Terrestrial and Aquatic Ecology Commons^™

Bottles, Butterflies, And Biomass: Recycled Glass Sand, Microbial Additions, And Herbivory Effects On Milkweed Growth, Kealey Skinner

Honors Theses

Plant-soil-microbe interactions are integral components of ecological networks and drive ecosystem function from the bottom-up. Whereas herbivores regulate ecosystem function from the top-down, having opposing and potentially complementary effects on ecosystem function. My thesis sought to understand how below-ground microbial communities contribute to herbivore preference and plant biomass across varied soil substrates. My thesis asked: how do substrate and soil microbial communities influence herbivore preference and plant biomass accumulation on swamp milkweed (Asclepias incarnata)? To address this question, seedlings of A. incarnata were sown in 2.5 cm wide × 10 cm deep pots filled with either natural beach sand or …

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.

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 …

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 …

New Insights On Hybridization In Potamogeton Floridanus (The Florida Pondweed), Kaitlyn R. Sampson

Graduate Theses and Dissertations (2019 - present)

Freshwater ecosystems are some of the most important and highest threatened habitats in the world, and aquatic plants play an important, but often-overlooked, role in maintaining them. Potamogeton is a diverse and ecologically important aquatic plant genus well known for taxonomic difficulty and rampant hybridization. lbis study aimed to 1) test the hypothesis that Potamogeton jloridanus (Florida pondweed) is a hybrid between P. oakesianus and P. pulcher, and 2) to investigate correlations in ecological conditions for the focal species. This study revealed the discovery of a new population of P. jloridanus in Big Coldwater Creek in Santa Rosa Co., FL, …

Lmpact Of Salmonella Enterica Effector Proteins On Plant Physiology And Immunity, Sara Qader

Honors Theses

Salmonella enterica serovar Typhimurium are primarily recognized as pathogens associated with foodborne illnesses in humans. Salmonella also can colonize plant tissue effectively. The pathogen relies on type III secretion systems (T3SS) to infect mammals and plants successfully and counteract the immune response. Understanding the molecular mechanisms underlying Salmonella’s interactions with plants is essential for developing effective strategies to reduce its impact on human health and agriculture. Effector proteins, known for their role in modulating host-pathogen interactions, have been implicated in the virulence and pathogenicity of Salmonella. However, their specific functions and contributions to Salmonella’s interactions with plants remain largely unknown. …

Survey Of The Bolctes From Fish River Nature Preserve, Noah T. Nelson

Honors Theses

Boletes are a special kind of mushroom inside of the Kingdom Fungi that are distinguished from other mushrooms by their uniquely pored hymenium, as opposed to gills. Many boletes are ectomycorrhizal, meaning they are mutualists with vascular plants, and thus beneficial to the overall health of the terrestrial ecosystem. Some are well-known for their edibility and are of economic importance. In the United States 59 genus-level clades comprising 290 operational taxonomic units have been reported. The southeastern US and Gulf Coast regions however are less researched and recorded for their mushroom ecology. In Alabama, only 56 bolete species have been …

Thamnophis And Their Toxic Relationship: Testing For Intraspecific Venom Variation In The Common Garter Snake, Thamnophis Sirtalis, Grace E. Coppinger

Poster Presentations

Project Objective - Estimate intraspecific venom variation between male and female garter snakes collected from the University of South Alabama of different sizes.

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 …

Unlocking The Mysteries Of Opportunism: Neuroendocrine Insights From An Aseasonal Breeder (Taeniopygia Guttata), Jessica A. Moodie

Graduate Theses and Dissertations (2019 - present)

The regulation of reproductive physiology in animals is mediated by the Hypothalamus-Pituitary-Gonad (HPG) axis. In seasonal breeders, a conserved reciprocal switching of deiodinase enzymes alters thyroid hormone signaling, which controls HPG activity. This study tested the hypothesis that neural regulation of the HPG axis as described in seasonal systems is conserved and repurposed to respond to other cues in aseasonal species. Using water deprivation and nest restriction in the opportunistic Zebra Finch, we were able to create a breeding group and non-breeding group, confirmed by egg laying and changes in ovarian anatomy. Breeding females had clear follicular hierarchy, increased ovary …

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 …

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 …

Effect Of Temperature On The Microbiome Of A Laboratory Reared Colony Of Haemaphysalis Longicornis Ticks, Brianna Mitchell

Poster Presentations

Honors research poster.

Haemaphysalis longicornis is a species of tick native to eastern Asia, including eastern China, Japan, eastern Russia, and Korea. To date, it has invaded and has now established its existence in Australia, New Zealand, and several of the Pacific Islands. This species of tick has recently been introduced to the United States, having a confirmed sighting in November 2017 on a sheep farm in New Jersey and since establishing populations in 18 states along the east coast and Appalachia. Based on the existing locations of H. longicornis in its native regions, as well as in the United …

Effect Of Temperature On The Microbiome Of A Laboratory-Reared Colony Of Haemaphysalis Longicornis Ticks, Brianna L. Mitchell

Honors Theses

Haemaphysalis longicornis ticks are invasive to the United States with potential to transmit several tick-borne pathogens that are native to the United States. Based on existing locations of H. longicornis in its native regions in Asia, as well as its invasive populations that are established in the United States, several geographic range prediction models have been produced to help understand future range expansion and distribution of this invasive tick in North America. Unfortunately, these models do not all agree and there is uncertainty associated with the potential geographic range expansion of H. longicornis ticks in North America. Climate can affect …

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 …

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 …

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 …

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 …