Life Sciences Commons^™

Nursery Exposure Of Oyster Spat To Different Predators Strengthens Oyster Shells, Melanie Ponce, Benjamin Belgrad, William Walton, Lee Smee

Gulf and Caribbean Research

No abstract provided.

Small-Scale Variability In Carbon Isotope Ratios Of Microphytobenthos And Dissolved Inorganic Carbon In A Northern Gulf Of Mexico Salt Marsh, Trinity Curry, Jeffrey Krause, Ronald Baker

Gulf and Caribbean Research

No abstract provided.

Life History Metrics Of Wahoo (Acanthocybium Solandri) From The Northern Gulf Of Mexico, Erik T. Lang, Chris A. Levron, Cijii D. Marshall, Brett J. Falterman

Gulf and Caribbean Research

Wahoo (Acanthocybium solandri) are highly sought in recreational and commercial fisheries in the Gulf of Mexico (GOM), yet the harvest of Wahoo is currently unmanaged in the GOM region outside of Florida waters. Life history metrics are critical to stock assessments and science-based management. Between 2014-2017, Louisiana Department of Wildlife and Fisheries (LDWF) biologists collected Wahoo otoliths and ovaries (n=198) from the northern GOM Wahoo recreational fishery based in Venice, LA to estimate life history metrics of age, growth, and maturity. A protocol was developed to section and age the small, fragile otoliths. A 2-parameter Von Bertalanffy growth …

Abundance And Occurrence Of Common Bottlenose Dolphins (Tursiops Truncatus) In Three Estuaries Of The Northwestern Gulf Of Mexico, Errol Ronje, Heidi Whitehead, Kevin Barry, Sarah Piwetz, Juliane Struve, Vincent Lecours, Lance Garrison, Randall S. Wells, Keith D. Mullin

Gulf and Caribbean Research

Current abundance estimates for populations of common bottlenose dolphins (Tursiops truncatus, Montagu, 1821) in bays, sounds, and estuaries are lacking throughout most of the northwestern Gulf of Mexico, including areas of Texas and western Louisiana. To address this issue, we conducted 92 small-boat photographic identification surveys covering ~2000 km² and comprising ~11,000 km of track-line in winter and summer seasons in West Bay, TX (2014 – 2015, n = 25), the Galveston Bay, TX system (2016, n = 50), Sabine Lake, TX (2017, n = 17), and adjacent coastal waters. Individual dolphin encounter histories were constrained by …

Distribution, Relative Abundance, And Reproductive Output Of Spawning Female Blue Crab (Callinectes Sapidus) In Offshore Waters Of The Gulf Of Mexico, Adam A. Kemberling, M. Zachary Darnell

Faculty Publications

Effective assessment and management of migratory species require an understanding of stock boundaries and habitat use during critical life history periods. The blue crab (Callinectes sapidus) is considered a primarily estuarine species and has traditionally been assessed and man-aged on a state basis, relying on abundance estimates derived from estuarine sampling. Females undertake a sea-ward spawning migration, and recent evidence indicates that coastal and offshore waters may provide important spawning habitat. We investigated occurrence and reproductive output of spawning blue crab in offshore waters of the northwestern Gulf of Mexico, and results indicate that these waters may be …

Development Of Highly Sensitive Environmental Dna Methods For The Detection Of Bull Sharks, Carcharhinus Leucas (Müller And Henle, 1839), Using Droplet DigitalTm Pcr, Katherine E. Schweiss, Ryan N. Lehman, J. Marcus Drymon, Nicole M. Phillips

Faculty Publications

Background: As apex and mesopredators, elasmobranchs play a crucial role in maintaining ecosystem function and balance in marine systems. Elasmobranch populations worldwide are in decline as a result of exploitation via direct and indirect fisheries mortalities and habitat degradation; however, a lack of information on distribution, abundance, and population biology for most species hinders their effective management. Environmental DNA analysis has emerged as a cost‐effective and non‐invasive technique to fill some of these data gaps, but often requires the development of species‐specific methodologies.

Aims: Here, we established eDNA methodology appropriate for targeted species detections of Bull Sharks, Carcharhinus …

Spatio-Temporal Models Of Juvenile And Adult Sheepshead (Archosargus Probatocephalus) In Tampa Bay, Florida From 1996 To 2016, Bridgette F. Froeschke, Leslie B. Jones, Brian Garman

Gulf and Caribbean Research

Spatio-temporal distribution models for juvenile and adult Sheepshead (Archosargus protocephalus) were developed for Tampa Bay, FL using Boosted Regression Trees. Juvenile Sheepshead were primarily associated with month of collection (highest occurrence in May and June), low salinities (<10), and increased distance from a tidal inlet. Adult Sheepshead were more frequently detected closer to inlets in September through November, with an increasing trend through time, and had the highest probability of detection in areas with the highest salinity levels. Our results indicate that juvenile Sheepshead are associated with tidal tributaries on the east side of Tampa Bay and adult Sheepshead are associated with the major inlet into the Gulf of Mexico. These findings reflect seasonal and ontogenetic shifts in distribution that are necessary to inform spatially-based management approaches and to prioritize areas for habitat conservation.

Red Hind Epinephelus Guttatus Vocal Repertoire Characterization, Behavior And Temporal Patterns, Carlos M. Zayas Santiago, Richard S. Appeldoorn, Michelle T. Schärerer-Umpierre, Juan J. Cruz-Motta

Gulf and Caribbean Research

Passive acoustic monitoring provides a method for studying grouper courtship associated sounds (CAS). For Red Hind (Epinephelus guttatus), this approach has documented spatio—temporal patterns in their spawning aggregations. This study described vocalizations produced by E. guttatus and their respective behavioral contexts in field and laboratory studies. Five sound types were identified, which included 4 calls recorded in captivity and one sound recorded in the wild, labeled as Chorus. Additionally, the Grunt call type recorded was presumed to be produced by a female. Call types consisted of variations and combinations of low frequency (50—450 Hz) pulses, grunts and tonal …

Short-Term Estimate Of Finfish Bycatch Discards In The Inshore Artisanal Shrimp Fishery Of Guyana, Leanna Kalicharan, Hazel A. Oxenford

Gulf and Caribbean Research

The artisanal shrimp fishery in Guyana is important for livelihood and food security, involving around 300 vessels owned and crewed exclusively by Guyanese nationals. This fishery uses Chinese seines and operates in major river estuaries. It targets penaeid shrimp, but also retains some finfish and is known to discard a significant but undocumented quantity of smaller finfish bycatch. The lack of knowledge regarding the bycatch is a concern for fishery management and biodiversity conservation. In this study, we quantify for the first time the finfish bycatch discards through onboard observations (July—August 2016) of a single typical vessel operating in the …

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 …

Exploring Scale In Ocean And Coastal Governance In The Wider Caribbean, Robin C. Mahon

Gulf and Caribbean Research

An early childhood attraction to the sea led to a career in marine ecology, fisheries and ocean and coastal governance. This paper tracks the development of my career from tertiary education, through a variety of jobs and positions with government, private sector, international and academic organizations. These positions took me from national to regional levels of governance, then down to local levels and ultimately back up to regional and global levels. At each stage new concepts join those already there to build what is ultimately a multilevel perspective on ocean and coastal governance. This perspective is built around ideas of …

Habitat Characterization Of Juvenile Atlantic Tarpon (Megalops Atlanticus) In Isle Of Youth, Cuba, Zenaida M. Navarro-Martínez, Jorge Angulo-Valdés, Lisandra García-Córdova, Aaron Adams

Gulf and Caribbean Research

Tarpon is considered a ‘Vulnerable’ species by IUCN but is also a highly prized recreational species. It is reportedly abundant in Cuba and may be threatened by high levels of fishing pressure. However, the current knowledge about Tarpon habitat characteristics and ecology in Cuba is very poor, which limit any attempt for its management and conservation. Here we summarize abiotic characteristics of juvenile Tarpon habitats in Lanier Swamp, Isle of Youth, Cuba, which is a RAMSAR site and Faunal Refuge. Three locations in Lanier Swamp were sampled for juvenile Tarpon presence during 2015-2017: Colony Lagoon (CL), Punta Francés Lagoon (PFL) …

First Records For Spawning Of Caribbean Acropora Species In Colombian Mpas, David M. Hudson, Barrett L. Christie, Luis A. Gómez-Lemos, Camilo Valcarcel, Diego Duque, Juan C. Zárate Arévalo, Jaime Rojas, Otto Reyes, Milena Marrugo, Maria Rosa, Israel A. Caicedo Torrado, Diana Tarazona, Carlos Zuluaga

Gulf and Caribbean Research

Estimates of Colombian Caribbean coral percent cover in the Southern Caribbean are consistent with those throughout the Caribbean Sea, which has declined to about 10% of historical levels in the last few decades. Human activities like destructive fishing techniques in the marine parks have degraded the reefs over the last few decades. Colombia’s Marine Protected Areas (MPAs) have thousands of square kilometers to map and patrol and few resources to devote to scientific and restoration efforts. Efforts to implement sexual reproduction techniques for restoration are starting to successfully propagate and settle corals on ceramic plates for reef deployment in the …

Size At Maturation, Spawning Variability And Fecundity In The Queen Conch, Aliger Gigas, Richard S. Appeldoorn

Gulf and Caribbean Research

The queen conch (Aliger gigas) resource is one of the most important in the Caribbean. While aspects of queen conch reproduction have been studied, e.g., size—at—maturity, spawning season, and density—based Allee effects, there is little information on other important aspects. From 210 lipped queen conch collected off southwest Puerto Rico, histological examination of gonads showed that 50% maturation occurred at 9 mm lip thickness. Experimental caged queen conch held on a natural spawning ground were monitored across the spawning season to evaluate fecundity and its variability across individuals and between nominal density treatments (2,000 vs 143 conch/ha). Near …

Pelagic Sargassum Prediction And Marine Connectivity In The Tropical Atlantic, Donald R. Johnson, James S. Franks, Hazel A. Oxenford, Shelly-Ann L. Cox

Gulf and Caribbean Research

Since 2011, pelagic Sargassum has experienced extraordinary blooms in the Tropical Atlantic where a system of persistent but seasonally variable currents has retained and consolidated it in large masses. Although beneficial at sea, principally as a unique pelagic habitat, when Sargassum inundates the nearshore environment it can have catastrophic effects on tourism, fisheries, health, and local ecosystems. Providing advanced warning of arrival dates of large masses of Sargassum is critical for enabling preparations and planning for its removal, use, and mitigation. Predictions of arrival time and location involve satellite identification of Sargassum at sea together with ocean current data for …

The Antimicrobial Activity And Cellular Pathways Targeted By P-Anisaldehyde And Epigallocatechin Gallate In The Opportunistic Human Pathogen Pseudomonas Aeruginosa, Yetunde Adewumni, Sanchirmaa Namjilsuren, William D. Walker, Dahlia N. Amato, Douglas V. Amato, Olga V. Mavrodi, Derek L. Patton, Dmitri V. Mavrodi

Faculty Publications

Plant-derived aldehydes are constituents of essential oils that possess broad-spectrum antimicrobial activity and kill microorganisms without promoting resistance. In our previous study, we incorporated p-anisaldehyde from star anise into a polymer network called PANDAs (Pro-Antimicrobial Networks via Degradable Acetals) and used it as a novel drug delivery platform. PANDAs released p-anisaldehyde upon a change in pH and humidity, and controlled growth of the multi-drug resistant pathogen Pseudomonas aeruginosa PAO1. In this study, we identified cellular pathways targeted by p-anisaldehyde, by generating 10,000 transposon mutants of PAO1 and screened them for hypersensitivity to p-anisaldehyde. To improve the …

Argulus From The Pascagoula River, Ms, Usa, With An Emphasis On Those Of The Threatened Gulf Sturgeon, Acipenser Oxyinchus Desotoi, Michael J. Andres, Jeremy M. Higgs, Paul O. Grammer, Mark S. Peterson

Faculty Publications

Species of Argulus (Branchiura Thorell, 1864) are common ectoparasites of freshwater, estuarine, and marine fishes. Argulid identification and taxonomy is often confusing because many species are reported to parasitize multiple host species, have similar morphological characters, and come from various salinity regimes. Gulf sturgeon is an anadromous fish natal to drainages in the north-central Gulf of Mexico, and as with many endangered species, has a poorly documented parasite community. During Gulf sturgeon tagging and monitoring studies (2016–2019) in the Pascagoula River, MS, USA, species of Argulus were collected from Gulf sturgeon as well as other incidentally captured fishes. Argulus flavescens …

The Histoplasma Capsulatum Ddr48 Gene Is Required For Survival Within Macrophages And Resistance To Oxidative Stress And Antifungal Drugs, Logan Blancett

Dissertations

Histoplasma capsulatum(Hc)is a systemic, dimorphic fungal pathogen that affects upwards of 500,000 individuals in the United States annually. Hc grows as a multicellular mold at environmental temperatures; whereas, upon inhalation into a human or other mammalian host, it transforms into a unicellular, pathogenic yeast. The research presented in this dissertation is focused on characterizing the DNA damage-responsive gene HcDDR48. HcDDR48was originally isolated via a subtractive DNA library enriched for transcripts enriched in the mold-phase of Hcgrowth. Upon further analysis we found that HcDDR48is not just expressed in the mold morphotype, but both growth programs …

The Antimicrobial Activity And Cellular Targets Of Plant Derived Aldehydes And Degradable Pro-Antimicrobial Networks In Pseudomonas Aeruginosa, Yetunde Adewunmi

Dissertations

Essential oils (EOs) are plant-derived products that have been long exploited for their antimicrobial activities in medicine, agriculture, and food preservation. EOs represent a promising alternative to conventional antibiotics due to the broad-range antimicrobial activity, low toxicity to human commensal bacteria, and the capacity to kill microorganisms without promoting resistance. Despite the progress in the understanding of the biological activity of EOs, many aspects of their mode of action remain inconclusive. The overarching aim of this work was to address these gaps by studying molecular interactions between antimicrobial plant aldehydes and the opportunistic human pathogen Pseudomonas aeruginosa. We initiated …

Evaluation Of Detached Strawberry Leaves For Anthracnose Disease Severity Using Image Analysis And Visual Ratings, Melinda A. Miller-Butler, Barbara J. Smith, Kenneth J. Curry, Eugene K. Blythe

Faculty Publications

Inoculation of detached strawberry leaves with Colletotrichum species may provide an accurate, rapid, nondestructive method of identifying anthracnose-resistant germplasm. The purpose of this study was to statistically compare two methods (visual and image analysis) of evaluating disease severity of strawberry germplasm screened for anthracnose resistance. Detached leaves of 77 susceptible and resistant strawberry clones were inoculated with one Colletotrichum gloeosporioides (Penz.) Penz. & Sacc. and two C. fragariae A. N. Brooks isolates. Anthracnose disease symptoms on each leaf were assessed quantitatively via computer-based image analysis to determine percentage lesion area and qualitatively by two independent raters using a visual disease …

Distinguishing Anuran Species By High-Resolution Melting Analysis Fo The Coi Barcode (Coi-Hrm), Steven Everman, Shiao Y. Wang

Faculty Publications

Taxonomic identification can be difficult when two or more species appear morphologically similar. DNA barcoding based on the sequence of the mitochondrial cytochrome c oxidase 1 gene (COI) is now widely used in identifying animal species. High‐resolution melting analysis (HRM) provides an alternative method for detecting sequence variations among amplicons without having to perform DNA sequencing. The purpose of this study was to determine whether HRM of the COI barcode can be used to distinguish animal species. Using anurans as a model, we found distinct COI melting profiles among three congeners of both Lithobates spp. and Hyla spp. Sequence variations …

Distribution, Abundance, And Trophic Ecology Of Anguilliform Leptocephali In The Northern Gulf Of Mexico, Lillian Collins

Master's Theses

All species of anguilliform eels have pelagic leptocephalus larval stages, which provides a means of monitoring the population dynamics of these otherwise cryptic and hard to study species. The goals of this study were to: 1) describe the distribution and abundance of anguilliform eel leptocephali across the northern Gulf of Mexico, and 2) examine the trophic ecology of leptocephali using stable isotope values of carbon and nitrogen (δ13C and δ15N). A 25-year (1990-2014) ichthyoplankton dataset provided by the National Oceanic and Atmospheric Administration (NOAA) Southeast Area Monitoring and Assessment Program (SEAMAP) was used to examine interannual variations in leptocephalus distribution, …

The Thiol Specific Antioxidant (Tsa1) Gene Is Required For Survival In Macrophages And Oxidative Stress Resistance In Histoplasma Capsulatum, Lauren Kennedy

Master's Theses

Histoplasma capsulatum(Hc) is a pathogenic fungus that causes one of the most common invasive fungal respiratory diseases, Histoplasmosis. Histoplasmaundergoes a dimorphic shift from mold to yeast which is crucial to pathogenesis of the organism.

The thiol specific antioxidant gene, Tsa1,is strongly upregulated in the yeast (pathogenic) morphotype. This data led to the hypothesis that this gene plays a role in protecting Hcfrom host mediated oxidative attack. To characterize Tsa1 function, a knockdown strain (tsa1-RNAi) was created by RNAi gene silencing. Expression of Tsa1in the tsa1-RNAistrain was reduced to 10% that …

Development And Employment Of Environmental Dna Methods For The Detection Of Bull Sharks (Carcharhinus Leucas) In A Freshwater And Estuarine Interface In The Mobile-Tensaw Delta And Mobile Bay, Alabama, Katherine Schweiss

Master's Theses

Species conservation and management is influenced by the quality of monitoring methods employed, especially when targeting elusive, but ecologically significant species, like elasmobranchs. Bull Sharks (Carcharhinus leucas) are highly mobile predators that rely on estuaries and freshwater rivers for maturation, resources, and refuge; their ability to withstand changing environmental conditions may mean they are linking ecosystems through their habitat usage and movements. Rather than setting nets or attaching acoustic monitoring devices, which can be expensive, time-consuming, and invasive, the analysis of environmental DNA (eDNA) for tracing species presence was used to target C. leucasDNA. The present research …

Early Recruitment Of Crassostrea Virginica To Restored And Natural Oyster Reefs In The Western Mississippi Sound: Larval Supply And Post-Settlement Success, Leah Morgan

Master's Theses

The eastern oyster (C. virginica) is a foundation species that improves water quality, protects shorelines, provides refuge for other organisms, and contributes to commercial fisheries. Successful early recruitment of eastern oyster is vital for resupplying adult populations in the face of habitat loss. Coastal oyster populations are challenged by freshwater input, hypoxia, predation and overfishing. Consequently, substantial efforts have been dedicated toward oyster restoration within the northern Gulf of Mexico. The overall objective of this study was to consider the role and importance of early recruitment to oyster restoration in western Mississippi Sound. During the summer 2018 recruitment period, we …

Effects Of Water Table Depth And Edaphic Characteristics On Plant Diversity In A Southern Mississippi Pitcher Plant Bog, Patrick Kirby

Master's Theses

This study examined the effects that water table depth and soil characteristics have on plant species richness and species composition within pitcher plant bogs across seasons. Eight piezometers were installed at random distances to monitor long-term water table depth and pressure fluctuations along a ~710-meter line transect traversing upland and bog habitats. Vegetation sampling quadrats (n=128) were set up near each piezometer. Cover data and water table depths were collected in spring and late summer. Soil samples collected from each treatment group were used to obtain soil texture and nutrient data. The summer collection period yielded a total gdiversity of …

The Effect Of Historic Shipwrecks On Sediment Microbiomes In The Northern Gulf Of Mexico, Melissa Brock

Master's Theses

Microorganisms are ubiquitously distributed across all aquatic habitats, but it is the environmental conditions of a habitat that determine which microorganisms can thrive in terms of abundance or metabolic activity. Habitats that experience consistent physical and chemical environmental conditions repeatedly favor specific taxonomic groups which may result in a microbial assemblage that is commonly associated with that habitat (i.e., a core microbiome). Core microbiomes have been identified for a variety of natural marine habitats including methane seeps, wood falls, octocoral, and deep-sea sediments. However, it was unknown if the presence of man-made structures on the seafloor, including historic shipwrecks, also …

Assessing Prevalence Of Eating Disorders Among College Students, Taylor Jordan Duncan

Honors Theses

Eating disorders have become a subject of concern for college-aged young adults in recent years. Risk factors like social media use are contributing to an increase in affected students, and research suggests that gender along with other variables plays a significant role. This thesis examined the current research on eating disorders and risk factors associated with their development. Through an online survey, information from freshman, sophomore, junior, senior, and graduate students at The University of Southern Mississippi regarding their current eating behaviors, feelings toward food and body, and demographic information was collected. Data collected indicated the student population’s level of …

The Impact Of Msaabcr On Sara-Associated Phenotypes Is Different In Divergent Clinical Isolates Of Staphylococcus Aureus, Joseph S. Rom, Aura M. Ramirez, Karen E. Beenken, Gyan S. Sahukhal, Mohamed O. Elasri, Mark S. Smeltzer

Faculty Publications

The staphylococcal accessory regulator (sarA) plays an important role in Staphylococcus aureus infections including osteomyelitis, and the msaABCR operon has been implicated as an important factor in modulating expression of sarA. Thus, we investigated the contribution of msaABCR to sarA-associated phenotypes in the S. aureus clinical isolates LAC and UAMS-1. Mutation of msaABCR resulted in reduced production of SarA and a reduced capacity to form a biofilm in both strains. Biofilm formation was enhanced in a LAC msa mutant by restoring the production of SarA, but this was not true in a UAMS-1 msa mutant. Similarly, …

Analysis Of The Cody Rnome Reveals Rsad As A Stress-Responsive Riboregulator Of Overflow Metabolism In Staphylococcus Aureus, Yoann Augagneur, Alyssa N. King, Noëlla Germain-Amiot, Mohamed Sassi, John W. Fitzgerald, Gyan S. Sahukhal, Mohamed O. Elasri, Brice Felden, Shaun R. Brinsmade

Faculty Publications

In Staphylococcus aureus, the transcription factor CodY modulates the expression of hundreds of genes, including most virulence factors, in response to the availability of key nutrients like GTP and branched‐chain amino acids. Despite numerous studies examining how CodY controls gene expression directly or indirectly, virtually nothing is known about the extent to which CodY exerts its effect through small regulatory RNAs (sRNAs). Herein, we report the first set of sRNAs under the control of CodY. We reveal that staphylococcal sRNA RsaD is overexpressed >20‐fold in a CodY‐deficient strain in three S. aureus clinical isolates and in S. epidermidis. …