Life Sciences Commons^™

Seagrass Epibiont Biodiversity In The Northern Gulf Of Mexico, Kathryn Wyssmann

University of New Orleans Theses and Dissertations

Epibionts on seagrass leaves contribute substantially to productivity and trophic interactions in seagrass ecosystems. Differences in epibiont assemblages and factors that contribute to epibiont diversity have been little studied on the seagrass Halodule wrightii in the northern Gulf of Mexico (nGoM). We used a metabarcoding approach to describe epibiont assemblages on H. wrightii leaves in four bays across the nGoM and to test whether epibiont assemblages differed spatially at local levels (within bays) or regional levels (from west to east). Furthermore, we tested if epibiont diversity was related to environmental conditions and/or seagrass productivity. Epibiont assemblages differed significantly between bays …

Morphological And Transcriptional Effects Of Crude Oil And Dispersant Exposure On The Marine Sponge Cinachyrella Alloclada, Yvain Desplat, Jacob F. Warner, Emily J. Blake, Nidhi Vijayan, Marie Cuvelier, Patricia Blackwelder, Jose V. Lopez

Biology Faculty Articles

Marine sponges play important roles in benthic ecosystems. More than providing shelter and food to other species, they help maintain water quality by regulating nitrogen and ammonium levels in the water, and bioaccumulate heavy metals. This system, however, is particularly sensitive to sudden environmental changes including catastrophic pollution event such as oil spills. Hundreds of oil platforms are currently actively extracting oil and gas in the Gulf of Mexico. To test the vulnerability of the benthic ecosystems to oil spills, we utilized the Caribbean reef sponge, Cinachyrella alloclada, as a novel experimental indicator. We have exposed organisms to crude …

Can Larvae Of A Deep-Sea Gastropod, Thalassonerita Naticoidea, Swim To The Surface To Find Food In The Gulf Of Mexico?, Mitchell Hebner

WWU Graduate School Collection

For larvae of benthic organisms living in the deep-sea, the location where they begin their dispersal influences their vector of travel because ocean currents affect larval dispersal when the larvae are in the water column during a possible vertical migration. The deep-sea is food-poor when compared to the food-rich surface waters, but planktotrophic (feeding) larval development of deep-sea benthic organisms is common. Despite the potential need for planktotrophic larvae of deep-sea organisms to access more nutrient-rich food sources and knowing a larva’s position in the water column can impact larval transport, we have very little understanding of where in the …

Investigating Local Adaptation To Hypoxia Stress In The Eastern Oyster Through Comparative Transcriptomics, Heather Nichole Smith

LSU Master's Theses

Climate change represents one of the most important challenges to biodiversity, therefore it is important to understand the mechanisms that allow species to respond to rapid environmental change. Here, we compared two populations of eastern oysters, Crassostrea virginica, from the Gulf of Mexico to study the mechanisms underlying hypoxia tolerance. Using a common garden experiment and comparative transcriptomics, we identified sets of genes involved in the hypoxia response and found differences in both the timing and baseline expression of hypoxia-responsive genes between tolerant and sensitive populations, consistent with a scenario of local adaptation. These genes include the signaling transcription factor …

Applications And Mechanisms Of Near Infrared Spectroscopy For Age Estimation In Otoliths Of Red Snapper Lutjanus Campechanus, Michelle S. Passerotti

Theses and Dissertations

Near infrared spectroscopy (NIRS) is a light spectroscopy method useful for non-invasively discriminating and quantifying chemical composition of a wide variety of substances. Recently-developed applications of NIRS to fish age estimation across a range of taxa have sparked intense interest in exploring the feasibility of its use for rapid age estimation in fisheries population management. In this pursuit, development of species-specific calibration models relating traditionally-derived age estimates (i.e., those estimated from growth band counts) to NIR spectral signatures from ageing structures is required to derive predictive models that can then estimate age from rapid scans of whole ageing structures alone. …

Combined Edna And Acoustic Analysis Reflects Diel Vertical Migration Of Mixed Consortia In The Gulf Of Mexico, Cole G. Easson, Kevin M. Boswell, Nicholas Tucker, Joseph D. Warren, Jose V. Lopez

Biology Faculty Articles

Oceanic diel vertical migration (DVM) constitutes the daily movement of various mesopelagic organisms migrating vertically from depth to feed in shallower waters and return to deeper water during the day. Accurate classification of taxa that participate in DVM remains non-trivial, and there can be discrepancies between methods. DEEPEND consortium (www.deependconsortium.org) scientists have been characterizing the diversity and trophic structure of pelagic communities in the northern Gulf of Mexico (nGoM). Profiling has included scientific echosounders to provide accurate and quantitative estimates of organismal density and timing as well as quantitative net sampling of micronekton. The use of environmental DNA (eDNA) can …

Oceanographic Structure And Light Levels Drive Patterns Of Sound Scattering Layers In A Low-Latitude Oceanic System, Kevin M. Boswell, Marta D'Elia, Matthew Johnston, John A. Mohan, Joseph D. Warren, R. J. David Wells, Tracey Sutton

Biology Faculty Articles

Several factors have been reported to structure the spatial and temporal patterns of sound scattering layers, including temperature, oxygen, salinity, light, and physical oceanographic conditions. In this study, we examined the spatiotemporal variability of acoustically detected sound scattering layers in the northern Gulf of Mexico to investigate the drivers of this variability, including mesoscale oceanographic features [e.g., Loop Current-origin water (LCOW), frontal boundaries, and Gulf Common Water]. Results indicate correlations in the vertical position and acoustic backscatter intensity of sound scattering layers with oceanographic conditions and light intensity. LCOW regions displayed consistent decreases, by a factor of two and four, …

Comparative Population Genomics And Biophysical Modeling Of Shrimp Migration In The Gulf Of Mexico Reveals Current-Mediated Connectivity, Laura Timm, Lys M. Isma, Matthew Johnston, Heather D. Bracken-Grissom

Biology Faculty Articles

The Gulf of Mexico experiences frequent perturbations, both natural and anthropogenic. To better understand the impacts of these events, we must inventory natural variability within the ecosystem, communities, species, and populations, and contextualize these findings in relation to physical features. Here, we present an integrated study of comparative population genomics and biophysical oceanography. Targeting three species of mesopelagic shrimp common to the Gulf of Mexico midwater (Acanthephyra purpurea, Systellaspis debilis, and Robustosergia robusta), we analyzed genetic diversity and population connectivity as proxies for species health and resilience, respectively. We also simulated a range of vertical migratory behaviors …

Comparative Population Genomics And Biophysical Modeling Of Shrimp Migration In The Gulf Of Mexico Reveals Current-Mediated Connectivity, Laura Timm, Lys M. Isma, Matthew Johnston, Heather D. Bracken-Grissom

Biology Faculty Articles

The Gulf of Mexico experiences frequent perturbations, both natural and anthropogenic. To better understand the impacts of these events, we must inventory natural variability within the ecosystem, communities, species, and populations, and contextualize these findings in relation to physical features. Here, we present an integrated study of comparative population genomics and biophysical oceanography. Targeting three species of mesopelagic shrimp common to the Gulf of Mexico midwater (Acanthephyra purpurea, Systellaspis debilis, and Robustosergia robusta), we analyzed genetic diversity and population connectivity as proxies for species health and resilience, respectively. We also simulated a range of vertical migratory behaviors …

Gulf Coast Marine Laboratories Past, Present And Future, Donald F. Boesch

Gulf and Caribbean Research

I spent my nearly 50—year career in marine science working at marine laboratories, most of that as a chief executive officer. So, it is appropriate that my reflections are about marine laboratories, rather than my own science. After relating my career course, I turn my attention to the history and development of marine laboratories along the U.S. coast of the Gulf of Mexico (GOM). Surprisingly, the region’s first laboratory was actually constructed in 1903 at Cameron, LA, but operated less than a decade before closing. It was not until after World War II that the university—affiliated marine laboratories of today …

Characterization Of The Microbiome And Bioluminescent Symbionts Across Life Stages Of Ceratioid Anglerfishes Of The Gulf Of Mexico, Lindsay L. Freed, Cole Easson, Lydia Baker, D. Fenolio, Tracey Sutton, Yasmin Khan, Patricia Blackwelder, Tory Hendry, Jose Lopez

Biology Faculty Articles

The interdependence of diverse organisms through symbiosis reaches even the deepest parts of the oceans. As part of the DEEPEND project (deependconsortium.org) research on deep Gulf of Mexico biodiversity, we profiled the bacterial communities (‘microbiomes’) and luminous symbionts of 36 specimens of adult and larval deep-sea anglerfishes of the suborder Ceratioidei using 16S rDNA. Transmission Electron Microscopy was used to characterize the location of symbionts in adult light organs (esca). Whole larval microbiomes, and adult skin and gut microbiomes, were dominated by bacteria in the genera Moritella and Pseudoalteromonas genera. 16S rDNA sequencing results from adult fishes corroborate …

Depth-Dependent Environmental Drivers Of Microbial Plankton Community Structure In The Northern Gulf Of Mexico, Cole Easson, Jose Lopez

Biology Faculty Articles

The Gulf of Mexico (GoM) is a dynamic marine ecosystem influenced by multiple natural and anthropogenic processes and inputs, such as the intrusion of warm oligotrophic water via the Loop Current, freshwater and nutrient input by the Mississippi River, and hydrocarbon inputs via natural seeps and industrial spills. Microbial plankton communities are important to pelagic food webs including in the GoM but understanding the drivers of the natural dynamics of these passively distributed microorganisms can be challenging in such a large and heterogeneous system. As part of the DEEPEND consortium, we applied high throughput 16S rRNA sequencing to investigate the …

Evolutionary And Population Dynamics Of Crustaceans In The Gulf Of Mexico, Laura Timm

FIU Electronic Theses and Dissertations

Evolution occurs and can be conceptualized along a spectrum, bounded on one extreme by the relationships between deep lineages – such as phyla, classes, and orders – and on the other by the molecular dynamics of operational taxonomic units within a species, defined as population genetics. The purpose of this dissertation was to better understand the evolutionary and population dynamics of crustaceans within the Gulf of Mexico. In the second chapter of my dissertation, I provide a guide to best phylogenetic practice while reviewing infraordinal relationships within Decapoda, including the promise held by next-generation sequencing (NGS) approaches such as Anchored …

A Phylogeographic Analysis Of Black Coral (Antipatharia) On Artificial And Natural Reefs In The Northwestern Gulf Of Mexico, Heather Otte

Theses and Dissertations

NOAA's Islands in the Stream concept (IitS) of designating networks of marine protected areas as refugia in the Gulf of Mexico depends on genetic connectivity. Isolated habitats like those proposed by the IitS occur naturally off the Texas coast where hard-bottom structures protrude from mudflats, offering a small-scale study of the IitS feasibility. Two sequences, mitochondrial 16S ribosomal RNA and nuclear internal transcribed spacer, were used to build haplotype networks of Antipatharians (Anthozoa: Hexacorallia), corals with planktonic larvae that can act as a proxy for connectivity of other organisms. Two species showed no significant genetic differentiation or pattern of genetic …

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 …

Utilizing Accelerometer Telemetry Tags To Compare Red Snapper (Lutjanus Campechanus) Behavior On Artificial And Natural Reefs, Ethan T. Getz

Theses and Dissertations

The Texas Parks and Wildlife Department Artificial Reef Program has deployed over 2,800 hectares of reefing area composed of petroleum platforms, steel vessels, and concrete. Artificial reefs have been shown to support many important reef fishes such as red snapper (Lutjanus campechanus), however, few studies have compared fish behavior on artificial reefs and natural habitats. We examined activity levels, behavioral patterns and habitat preferences of red snapper over natural reefs, oil platforms and submerged ships. Telemetry tags (Sonotronics model MTT) with tri-axial acceleration range, average depth, and average temperature were programmed to optimize data collection and tag life. …

Phylogeography Of An Estuarian Calanoid Copepod; Acartia Tonsa In The Texas Gulf Of Mexico, Nicole J. Figueroa

Theses and Dissertations

The calanoid copepod, Acartia tonsa is one of the most abundant and well-studied estuarian species. However, the idea that this cosmopolitan species has unrestricted dispersal and high gene flow has been challenged. In this study, a more holistic picture of the phylogeography of A. tonsa was developed using the mitochondrial gene cytochrome oxidase one (mtCOI). Multiple new lineages were found in the Texas Gulf of Mexico that are basal to Northeastern Atlantic lineages. Connectivity was also observed between Brazil and the Texas Gulf of Mexico. The revised phylogeny shows a clear pattern of cryptic speciation as the species made a …

Anaerobic Oxidation Of Ethane, Propane, And Butane By Marine Microbes: A Mini Review, Rajesh Singh, Michael S. Guzman, Arpita Bose

Biology Faculty Publications & Presentations

The deep ocean and its sediments are a continuous source of non-methane short-chain alkanes (SCAs) including ethane, propane, and butane. Their high global warming potential, and contribution to local carbon and sulfur budgets has drawn significant scientific attention. Importantly, microbes can use gaseous alkanes and oxidize them to CO₂, thus acting as effective biofilters. A relative decrease of these gases with a concomitant ¹³C enrichment of propane and n-butane in interstitial waters vs. the source suggests microbial anaerobic oxidation. The reported uncoupling of sulfate-reduction (SR) from anaerobic methane oxidation supports their microbial consumption. To date, strain …

Hotspots, Extinction Risk And Conservation Priorities Of Greater Caribbean And Gulf Of Mexico Marine Bony Shorefishes, Christi Linardich

Biological Sciences Theses & Dissertations

Understanding the status of species is important for allocation of resources to redress biodiversity loss. Regional organizations tasked with managing threats to the 1,360 marine bony shorefishes of the Caribbean and Gulf of Mexico would benefit from a delineation of conservation priorities. However, prior to this study, conservation status was known for only one quarter of these shorefishes. Extinction risk assessment under IUCN Red List Criteria is a widely-used, objective method to communicate species-specific conservation needs. Data were collated on each species’ distribution, population, habitats and threats and experts at three Red List workshops assigned a global level extinction risk …

Validating Side Scan Sonar As A Fish Survey Tool, Michael A. Bollinger

Theses and Dissertations

Hydroacoustic methods can be used to answer a variety of questions regarding fish populations and behavior. In this study, side scan sonar methodology was developed to quantify abundance and biomass and compared to established visual observation methods on SCUBA over artificial reef structures in the western Gulf of Mexico. Side scan sonar methods were equivalent to SCUBA surveys for measuring fish abundance over the same reef areas, however, abundances were significantly higher when the larger area sampled by side scan was utilized. Side scan sonar methods were also more time efficient than SCUBA, ROV and long line fishing methods (66.7%, …

Recruitment Patterns Of Juvenile Fish At An Artificial Reef In The Gulf Of Mexico, Rachel Noel Arney

Theses and Dissertations - UTB/UTPA

In 2011, the Texas Parks and Wildlife Department deployed 4,000 culverts as an artificial reef off Port Mansfield, TX to serve as habitat for sport fish species in the Gulf of Mexico. The aim of this study was to assess juvenile fish recruitment at particular culvert densities among the reef. Standard monitoring units for the recruitment of reef fish (SMURFs) were used in this study and acted as sampling devices. SMURFs were placed at thirteen sampling stations among four different reef patch densities and sampled repeatedly from 2013-2014. Culvert densities included stations with: zero culverts, 1-50 culverts, 51-100 culverts, and …

Taxonomy, Diversity, And Distribution Patterns Of Portunid Crab Megalopae In The Northern Gulf Of Mexico During Fall Of 2003, Carley Rain Knight

Master's Theses

The field of zooplankton biology contributes to more accurate stock assessments as well as to a greater understanding of the marine food web. However, adequate information for the invertebrate component of zooplankton is lacking compared to the ichthyoplankton component. In this thesis, identification of Portunidae (Crustacea: Decapoda) megalopae collected during the fall of 2003 from a NOAA SEAMAP cruise revealed 7 species and 11 morphs with 90% of the total density comprised of Callinectes sapidus, Achelous gibbesii, Callinectes similis, Achelous spinicarpus, and Achelous sp.I. Keys and detailed descriptions are provided along with photographs and morphological drawings for each morph to …

Intraspecific Relationships In Paracalanus Quasimodo [Calinoideae] And Temora Turbinata [Calinoideae] Along The Southeastern Coast Of The United States, Richard Y. Chang

FIU Electronic Theses and Dissertations

Paracalanus quasimodo and Temora turbinata are two calanoid copepods prominent in the planktonic communities of the southeastern United States. Despite their prominence, the species and population level structure of these copepods is yet unexplored. The phylogeographic, temporal and phylogenetic structure of P. quasimodo and T. turbinata are examined in my study. Samples were collected from ten sites along the Gulf of Mexico and Florida peninsular coasts. Three sites were sampled quarterly for two years. Individuals were screened for unique ITS-1 sequences with denaturing gradient gel electrophoresis. Unique variants were sequenced at the nuclear ITS-1 and mitochondrial COI loci. Sampling sites …

Marine Fungi Of U.S. Gulf Of Mexico Barrier Island Beaches: Biodiversity And Sampling Strategy, Allison Kathleen Walker

Dissertations

Marine fungi are an important but often overlooked component of marine ecosystems. Primarily saprotrophic, they are vital to coastal nutrient cycling processes and food webs. However, basic marine fungal distribution data are lacking in many parts of the world, as is knowledge of the sampling intensity required to characterize the biodiversity of these communities. The roles of substrate, season and latitude in shaping intertidal ascomycete community structure were examined for the U.S. Gulf of Mexico, and the role of sampling frequency on species richness estimates was also addressed. Best sampling practices were developed and 750 collections of beach detritus, sand …

Thermal Tolerance Of Age-0 Gulf Of Mexico Striped Bass (Morone Saxatilis): Ontogenetic And Genetic Effects, Corey Robert Anderson

Master's Theses

Striped bass, Morone saxatilis, were historically abundant in the Gulf of Mexico region but were largely extirpated from most Gulf rivers by the early 1960s. Since 1967 hatchery stocking has supported populations in Mississippi rivers and to date there is no evidence of natural reproduction. Intolerance of striped bass to high water temperature is a potential factor negatively impacting Gulf striped bass survival and reproductive fitness, and may be a limiting factor to reintroduction of the species in Mississippi. This work contributed to restoration efforts by establishing molecular tools necessary for genetic monitoring of striped bass restoration, and evaluating …

Gulf Of Mexico Oil Blowout Increases Risks To Globally Threatened Species, Claudio Campagna, Frederick T. Short, Beth A. Polidoro, Roger Mcmanus, Bruce B. Collette, Nicolas J. Pilcher, Yvonne Sadovy De Mitcheson, Simon N. Stuart, Kent E. Carpenter

Biological Sciences Faculty Publications

Fourteen marine species in the Gulf of Mexico are protected by the US Endangered Species Act, the Marine Mammal Protection Act, and the Migratory Bird Treaty Act. As the British Petroleum oil spill recovery and remediation proceed, species internationally recognized as having an elevated risk of extinction should also receive priority for protection and restoration efforts, whether or not they have specific legal protection. Forty additional marine species-unprotected by any federal laws-occur in the Gulf and are listed as threatened on the International Union for Conservation of Nature's (IUCN) Red List. The Red List assessment process scientifically evaluates species' global …

Life History And Habitat Use Of The Juvenile Alabama Shad (Alosa Alabamae) In Northern Gulf Of Mexico Rivers, Paul Fraser Mickle

Dissertations

The Alabama shad, Alosa alabamae, is an anadromous species that is in decline and has seen extirpations from impoundments as well as decreased water quality. Alabama shad live in the Gulf of Mexico and ascend Northern Gulf of Mexico Drainages to reproduce early in the year (January-May). The juveniles spend the majority of the year in these freshwater systems before emigrating out to the Gulf of Mexico as late as December.

This dissertation focuses on the juvenile life stages that occur within the Northern Gulf of Mexico drainages. Spawning conditions of the river, as well as the habitat and diet, …

Mercury Concentrations In South Texas Game Fishes, E. Anthony Reisinger

Theses and Dissertations - UTB/UTPA

Mercury (Hg) is one of the most ubiquitous and controversial metals in the world primarily due to the toxicity of the organic form of the metal, methylmercury (MeHg). MeHg is a neurotoxin at high levels, known to manifest its effects on humans primarily through consumption of certain fish and marine mammals, which tend to bioaccumulate MeHg in their tissues over time. Increased fish consumption and, thus, mercury intake in residents of coastal areas necessitates a better awareness of MeHg content in game fish species, thus the subject of this study.

Three hundred thirty-nine tissue samples were taken from 19 south …