Marine Biology Commons^™

Microplastic Abundance, Distribution And Impacts On Sargassum-Associated Juvenile Fishes In The Gulf Of Mexico, Olivia Lestrade

Master's Theses

Microplastics are a concern in marine environments because they are highly durable, ubiquitous, and can be mistaken for food and ingested by small organisms. Pelagic Sargassum, an important habitat for larval and juvenile stages of many fish species, is found in large surface aggregations, and may provide complex structure in which microplastics become trapped. This could lead to greater risk of microplastic ingestion by fish early life stages associated with Sargassum habitats. To better understand the impacts of microplastics within Sargassum communities, this study examined 1) microplastic concentrations and ingestion by juvenile fishes associated with Sargassum; 2) the microbial …

Assessment Of Genetic Diversity In Largetooth Sawfish, Pristis Pristis, Populations Over The 20th Century, Ann Fearing

Master's Theses

The Critically Endangered Largetooth Sawfish, Pristis pristis, experienced global declines in range and abundance over the past century and Australia is now their last stronghold. This research aimed to understand whether these declines have been accompanied by a reduction in levels of genetic diversity. Using P. pristis tissue samples sourced from natural history specimens, three fragments (616-bp, 386-bp, 141-bp) in the mitochondrial DNA (mtDNA) control region were PCR-amplified. At each fragment, significant genetic structure was found in P. pristis overall (Φ_ST=0.946, N=9; 0.813, N=54; 0.771, N=99). The Indo-West Pacific and Atlantic/Eastern Pacific each harbor genetically distinct lineages of …

Determining The Trophic Role Of Red Snapper (Lutjanus Campechanus) In Mississippi State Waters Using Stomach Content And Stable Isotope Analysis, Branden Kohler

Master's Theses

The goal of this study was to determine the diet composition, trophic position and ecological role of red snapper (Lutjanus campechanus) in Mississippi state waters utilizing stable isotopes (δ¹³C and δ¹⁵N) and stomach content analysis. Stable isotope analysis of fish and their prey can provide information on species-specific basal resource utilization, diet composition and trophic position which can improve food web models and inform fisheries management decisions. Particulate organic matter (POM), the presumed base of the food web, red snapper muscle tissue, and red snapper stomach contents were collected from 25 sites in 2016 and …

Consequences Of Plume Encounter On Larval Fish Growth And Condition In The Gulf Of Mexico, Kelia E. Axler, Su Sponaugle, Frank Hernandez, Carla Culpepper, Robert K. Cowen

Faculty Publications

© Inter-Research 2020. Freshwater input into nearshore continental shelf waters from coastal river-estuarine plumes can greatly alter the physical and trophic environments experienced by fish larvae. However, the biological consequences of plume encounter on larval fish survival remain equivocal, largely due to the extreme variability of these systems but also because traditional sampling techniques alone are too coarse to effectively characterize the dynamic biophysical environment at spatiotemporal scales relevant to individual larvae. Using a multidimensional approach, we simultaneously collected in situ imagery and net samples of larval fishes and zooplankton from the Mobile Bay plume (Alabama, USA) and ambient continental …

The Effect Of Constant Relative Growth Rate Versus Constant Specific Growth Rate On Oocystis Sp, Rachel Kriner

Master's Theses

In this study, a strain of Oocystis sp. (S002) was grown using two different growth strategies at three different temperatures (15°C, 20°C, 25°C). One strategy (GS1) kept a constant specific growth rate (µ) and the other (GS2) kept a constant relative growth rate (µ/µ_max). In both strategies, the cultures were grown following the protocols of a hybrid growth system. The Dilution Phase is an initial semi-continuous growth phase that involves daily dilutions until set growth criteria are met. Followed by a batch culture growth protocol where the cultures were diluted at the onset of the first day and …

Quantifying Spatiotemporal Variability In Zooplankton Dynamics In The Gulf Of Mexico With A Physical-Biogeochemical Model, Taylor A. Shropshire, Steven L. Morey, Eric P. Chassignet, Alexandra Bozec, Victoria J. Coles, Michael R. Landry, Rasmus Swalethorp, Glenn Zapfe, Michael R. Stukel

Faculty Publications

© 2020. This work is distributed under the Creative Commons Attribution 4.0 License. Zooplankton play an important role in global biogeochemistry, and their secondary production supports valuable fisheries of the world's oceans. Currently, zooplankton standing stocks cannot be estimated using remote sensing techniques. Hence, coupled physical–biogeochemical models (PBMs) provide an important tool for studying zooplankton on regional and global scales. However, evaluating the accuracy of zooplankton biomass estimates from PBMs has been a major challenge due to sparse observations. In this study, we configure a PBM for the Gulf of Mexico (GoM) from 1993 to 2012 and validate the model …

Temporal And Stoichiometric Patterns Of Algal Stimulation Of Litter-Associated Heterotrophic Microbial Activity, Steven N. Francoeur, Robert K. Neely, Savannah Underwood, Kevin A. Kuehn

Faculty Publications

1. Periphyton communities associated with submerged plant detritus contain interacting autotrophic and heterotrophic microbes, and are sites of extracellular enzymatic activity. The strength and nature of these interactions might be expected to change over time as microbial communities develop on plant litter. Microbial interactions and enzymatic activity can be altered by nutrient availability, suggesting that litter stoichiometry could also affect these phenomena.
2. We grew wetland plants under ambient and nutrient‐enriched conditions to generate plant litter of differing nutrient content. In two experiments, we investigated: (1) the influence of algal photosynthesis on fungal and bacterial production and the activities of four extracellular …

Combined And Independent Effects On Hypoxia And Tributylin On Mrna Expression And Physiology Of The Eastern Oyster (Crassostrea Virginica), Ann Fairly Barnett, James H. Gledhill, Robert J. Griffitt, Marc Slattery, Deborah J. Gochfeld, Kristine L. Willett

Faculty Publications

Oyster reefs are vital to estuarine health, but they experience multiple stressors and globally declining populations. This study examined effects of hypoxia and tributyltin (TBT) on adult Eastern oysters (Crassostrea virginica) exposed either in the laboratory or the field following a natural hypoxic event. In the laboratory, oysters were exposed to either hypoxia followed by a recovery period, or to hypoxia combined with TBT. mRNA expression of HIF1-α and Tβ-4 along with hemocyte counts, biomarkers of hypoxic stress and immune health, respectively, were measured. In field-deployed oysters, HIF1-α and Tβ-4 expression increased, while no effect on hemocytes was …

Antibiotic Resistant Bacteria, Antibiotic Resistance Genes And Potential Drivers In The Aquatic Environments, Shuo Shen

Dissertations

As antibiotic resistance genes in aquatic environment have been increasing across the world, affecting water quality and public health, many studies documented concentrations of antibiotic resistance genes and some studies discussed their potential drivers. However, systematic and quantitative reviews that link antibiotic resistance genes (ARGs) to anthropogenic and environmental factors are limited. Nevertheless, this information will be important for developing regulation policy on controlling antibiotic use and therefore reducing potential risks to antibiotic resistance. I conducted meta-analysis of ARGs concentration at a global scale using Bayesian inference to explore climatic and socio-economic factors as drivers. I found local-scale climatic variables …

Vegetative Community And Health Assessment Of A Constructed Juncus-Dominated Salt Marsh In The Northern Gulf Of Mexico, Nickolas R. Murphy

Master's Theses

Deer Island is a coastal habitat which provides a buffer from storm and flood damage as well as shore-line stabilization to the mainland of Biloxi, Mississippi. A third of the land has been lost since 1850, largely driven by tropical storm and hurricane impacts as well as sea level rise. The United States Army Corps of Engineers and Mississippi Department of Marine Resources have targeted the shores of the island as sites for restoration using beneficial use dredged material, and two sites of differing age have since been planted with Spartina alterniflora, Juncus roemerianus, Uniola paniculata, S. patens, and Panicum …

An Analysis Of Dredge Efficiency For Surfclam And Ocean Quahog Commercial Dredges, Leanne Poussard

Master's Theses

Between 1997 and 2011, The National Marine Fisheries Service conducted 50 depletion experiments to estimate survey gear efficiency and stock density for Atlantic surfclam (Spisula solidissima) and ocean quahog (Arctica islandica) populations using commercial hydraulic dredges. The Patch Model was formulated to estimate gear efficiency and organism density from the data. The range of efficiencies estimated is substantial, leading to uncertainty in the application of these estimates in stock assessment. Analysis of depletion experiment simulations showed that uncertainty in the estimates of gear efficiency from depletion experiments was reduced by higher numbers of dredge tows per experiment, more tow overlap …

Development And Characterization Of Genomic Resources For A Non-Model Marine Telost, The Red Snapper (Lutjanus Campechanus, Lutjanidae): Construction Of A High-Density Linkage Map, Anchoring Of Genome Contigs And Comparative Genomic Analysis, Adrienne E. Norrell, Kenneth L. Jones, Eric A. Saillant

Faculty Publications

The red snapper Lutjanus campechanus is an exploited reef fish of major economic importance in the Gulf of Mexico region. Studies of genome wide genetic variation are needed to understand the structure of wild populations and develop breeding programs for aquaculture but interpretation of these genome scans is limited by the absence of reference genome. In this work, the first draft of a reference genome was developed and characterized for the red snapper. P-454 and Illumina sequencing were conducted to produce paired-end reads that were assembled into reference contigs and scaffolds. The current assembly spans over 770 Mb, representing an …

Respiration By The Opportunistic Spionid Polychaete Streblospio Gynobranchiata During Adjustment To And Recovery From Moderate Hypoxia, Alyssa D. Bennett, Chet F. Rakocinski

Faculty Publications

Understanding the capacity of estuarine organisms to acclimate to stressful conditions provides insights into how communities cope within fluctuating environments. The opportunistic spionid polychaete, Streblospio gynobranchiata Rice and Levin, 1998, regularly experiences intermittent moderate hypoxia within shallow sedimentary habitats. To better understand fine-scale adjustments by this opportunistic species to short-term moderate hypoxia, the aerobic respiration response of three size classes was examined over a 12 h period and after 24 h of exposure to moderate hypoxia (i.e., 20% air saturation) at 25 °C. In addition, the capacity to resume standard respiration was examined over a 12 h period following a …

Exposure To Oil And Hypoxia Results In Alterations Of Immune Transcriptional Patterns In Developing Sheepshead Minnows (Cyprinodon Variegatus), Maria L. Rodgers, Danielle Simning, Maria S. Sepúlveda, Sylvain De Guise, Thijs Bosker, Robert J. Griffitt

Faculty Publications

The area and timing of the Deepwater Horizon oil spill highlight the need to study oil and hypoxia exposure in early life stage fishes. Though critical to health, little research has targeted the effect of oil and hypoxia exposure on developing immune systems. To this end, we exposed sheepshead minnows (Cyprinodon variegatus) at three early life stages: embryonic; post-hatch; and post-larval, to a high energy water accommodated fraction (HEWAF) of oil, hypoxia, or both for 48 hours. We performed RNAseq to understand how exposures alter expression of immune transcripts and pathways. Under control conditions, the embryonic to post-hatch …

Leaf-Tip Morphology Does Not Support Species Status For The Seagrass Halodule Beaudettei In Florida, Usa, Michael E. Wheeler, Bradley T. Furman, Margaret O. Hall

Gulf and Caribbean Research

No abstract provided.

Focus-Stacked Images Of Fish Jawbones For Stomach Content Analyses: A Case Study With Select Taxa From Tampa Bay, Florida, Gabriel E. Ramos-Tafur, Kevin A. Thompson, Julianne Knight-Gray, Brittany J. Hall-Scharf, David D. Chagaris, Ted S. Switzer, Richard E. Matheson, Robert H. Mcmichael Jr.

Gulf and Caribbean Research

Trophodynamics and ecosystem models have been increasingly used in evaluating fish stocks, requiring accurate diet data; however, complications with identifications arise when the soft tissues of fish prey break down during digestion, limiting the taxonomic resolution obtained during stomach content analyses. Although scales and otoliths are relatively resistant to digestion, their usefulness for distinguishing among fish prey species is limited. Jawbones are frequently observed in predator stomach contents, and while morphologies of some fishes have been described, available information is frequently inadequate for practical application in stomach content analyses. Line drawings have long been the traditional means to convey complex …

Lake Or Estuary? Sedimentary And Benthic Foraminiferal Characterization Of A Gulf Of Mexico Coastal Dune Lake, Kaylyn C. Bellais, Samuel T. Barber, Donald A. Beebe, Murlene W. Clark

Gulf and Caribbean Research

Coastal dune lakes are shallow estuaries located within dune environments that share a permanent or intermittent connection with the sea. Because coastal dune lakes are found in few locations worldwide (e.g. Australia, New Zealand, Florida, etc.) they represent unique environments worthy of protection. However; there is a distinct lack of scientific data related to the function and ecology of coastal dune lakes, especially in the Gulf of Mexico. Therefore, the purpose of this study was to characterize the sedimentology and foraminifera of a representative coastal dune lake in Walton County, FL (i.e. Eastern Lake) and determine whether it shares geologic …

Intraspecific Aggression Towards Common Bottlenose Dolphin Calves, Northern Gulf Of Mexico, Errol Ronje, Sarah Piwetz, Heidi Whitehead, Keith D. Mullin

Gulf and Caribbean Research

Infanticide has been widely documented throughout the animal kingdom, and has generally been viewed as an evolved, or adaptive behavior for the perpetrators. Infanticide motivated by increased sexual access to females with calves, or the elimination of potential genetic competition in the form of calf-directed aggression or infanticide, has been proposed for delphinids including killer whales, Indo-Pacific humpback dolphins, Guiana dolphins, and bottlenose dolphins. However, reports of intraspecific aggression towards bottlenose dolphin calves are relatively infrequent, and accounts of confirmed infanticide are rarer still. Reporting instances of intraspecific calf-directed aggression aids researchers to better understand the socio-behavioral context of these …

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.

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 …

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 …

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.

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 …

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 …

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 …