Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 4 of 4
Full-Text Articles in Entire DC Network
Hydrodynamic Modeling Of Newly Emergent Coastal Deltaic Floodplains, Alexandra Christensen
Hydrodynamic Modeling Of Newly Emergent Coastal Deltaic Floodplains, Alexandra Christensen
LSU Master's Theses
Coastal deltaic floodplains provide an important ecosystem service by removing or retaining nitrate from enriched riverine water. Wetland plants, soils, and microbes within these floodplains use nitrate through uptake, burial, and denitrification, thereby reducing the impact of nitrate on algal blooms and hypoxia in the Gulf of Mexico. However, these processes depend on the physical, biological, and chemical conditions within the floodplain. Understanding and characterizing the hydrodynamics of these systems and the relative impact of river, tide, and wind forcings are the first steps in understanding the biogeochemical processes controlling nitrate removal. Motivated by the desire to identify biogeochemical hotspots …
Tropospheric Ozone Prediction With Land Cover Regression In Baton Rouge, Louisiana, Mallory Nance Thomas
Tropospheric Ozone Prediction With Land Cover Regression In Baton Rouge, Louisiana, Mallory Nance Thomas
LSU Master's Theses
Ground level ozone (O3) is a pollutant of great public health concern. Spatial interpolation techniques provide powerful tools in estimating O3 exposure, but many fall short when predicting O3 on complex surfaces, especially given the high local variability typically associated with O3 data. Like most other locations, the Baton Rouge, Louisiana, O3 non-attainment zone (BRNZ) is plagued by a sparse density of O3 monitoring stations. This research explores land use regression (LUR) as an alternative spatial prediction method in and around the BRNZ. Multiple years of data are used to partially compensate for the small sample of spatial points. To …
Living On The Edge: An Assessment Of The Habitat Use Of Waterbirds In Estuarine Wetlands Of Barataria Basin, La, Brett Ashley Patton
Living On The Edge: An Assessment Of The Habitat Use Of Waterbirds In Estuarine Wetlands Of Barataria Basin, La, Brett Ashley Patton
LSU Master's Theses
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 …
Fishes Associated With Oil And Gas Platforms In Louisiana's River-Influenced Nearshore Waters, Ryan Thomas Munnelly
Fishes Associated With Oil And Gas Platforms In Louisiana's River-Influenced Nearshore Waters, Ryan Thomas Munnelly
LSU Master's Theses
A distinctive feature of coastal Louisiana is the unrivaled network of oil and gas installations (platforms) extending from inshore waters to the deep Gulf of Mexico. Since 2007 there has been a 38% reduction in platform numbers with the highest removal rates occurring in shallow (< 18 m) nearshore waters. Many fishes and invertebrates are attracted to platforms, presenting a unique opportunity to study detailed species-specific responses to the river-influenced hydrographic characteristics of Louisiana’s nearshore zone (5–25 km water depth). Prior studies of fishes around platforms focused on a few relatively large platforms in water depths ≥ 18 m. However, about one-third of all platforms are small, unmanned and non-drilling platforms located in waters < 18 m depth. Paired video and hydrographic data were collected at 150 small platforms in < 18 m water depth during the summers of 2013–2014. Fifty-four species of fishes were associated with small platforms. The assemblage(s) included juveniles of 29 species, indicating the importance of nearshore platforms as diverse nursery habitat. The coastal zone was divided into three regions based on broad-scale interactions between freshwater input and bathymetry driving major distinctions in interregional hydrography and fish assemblages. Co-occurring within this expansive artificial reef network is the second largest hypoxic area (dissolved oxygen (DO) < 2.0 mg l−1) on Earth. Platforms offer reef-like habitat features in the upper water column that may offer refugia for some reef-associated species during hypoxic events. Significant intraregional differences in physicochemical features were related to the presence of hypoxia (defined as DO < 50% saturation), as well as the distribution of sandy shoals. Eleven species accounted for most of the assemblage dissimilarities, composing ~93% of fishes observed. Habitat suitability indices for these 11 species provided information about habitat selection across horizontal and vertical physicochemical gradients throughout the coastal zone, and within hypoxic and well-oxygenated stratified water columns. East Bay, near the outlet of the Mississippi River, exhibited less hypoxia and a distinct fauna that included four adult goliath grouper (Epinephelus itajara). This endangered fish was observed during spawning season (summer), suggesting that East Bay might support a spawning aggregation.