river basins. Permutational MANOVA models indicated significantly different stream habitat between Uplands and Prairie, …


Application Of Biomass Derived Materials In Nanocomposites And Drilling Fluids, Kunlin Song Jan 2016

Application Of Biomass Derived Materials In Nanocomposites And Drilling Fluids, Kunlin Song

LSU Doctoral Dissertations

Tar is inevitably produced from biomass thermochemical processes, and is often disposed as an industrial waste, leading to environmental pollution. As a result of its high carbon content, tar was expected to be a promising precursor for manufacturing carbon materials. Consequently, low-cost porous carbon nanofibers (CNFs) using tar, polyacrylonitrile (PAN), and silver nanoparticles was fabricated through electrospinning and subsequent stabilization and carbonization processes. The continuous electrospun nanofibers were obtained with diameters ranging from 392 to 903 nm. The addition of biomass tar resulted in increased fiber diameters, reduced thermal stabilities, and slowed cyclization reactions of PAN in the as-spun nanofibers. …


Arsenic Speciation And Phytoremediation Modeling For Environmental Management, Sidney Joseph Marlborough Jan 2016

Arsenic Speciation And Phytoremediation Modeling For Environmental Management, Sidney Joseph Marlborough

LSU Doctoral Dissertations

Arsenic has been used throughout recorded history but during the industrial revolution widespread use led to global environmental impact. The two forms that should be considered in environment management are arsenate and arsenite. The calculations of environmental risk for arsenic exposure relies the toxicity of arsenite however, in well aeriated surface soils arsenate may be the predominate form. Ecological risk assessments based on arsenite studies will lead to restrictive remediation requirements that do not adequately reflect the level of risk. Arsenate resembles phosphate and as such has a greater affinity for phytoremediation. Phytoremediation is one of the most viable and …


A Spatial Dynamic Model Of Population Changes In A Vulnerable Coastal Environment, Kenan Li Jan 2015

A Spatial Dynamic Model Of Population Changes In A Vulnerable Coastal Environment, Kenan Li

LSU Doctoral Dissertations

Achieving coastal sustainability in low-lying coastal areas is a great challenge. This study developed a spatial dynamic model to study the coupled natural-human responses in the form of population changes in the Lower Mississippi River Basin region. The goal was to identify the key social-economic factors (utility) and selected environmental factors (such as hazards damage, elevation, and subsidence rate) that affect population changes, as well as how population changes affect the local utility and the local environment reciprocally. The study area was partitioned into the “north’ and the “south” by a hypothetical boundary to test the differences of the emergence. …


Effects Of Inbreeding On Endangered Red Wolves (Canis Rufus), Kristin E. Brzeski Jan 2015

Effects Of Inbreeding On Endangered Red Wolves (Canis Rufus), Kristin E. Brzeski

LSU Doctoral Dissertations

Inbreeding depression, the reduction in offspring fitness caused by mating among close relatives, is widespread in small populations and a major concern in conservation biology because it can affect population persistence. The negative effects of inbreeding results in the evolution of inbreeding avoidance behaviors; within small populations, such behaviors may encourage individuals to select mates outside of their respective species. Mate choice may also be facilitated by variation at major histocompatibility complex (MHC) genes, a gene group critical for immune response and disease resistance. Given broad impacts of inbreeding and MHC variation on fitness and behavior, evaluating their effects is …


Cellulose Nanofibers From Energycane Bagasse And Their Applications In Core-Shell Structured Hydrogels, Yiying Yue Jan 2015

Cellulose Nanofibers From Energycane Bagasse And Their Applications In Core-Shell Structured Hydrogels, Yiying Yue

LSU Doctoral Dissertations

Cellulose fibers (Cellulose I, cellulose II and cellulose I/II Hybrid fibers) were successfully extracted from energycane bagasse by using a combined NaOH and NaClO2 treatment. After the delignification process, most lignin and hemicellulose were removed with a 27.4wt% yield of cellulose fibers, and the mean diameter of cellulose fibers decreased from 137±46 (raw fiber bundles) to 12±5μm (unpacked fibers). The raw bagasse fibers showed a three-step pyrolysis process, while isolated cellulose fibers had a one-step pyrolysis process. NaClO2 treatment caused the reduction of cellulose thermal stability due to its acting on lignin and cellulose. With 10h NaOH treatment, the ribbon …


Three Year Assessment Of Nearshore Crude Oil Contamination In The Gulf Of Mexico Using Gulf Menhaden (Brevoortia Patronus) As An Indicator Species: Menhaden Watch, Gregory Michael Olson Jan 2015

Three Year Assessment Of Nearshore Crude Oil Contamination In The Gulf Of Mexico Using Gulf Menhaden (Brevoortia Patronus) As An Indicator Species: Menhaden Watch, Gregory Michael Olson

LSU Doctoral Dissertations

Approximately 4.9 million barrels of crude oil along with natural gas were released into the Gulf of Mexico (GoM) from April to July 2010 (Deepwater Horizon, DWH, spill). Impacts of this magnitude seldom occur in the GoM (Ixtoc I was the last spill close to this magnitude occurring in 1979), and one cannot predict when they will happen. Major constituents of concern found in crude oil are Polycyclic Aromatic Hydrocarbons (PAHs), which often have low volatility that allows for prolonged existence in the environment. PAHs are compounds of concern according to the United States Environmental Protection Agency (USEPA), with one …


Game Theoretic Analyses Of The United States-Canada Softwood Lumber Trade, Rajan Parajuli Jan 2015

Game Theoretic Analyses Of The United States-Canada Softwood Lumber Trade, Rajan Parajuli

LSU Doctoral Dissertations

The ongoing softwood lumber trade dispute between the United States (U.S.) and Canada is one of the most contentious and largest bilateral trade battles over the recent decades. The bilateral trade debate is mostly because of the different forestland ownership systems in the U.S. and Canada, and the alleged timber subsidies by provincial governments to Canadian lumber producers. The Softwood Lumber Agreement (SLA) 2006 between the U.S. and Canada is the latest transitory solution of this dispute, entailing Canada to impose mandatory export charges on its lumber shipments to the U.S. In order to understand this trade dispute from a …


Enhancement Of Gulf Killifish, Fundulus Grandis, Fitness And Reproduction, Joshua Thomas Patterson Jan 2014

Enhancement Of Gulf Killifish, Fundulus Grandis, Fitness And Reproduction, Joshua Thomas Patterson

LSU Doctoral Dissertations

Gulf killifish, Fundulus grandis, shows promise for commercial development as a marine baitfish species. Significant markets for F. grandis already exist throughout the Gulf Coast, with the vast majority of supply coming from wild-harvests, which can be hampered by seasonal availability and inconsistent fish health and size. The genus Fundulus also represents an important group of model vertebrates for biological study. A recent review paper described this genus as the premier teleost model for environmental biology. New information generated as a result of the work contained in this dissertation may be more broadly applicable to sister species of F. grandis, …


A Contrast Of Hunter Characteristics And Attitudes Between Random And Convenience Samples In The 2010, 2012, And 2013 Surveys Of Louisiana Waterfowl Hunters, Lucien Jr. Paul Laborde Jan 2014

A Contrast Of Hunter Characteristics And Attitudes Between Random And Convenience Samples In The 2010, 2012, And 2013 Surveys Of Louisiana Waterfowl Hunters, Lucien Jr. Paul Laborde

LSU Doctoral Dissertations

I surveyed random (mail and internet panel surveys) and convenience samples (web surveys) of Louisiana waterfowl hunters following the 2009-2010, 2011-2012, and 2012-2013 seasons. I hypothesized significant differences in effort, success, satisfaction and demographics, but no difference in attitudes, in responses between random and convenience survey methods. I mailed to stratified random samples of 2,500 in 2010, 6,400 in 2012, and 2,500 each for mail and on-line internet panel response in 2013. An identical web survey, hosted each year during the same time period, facilitated open-access response. I received 1,676 usable responses in 2010 (727 mail and 949 web), 2,382 …


A Standardized Ultrasonography Classification For Channel Catfish Ovarian Development, Noel D. Novelo Jan 2014

A Standardized Ultrasonography Classification For Channel Catfish Ovarian Development, Noel D. Novelo

LSU Doctoral Dissertations

The goal of this dissertation was to develop application of ultrasonography as a decision-making tool in genetic improvement programs for channel catfish Ictalurus punctatus. A literature review on the use of ultrasonography in fish reproduction generated a comprehensive reference data set intended to benefit existing and potential users. It exposed the need for reporting of instrument control settings and standardization of fish handling and imaging procedures. These issues were addressed from the onset of this work by assessing more than 6,300 channel catfish ovaries by use of initial fish handling and imaging procedures developed (2004-2005) at the Louisiana State University …


Species Composition And Spatial Ecology Of Amazonian Understory Mixed-Species Flocks In A Fragmented Landscape, Karl Mokross Jan 2014

Species Composition And Spatial Ecology Of Amazonian Understory Mixed-Species Flocks In A Fragmented Landscape, Karl Mokross

LSU Doctoral Dissertations

With the ongoing advance of the agricultural frontier in the Amazon basin, it is inevitable that heterogeneous landscapes will play a key role in conservation. These landscapes are mostly composed of patchworks of small forest fragments, secondary forests and roads. Conservation, however must take species interactions into consideration as they play a pivotal part the maintenance of several biological processes in the tropics. One of the most conspicuous interspecific interactions are seen in mixed-species flocks of birds, which in the Amazon, represent one of the best organized systems of bird aggregations. In this research, I assess how flock spatial behavior …


Effects Of Forest Fragmentation On Central Amazonian Bird Demography, Jared Desmond Wolfe Jan 2014

Effects Of Forest Fragmentation On Central Amazonian Bird Demography, Jared Desmond Wolfe

LSU Doctoral Dissertations

Avian diversity in degraded fragmented Amazonian landscapes depends on the persistence of species in cleared and disturbed areas. Regenerating forest facilitates bird dispersal within degraded Amazonian landscapes and may tip the balance in favor of persistence in previously depauperate habitat patches. Despite the potential value of Amazonian second growth, we lack comparisons of demography among second growth, continuous forest, forest fragments in regenerating landscapes, and truly isolated fragments. Here, we used point-count and capture data to compare Amazonian bird communities among continuous forest plots, 100 ha forest fragments with adjacent second growth, 100 ha forested islands bounded by water, young …


Ecosystem Metabolism In Coastal Plain Streams Of Southeast Louisiana : Environmental And Watershed Effects, Jonathan L. West Jan 2013

Ecosystem Metabolism In Coastal Plain Streams Of Southeast Louisiana : Environmental And Watershed Effects, Jonathan L. West

LSU Doctoral Dissertations

Since its introduction in 1956, the use of open-system, diel dissolved oxygen curves for estimating the components of ecosystem metabolism in the lotic setting have been important in determining the current ecosystem theory of streams, both spatially among multiple systems and longitudinally within the same system, as well as identifying potentially impaired systems, especially when contrasted with streams considered unimpaired. Several factors have been identified as controls on both components of ecosystem metabolism and include light, nutrients, and stable substrates for gross primary production (GPP) and a source of organic matter (OM) for ecosystem respiration (ER). Stream size is important …


Recovery Of Understory Bird Movement In Post-Pasture Amazonia, Luke L. Powell Jan 2013

Recovery Of Understory Bird Movement In Post-Pasture Amazonia, Luke L. Powell

LSU Doctoral Dissertations

I sought to understand how forest fragmentation and secondary growth affect avian movement at the Biological Dynamics of Forest Fragments Project (BDFFP) near Manaus, Brazil. When deforested areas are abandoned, secondary forests regenerate, allowing rainforest animals to gradually recovery their ability to use formerly inhospitable habitat. My colleagues and I captured 2773 understory birds of ten foraging guilds along the edges of primary forest fragments and variable secondary forest. Age of secondary forest along edges was the most important variable driving capture rates on primary/secondary edges. Mean recovery to pre-isolation capture rates was 26 years after abandonment, but terrestrial insectivores …


Preparation And Characterization Of Cellulose Nanoparticles And Their Application In Biopolymeric Nanocomposites, Jingquan Han Jan 2013

Preparation And Characterization Of Cellulose Nanoparticles And Their Application In Biopolymeric Nanocomposites, Jingquan Han

LSU Doctoral Dissertations

Regenerated cellulose nanoparticles (RCNs) including both elongated fiber and spherical structures were prepared from microcrystalline cellulose (MCC) and cotton using 1-butyl-3-methylimidazolium chloride followed by high-pressure homogenization. The RCN has a two-step pyrolysis, different from raw MCC and cotton that had a one-step process. The crystalline structure of RCNs was cellulose II in contrast to the cellulose I form of the starting materials. Also, the RCNs have decreased crystallinity and crystallite size. The elongated RCNs produced from cotton and MCC had average lengths of 123 ± 34 and 112 ± 42 nm, and mean widths of 12 ± 5 and 12 …


Energy, Environment, And Sustainability: A Hierarchical Analysis Of South Louisiana, Matthew Korbel Moerschbaecher Jan 2012

Energy, Environment, And Sustainability: A Hierarchical Analysis Of South Louisiana, Matthew Korbel Moerschbaecher

LSU Doctoral Dissertations

This dissertation details research into the sustainability of industrial, human, and natural systems in south Louisiana. Chapter 1 is a general introduction. Chapter 2 calculates the energy return on financial investment (EROFI) of oil and gas production in the ultra-deepwater Gulf of Mexico (GoM) in 2009 and the Macondo Prospect (Mississippi Canyon Block 252). I calculated a preliminary Energy Return on Investment (EROI) using a range of energy intensity ratios. The EROFI for ultra-deepwater oil and gas at the wellhead was roughly 0.85 gallons, per dollar. These estimates of EROI for 2009 ultra-deepwater oil and natural gas at the wellhead …


Nitrogen And Carbon Export To The Gulf Of Mexico By The Atchafalaya River, A Major Distributary Of The Mississippi River, April Elizabeth Bryantmason Jan 2012

Nitrogen And Carbon Export To The Gulf Of Mexico By The Atchafalaya River, A Major Distributary Of The Mississippi River, April Elizabeth Bryantmason

LSU Doctoral Dissertations

Summer hypoxia in the Northern Gulf of Mexico has been attributed to large nutrient inputs, especially nitrate-nitrogen, from the Mississippi-Atchafalaya River system. The 2008 Gulf Hypoxia Action Plan calls for river corridor wetland restoration to reduce nitrate loads, but it is largely unknown how effective riverine wetland systems in the lower Mississippi River (MR) are for nitrate removal. This dissertation research examined nitrate and carbon export from the Atchafalaya River (AR) to: (1) determine nitrate processing by a river swamp basin under varied seasons, (2) investigate nitrate retention and processing in the AR during a major flood event, and (3) …


Modeling The Spatial And Temporal Dynamics Of Coastal Marsh Birds, Bradley A. Pickens Jan 2012

Modeling The Spatial And Temporal Dynamics Of Coastal Marsh Birds, Bradley A. Pickens

LSU Doctoral Dissertations

Wetland birds are likely to be influenced by habitat at multiple spatial scales, yet few studies have investigated bird responses at both broad and fine scales. Northern Gulf Coast marshes are dynamic ecosystems, and they provide an ideal place to examine habitat across spatial and temporal scales. My research focused on the secretive marsh bird guild (i.e. bitterns, rails, gallinules, grebes) with an emphasis on the king rail (Rallus elegans), a species of high conservation concern. My objectives were to investigate the wetland bird-environment relationship across scales, and to model annual changes in bird distribution. Study sites were in the …


The Effects Of Hydrologic Modifications On Floodplain Forest Tree Recruitment And Growth In The Mississippi River Alluvial Valley, Usa, Hugo Gee Jan 2012

The Effects Of Hydrologic Modifications On Floodplain Forest Tree Recruitment And Growth In The Mississippi River Alluvial Valley, Usa, Hugo Gee

LSU Doctoral Dissertations

Floodplains forests are productive and diverse ecosystems characterized by frequent riverine flooding. Levees and dams have eliminated or altered riverine flooding which can potentially affect floodplain tree recruitment and growth. Increased light availability from canopy disturbances may increase photosynthesis given sufficient soil moisture, but information on the combined effect of canopy disturbances and hydrologic modifications on tree recruitment and growth is lacking. I used dendrochronological techniques to reconstruct tree recruitment, growth (Quercus lyrata, Fraxinus pennsylvanica), and canopy disturbance patterns over a 90-year period at several floodplains in the Mississippi River Alluvial Valley, USA: an unleveed site below dams and two …


Pmi 5011 Regulates The Ubiquitin Proteasome System In Skeletal Muscle, Heather Christianne Kirk-Ballard Jan 2012

Pmi 5011 Regulates The Ubiquitin Proteasome System In Skeletal Muscle, Heather Christianne Kirk-Ballard

LSU Doctoral Dissertations

Insulin resistance in type 2 diabetes is associated with impaired glucose and protein metabolism in skeletal muscle. The impaired insulin signaling in skeletal muscle affects muscle mass by tilting the balance between skeletal muscle protein synthesis and degradation toward degradation, a process that is primarily regulated by the ubiquitin-proteasome system. Studies have shown that an extensively characterized ethanol extract of Artemisia dracunculus L (Russian Tarragon), termed PMI 5011, enhances insulin signaling in human primary skeletal muscle cells and in a rodent model of insulin resistance. The aim of this project is to determine if the effect of PMI 5011 on …


Biomass Energy Production In Louisiana: A Gis Study On The Supply Chain, Anil Raj Kizhakkepurakkal Jan 2012

Biomass Energy Production In Louisiana: A Gis Study On The Supply Chain, Anil Raj Kizhakkepurakkal

LSU Doctoral Dissertations

One major drawback of biomass fuel is its bulky nature and the resulting high cost of transporting the fuel to the facility where the energy is being produced. Hence, supply chain of biomass residues plays a crucial role in determining the financial viability of bioenergy production. Transporting biomass for energy purposes more than 50 miles (80 km) is not considered economically feasible in most conditions. In the wood energy scenario, the maximum distance is more often restricted to distances of less than 200 km between production and consumption (via road). A study was done to determine logging residues and agricultural …


Red Swamp Crayfish Procambarus Clarkii In The Atchafalaya River Basin: Biotic And Abiotic Effects On Population Dynamics And Physiological Biomarkers Of Hypoxic Stress, Christopher Paul Bonvillain Jan 2012

Red Swamp Crayfish Procambarus Clarkii In The Atchafalaya River Basin: Biotic And Abiotic Effects On Population Dynamics And Physiological Biomarkers Of Hypoxic Stress, Christopher Paul Bonvillain

LSU Doctoral Dissertations

Crayfish harvested from the Atchafalaya River Basin (ARB) represent the majority of Louisiana wild crayfish landings. However, excluding water level influences, it is difficult to elucidate inter-annual harvest differences and intra-annual population variability among habitats. This research investigated ecological influences on population characteristics of red swamp crayfish Procambarus clarkii in the southeastern ARB as well as physiological biomarkers of hypoxic stress in P. clarkii. Biotic and abiotic effects on P. clarkii populations were examined throughout the 2008 and 2009 commercial crayfish seasons. P. clarkii catch per unit effort (CPUE) at sampling locations increased nearly 600% between sample years despite similar …