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Exploring The Influence Of Diurnal Forcing On Tidal Inlet Exchange And The Impact On The Movement Of Oxygen Depleted Waters In The Mississippi Sound And Bight Region, Courtney Bouchard

Master's Theses

A small yet notable hypoxic event manifests east of the Birdfoot Delta in the Mississippi Sound and Bight (MSAB). The shallow shelf environment of the MSAB is affected by a host of complex physical interactions and separating the influences of each process is difficult to accomplish with in-situ data alone. A physical model using high-resolution atmospheric forcing has been developed which provides insights into the physical interactions in this coastal marine system heavily influenced by freshwater plumes and diurnal wind forcing. Twin experiments using a high temporal (hourly) and spatial (0.01 deg) resolution meteorological analysis product, along with a temporally …

Influence Of Natural And Anthropogenic Environmental Variability On Larval Fish Diet, Growth, And Condition In The Northcentral Gulf Of Mexico, Angie Hoover

Master's Theses

The northern Gulf of Mexico experiences high levels of freshwater runoff annually from various sources including the Mississippi River and Mobile Bay, among other sources. Early life history stages of fishes are especially vulnerable to environmental variability created by freshwater discharge. The objectives of this study were to describe the available prey field, diet, growth and condition of larval fishes with respect to various effects of freshwater discharge in the northern Gulf. The first chapter compared these parameters in larval Gulf Menhaden (Brevoortia patronus) collected from three different water masses characterized by physical and biological parameters after the …

Impacts Of Oil Exposure During Early Life Development Stages In Sheepshead Minnows (Cyprinodon Variegatus) Under Different Environmental Factors, Danielle Simning

Master's Theses

The release of approximately 5 million barrels of crude oil into the northern Gulf of Mexico during the 2010 Deepwater Horizon oil spill jeopardized estuarine ecosystem health from Texas to Florida. These estuarine habitats, which serve as nurseries for many important fisheries are also prone to rapid fluctuations in environmental stressors such as oxygen concentration, and salinity. The consequence of combined exposure to crude oil and suboptimal environmental factors during early life stage development of fish is still largely unknown. The objective of this project was to investigate the impacts of exposure to crude oil in combination with varying environmental …

Combined Effects Of Dissolved Oxygen And Temperature On Aerobic Respiration And Respiratory Recovery Responses Of The Spioniform Polychaete, Streblospio Gynobranchiata, In Relation To Body Size, Alyssa Bennett

Master's Theses

Elevated surface temperatures exacerbate the threat of hypoxia within coastal ecosystems. These two primary stressors likely interact as they elicit opposing physiological responses from marine organisms. Metabolic depression is typically associated with hypoxia, while metabolic rates increase with temperature. Moreover, physiological effects of combined stressors may not be additive. In light of increasing pressures from hypoxia, elevated ocean temperatures, and other stressors within coastal regions, studies need to examine effects of multiple stressors on physiology of coastal organisms.

Mass-specific aerobic respiration (V_O2) was characterized as a proxy for metabolic cost of Streblospio gynobranchiata, at combined levels of …

A Statistical Model For The Prediction Of Dissolved Oxygen Dynamics And The Potential For Hypoxia In The Mississippi Sound And Bight, Andreas Moshogianis

Master's Theses

Hypoxia events occur when dissolved oxygen concentrations fall below the minimum threshold (dissolved oxygen concentrations < 2 mg O₂ L^-1) necessary to avoid respiratory distress among aquatic organisms. In the Mississippi Sound and Bight, hypoxia is most prevalent from late-spring through late summer. Since hypoxia events can have dramatic effects on coastal fisheries, the spatial and temporal magnitude of hypoxia presents a clear threat to the productive fisheries in the northern Gulf of Mexico. Long-term hydrographic data were collected from eight sampling stations on a monthly basis from January 2009 to December 2011 along a cross-shelf transect from the mouth of …