Marine Biology Commons^™

2026 Workshop On Bridging The Gaps: Tackling Microplastics And Nanoplastics Challenges In Coastal Ecosystems, Shenghua Wu, Kaushik Venkiteshwaran, Melike Dizbay-Onat, Alexandra Stenson, Jinhui Wang, Tina Miller-Way, Ebenezer Nyadjro, Bhuvnesh Bharti, John Weinstein, Yi Bao, Shihui Shen, Valerie Longa, Shenghua Zha, John Cleary, Marty Lind

Workshops

This report presents the findings from the 2026 Workshop on Tackling Microplastics and Nanoplastics (MNPs) in Coastal Ecosystems, which took place in Mobile, Alabama. More than 140 experts from universities, government, industry, and community organizations gathered to address the increasing issue of MNPs in coastal regions.

Evaluating Fungal Endophytes Inoculation As A Mechanism For Salt Tolerance In Juncus Roemarianus, Rani Badve

Honors Theses

Salinity stress is increasing in coastal and estuarine ecosystems due to increasing temperatures and the reduction of freshwater inputs via precipitation pattern changes. Elevated salinity can negatively affect plant survival, threatening the stability of coastal wetlands and the ecosystem services they provide. Juncus roemerianus is a common and dominant marsh plant in the Northern Gulf Coast that lives in varying salinities. Growing evidence suggests that root-associated fungal endophytes may contribute to enhanced stress tolerance; however, the response of fungal communities to salinity remains poorly understood.

This study evaluated how salinity influences the abundance and diversity of culturable root-associated fungal communities …

Acute Effects Of The Psychoactive Pollutant Fluoxetine On The Antipredator Behavior Of The Gulf Killifish (Fundulus Grandis), Semyra Reus

Honors Theses

Pharmaceutical contaminants are increasingly prevalent in aquatic environments, yet their sublethal effects on ecologically relevant behaviors remain poorly understood, particularly in estuarine systems. Selective serotonin reuptake inhibitors (SSRIs), such as fluoxetine, are of particular concern due to the conserved role of serotonin in regulating behavior across vertebrates. Here, we investigated how acute exposure to environmentally relevant concentrations of fluoxetine influences anti-predator behavior in Gulf killifish (Fundulus grandis), a key estuarine fish commonly found in saltmarsh habitats. Killifish were exposed to control (0 ng/L), low (17.8 ng/L), and high (596 ng/L) fluoxetine concentrations and subsequently tested in the presence …

Ecological Responses To Living Shoreline Restoration, Aaron S. Bland

Graduate Theses and Dissertations (2019 - present)

Coastal built communities and natural coastal ecosystems face similar and interrelated hazards: shoreline sediment erosion, shoreline retreat, and worsening storms, each of which is exacerbated by relative sea level rise. Living shorelines are coastal defense projects that incorporate natural habitats to provide more sustainable shoreline defense and improve the coastal ecosystem. Living shorelines have been widely adopted, but their performance has been highly variable, and the mechanisms of project success and failure are unclear. The overarching goal of this dissertation was to better understand the ecosystem responses to coastal restoration, focusing on the primary habitats of coastal salt marsh and …

Feeding Ecology In Coastal Systems, Randi L. Cannon

Graduate Theses and Dissertations (2019 - present)

Oysters (Crassostrea virginica) are critical foundation species in estuaries, providing numerous ecological and economic benefits. However, oyster populations have diminished worldwide. Effective oyster restoration and aquaculture require a mechanistic understanding of the physiological and environmental factors that govern oyster feeding, growth, and resilience under changing coastal conditions. We investigated how oyster ploidy and environmental conditions influenced oyster feeding and investigated how changes in abiotic conditions affected behavioral performance of oyster drills (Stramonita spp.), a key oyster predator. To better understand feeding responses and behaviors of both predator and prey we 1) used in-situ filter feeding assays to determine if feeding …

Impacts Of Nutrient Addition And Disturbance On Coastal Dune Arthropod Communities And Trophic Interactions, Kayla Beitzel

Graduate Theses and Dissertations (2019 - present)

Coastal dune ecosystems face ongoing threats from human-mediated disturbance and altered resource availability. Because these dunes provide critical habitat for many organisms, including shorebirds, beach mice, and arthropods, changes in disturbance regimes or resource availability can impact plant communities and higher trophic levels by altering plant richness and productivity, which in turn influence arthropod abundance and diversity. To examine how disturbance and nutrient addition affect arthropod communities, we established twenty 5×5 m plots on Dauphin Island, crossing mechanical disturbance with a 10 g m⁻² addition of nitrogen, phosphorus, and potassium, replicated across five experimental blocks. Arthropods were sampled using three …

Taxonomy Of Endophytic Fungi Associated With Vallisneria Neotropicalis, Md. Arafat Rashid

Graduate Theses and Dissertations (2019 - present)

This study presents the first comprehensive taxonomic and ecological investigation of endophytic fungi (EF) associated with the submerged aquatic macrophyte Vallisneria neotropicalis in the southern United States. Over a 12 month period, from April 2023 to March 2024, leaf samples were collected from two distinct sites in Mobile Bay, Alabama a disturbed, brackish Causeway location and a cleaner, less impacted site at Meaher State Park. Using culture dependent methods, a total of 257 fungal endophytes were isolated from 1,200 leaf segments. All isolates belonged to the phylum Ascomycota, distributed across 3 classes, 6 orders, 10 families, and 19 taxa. The …

Ghosts In Glass: Ghost Crabs (Ocypode Quadrata) As Judges Of Glass Sand For Coastal Restoration, Emily Parrish

Poster Presentations

Coastal erosion is heavily impacting coastal ecosystems across the Gulf. For instance, the state of Louisiana loses a football field worth of land every 100 minutes (Couvillion, 2017). The drastic loss of coastline highlights the dire need for restoration in the Northern Gulf Coast. An unexpected solution to this sediment loss may solve two major environmental issues at once by diverting millions of tons of glass waste from entering America’s landfills each year. By crushing glass to create sand and gravel for coastal restoration, we may generate a consistent and sustainable source of substrate. Our goal is to determine the …

Design And Optimization Of Aquaculture Gear: Development Of A Cage-Integrated Reeling Mechanism For Oyster Farming, Felicity Bryant

Honors Theses

This project encompasses the design, fabrication, and testing of a cage-integrated reeling system aimed at reducing the physical labor required in oyster aquaculture at Bama Bay Oyster Farm, the last operational oyster farm in Mobile Bay. The proposed system includes two primary components: lightweight, modular oyster cages and a dual-winch reeling device for automated retrieval. Three cage prototypes—rectangular, oval, and hexagonal—were evaluated for structural performance and fabrication feasibility. The oval design was ultimately excluded due to practical fabrication limitations. The rectangular and hexagonal designs were fabricated using recycled materials and tested under the most extreme environmental conditions derived from years …

Ghosts In Glass: Ghost Crabs As Judges Of Glass Sand For Coastal Restoration, Emily Parrish

Honors Theses

Over 60% of the Gulf of Mexico coastline is actively eroding, which has resulted in thousands of miles of lost coastline over the last 100 years. This drastic loss of coastal land highlights the dire need for coastal restoration across the entirety of the Gulf Coast. A vital aspect of restoring these eroded areas is replenishing eroded substrate, traditionally conducted through offshore dredging of substrates which comes with high economic and ecological costs. Recycled glass sand may be able to fill this role and reduce our reliance on dredging while lowering the amount of glass waste entering landfills each year. …

Phytoplankton Responses To Changing Irradiance And Carbon Fertilization, Alison Siersma

Graduate Theses and Dissertations (2019 - present)

Phytoplankton play a crucial role in marine ecosystems due to their innate ability to fix carbon. As atmospheric CO2 levels continue to rise from fossil fuel combustion, the resulting increase in dissolved CO2 and the concurrent decrease in ocean pH are likely to impact the phytoplankton community. The response of phytoplankton to elevated CO2 can vary significantly among species and environmental conditions (e.g. light, temperature, nutrient availability). To address these variations, an experiment was conducted using a controlled photobioreactor system, maintaining high and low light, constant temperature, nutrient levels, and two pCO2 concentrations. This study focused on two regionally relevant …

Fauna, Flora, And Land Cover Changes Over The Last Two Decades In The Mobile-Tensaw River Delta, Gabriel De Oliveria, Steven R. Schultze, Guilherme Mataveli

Technical Reports

A technical report documenting ecosystem changes to the Mobile-Tensaw River Delta region due to urban expansion over approximately two decades (2001-2019).

Impacts Of Disturbance And Nutrient Addition On Coastal Dune Arthropod Communities, Kayla Beitzel

Honors Theses

Coastal dune ecosystems are globally distributed ecosystems that occur from the tropics to the poles and serve as the first line of defense during storms. They are critical habitats for a variety of organisms and also play a critical role in stabilizing coastal habitats. These systems face increased pressure via urban development, recreational expansion, and sea-level rise (Newman et al. 2023; Webster et al. 2005). Insects are vital consumers in coastal ecosystems and act as regulators of plant growth. Low-diversity ecosystems, like coastal dune systems, often contain a higher abundance of low-diverse insect consumers (Ripple et al. 2021), which can …

Interactions Between Sediment Mechanical Structure And Infaunal Community Structure Following Physical Disturbance, William Cyrus Roger Clemo

Graduate Theses and Dissertations (2019 - present)

Shallow, river-influenced coastal sediments are important for global carbon storage and nutrient cycling and provide a habitat for diverse communities of invertebrates (infauna). Elevated bed shear stress from extreme storms can resuspend, transport, and deposit sediments, disrupting the cohesive structure of muds, and sorting and depositing sand eroded from beaches. These physical disruptions can also resuspend or smother infauna, decreasing abundances and changing community structure. Infaunal activities such as burrowing, tube construction, and feeding can impact sediment structure and stability. However, little is known about how physical disturbance impacts short and long-term sediment habitat suitability and whether disturbance-tolerant infauna influence …

Linking The Metabolic And Ecological Fate Of Caribbean Ciguatoxins And Related Neurotoxins In Reef Herbivores, Jessica K. Gwinn

Graduate Theses and Dissertations (2019 - present)

Ciguatera poisoning (CP) is one of the most prominent seafood-borne illnesses worldwide, affecting between 25,000–500,000 people annually. Ciguatera is caused by the ingestion of seafood contaminated with algal-derived ciguatoxins (CTX), the precursors of which are produced by benthic and toxigenic dinoflagellates in the genera Gambierdiscus and Fukuyoa. These compounds enter marine food webs through herbivory and are subsequently transferred to higher trophic levels, undergoing complex metabolic biotransformations, which produce structurally related CTX derivatives. Consumption of CTX induces a variety of severe neurological, gastrointestinal, and/or cardiovascular symptoms beginning within hours and lasting for weeks to months following exposure. Despite the impact …

Cadmium And Salinity Stressor Antagonism On Vallisneria Neotropicalis, Christopher P. Mikolaitis

Graduate Theses and Dissertations (2019 - present)

Submerged macrophytes form the foundation of freshwater ecosystems. These organisms are sessile and are very susceptible to shifts in their environment. Heavy metals are of particular concern as they can be sequestered indefinitely in sediments and are readily taken up by rooted vegetation. In the presence of saltwater intrusions, these metals can interact with salt ions potentially changing their availability to submerged vegetation. In this study a freshwater macrophyte, Vallisneria neotropicalis, was used as a test species for interactive effects between Cd, a non-essential heavy metal, and salt stress. The metrics used to establish the individual as well as …

Determination Of Cadmium Uptake In Crassostrea Virginica Shell Under Controlled Conditions, Joseph John Pavelites Ii

Graduate Theses and Dissertations (2019 - present)

The objective of this thesis was to meet growing demand for the development of environmental biomonitors that protect ecosystems and public health. To do this, I determined the potential of oyster shell as a bioindicator of cadmium (Cd) in the environment by determining the mode of Cd uptake and relationships between Cd concentrations in the environment, shell, and soft tissues of juvenile eastern oysters (Crassostrea virginica Gmelin). I performed a review of the literature on the ability of oyster shell to retain metal contaminants and the factors that could affect this process (Chapter 2). I then reared C. virginica …

Characterizing Gray Snapper (Lutjanus Griseus) Life History In The Northcentral Gulf Of Mexico: Age And Growth, Mortality, And Reproduction, Edward Kim

Graduate Theses and Dissertations (2019 - present)

Gray Snapper (Lutjanus griseus) constitute a significant recreational fishery and minor commercial fishery throughout the Gulf of Mexico, and review of the recent assessment determined that the stock is overfished and has been undergoing overfishing. The absence of regional baseline data in the northcentral Gulf of Mexico, combined with projections of range expansion and subsequent population growth due to climatic warming, highlight the need for the present investigation into the age and growth, mortality, and reproduction of this species in Alabama and Mississippi. Sex-specific growth curves constructed using the von Bertalanffy growth function demonstrated a significantly greater mean asymptotic length …

Site Fidelity Of Bottlenose Dolphins (Tursiops Truncatus) Using Elemental Analyses And Photo-Identification, Lauren R. Clance

Graduate Theses and Dissertations (2019 - present)

The objective of this study was to determine if bottlenose dolphins (Tursiops truncatus) in Alabama waters acquire location-specific elemental signatures indicative of site fidelity. I measured trace metal concentrations (Chapter II) and stable isotope ratios (Chapter III) in skin from free-ranging dolphins remotely biopsied in Mobile Bay, the northern Gulf of Mexico (Gulf) and eastern Mississippi Sound (EMSS). Elemental findings were corroborated with photo-identification data. I found that dolphins acquired some location-specific elements indicative of site fidelity, with the greatest differences at geographic extremes, particularly relative to salinity. For trace metals, highest concentrations were found in winter, consistent with higher …

Coastal Sediment Response To The Diel Oxygen Cycle, Kara Gadeken

Graduate Theses and Dissertations (2019 - present)

Shallow coastal sediments are sites of intense respiration and organic matter breakdown. Macroinfauna bioturbate and bioirrigate sediments which supplies microbes with oxygen and newly deposited organic material from surface sediments, facilitating microbial remineralization of organic matter. These processes depend heavily on the concentration of dissolved oxygen in overlying water. Shallow water oxygen patterns often follow a diel cycle as dissolved oxygen decreases at night due to respiration and then increases during the day with photosynthesis, creating recurring suboxic conditions that are potentially stressful to organisms. Sediment oxygen flux is known to depend on ambient dissolved oxygen concentration, but behavioral responses …

Underwater Video As A Tool To Quantify Fish Density In Complex Coastal Habitats, Ronald Baker, Dakota Bilbrey, Aaron Bland, Frank D’Alonzo Iii, Hannah Ehrmann, Sharon Havard, Zoe Porter, Sarah Ramsden, Alexandra Rodriquez

University Faculty and Staff Publications

Habitat loss is a serious issue threatening biodiversity across the planet, including coastal habitats that support important fish populations. Many coastal areas have been extensively modified by the construction of infrastructure such as ports, seawalls, docks, and armored shorelines. In addition, habitat restoration and enhancement projects often include constructed breakwaters or reefs. Such infrastructure may have incidental or intended habitat values for fish, yet their physical complexity makes quantitatively sampling these habitats with traditional gears challenging. We used a fleet of unbaited underwater video cameras to quantify fish communities across a variety of constructed and natural habitats in Perdido and …

Fish And Invertebrate Use Of Restored Vs. Natural Oyster Reefs In A Shallow Temperate Latitude Estuary, Jonathan H. Grabowski, Christopher J. Baillie, Adam Baukus, Rachael Carlyle, F. Joel Fodrie, Rachel K. Gittman, A. Randall Hughes, David L. Kimbro, Juhyung Lee, Hunter S. Lenihan, Sean P. Powers, Kevin Sullivan

University Faculty and Staff Publications

Coastal marine habitats continue to be degraded, thereby compelling largescale restoration in many parts of the world. Whether restored habitats function similarly to natural habitats and fully recover lost ecosystem services is unclear. In estuaries, oyster reefs have been degraded by multiple anthropogenic activities including destructive fishing practices and reduced water quality, motivating restoration to maintain oyster fisheries and other ecosystem services, often at relatively high cost. We compared fish and invertebrate communities on recently restored (0–1 year post-restoration), older restored (3–4 years post-restoration), and natural oyster reefs to determine if and when restored reefs support functionally similar faunal communities. …

Population Dynamics, Relative Abundance, And Habitat Suitability Of Adult Red Drum (Sciaenops Ocellatus) In Nearshore Waters Of The North-Central Gulf Of Mexico, Crystal Hightower, J. Marcus Drymon, Amanda E. Jefferson, Matthew B. Jargowsky, Emily A. Seubert, Simon Dedman, John Mareska, Sean P. Powers

University Faculty and Staff Publications

In the Gulf of Mexico, the red drum (Sciaenops ocellatus) is an immensely popular sportfish, yet the Gulf of Mexico stock is currently managed as data-limited in federal waters. The results of the federal stock assessment conducted in 2016 for Gulf of Mexico red drum were not recommended for providing management advice. Consequently, we sought to address data gaps highlighted in the assessment by producing up-to- date overall and sex-specific growth models, standardized indices of relative abundance, and predictions of habitat suitability and by updating estimates of natural mortality. Using a time series for the period of 2006–2018, we assigned …

Tracking Vibrio: Population Dynamics And Community Ecology In Alabama Estuaries, Blair H. Morrison

Graduate Theses and Dissertations (2019 - present)

Integral parts of local culture along the Eastern Mississippi Sound System (EMSS)- eating raw oysters and fishing- can involve contact with vectors of pathogenic Vibrio spp. bacteria. High mortality rates from vibrio infections demonstrate the need for improved understanding of V. vulnificus and V. parahaemolyticus dynamics in the region. This study assessed: 1) meteorological, 2) hydrographic, and 3) biological correlates of V. parahaemolyticus and V. vulnificus in the EMSS from April-October 2019. Spearman’s correlations, linear mixed models, and non-metric dimensional scaling identified significant relationships between Vibrio spp., abiotic, and biotic parameters of the ecosystem. Vibrio spp. population dynamics were largely …

Red Drum And Spotted Seatrout Live-Release Tournament Mortality And Dispersal, T. Reid Nelson, Crystal Hightower, Sean P. Powers

University Faculty and Staff Publications

Although catch-and-release fishing tournaments undoubtedly reduce mortality of target species, postrelease mortality and fish stockpiling at release sites remain common concerns related to these tournaments. The impacts of liverelease tournaments on freshwater species have been widely studied. However, research on estuarine sport fishes is lacking even though catch-and-release tournaments targeting these species are prevalent and popular recreational fisheries exist. Therefore, we estimated the post-weigh-in mortality and dispersal of Red Drum Sciaenops ocellatus and Spotted Seatrout Cynoscion nebulosus released from the 2016–2018 Alabama Deep Sea Fishing Rodeo live-weigh-in categories using acoustic telemetry. To concurrently estimate overall post-weigh-in mortality and dispersal, we …

Age, Growth, And Mortality Of Atlantic Tripletail In The North-Central Gulf Of Mexico, Amanda E. Jefferson, Matthew B. Jargowsky, Meagan N. Schrandt, Pearce T. Cooper, Sean P. Powers, John Dindo, J. Marcus Drymon

University Faculty and Staff Publications

In the southeastern USA and the Gulf of Mexico (GOM), Atlantic Tripletail Lobotes surinamensis are increasingly targeted by recreational anglers, indicating that stock status should be assessed. A critical need for such assessments is age-specific data; however, previous studies have drawn conflicting conclusions regarding the most appropriate structure for aging. Moreover, growth parameters and mortality rates for GOM Atlantic Tripletail are unknown. Therefore, the goals of this study were to (1) evaluate sagittal otoliths and first dorsal spines as aging structures; (2) model combined and sex-specific growth; and (3) estimate mortality rates for GOM Atlantic Tripletail. From 2012 to 2019, …

Documentation Of Atlantic Tarpon (Megalops Atlanticus) Space Use And Move Persistence In The Northern Gulf Of Mexico Facilitated By Angler Advocates, J. Marcus Drymon, Matthew B. Jargowsky, Michael A. Dance, Mitchell Lovell, Crystal L. Hightower, Amanda E. Jefferson, Andrea M. Kroetz, Sean P. Powers

University Faculty and Staff Publications

Atlantic tarpon (Megalops atlanticus, hereafter tarpon) are facing a multitude of stressors and are considered Vulnerable by the IUCN; however, significant gaps remain in our understanding of tarpon space use and movement. From 2018 to 2019, citizen scientists facilitated tagging of 23 tarpon with SPOT tags to examine space use and movement across the northern Gulf of Mexico. Movement-based kernel densities were used to estimate simplified biased random bridge-based utilization distributions and a joint move persistence model was used to estimate a behavioral index for each fish. Tarpon showed consistent east–west movement from the Alabama/Florida border to Louisiana, and utilization …

Habitat Associations And Co-Occurrence Patterns Of Two Estuarine-Dependent Predatory Fishes, Mariah C. Livernois, Sean P. Powers, Mark A. Albins, John F. Mareska

University Faculty and Staff Publications

Estuarine-dependent fishes experience a wide range of environmental conditions, and most species exhibit distinct associations with particular habitats. However, similar species or multiple conspecifics often overlap spatiotemporally, which can result in ecological interactions that have consequences for behaviors that can shape the structure and function of ecosystems. We used a long-term gill-net data set (2001–2015) to investigate the habitat associations and cooccurrence patterns of two estuarine-dependent predatory fishes, Red Drum Sciaenops ocellatus and Spotted Seatrout Cynoscion nebulosus, in coastal Alabama, USA. Both species were associated with similar environmental conditions, primarily low dissolved oxygen and low salinity, especially when temperature was …

Estimates Of Red Drum Mortality Via Acoustic Telemetry, T. Reid Nelson, Sean P. Powers

University Faculty and Staff Publications

Subadult (age < 3) Red Drum Sciaenops ocellatus support a valuable recreational fishery, and mortality estimates for young Red Drum are needed for proper management. To obtain these estimates, age-1 and age-2 Red Drum were implanted with acoustic transmitters and external Floy tags in two coastal Alabama rivers (Fowl and Dog rivers). Fates of tagged fish were inferred from stationary receiver detections and active relocations over 1 year. These fates were used in a Bayesian multistate model to estimate instantaneous monthly and annual mortality and emigration rates for each river and overall from both rivers. Instantaneous monthly fishing mortality (F) ranged from 0.001 to 0.112 (annual F = 0.414) in Dog River, from 0.001 to 0.126 in Fowl River (annual F = 0.309), and was 0.001–0.054 (annual F = 0.337) overall. Instantaneous monthly natural mortality (M) ranged from 0.001 to 0.002 (annual M= 0.069) in Dog River, from 0.001 to 0.036 (annual M= 0.178) in Fowl River, and from 0.001 to 0.017 (annual M= 0.090) overall. The overall annual estimate of instantaneous total mortality (Z) was 0.435. The median escapement percentage was estimated at 36.3% (95% posterior credible interval = 19.5–56.0%) using M and Z from the overall model. Unfortunately, the error on this estimate was large and inconclusive as to whether the 30% escapement goal for juvenile Red Drum to the adult population from Dog and Fowl rivers is being met. Monthly residency estimates were typically greater than 0.90, and overall annual residency was estimated at 0.716. Fishing mortality estimates from the current study are higher than recent catch curve estimates that did not include young Red Drum. These results demonstrate that young Red Drum need to be accounted for when generating mortality estimates and provide needed data for the Red Drum recreational fishery.

Hypoxia In Mangroves: Occurrence And Impact On Valuable Tropical Fish Habitat, Alexia Dubuc, Ronald Baker, Cyril Marchand, Nathan Waltham, Marcus Sheaves

School of Marine and Environmental Sciences Faculty and Staff Publications and Presentations

Intertidal mangrove forests are harsh environments that can naturally experience hypoxia in association with low tide. However, we know relatively little about dissolved oxygen (DO) fluctuations and DO-induced responses by fish, although DO is a fundamental water quality parameter. This study examines DO as a potential factor regulating the utilization of intertidal mangrove forests by fish and consequently their widely recognized feeding, refuge and nursery values. We deployed underwater video cameras, coupled with DO and depth loggers, in a mangrove forest to record changes in fish assemblages in response to tidal variations in DO and other associated environmental parameters. Our …