The red swamp crayfish, Procambarus clarkii, represents an important aquaculture species responsible for over half of all commercial aquaculture profits in Louisiana. White spot syndrome virus (WSSV) is highly pathogenic and induces mass mortality in crustacean aquaculture operations worldwide. Crayfish lack the adaptive ability of the vertebrate immune system, and must depend on primitive, innate immune responses to combat viral infections. This study aims to investigate the dose-response of WSSV in P. clarkii and to examine viral-host interactions by examining the biochemical and immunological changes induced by WSSV infection in this species. Viable viral particles were isolated from naturally infected P. clarkii gill tissue, quantified using a novel digital PCR approach, and inoculated into P. clarkii to determine a median lethal dose (LD50) value of WSSV particles. After estimating an LD50 value, crayfish were inoculated at this nominal concentration of viral particles, and biological tissues were sampled across time to observe physiological and immunological changes throughout the course of WSSV infection. Antioxidant activity increased over time, while immunological gene expression was downregulated in the gill tissue of WSSV-infected crayfish. Knowledge of the infectivity of WSSV in native crayfish is of critical importance to the management of the commercial aquaculture industry in Louisiana. Examination of the viral-host interactions in crayfish can be used to facilitate future investigations towards WSSV prevention and management, and serve to develop the use of P. clarkii to model innate immune responses to WSSV infection in other decapod crustaceans. This is the first study to investigate dose-response and immunological changes induced by the Louisiana strain of WSSV in native crayfish.

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, first chapter presents a brief review of various properties of biomass feedstocks that are critical for gasification. It reviews the thermochemical conversion processes and the major issues related with biomass gasification with reference to some promising gasifier technology systems. Based on literature, second chapter examines the importance of national and sub-national policies supporting the development of bioenergy industry (including gasification for electricity generation) in various countries. The policies and instruments deployed globally are compared with those deployed in India. Third chapter posits a framework for conducting financial evaluation of a gasification power project. A case study of pine needle gasification power project in a remote rural area of Northern India is considered. In absence of historical data related with similar projects, a probability distribution for the Net Present Value (NPV) for the project is generated with the help of Monte Carlo Simulation. The simulation for NPV uses estimates of input variables from the data gathered from an existing pine needle based gasifier operating in the study area. Continuing with the case study, fourth chapter studies the villagers perspective on supplying pine needles to the gasification project. . A survey was administered to estimate villagers willingness to collect pine needles from the forests and supply it at a price to the gasification project. The willingness is modeled on demographic, livelihood, and latent factors, that are used in a Multinomial Logistic Regression Model to estimate the probability of households willingness to collect and supply pine needles to the project.

Methane has a warming potential 28 times that of carbon dioxide and has been increasing in the Earths 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 two salt marsh plant species, Spartina alterniflora and Juncus romerianus via bacterial, archaeal, and fungal gene fragments, and extracellular enzyme assays to determine whether wetland microbial communities were structured by vegetation, and whether communities were functionally different. Bacterial communities were differentiated by plant species in two of three sites, suggesting while vegetation likely plays a role in structuring these communities, specific site characteristics are likely of equal importance. Fungal communities were influenced more by site than vegetation, and archaeal communities appeared to be structured by vegetation. Second, four freshwater wetland plants (Sagittaria lancifolia, Panicum hemitomon, Eleocharis macrostachya, Echinochloa walteri) were transplanted and grown in large mesocosms, and clipped to differing heights under different nutrient treatments to detect changes in methane emissions, methanogen, and methanotroph communities. Methane emission rates were plant species specific, and a three way interaction indicated that species, nutrient level, and clipping level altered methane emission. Methanogen and methanotroph communities were not altered by the treatments. Lastly, densities of marsh periwinkle snails and southern ribbed mussels were manipulated inside fenced enclosures within a S. alterniflora salt marsh, and methane emissions and extracellular enzyme activities were measured over the course of a year. Southern ribbed mussels increased the emission of methane when present, but marsh periwinkle snail density had no effect. The data collected show that microbial community structure in wetlands are influenced by vegetation, that methane emission rates are plant species specific, and that southern ribbed mussels have the potential to increase methane emissions from S. alterniflora marshes.

The wetlands of Louisiana are losing area at the rapid rate of 42.9 km2 yr-1 and the trend is expected to continue. This combined with expected sea-level rise will likely cause large shifts in vegetation and salinity regimes that will affect the wildlife species reliant on these ecosystems. Waterbirds serve as indicator species of ecosystem health in estuarine wetland habitats; therefore, these species are often the targets of wetland management goals in Louisiana. However, many proposed wetland restoration projects are focused primarily on social impacts with only a few specific waterbird species designated for management. The majority of these waterbird habitat-use studies in Louisiana wetlands have focused on waterfowl species and their abundance in wetland habitats during migration and winter. My overall objective was to compare habitat use of all waterbird taxa in fresh and saline estuarine wetland habitats. Additionally, I examined habitat use at finer spatial scales to assess a possible preference for marsh edge microhabitats when compared to open water and interior emergent vegetation. I also investigated waterbird associations with the environmental parameters of emergent and aquatic species composition, percentage of open water, and salinity. From July 2014 to December 2015, I compared waterbird density and species richness both spatially and temporally to assess habitat use. I found that species richness differed between fresh and saline habitats depending on the month, with the month of April having the greatest species richness. Waterbird density was greatest among edge microhabitat regardless of salinity type, and birds utilized this habitat up to 15 m from the edge. Density did not vary in open water plots in relation to salinity type. The relationships between environmental variables and species were significant (p=0.002) as well as relationships between guilds and environmental variables (p=0.002). These data will be useful in attempts to simulate the effects of wetland loss and salinity changes on habitat quality for waterbirds in coastal Louisiana, and will inform habitat restoration and management decisions for optimal waterbird use.

Patterns from hurricane damage give an indication that longleaf pine (Pinus palustris) is more windfirm than loblolly pine (Pinus taeda). Tree windfirmess has been attributed to many factors including species and material properties like wood strength and stiffness. Because longleaf pine wood is stronger and stiffer than loblolly pine wood, this study used static winching methodology to see if these properties account for differences in windfirmness by measuring bending force required to break stems (MMAX). Stress-strain diagrams were constructed for pulled trees to explore how they behave under increasing loads. Based on these diagrams, it appears that living trees can act as linear elastic materials as they experience increasing static lateral stress. As expected, longleaf pine stems were stiffer than loblolly pine wood in situ based on Youngs modulus of elasticity derived from these diagrams. Tree basal area was the best predictor of MMAX for both species, however, species had no effect on the maximum bending moment required to break tree stems of a given basal area for these trees under these conditions. The stiffness of the stems was higher for longleaf than loblolly as indicated by the modulus of elasticity, but the strength of the stems as indicated by the modulus of rupture was not significantly different between the species.

Louisiana leads all U.S. states in blue crab (Callinectes sapidus) landings, but high fuel and bait costs have hindered commercial fishing productivity of Louisiana in recent years. The primary baitfish, Atlantic menhaden (Brevoortia tyrannus), has steadily increased in price and decreased in availability, while crab prices remain low. To reduce costs for fishermen, an alternative bait was developed that incorporates shrimp waste into a semi-rigid alginate matrix. Lab testing and preliminary field tests show that shrimp-alginate bait may be a suitable alternative to menhaden for Louisiana crab fishermen. I evaluated bait performance by conducting field sampling to compare catch rates and longevity of standard baitfish and shrimp-alginate bait. I performed seasonal fishery-independent testing at three sites across Southern Louisiana from summer 2014 to spring 2015, and tested the bait on commercial crabbing boats throughout coastal Louisiana during peak crab season in 2015. Catch rates of shrimp-alginate were less than menhaden overall, however, bait performance changed with site and season, and did not significantly differ when I evaluated commercially relevant crab classes. Analysis of remaining bait quantity after fishing showed that shrimp-alginate remains intact as long, or longer, than standard baitfish during peak crab fishing from June through August. After testing shrimp-alginate bait in the field, I evaluated the economic feasibility of producing the bait with a partial budget supply line. With its current formulation, shrimp-alginate can only be produced at a cost lower than menhaden (currently $0.50/lb.) under optimal production scenarios, however, slight modifications that improve shelf life could dramatically decrease the cost of bait production. Findings from both field work and feasibility analysis show promise in the alternative shrimp-alginate bait with given improvements to catch rate efficacy and product storage.

The Perspectives/Visions/Actions framework is designed to facilitate deeper understanding of issues and broader inclusion of publics in landscape decision-making conversations. A parallel analysis of landscape and policy theory was used to constructed the framework. Common terminology and visual expression of spatial/temporal aspects of landscape are viewed through the interactive segments of Perspectives, Visions, and Actions. Perspectives described through landscape/human relationships and intuitive images of landscape provide insight into various viewpoints. Visions, visual landscape features described in landscape ecology terminology, provide a base for development of potential scenarios. Actions, Tools and Rules, relate viewpoints and scenarios to a range of choices for implementing change. Document content analysis, open-ended interviews, and systematic establishment of a transect baseline from aerial photographs were used to historically analyze three shoreline landscapes (Indiana Dunes National Lakeshore, Cape Cod and Point Reyes National Seashores) through framework language and schematic. Landscape information, viewpoints, and choices within the case study landscapes were uniquely illustrated. Perspectives groupings of intuitive images indicated ovelapping viewpoints and set an inclusive base for landscape information types. Visions landscape ecology language used both to construct the schematic and to translate information into comron expressions provided a base for issue discussion. Actions tools and rules data provided examples of implementation choices which related to the Perspectives and Visions.

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 Agricultural Center Aquaculture Research Station. The development of a standardized and systematic approach to interpretation of ultrasound images emphasized the interplay of technical and biological aspects of ultrasonography assessments. This showed the importance of the control settings and identified disruptive ultrasound artifacts to avoid for observation of the ovary and oocytes. A preliminary ultrasound imaging classification index for assessing ovarian development during the annual reproductive cycle was developed, used and evaluated. This led to the creation of seven well-defined, standardized ultrasound imaging classifications of channel catfish ovarian development based on the annual cycle. Histology of each ultrasound image in the classification index was included as a Reference Guide to provide insight into the processes observed during ultrasonography. Finally, the ultrasound imaging classification index was used for identification and selection of females for hormone-induced spawning in commercial hatchery production of F1 hybrids (channel catfish female x blue catfish male I. furcatus). In sum, this dissertation provides a systematic method of ultrasound imaging assessment of channel catfish ovarian development enabling progress towards standardization in the use of ultrasonography in fish reproduction.

Algal production is often the limiting factor in large-scale oyster hatcheries, and constant, reliable production is required to grow enough algae to support all oyster larvae and broodstock grown and conditioned in a hatchery. The algal rooms in the Michael C. Voisin Oyster Hatchery at Grand Isle, LA are temperature-controlled to maintain consistent temperature, but this hatchery is also unique in its ability to recycle natural seawater pumped from the northern Gulf of Mexico. Effects of recycling seawater on algal production in an oyster hatchery, however, are undocumented. In this study, Tisochrysis lutea, Chaetoceros calcitrans and C. muelleri were grown in different water sources to determine if productivity would be affected by water source. Algae were grown in ambient filtered seawater, recycled filtered seawater, and artificial seawater for a period of 10 days. To evaluate algal production, cell concentrations were measured every other day and dry biomass and growth rate were calculated. Water chemistry (nitrate, phosphate, and silicate concentrations) was measured initially and at ten days. Dry weights and growth were significantly different between species (p=0.0475, p<0.0001), but not water sources. C. muelleri grew the greatest in biomass and the slowest growth rate , followed by C. calcitrans, and T. lutea. Nitrate and phosphates had no significant effects on growth between species, although silicate content was significantly higher in T. lutea. Overall there were no statistically significant effects for the interaction of the three water sources on the growth of these algal species over time (p=0.2882). Although there were no significant differences, algae grown in ambient bay water grew denser and greater biomass than those in recycled bay water or artificial seawater.

The eastern oyster (Crassostrea virginica) and the reefs they create are highly valued for the ecosystem services they provide to coastal estuaries. Recently, their capacity to contribute to nutrient mitigation has spurred interest as researchers have identified 3 mechanisms directly or indirectly associated with oyster reef habitat. This study measured bioassimilation, long-term nutrient burial, and oyster-mediated denitrification in shallow-water (< 1 m water depth) and deep-water (> 1 m water depth) oyster reefs located in two southern Louisiana estuaries. Carbon and nitrogen assimilated into shell and tissue of small (< 75 mm) and large (> 75 mm) oysters was within the range of previous studies but was found to be less influenced by reef type, and more dependent on location specific factors and reproductive status. Post-spawning oysters were found to have higher percent nitrogen content in tissue compared to pre-spawning populations, likely a result of the loss of gametes and increase in feeding related activities during the post-spawn season. Carbon and nitrogen burial rates at oyster reefs ranged from 23.02-57.69 g m-2 yr-1 and 1.09-4.49 g m-2 yr-1 respectively and did not exceed that of other habitat types in Louisiana. However, they were considered to be an important source of nutrient mitigation in these estuaries. Shallow-water reefs buried significantly more nitrogen and carbon, which may be attributed to their proximity to the marsh edge and thus greater influx of detrital material. Closed-system ex-situ incubations revealed some of the highest ever recorded sediment denitrification rates at oyster reefs in the United States (> 1000 µmol m-2 hr-1). However, these values were within the range of those documented in Louisiana coastal systems, and similar to those recorded in nearby reference sediments. Variation in denitrification was found to correspond to site and season, rather than the influence of oyster reef habitat. Because the estuaries in this study are a matrix of reefs and soft bottom sediments, oysters may influence nutrient mitigation outside the boundaries of their active reefs. Thus, bioassimilation, burial, and denitrification may not be localized, but instead may resonate across larger areas as determined by historical reef acreage and hydrodynamics. These are among the first estimates for nutrient mitigation at oyster reefs in Louisiana, and indicate the potential of this ecosystem service in our region. Future research should consider site-specific conditions such as nutrient loading rates, oyster density, and active harvest to accurately quantify this ecosystem service across the coastal region of the state.