Life Sciences Commons^™

Addition And Subtraction: Coral Reproduction And Disease In A Changing Ocean, Ashley Rossin

LSU Doctoral Dissertations

Marine diseases are changing the landscapes of coral reefs particularly throughout the Western Atlantic. Stony coral tissue loss disease (SCTLD) swept through this region impacting at least 22 stony coral species. White plague (WP) is a more ephemeral disease, but still has a significant impact on coral reef health and perseverance, especially under a changing ocean. While these impacts are seen on the reef-scale, we can zoom into the tissue-level to identify disease markers for both diseases and identify their differences. This has ramifications for disease intervention, as well as mitigation strategies. Despite continuous disease outbreaks, healthy corals persist and …

Tropical Fish Study In Tahiti, French Polynesia, Miranda Brainard, Caitlyn Swango, Paityn Houglan, Richard Londraville

Williams Honors College, Honors Research Projects

In May of 2023, I embarked on an exciting research journey to Moorea, French Polynesia, alongside fellow students and faculty members from the University of Akron and Syracuse University. This expedition was part of the university-sponsored Tropical Vertebrate Biology course, where we delved into the exploration of various tropical species inhabiting the island, including sea urchins, geckos, and my primary focus, the blackspotted rockskipper.

My research team, composed of my co-authors and me, was particularly intrigued by the unique refuge-seeking behavior displayed by blackspotted rockskippers. These amphibious fish are renowned for their remarkable ability to inhabit tide pools and rocky …

Habitat Utilization Of Marsh And Adjacent Submerged Landscape By Fish And Macroinvertebrates In A Gulf Of Mexico Tidal Oligohaline Environment, Tia Offner

Theses and Dissertations

Estuarine habitats are considered nursery habitats for fishes and invertebrates, but oligohaline environments are critically understudied. Using a seine net and fyke nets, we sampled Back Bay, Mississippi (USA), a low salinity estuary, once a month for a year to explore the temporal use of the marsh and adjacent submerged landscape by nekton species. We also looked at whether there is evidence of habitat preference in the most numerous nekton species. We used a novel habitat usage index (HUI) to compare seine and fyke net catches of our top 10 species, and evaluated catch size in relation to maturation size. …

Biophysical Factors Affecting Habitat Suitability For Crassostrea Virginica, Jason D. Tilley

Dissertations

Oyster reefs provide a variety of important ecosystem services. However, the mortality rate of eastern oyster, Crassostrea virginica, the dominant species that produces oyster reefs in the northern Gulf of Mexico, is increasing at an alarming rate due to a variety of abiotic and biological factors. I examined how biophysical factors, including the less-studied fatty acid profiles of the suspended particulate matter on which oysters feed, influenced morphometric condition of C. virginica.

I sampled suspended particulate matter (SPM) and oysters in-situ in the western Mississippi Sound, which historically supported the majority of oyster production in Mississippi waters. Sampling …

Evaluating Habitat Use By Nekton In Widgeon Grass (Ruppia Maritima), Shoal Grass (Halodule Wrightii), And Unvegetated Bottom Habitats In The Grand Bay National Estuarine Research Reserve, Jessica Woodall

Master's Theses

Seagrass beds support high biodiversity and animal abundance, serve as feeding grounds for a variety of animals, offer shelter from predation, and act as a nursery habitat for juveniles. The species composition of seagrass beds can impact their use as habitat by animals. Two common species of seagrass in the Gulf of Mexico are Ruppia maritima (widgeon grass) and Halodule wrightii (shoal grass). The shallow coastal waters of the Grand Bay National Estuarine Research Reserve (NERR) support both species, but the use of each seagrass as habitat by nekton is poorly understood, which can limit management decision-making. Nekton communities were …

Spawning Asynchrony Of The Endangered Acropora Cervicornis: Are Light Pollution And Abnormally Warm Temperatures The Culprits?, Krista Laforest

All HCAS Student Capstones, Theses, and Dissertations

The persistence of reefs relies on mature corals spawning synchronously to maximize fertilization and produce larvae to replenish local populations. Corals synchronize the release of gametes by responding to temperature, sun, and moon light cycles; however, abnormalities in these patterns can disrupt synchrony. This study is the first to describe regional asynchronous spawning of Acropora cervicornis by quantifying gamete development and spawning times among two reefs, an in situ nursery off Fort Lauderdale, and an in situ nursery in the Florida Keys. While A. cervicornis in the Florida Keys synchronously spawned within the predicted window of 2-5 days after the …

Fishing And Fear Effects Interact To Shape Herbivory On Coral Reefs, Bethany M. Tilton

All HCAS Student Capstones, Theses, and Dissertations

Predation influences animal behavior and shapes ecological structure and function through lethal effects and fear effects. On coral reefs, fear effects can alter the distribution and intensity of herbivory by herbivorous reef fishes. This includes the browsing functional group, which potentially reverses macroalgal phase shifts and promotes reef recovery. Herbivory by multiple functional groups may increase on coral reefs through the use of NTZs (no-take zones) but few studies have examined the extent to which small-scale NTZs (< 0.5 km²) influence fear effects and perceived predator presence on reefs. This study aimed to determine whether fear effects on browsers on …

A Rapid Site Selection Assessment As An Indicator Of Stony Coral Microfragment Outplant Success, John J. Alfirevich

All HCAS Student Capstones, Theses, and Dissertations

Microfragmentation of massive stony coral species is a technique being utilized to propagate corals asexually to help restore coral reefs. Microfragmentation consists of cutting corals into 3 cm diameter or less fragments, which boosts growth rates. However, in some locations the size of microfragments make them vulnerable to parrotfish predation and benthic overgrowth, reducing survival. As such, a method to identify key site characteristics which promotes microfragment outplant success, particularly one that can be performed quickly across multiple areas is needed. A rapid site assessment conducted prior to microfragment outplanting was performed at 12 randomly selected sites within the Kristin …

Psammocora Stellata Distribution At Devil's Crown, Floreana Island, Galápagos Islands, Ecuador, María José Guarderas Sevilla

All HCAS Student Capstones, Theses, and Dissertations

In the Galápagos Archipelago, the free-living nodular coral Psammocora stellata is a common species that does not form reef structures. However, it is a key component of the ecosystem by increasing habitat complexity and, consequently, species diversity. This species experienced a drastic decline in Devil’s Crown channel, Floreana Island, where it disappeared after the 1982-83 El Niño-Southern Oscillation, presumably by displacement of unattached colonies by strong surface waves and currents. This assemblage has now recovered to pre-impact levels. A combination of underwater photoquadrats from 2007 and 2009 and recent (2023) orthomosaics were used to determine changes in coral densities and …

Effects Of Short-Term Pesticides Exposure On Swimming Behavior, Tissue Morphology, Oxidative-Nitrative Stress, Antioxidant Expression, And Cellular Apoptosis In Kidneys Of Goldfish, Esmirna Cantú

Theses and Dissertations

The prevalence of pesticides in the aquatic environment continues to increase due to anthropogenic activities and poses a threat to aquatic organisms. The aim of this study was to determine the short-term exposure (one-week) of pesticide mixtures (metolachlor, linuron, isoproturon, tebucanazole, alconifen, atrazine, pendimethalin; azinphos-methyl) on swimming behaviors, kidney morphology, and expression of nitrotyrosine protein (NTP), dinitrophenyl protein (DNP), superoxide dismutase (SOD), catalase (CAT), renin, and cellular apoptosis in goldfish (Carassius auratus). Results indicated that both low- and high-dose pesticide mixtures decreased the distance swimming behavior. Histological analysis showed pesticide exposure alters kidney morphology. DNP, NTP, and renin expressions, and …

The Relationship Between Biofouling Adhesion And Frequency Of Mechanical Cleaning To Control The Recruitment To Clear Coatings, Dylan Thomas Eggers

Theses and Dissertations

There is a need to control biofouling on sensors and transparent windows in the marine environment. Clear silicone coatings offer a method to reduce the adhesion strength of marine organisms to the surface, however, these also require mechanical cleaning to maintain the surfaces free of fouling. This research evaluated the performance of eighty seven formulations and took the top two candidates to investigate a) the frequencies of wiping required by a brush to maintain two coatings and uncoated glass surfaces free of fouling and b) the effects of clear silicone coatings fouling release properties on required frequencies. The panels were …

Do Mesopelagic Fish Biomass Patterns Change In Response To Major Oceanographic Features In The Northern Gulf Of Mexico?, Ian M. Areford

All HCAS Student Capstones, Theses, and Dissertations

In recent years interest in mesopelagic fishes has grown due to their ecological significance and economic potential. A major outstanding question is how the assemblage is potentially structured by mesoscale (10 - 100s km) oceanographic features such as eddies, fronts, and riverine plumes. Mesoscale features are known to influence micronekton and zooplankton’s spatial distributions but data on individual mesopelagic fish species’ responses are limited. The Gulf of Mexico (GoM) is an area of particular interest due to its diverse mesopelagic fish assemblage, its well-defined mesoscale oceanographic features, its history of anthropogenic impacts such as oil spills, and its diverse mesopelagic …

Deep Ocean Vehicle Applications And Modifications, Nichole "Nikki" T. Arm

Master's Theses

This project had two primary goals: (1) to explore opportunities to further a deep-ocean vehicle’s reach using alternative pressure spheres, and (2) to implement an existing deep-ocean vehicle (lander) in active scientific research.

I gained a greater understanding of the limitations and design choices made for existing pressure spheres using Finite Element Analysis (FEA). My simplified FEA model predicted sphere failure for the existing 30% Fiber Glass 70% Nylon injection molded spheres at an external pressure of 3,954psi or 2,690m ocean-depth (only a 7.38% error compared to the tested minimum failure depth), so I determined it a valid model. I …

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

<strong> Theses and Dissertations </strong>

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 …

An Intersection Of Science & Art: Vitrification Approaches And Open-Fabricated Tools For The Biomedical Model Sea Hare, Aplysia Californica, Allyssa M. Oune

LSU Master's Theses

The California sea hare (Aplysia californica) is an important biomedical model for molecular neurobiology, electrophysiology, learning, and memory due to their well-mapped and large neurons and well-characterized learning capabilities. The National Resource for Aplysia (NRA, University of Miami) maintains large stocks of live animals and relies on regular shipments of wild-caught individuals to maintain genetic diversity. This is labor and cost-intensive, and environmental changes could alter the availability of wild animals increasing the need to preserve this genetic resource. One solution is vitrification, ultra-fast cooling which produces an amorphous glass that minimizes damage to cells. Aplysia californica presents …

Identification Of Biomarkers Of Sub-Lethal Algal Toxin Exposure In Atlantic Salmon (Salmo Salar) And Chinook Salmon (Oncorhynchus Tshawytscha) Using Differential Gene Expression Analysis, Brandon Ellingson

Biology Theses

Atlantic Salmon (Salmo salar) and Chinook Salmon (Oncorhynchus tshawytscha) are important culturally, recreationally, economically, and are a common aquaculture species in Canada and the United States. In the Pacific Northwest, blooms of toxic algae result in millions of dollars annually in losses for salmonid aquaculture producers. Blooms of harmful cyanobacteria produce microcystins which have been linked to net-pen liver disease which has large financial impacts on net pen salmon operations. Microcystin-LR, the most toxic variant, bioaccumulates in the liver and disrupts normal cellular activity by inhibiting protein phosphatases leading to deleterious effects on growth, immune status, and liver function. To …

Population Genomics, Ecology And Conservation Of Asterias Sea Stars In The North Atlantic, Melenia I. Giakoumis

Dissertations, Theses, and Capstone Projects

Uncovering how species respond to environmental change is a central question in biology (Ehrlén & Morris 2015; Habibullah et al. 2022). It is the key to elucidating the past, understanding the present and predicting the future of species’ population dynamics. This dissertation investigates the influence of environmental change on intertidal species’ distributions and genomics at several timescales, with implications for conservation.

Environmental changes have occurred throughout history, on a geological scale, and have shaped the global patterns of species’ distributions and population sizes. Biologists have long studied how geological history has shaped species distributions (Sanmartín 2012) in both terrestrial (Liu …

Predicting Marine Teleost Responses To Ocean Warming And Pollution, Akila Harishchandra

Electronic Theses and Dissertations

Ocean warming and pollution are two detrimental anthropogenic factors causing rapid marine ecosystem degradation recorded in the past decades. These factors alter the marine environment intolerable for many marine species, forcing them to either adapt or shift their contemporary habitat ranges to reduce the extinction risk embedded with environmental degradation. Estimating marine species’ habitat range shifts, and their potential for developing adaptive mechanisms are critical for ecosystem conservation and management, human health risk assessment, and climate change vulnerability assessments. Given that, for the first chapter of this thesis, we focused on developing a species distribution model (SDM) integrating marine species …

Parasites Versus Predation: The Role Of Chronic And Acute Parasite Exposure In Infection Risk And Anti-Predator Behavior, Delaney Farrell

All HCAS Student Capstones, Theses, and Dissertations

Parasites with complex, multi-host lifecycles often engage in host behavior manipulation to increase transmission between successive hosts. In intermediate fish hosts, previous research has measured increased frequency of conspicuous behaviors, decreased swimming performance, and reduced antipredator behavior, which would collectively increase the fish’s risk of predation. In ecosystems where this type of parasite increased trophic transmission (PITT) occurs, parasites can play a substantial role in food webs. In this study, I investigate how chronic versus acute exposure to the trematode Euhaplorchis sp. A. affects the antipredator behavior of the Gulf killifish Fundulus grandis. Using a fully crossed design, I …

Desperate Larva Or Death Before Dishonor: Can Old Coral Larvae Replenish Degraded Reefs?, Nepsis García Lara

All HCAS Student Capstones, Theses, and Dissertations

The recovery of coral populations depends largely on larval recruitment. Coral larvae settle in response to environmental cues that indicate habitat quality. Newly competent larvae typically avoid settling on substrates with high macroalgal cover and sedimentation, and thus might never recruit to degraded reefs, hindering their recovery. What is unknown is if settlement preferences change as larvae age. In the absence of suitable settlement cues, lecithotrophic larvae delay settlement and might do this until either dying (Death Before Dishonor Hypothesis) or becoming less discriminatory and settling regardless of their specific habitat requirements (Desperate Larva Hypothesis). To test these hypotheses in …

The Effect Of Water Flow Rates On The Survival And Growth Rates Of Three Caribbean Bouldering Coral Species Juveniles In An Indoor Versus Outdoor Environment, Ian Michael Johnson

All HCAS Student Capstones, Theses, and Dissertations

Coral reefs are vital ecosystems for the world’s oceans and humanity; however, they are threatened by climate change, disease, and local anthropogenic stressors, and need assistance to recover. Traditional reef restoration efforts (fragmentation and outplanting are helping but are limited in effectiveness by not increasing genetic diversity. Ex situ sexual propagation for corals provides new, genetically different coral recruits. However, this process is laborious, expensive and time consuming, especially at the scale required to effectively contribute to the widespread recovery. To lower costs, two key parameters that require optimization to hasten the growth of coral recruits are water flow and …

Evaluating The Effect Of Symbiodiniacea On Survival, Growth, And Acquisition Of Newly Settled Corals Of Three Caribbean Species, Michael B. Hood

All HCAS Student Capstones, Theses, and Dissertations

Symbiosis between corals and Symbiodiniaceae is critical to coral reef health. However, this mutually beneficial relationship is threatened by a variety of stressors. This study aims to assess if seeding newly settled corals with different species of Symbiodiniaceae promotes differences in survival, growth, and symbiont acquisition in corals. Three reef-building species (Colpophyllia natans, Orbicella faveolata, and Pseudodiploria strigosa) reared in sterile saltwater baths were seeded with one of four Symbiodiniaceae species (Breviolum minutum, Durusdinium trenchii, Fugacium kawagutii, and Symbiodinium microadriaticum). Coral survival, growth, and symbiont acquisition were assessed biweekly during the first two months and monthly …

On The Edge Of The "Er-Ocean" State, Mariesa Travers

Masters Theses

This thesis will explore how hard coastal infrastructure methods can be redesigned by softening the coastal edge to support the ecosystem and enhance public access to the beach. By referencing and arguing against techniques used by the U.S. Army Corps of Engineers (USACE) as a solution to deal with coastal erosion, this process will propose a regenerated design system. Through a series of material experiments, this research works with natural processes and flows, to create transitory systems that erode and ebb with the coast.

Effects Of Intertidal Position On The Response To Oxygen And Desiccation Stress In The Common Acorn Barnacle, Balanus Glandula, Megan M. Dotterweich

Master's Theses

Sessile invertebrates in the rocky intertidal experience intermittent periods of air exposure due to tidal flux, presenting risks of temperature extremes, hypoxia, nutrient limitation, and most dangerously, desiccation. Microscale variation in severity and frequency of these risks is widely dependent on vertical position within the intertidal zone. Common acorn barnacles (Balanus glandula) have a wide vertical distribution in the intertidal, creating large differences in microhabitat between the highest and lowest individuals in the population. This study set out to explore whether tidal position dependent differences exist in the response to oxygen and desiccation stress in B. glandula. …

Practical Solutions To The Invasion Of Lionfish In Utila, Honduras: Science, Education, Food, And Jewelry, Carolyn Corley

Undergraduate Honors Theses

Lionfish (Pterois sp.) are invasive species capable of devastating coral reef ecosystems due to their lack of predators, large appetites, generalist diet, high fecundity, and rapid spawning rates. As lionfish have expanded their distribution across the Caribbean, many conservation groups have taken it upon themselves to systematically remove these predators from environments where they are threatening native species. However, few have involved the community the way I observed while interning with the Whale Shark and Oceanic Research Center in Utila, Honduras. Protecting coral reefs is extremely important, especially in small communities like Utila, where the majority of people’s …

Estimation Of Mortality Rates For The Gulf Menhaden Stock And Reference Point Implementation For The Fishery, Catherine Wilhelm

Master's Theses

The Gulf menhaden stock is the target of a large commercial fishery in the Gulf of Mexico. To address the needs of both the stock and fishery, I performed two studies. I first addressed the natural mortality rates currently used in the Gulf menhaden stock assessment. To update these rates, I used data from a tagging study conducted from 1970 to 1988. Adult and juvenile menhaden were tagged, released, and recovered in fish processing plants. To evaluate the data, I built a Bayesian model using the negative binomial distribution to estimate natural mortality, catchability, and the overdispersion factor parameters. I …

Connecting Social And Ecological Systems In Small-Scale Fisheries In The Philippines, Sara Eisler Marriott

Dissertations

Nearly 50% of all marine fish capture in the Philippines is from artisanal fisheries, most of which is un- or under-reported. As in many emerging nations around the world, the Philippines cannot fully address overfishing by managing only half of the catch that comes from commercial fisheries. Marine reserves are a popular governance strategy for conservation and of growing interest for fisheries management. Many marine reserves in the Philippines, however, are not considered effective. In 2014, Rare, an international NGO, implemented a community-based management program to increase the effectiveness of the marine reserves, and while it found biomass increased, there …

The Impacts Of Seasonality And Nutrient Loading On Microcystis Bloom Development In Wall Pond, Alyssa Antolak

Honors Theses

The harmful cyanobacteria Microcystis globally dominates eutrophic freshwater systems. Eutrophication leading to nitrogen and phosphorus loading into aquatic systems is increasing bloom propagation and shifting diatom/dinoflagellate dominated systems to cyanobacteria dominated systems. Understanding seasonal variability and environmental parameters combined with nutrient loading will allow for a better understanding of what factors are influencing Microcystis blooms. Biweekly plankton samples and environmental parameters were collected from Wall Pond from spring 2022-spring 2023. Results show that yearly plankton samples shifted from Microcystis dominated in the early summer to diatom dominated in the late summer-early fall then back to Microcystis dominated in late fall-early …

Biophysical Factors Impacting Sea Lice Settlement And Survival, Eleanor R. Glahn

Electronic Theses and Dissertations

Atlantic salmon (Salmo salar L.) aquaculture production in Maine is a valuable contributor to the economy, the expansion of which has been challenged by the parasitic salmon louse Lepeophtheirus salmonis. As planktonic organisms, the life of the salmon louse is primarily dictated by the physical conditions of the environment: the temperature for development time, salinity for survival, and current velocity for transport. Salmon lice are obligate parasites for whom the successful infection of a suitable host is critical to completion of their life cycle. However, little is understood about the effects of current velocity on infection success. Hydrodynamic …

Dolphin Behavioral Responses To Uncrewed Aerial Systems As A Function Of Exposure, Height, And Type, Savannah Damiano

Electronic Theses and Dissertations

Uncrewed aerial systems (UAS) are becoming a standard tool in the study of cetaceans, however, a comparative assessment of animal responses to UAS has not been established to gauge the most effective systems for cetacean study. We utilized Dolphin Quest Bermuda’s eleven bottlenose dolphins as subjects for such an investigation taking place over five weeks in 2022 and five weeks in 2023. The dolphins were evaluated for investigative behavioral responses to six off-the-shelf UAS types and a custom fixed wing system. Each UAS was flown in decreasing height vertically above the main dolphin lagoon to evaluate dolphin behavioral responses in …