Physical Sciences and Mathematics Commons^™

Braving The Elements: Loss Of Metals From Mardi Gras Beads Due To Handling And Weathering, Thomas O. Carmichael, Ruth H. Carmichael

Gulf and Caribbean Research

The largest Mardi Gras celebrations in the U.S. are found along the Gulf of Mexico coast. With increasing awareness of and concern for environmental and human health risks due to pollution from Mardi Gras celebrations, there is a need for studies to quantify potential harms. We conducted a 2—part study to determine whether use—related handling and weathering of common Mardi Gras beaded necklaces results in loss of potentially harmful metals to the environment at levels of ecological or human health concern. Our data indicate that weathering and use—related handling can cause metals to be shed from the metallic coating of …

Growth And Mortality Of American Oysters (Crassostrea Virginica) For Several Years In The Mississippi Sound – Effects Of Freshwater Influence, Taylor Slade

Honors Theses

The American oyster, Crassostrea virginica, is a filter feeding bivalve native to the Gulf of Mexico, and an essential part of the Mississippi Sound estuarine ecosystem. In recent years, influx of freshwater into the Mississippi Sound as a result of frequent rainfall events has altered the water chemistry in several ways that are detrimental to the oyster populations. In this thesis, I examine the growth rate of C. virginica over the last five years in association with salinity fluctuations in the Mississippi Sound. Given diminishing populations and limited recruitment, researchers have facilitated citizen-scientist managed oyster gardens along the coast …

Effects Of Pier Shading On Salt Marsh Plants In Mississippi, Daniel Taylor

Master's Theses

Saltmarshes are important environments that are valuable to both humans and wildlife. As saltmarshes are under threat from erosion, sea level rise, and human development, efforts should be made to conserve them. The vegetation that occupies these environments are vital to the continued preservation of saltmarshes. This study focuses on one potential threat, the effect that pier shading has on prominent saltmarsh plants of Mississippi, Sporobolus alterniflorus and Juncus roemarianus. Sample piers were selected in the three coastal counties of Mississippi and visited at two time periods (2006 and 2021). I focused on the use of irradiance measurements at …

A Comparison Of Natural, Living, And Hardened Shorelines Ability To Prevent Coastal Erosion And Maintain A Healthy Ecosystem, Gabrielle Spellmann

Master's Theses

It is important to find a suitable method to protect the U.S. Gulf Coast shoreline, since its’ low elevation and the Loop current make it vulnerable to sea level rise. I focused on two manmade methods, hardened, and living shorelines, of coastal protection for when the natural marsh suffers excess erosion rates. Living shorelines are a suite of shoreline conservation and restoration techniques that usually involve some sort of hardened structure that dampens wave energy so that the native vegetation behind it can take root and stabilize the shoreline. This study looked at six different sites, all containing a natural, …

Dispersed Crude Oil Induces Dysbiosis In The Red Snapper Lutjanus Campechanus External Microbiota, Andrew M. Tarnecki, Christelle Miller, Tracy A. Sherwood, Robert J. Griffitt, Ryan W. Schloesser, Dana L. Wetzel

Faculty Publications

The fish external microbiota competitively excludes primary pathogens and prevents the proliferation of opportunists. A shift from healthy microbiota composition, known as dysbiosis, may be triggered by environmental stressors and increases host susceptibility to disease. The Deepwater Horizon (DWH) oil spill was a significant stressor event in the Gulf of Mexico. Despite anecdotal reports of skin lesions on fishes following the oil spill, little information is available on the impact of dispersed oil on the fish external microbiota. In this study, juvenile red snapper (Lutjanus campechanus) were exposed to a chemically enhanced water-accommodated fraction (CEWAF) of Corexit 9500/DWH …

Polycyclic Aromatic Hydrocarbons And The Microbiomes Of Two Benthic Species, Samantha Ells

Master's Theses

The presence of oil has been shown to affect the microbiomes of the water column, sediments, and organisms, both by altering the diversity and the composition of those microbial communities. If the microbiome is altered it may no longer provide benefits to its host organism, impacting its ability to survive. Thus, it is important to understand the effects of large-scale contamination events including the Deepwater Horizon oil spill. This study set out to examine the effects of oil exposure on the microbiome of two benthic species, southern flounder (Paralichthys lethostigma) and eastern oysters (Crassostrea virginica) to further understand the effects …

Hurricane Disturbance Stimulated Nitrification And Altered Ammonia Oxidizer Community Structure In Lake Okeechobee And St. Lucie Estuary (Florida), Justyna J. Hampel, Mark J. Mccarthy, Sanni L. Aalto, Silvia E. Newell

Faculty Publications

© Copyright © 2020 Hampel, McCarthy, Aalto and Newell. Nitrification is an important biological link between oxidized and reduced forms of nitrogen (N). The efficiency of nitrification plays a key role in mitigating excess N in eutrophic systems, including those with cyanobacterial harmful algal blooms (cyanoHABs), since it can be closely coupled with denitrification and removal of excess N. Recent work suggests that competition for ammonium (NH₄⁺) between ammonia oxidizers and cyanoHABs can help determine microbial community structure. Nitrification rates and ammonia-oxidizing archaeal (AOA) and bacterial (AOB) community composition and gene abundances were quantified in Lake Okeechobee …

Deep Sea Biofilms, Historic Shipwreck Preservation And The Deepwater Horizon Spill, Rachel L. Mugge, Melissa L. Brock, Jennifer L. Salerno, Melanie Damour, Robert A. Church, Jason Lee, Leila J. Hamdan

Faculty Publications

Exposure to oil from the Deepwater Horizon spill may have lasting impacts on preservation of historic shipwrecks in the Gulf of Mexico. Submerged steel structures, including shipwrecks, serve as artificial reefs and become hotspots of biodiversity in the deep-sea. Marine biofilms on submerged structures support settlement of micro- and macrobiota and may enhance and protect against corrosion. Disruptions in the local environment, including oil spills, may impact the role that biofilms play in reef preservation. To determine how the Deepwater Horizon spill potentially impacted shipwreck biofilms and the functional roles of the biofilm microbiome, experiments containing carbon steels disks (CSDs) …

Water Quality Trends Following Anomalous Phosphorus Inputs To Grand Bay, Mississippi, Usa, Marcus W. Beck, Kimberly Cressman, Cher Griffin, Jane Caffrey

Gulf and Caribbean Research

Grand Bay National Estuarine Research Reserve (GBNERR) is a 7500 ha protected area in Jackson County, MS. In 2005, a levee breach at a fertilizer manufacturing facility released highly acidic and phosphate—rich wastewater into the reserve. A second spill occurred in September 2012 following Hurricane Isaac. We used orthophosphate (PO₄^3-) concentrations to categorize the 2 events, post— events, and non—impact periods between the 2 spills. We examined spatial and temporal patterns in nutrients, chlorophyll, pH, and other parameters within and between monitoring stations. After the first event, pH at the Bangs Lake water quality station decreased to …

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 …

Effects Of Temperature On Growth And Molting In Blue Crabs (Callinectes Sapidus) And Lesser Blue Crabs (Callinectes Similis), Abigail Ann Kuhn

Master's Theses

Temperature can exert impacts on many processes in ectotherms. With global temperatures rising due to climate change, many ectothermic species may exhibit changes in growth rates and size at maturity, and these changes can have population-level effects. Predicting responses of species to climate change will require not only knowledge of thermal tolerance limits, but also effects of temperature change on growth rates and other life history parameters. For arthropods that exhibit discontinuous growth (i.e., molting), this includes both intermolt period and growth per molt. Previous laboratory and field experiments suggest that temperature affects both intermolt period (IMP) and growth per …

Modern Fair-Weather And Storm Sediment Transport Around Ship Island, Mississippi: Implications For Coastal Habitats And Restoration Efforts, Eve Rettew Eisemann

Master's Theses

The Mississippi – Alabama barrier island chain is experiencing accelerated sea level rise, decreased sediment supply, and frequent hurricane impacts. These three factors drive unprecedented rates of morphology change and ecosystem reduction. All islands in the chain have experienced land loss on the order of hectares per year since records began in the 1840s. In 1969, Hurricane Camille impacted as a Category 5, breaching Ship Island, and significantly reduced viable seagrass habitat. Hurricane Katrina impacted as a Category 3 in 2005, further widening Camille Cut. To better understand the sustainability of these important islands and the ecosystems they support, sediment …

Sustained Deposition Of Contaminants From The Deepwater Horizon Spill, Beizhan Yan, Uta Passow, Jeffrey P. Chanton, Eva-Maria Nöthig, Vernon Asper, Julia Sweet, Masha Pitiranggon, Arne Diercks, Dorothy Pak

Faculty Publications

The 2010 Deepwater Horizon oil spill resulted in 1.6–2.6 × 10¹⁰ grams of petrocarbon accumulation on the seafloor. Data from a deep sediment trap, deployed 7.4 km SW of the well between August 2010 and October 2011, disclose that the sinking of spill-associated substances, mediated by marine particles, especially phytoplankton, continued at least 5 mo following the capping of the well. In August/September 2010, an exceptionally large diatom bloom sedimentation event coincided with elevated sinking rates of oil-derived hydrocarbons, black carbon, and two key components of drilling mud, barium and olefins. Barium remained in the water column for months …

Macrobenthic Communities In The Northern Gulf Of Mexico Hypoxic Zone: Testing The Pearson-Rosenberg Model, Shivakumar Shivarudrappa

Dissertations

The Pearson and Rosenberg (P-R) conceptual model of macrobenthic succession was used to assess the impact of hypoxia (dissolved oxygen [DO] ≤ 2 mg/L) on the macrobenthic community on the continental shelf of northern Gulf of Mexico for the first time. The model uses a stress-response relationship between environmental parameters and the macrobenthic community to determine the ecological condition of the benthic habitat. The ecological significance of dissolved oxygen in a benthic habitat is well understood. In addition, the annual recurrence of bottom-water hypoxia on the Louisiana/Texas shelf during summer months is well documented.

The P-R model illustrates the decreasing …

Recreation Ecology Of Colorado Fourteeners: An Assessment Of Trail Usage And Impacts, James C. Ewing

Master's Theses

The popularity of climbing Colorado’s 14,000 ft. peaks, or “Fourteeners”, has risen dramatically in recent years, raising important sustainability and management questions. Moreover, groups managing the peaks operate with major capital constraints so their efforts need to be informed, prioritized, and efficient. This paper gauges the dynamics of trail usage, explanatory variables, and recreational impacts across all 58 Fourteeners, and details evaluation adjustments that minimize error and produce results in-step with the resource management framework. Relative to a baseline study completed in 2005, substantial changes occurred in trail usage and impact dynamics. The greatest changes were concentrated on peaks previously …

Fluctuating Asymmetry In Menidia Beryllina Before And After The 2010 Deepwater Horizon Oil Spill, Savannah A. Michaelsen, Jacob F. Schaefer, Mark S. Peterson

Faculty Publications

Assessing the impacts of the Deepwater Horizon oil spill with a dependable baseline comparison can provide reliable insight into environmental stressors on organisms that were potentially affected by the spill. Fluctuating asymmetry (small, non-random deviations from perfect bilateral symmetry) is an informative metric sensitive to contaminants that can be used to assess environmental stress levels. For this study, the well-studied and common Gulf of Mexico estuarine fish, Menidia beryllina, was used with pre and post-oil spill collections. Comparisons of fluctuating asymmetry in three traits (eye diameter, pectoral fin length, and pelvic fin length) were made pre and post-oil spill …

A Geographical Approach For Integrating Belief Networks And Geographic Information Sciences To Probabilistically Predict River Depth, Nathan Lee Hopper

Dissertations

Geography is, traditionally, a discipline dedicated to answering complex spatial questions. Although spatial statistical techniques, such as weighted regressions and weighted overlay analyses, are commonplace within geographical sciences, probabilistic reasoning, and uncertainty analyses are not typical. For example, belief networks are statistically robust and computationally powerful, but are not strongly integrated into geographic information systems. This is one of the reasons that belief networks have not been more widely utilized within the environmental sciences community. Geography’s traditional method of delivering information through maps provides a mechanism for conveying probabilities and uncertainties to decision makers in a clear, concise manner. This …

Evolution Of The Optical Properties Of Seawater Influenced By The Deepwater Horizon Oil Spill In The Gulf Of Mexico, Zhengzhen Zhou, Laodong Guo

Faculty Publications

The fluorescence excitation-emission matrix (EEM) technique coupled with parallel factor (PARAFAC) modeling and measurements of bulk organic carbon and other optical properties were used to characterize the oil components released from the Deepwater Horizon oil spill in the Gulf of Mexico and to examine the chemical evolution and transformation of oil in the water column. Seawater samples were collected from the Gulf of Mexico during October 2010 and October 2011, three months and fifteen months, respectively, after the oil spill was stopped. Together with previous results from samples collected during the oil spill in May/June 2010, these time series samples …

The Weathering Of Oil After The Deepwater Horizon Oil Spill: Insights From The Chemical Composition Of The Oil From The Sea Surface, Salt Marshes And Sediments, Zhanfei Liu, Jiqing Liu, Qingzhi Zhu, Wei Wu

Faculty Publications

The oil released during the Deepwater Horizon (DWH) oil spill may have both short- and long-time impacts on the northern Gulf of Mexico ecosystems. An understanding of how the composition and concentration of the oil are altered by weathering, including chemical, physical and biological processes, is needed to evaluate the oil toxicity and impact on the ecosystem in the northern Gulf of Mexico. This study examined petroleum hydrocarbons in oil mousse collected from the sea surface and salt marshes, and in oil deposited in sediments adjacent to the wellhead after the DWH oil spill. Oil mousses were collected …