Oceanography and Atmospheric Sciences and Meteorology Commons^™

The Variability Of High-Frequency Motions And Their Interactions With The Mesoscale On The Mississippi Shelf, Jordan Earls

Master's Theses

In this study, we examine the spatial and temporal variability of high-frequency and low-frequency motions across the Mississippi Shelf and how the high-frequency motions are modulated by low-frequency mesoscale motions. For this purpose, we use Acoustic Doppler Current Profiler (ADCP) measurements collected at nearshore (23 m), mid-shelf (60 m), and shelf break (88 m) stations. High-frequency motions are defined as motions with periods less than 36 hours, whereas mesoscale motions have larger periods. The collected datasets are analyzed through bandpass filtering, least square harmonic analysis, spectral analysis, and empirical orthogonal functions (EOF). We find that along-shelf barotropic mesoscale motions contain …

Dna Barcoding Reveals Unexpected Diversity In Octocorallia In The Northwestern Gulf Of Mexico, Chelsea L. Pavliska

Theses and Dissertations

Coral reefs are an integral tier of marine ecosystems. They provide habitat and foraging opportunities for many ecologically and economically important fishes. Protection of coral reef biodiversity and connectivity is imperative to the continued health and sustainability of marine fisheries. Mesophotic reefs, such as those found in the northwest Gulf of Mexico, have unique coral communities because of the limited light penetration at mesophotic depths (30 – 150m). Because there is limited knowledge in regards to the biodiversity of coral reefs of the northwestern Gulf of Mexico (GOM), particularly the South Texas Banks (STBs), thesis work presented here aims to …

Use Of Spectrofluorometry To Detect Petroleum Hydrocarbons In The Marine Environment, Mary Iris Abercrombie

USF Tampa Graduate Theses and Dissertations

The genesis of this research was the Deepwater Horizon oil spill, which discharged petroleum and gas into the Gulf of Mexico for 87 days in 2010. High-resolution fluorescence spectroscopy was employed for the detection of petroleum in seawater samples following the oil spill. Fluorescence arises from the chemical structure of π-bonding in C=C bonds, especially those in aromatic structures. Spectrofluorometry was also used to observe and track the formation of petroleum plumes in seawater undergoing controlled physical dispersion in a wave tank, both with and without the addition of chemical dispersant. Further, the changing fluorescence characteristics of a broad range …

Shallow- Water Hardbottom Communities Support The Separation Of Biogeographic Provinces On The West- Central Florida Gulf Coast, Shelby Eagan

HCNSO Student Theses and Dissertations

Several studies have found separation of biogeographic provinces on the West Florida Shelf (WFS), but the location of this separation differs depending on different organisms with faunal boundaries proposed at Apalachicola, Cedar Key, Anclote Key. Tampa Bay, Charlotte Harbor, Cape Romano, or Cape Sable. Biogeographic boundaries can be gradual over a given space and are often species-specific. Analyses of marine benthic mapping and community characterization of Florida’s West-central coast shallow water (depth) hardbottom habitats indicate a major shift in the benthos across Tampa Bay. Quantitative benthic surveys of 29 sites yielded a total of 4,079 individuals of nine stony coral …

Regeneration Of Trace Metals During Phytoplankton Decay: An Experimental Study, Adrienne P. Hollister

USF Tampa Graduate Theses and Dissertations

Trace metals act as important nutrients, and sometimes toxins, to phytoplankton and other marine microorganisms. When phytoplankton decay, the elements in their cells are released back into the water column through regeneration (also referred to as remineralization), one of the processes responsible for governing concentrations of dissolved trace metals and macronutrients in depth profiles. In order to experimentally study regeneration, controlled experimental incubations of mixed phytoplankton assemblages from the Gulf of Mexico (GoM) and monocultures of the diatom Pseudo-nitzschia dolorosa and the dinoflagellate Karenia brevis were placed in the dark and monitored as they decayed with naturally present bacteria. Over …

Vertical Marine Snow Distribution In The Stratified Hypersaline, And Anoxic Orca Basin (Gulf Of Mexico), Arne Diercks, Kai Ziervogel, Ryan Sibert, Samantha B. Joye, Vernon Asper

Faculty Publications

We present a complete description of the depth distribution of marine snow in Orca Basin (Gulf of Mexico), from sea surface through the pycnocline to within 10 m of the seafloor. Orca Basin is an intriguing location for studying marine snow because of its unique geological and hydrographic setting: the deepest ~200 m of the basin are filled with anoxic hypersaline brine. A typical deep ocean profile of marine snow distribution was observed from the sea surface to the pycnocline, namely a surface maximum in total particle number and midwater minimum. However, instead of a nepheloid (particle-rich) layer positioned near …

Empirical Validation And Comparison Of The Hybrid Coordinate Ocean Model (Hycom) Between The Gulf Of Mexico And The Tongue Of The Ocean, Cynthia A. Cleveland

HCNSO Student Theses and Dissertations

Ocean models are increasingly able to synthesize a large temporal domain with fine spatial resolution. With this increase in functionality and availability, ocean models are in high demand by researchers, establishing a critical need for validating a model’s ability to represent interior ocean dynamics. Satellite measurements are typically used for validation, however these measurements are limited to the upper layers of the ocean and therefore satellite measurements of sea surface height and sea surface temperature are the most validated output parameters of three-dimensional ocean models. Unfortunately there is a paucity of model validation studies for the interior ocean. This study …

Marine Threats Overlap Key Foraging Habitat For Two Imperiled Sea Turtle Species In The Gulf Of Mexico, Kristen M. Hart, Autumn R. Iverson, Ikuko Fujisaki, Margaret M. Lamont, David Bucklin, Donna J. Shaver

United States Geological Survey: Staff Publications

Effective management of human activities affecting listed species requires understanding both threats and animal habitat-use patterns. However, the extent of spatial overlap between high-use foraging areas (where multiple marine species congregate) and anthropogenic threats is not well-known. Our modeling approach incorporates data on sea turtle spatial ecology and a suite of threats in the Gulf of Mexico to identify and map “hot spots” of threats to two imperiled turtle species. Of all 820 “high” threats grid cells, our tracked turtles foraged at least 1 day in 77% of them. Although threat data were not available outside the U.S. Exclusive Economic …

Geotraces And Beyond: Studies Of Trace Elements In Coastal And Open Ocean Waters With An Emphasis On The Effects Of Oxygen Depletion And Hydrothermal Plumes, Peng Ho

Dissertations

We investigated various dissolved trace element (dTE) distributions in two distinct areas: the coastal northern Gulf of Mexico and the eastern tropical Pacific Ocean.

A multi-year (2007‒2011) chemical time series of eight stations in the western Mississippi Sound (MS) and northwestern Mississippi Bight (MB) was undertaken to examine the factors affecting chemical distributions in this dynamic region. Key findings include the frequent development of bottom water hypoxia in MB during late spring-summer, the likely contribution of submarine groundwater discharge (SGD) to the material flows, and observation of effects of episodic events including tropical storms and the opening of the Bonnet …

The Feasibility Of Using Inherent Optical Properties And The Apparent Optical Property Remote Sensing Reflectance To Estimate Suspended Particulate Matter, Particularly For Use In Airborne Hydrographic Surveys, Sarah Epps

Dissertations

Airborne hydrographic surveys are routinely used to create and update nautical charts around the world. This research is intended to assist in maximizing the utility of the data products made available from those surveys in accordance with the current survey–once, use–many–times initiatives. Specifically, this project evaluates the feasibility of using the data available airborne hydrographic systems that utilize bathymetric lasers and hyperspectral sensors to estimate the concentration of suspended particulate matter (SPM). SPM is sometimes also called suspended sediment. The ability to chart spatial distributions of SPM utilizing hydrographic survey systems already in operation will assist researchers, managers, and stakeholders …

Spatial And Temporal Distributions Of Pelagic Sargassum In The Intra-Americas Sea And Atlantic Ocean, Mengqiu Wang

USF Tampa Graduate Theses and Dissertations

Pelagic Sargassum is one type of marine macroalgae that is known to be abundant in the Gulf of Mexico and Sargasso Sea. It is also known to serve as a critical habitat for many marine animals. In the past few years, large amounts of Sargassum have been reported in the Tropical Atlantic and Caribbean Sea (CS), causing significant environmental and economic problems. The goal of this study is to improve the understanding of Sargassum distributions, quantity, transport pathways, and bloom mechanisms in the CS and Tropic Atlantic through combining a variety of techniques including satellite remote sensing, field and laboratory …

Madden-Julian Oscillation Relationships With Cool Season Cyclogenesis, Daily Precipitation, And Cool Season Severe Weather Frequencies In The Gulf Of Mexico Region, Stephen Paul Caparotta

LSU Doctoral Dissertations

Tropical cyclone variability in the Gulf of Mexico (GoM) has been the focus of a considerable amount of research. Variability on both interannual scales, related to the El Niño-Southern Oscillation (ENSO), and on subseasonal scales, related to the Madden-Julian Oscillation (MJO), is well documented. By contrast, very little research exists on the relationships between the MJO and cool season, non-tropical cyclones in the GoM.

The MJO influence on cool season (October-March) cyclogenesis in the GoM variability is explored here. Additionally, daily precipitation variability and cool season severe weather variability is examined for areas near and just inland of the GoM. …

Isotopic Composition Of Sinking Particles: Oil Effects, Recovery And Baselines In The Gulf Of Mexico, 2010-2015, Jeff Chanton, Sarah L.C. Giering, Samantha H. Bosman, Kelsey L. Rogers, Julia Sweet, Vernon Asper, Arne-R. Diercks, Uta Passow

Faculty Publications

The extensive release of oil during the 2010 Deepwater Horizon spill in the northern Gulf of Mexico perturbed the pelagic ecosystem and associated sinking material. To gauge the recovery and post-spill baseline sources, we measured D14C, d13C and d34S of sinking particles near the spill site and at a reference site and natural seep site. Particulates were collected August 2010–April 2016 in sediment traps moored at sites with depths of 1160–1660 m. Near the spill site, changes in D14C indicated a 3-year recovery period, while d34S indicated 1–2 years, which agreed with estimates of 1–2 years based on hydrocarbon composition. …

A Novel Multiproxy Approach To Reconstructing Sea Surface Temperature In The Southwestern Gulf Of Mexico, Marissa Anne Vara

LSU Master's Theses

Coral Sr/Ca is a widely-used proxy for sea surface temperature (SST); however, discrepancies in the coral Sr/Ca-SST relationship among colonies of the same species makes uncertainty in absolute temperature reconstructions larger than the climate signal yet climate variability studies are possible. Furthermore, the riverine input of terrestrial carbonate weathering products to the coastal waters can disrupt the coral Sr/Ca-SST signal by changing local seawater chemistry. This study evaluates the fidelity and reproducibly of coral SST proxies (Sr/Ca, Li/Ca, Mg/Li, Sr-U, Mg/Ca, and U/Ca) and a riverine-upwelling proxy (Ba/Ca) in four Orbicella faveolata colonies in two reefs offshore from Veracruz, Mexico …

Concorde Meteorological Analysis (Cma) - Data Guide, Patrick Fitzpatrick, Yee H. Lau

Faculty Publications

CONCORDE is the CONsortium for oil spill exposure pathways in COastal River-Dominated Ecosystems (CONCORDE), and is an interdisciplinary research program funded by the Gulf of Mexico Research Initiative (GoMRI) to conduct scientific studies of the impacts of oil, dispersed oil and dispersant on the Gulf’s ecosystem (Greer et al. 2018). A CONCORDE goal is to implement a synthesis model containing circulation and biogeochemistry components of the Northern Gulf of Mexico shelf system which can ultimately aid in prediction of oil spill transport and impacts.

The CONCORDE Meteorological Analysis (CMA) is an hourly gridded NetCDF dataset which provides atmospheric forcing for …

The Ecosystem Baseline For Particle Flux In The Northern Gulf Of Mexico, S.L.C. Giering, Beizhan Yan, Vernon Asper, Arne-R. Diercks, Jeff Chanton, Masha Pitiranggon, U. Passow

Faculty Publications

Response management and damage assessment during and after environmental disasters such as the Deepwater Horizon (DWH) oil spill require an ecological baseline and a solid understanding of the main drivers of the ecosystem. During the DWH event, a large fraction of the spilled oil was transported to depth via sinking marine snow, a routing of spilled oil unexpected to emergency response planners. Because baseline knowledge of particle export in the Northern Gulf of Mexico and how it varies spatially and temporally was limited, we conducted a detailed assessment of the potential drivers of deep (~1400 m depth) particle fluxes during …

Ecological And Oceanographic Influences On Leatherback Turtle Behavior And Scyphozoan Jellyfish Distributions In The Gulf Of Mexico, Katrina Aleksa

Dissertations

Leatherback turtles (Dermochelys coriacea) are a wide-ranging, oceanic species that feed exclusively on gelatinous zooplankton. Leatherback have been spotted in the Gulf of Mexico (GoM) for several decades and consistently had a high level of interactions with longline fisheries. However, no quantitative studies have been performed to address the spatiotemporal distribution of these turtles in the GoM. This research determines 1) leatherback movements and high-use areas in the GoM, 2) their association with oceanographic features, 3) the distribution and density of two abundant medusae in the northern GoM and any association with biophysical parameters, and 4) the body …

Genetic Identification And Population Characteristics Of Deep-Sea Cephalopod Species In The Gulf Of Mexico And Northwestern Atlantic Ocean, Amanda Sosnowski

USF Tampa Graduate Theses and Dissertations

Nearly all deep-sea cephalopod life history studies have been completed by examination of specimens collected in the wild. Much of this work is like piecing together a puzzle; knowledge of the life history of many species remains fragmented and hence, taxonomically and phylogenetically confused. Molecular approaches and sequencing technologies are powerful tools for deciphering wild-type cephalopod life history and population dynamics. Use of molecular markers offers additional certainty for identifying specimens damaged during deep-sea collections and can elucidate often cryptic, intra- and interspecific diversity. The research presented in this study assessed broad genetic patterns of biodiversity in deep-sea cephalopods from …

Environmentally-Driven Variation In The Population Dynamics Of Gulf Menhaden (Brevoortia Patronus), Grant D. Adams

Master's Theses

Gulf Menhaden (Brevoortia patronus) is an abundant forage fish distributed throughout the Northern Gulf of Mexico (NGOM). Gulf Menhaden support the second largest fishery, by weight, in the United States and represent a key linkage between upper and lower trophic levels. Variation in the population dynamics can, therefore, pose consequences for the ecology and economy in the NGOM. Here we aim to understand variation in the individual and population dynamics of Gulf Menhaden throughout ontogeny and how such variation relates to environmental processes. We utilized a suite of fishery-dependent and –independent, remote sensing, modeled, and in situ data …

Loop Current Spin-Off Eddies, Slope Currents And Dispersal Of Reef Fish Larvae From The Flower Gardens National Marine Sanctuary And The Florida Middle Grounds, Donald R. Johnson, Harriet Perry, Guillermo Sanchez-Rubio, Mark A. Grace

Gulf and Caribbean Research

Large energetic spin—off eddies from Loop Current intrusions into the Gulf of Mexico play a major role in water exchange between the continental shelf and the deep basin in the northern Gulf. Reef fish larvae, spawned on the outer shelf and planktonic during their early life history, are broadly dispersed by this mechanism, but may be lost to the cohort by transport away from suitable settlement habitat. In this study, satellite altimeter data—assimilative ocean model currents (HYCOM) from 2003—2015 are used to calculate kinetic energy of the mixed layer over the upper continental slope (200 m —1000 m) due to …

Sediment Transport And Slope Stability In The Northern Gulf Of Mexico, Jeffrey Blake Obelcz

LSU Doctoral Dissertations

Sediment transport and slope stability are fundamental organizing agents of the geological record. These processes have been extensively studied along the northern margin of the Gulf of Mexico basin for both basic and applied purposes, but our knowledge of them is limited by the spatial and temporal sampling capabilities of traditional geologic oceanographic surveying tools such as coring, single-beam echosounders, and sidescan sonar. This dissertation seeks to update the state of knowledge regarding northern Gulf of Mexico sediment transport and slope stability from annual to millennial timescales, primarily using relatively high-resolution acoustic geophysical tools such as swath bathymetric echosounders and …

The Vertical And Horizontal Distribution Of Deep-Sea Crustaceans Of The Order Euphausiacea (Malacostraca: Eucarida) From The Northern Gulf Of Mexico With Notes On Reproductive Seasonality., Charles Douglas Fine

HCNSO Student Theses and Dissertations

The vertical and horizontal distributions of Euphausiacea in the northern Gulf of Mexico, including the location of the Deepwater Horizon oil spill, were analyzed from 340 trawl samples collected between April-June, 2011. This study is the first comprehensive survey of euphausiid distributions from depths deeper than 1000 m in the Gulf of Mexico and included stratified sampling from five discrete depth ranges (0-200 m, 200-600 m, 600-1000 m, 1000-1200 m, and 1200-1500 m). In addition, this study encompasses the region heavily impacted by the Deepwater Horizon oil spill. Data presented here could potentially be used in ecosystem models investigating trophic …

Using Proxy Records To Document Gulf Of Mexico Tropical Cyclones From 1820-1915, Jordan V. Pino, Robert V. Rohli, Kristine L. Delong, Grant L. Harley, Jill C. Trepanier

Faculty Publications

Observations of pre-1950 tropical cyclones are sparse due to observational limitations; therefore, the hurricane database HURDAT2 (1851–present) maintained by the National Oceanic and Atmospheric Administration may be incomplete. Here we provide additional documentation for HURDAT2 from historical United States Army fort records (1820–1915) and other archived documents for 28 landfalling tropical cyclones, 20 of which are included in HURDAT2, along the northern Gulf of Mexico coast. One event that occurred in May 1863 is not currently documented in the HURDAT2 database but has been noted in other studies. We identify seven tropical cyclones that occurred before 1851, three of which …

Determining The Viability Of Recent Storms As Modern Analogues For North-Central Gulf Of Mexico Paleotempestology Through Sedimentary Analysis And Storm Surge Reconstruction, Joshua Caleb Bregy

Master's Theses

The northern Gulf of Mexico has been devastated by recent intense storms. Camille (1969) and Katrina (2005) are two notable hurricanes that made landfall in virtually the same location in Mississippi. However, fully understanding the risks and processes associated with hurricane impacts is impeded by a short and fragmented instrumental record. Paleotempestology could potentially use modern analogues from intense storms in this region to extend the hurricane record back to pre-observational time. Existing empirically based models can back-calculate surge heights over coastal systems as a function of transport distance, particle settling velocity, and gravitational acceleration. We collected cores in a …

Benthic Fluxes Of Dissolved Organic Carbon From Gas Hydrate Sediments In The Northern South China Sea, Chia Wei Hung, Kuo Hao Huang, Yung Yen Shih, Yu Shih Lin, Hsin Hung Chen, Chau Chang Wang, Chuang Yi Ho, Chin Chang Hung, David J. Burdige

OES Faculty Publications

Hydrocarbon vents have recently been reported to contribute considerable amounts of dissolved organic carbon (DOC) to the oceans. Many such hydrocarbon vents widely exist in the northern South China Sea (NSCS). To investigate if these hydrocarbon vent sites release DOC, we used a real-time video multiple-corer to collect bottom seawater and surface sediments at vent sites. We analyzed concentrations of DOC in these samples and estimated DOC fluxes. Elevated DOC concentrations in the porewaters were found at some sites suggesting that DOC may come from these hydrocarbon vents. Benthic fluxes of DOC from these sediments were 28 to 1264 µmol …

The Effect Of Artificial Light On The Community Structure And Distribution Of Reef-Associated Fishes At Oil And Gas Platforms In The Northern Gulf Of Mexico, Victoria Anne Barker

LSU Master's Theses

The northern Gulf of Mexico (GOM) contains approximately 2,500 oil and gas platforms, resulting in one of the largest de facto artificial reef systems in the world. As of 2013, 1,227 additional structures had ceased to produce oil and gas and have been decommissioned and removed. While active platforms are lit by high-pressure mercury vapor lights, inactive platforms are only minimally lit for navigation. The positively phototaxic behavior of many fish species causes lit oil platforms to act as fish attraction devices, especially at night. Though a variety of fish species have been reported near these structures, changes in fish …

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 …

Ecology, Population Dynamics, And Sexual Characteristics Of Commensal Leucothoid Amphipods With The Sponge Cliona Varians In The Florida Keys (Crustacea: Amphipoda), Stephanie Lynn Andringa

HCNSO Student Theses and Dissertations

Recent observations have identified a new species of leucothoid amphipod, Leucothoe “sp. F,” associated with the sponge Cliona varians. This project examined the relationship between this amphipod and its sponge host at three sites in the Florida Keys with differing hydrodynamic regimes. Ninety-eight sponge samples with a total of 2,030 amphipods were collected between December 2011 and September 2012. Leucothoe “sp. F” is currently a common species in the Florida Keys strongly associated with C. varians; its distribution strongly coincides with open tidal currents from the Gulf of Mexico. Seasonality, depth, and tidal regimes not only influence population …

Polycyclic Aromatic Hydrocarbons Dynamics In The Northern Gulf Of Mexico, Puspa Lal Adhikari

LSU Doctoral Dissertations

Polycyclic aromatic hydrocarbons (PAHs) are introduced into the marine environment via oil seeps/spills, riverine discharges, continental runoff, coastal erosion, and atmospheric deposition. An estimated 2.1 x 1010g of PAHs entered into the northern Gulf of Mexico (GOM) during the Deepwater Horizon (DWH) oil spill in 2010. It became evident following the oil spill that accurate quantification of ultimate fate of these potentially carcinogenic and/or mutagenic organic pollutants is extremely challenging. In general, very little is known about PAHs fate, distribution and accumulation in the open ocean ecosystems. This study determines the upper ocean vertical fluxes and sedimentary PAHs accumulation rates …

Otoliths Then And Now: A Study Of Ancient And Modern Fish Populations In Louisiana's Coastal Waters, Marshall James Kormanec

LSU Master's Theses

Fish otoliths are composed of inorganic calcium carbonate that aid in gravity and auditory reception. Substances permanently accrete to otolith surfaces in distinct temporal patterns of alternating opaque and translucent rings; these rings are direct proxies for a fish’s age. The objective of my research is to demonstrate how otoliths can be used through time and space to estimate both age and growth of fish. I investigated the spatial differences in age distributions and growth models for red snapper, Lutjanus campechanus, at four natural shelf-edge reefs in the northwestern Gulf of Mexico. Red snapper cohorts ranged 1987-2010 cohorts, with the …