Marine Biology Commons^™

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 …

Modeling Oyster Growth Dynamics In Flupsy Systems To Develop A Decision Support Tool For Seed Management, Gretchen Clauss

Honors Projects

As the Gulf of Maine warms and lobsters move north to colder waters, Maine’s working water front has begun to diversify. There is a thriving new ecosystem of aquaculturists looking to keep Maine’s waterfront traditions alive in a lasting, sustainable way. One of the most popular aquaculture industries is oyster farming. With an increasing number of oyster farms developing in Midcoast Maine each year, we seek to develop a decision support tool to aid farmers in seed management. Oyster farmers can choose weather or not to use an upweller on their farm, and our goal is to provide guidance on …

Community Ecology And Disease Dynamics In Pacific Oysters: Unraveling Microbiome-Pathogen Interactions In The Wild, Victoria E. Cifelli

Cal Poly Humboldt theses and projects

In the context of multispecies microbial assemblages, disruptions can occur when there are alterations in host conditions, such as the onset of a disease. Notably, viruses have the potential to reshape a host's microbial community. However, the role of the host's habitat and environment, which could be pivotal in communities with shifting niche space and habitat filters, is often overlooked in host-microbe-pathogen interactions. Recognizing the importance of these factors, I employed a field-based approach to understand microbial community dynamics in the presence of disease. To address the influence of geographical location, I conducted an analysis involving healthy and infected oysters …

Field Assessment Of The Pervious Oyster Shell Habitat: Enhancement Of Intertidal Habitat For The Eastern Oyster And Associated Nekton In Northeast Florida, Hunter Mathews

UNF Graduate Theses and Dissertations

A dramatic global decline in oyster reef habitat has led to widespread deployment of oyster restoration projects. Efforts are underway to move away from polluting methods like plastic mesh bags in oyster deployments. Additionally, increasing pressure on our estuaries from recreational boat wakes and intensified storms requires more robust structures for shoreline protection. The “Pervious Oyster Shell Habitat” (POSH) is a novel artificial reef structure composed of oyster shell bound by a thin layer of Portland cement, into the shape of a dome. The structure’s makeup greatly reduces its environmental impact, while providing quality substrate for provision of oyster reef …

Characterizing Endogenous Dicer Products To Unravel Novel Rnai Biogenesis Pathways, Jacob Oche Peter

Dissertations

ABSTRACT

RNA interference (RNAi) is a pervasive gene regulatory mechanism in eukaryotes based on the action of multiple classes of small RNA (sRNA). Exploiting RNAi pathways in non-model systems have great potential for creating potent RNAi technologies. Here, we accessed RNAi-mediated control of gene expression in the two-spotted spider mite, Tetranychus urticae (T. urticae) using engineered dsRNA designed to modulate the host RNAi pathway and increase RNAi efficacy. Analysis of Dicer (Dcr) generated fragments revealed how exogenous RNAs access the host RNAi pathway in this animal, opening avenues for designing RNAi technology for their control. Further, some organisms …

Crassostrea Gigas Invasion In Southern California: Macrofaunal Diversity And Local Community Impacts Of Ecosystem Engineers On Estuarine Habitats, Noah Jansen-Yee

Theses

Many marine ecosystems are facing the growing threat of biological invasions. These invasions can have a variety of different impacts on ecosystems and their inhabitants. The Pacific oyster, Crassostrea gigas, is currently in the relatively early stages of invasion in San Diego estuaries. Crassostrea gigas is a large, filter-feeding bivalve that forms dense oyster beds on hard substrate. These oysters are known to outcompete native counterparts and drastically alter habitats where they are present. Crassostrea gigas is an ecosystem engineer that, through shell creation and formation of a dense oyster matrix, impacts ecosystems in a variety of direct and indirect …

Screening Ocean Samples From Georgia For The Presence Of Msx And Dermo Using Pcr And Qpcr Methods, Olivia Michelle Williams

Honors Theses and Capstones

This Senior Thesis project aimed to be able to screen samples that came in from a PhD student in Georgia for the presence of two oyster diseases, MSX and Dermo. This study was done using PCR followed by visualizing on E-gels for initial presence of disease. These were then followed by qPCR and visualization on Criterion gels. These Criterion gels were able to be analyzed in order to calculate the pg/uL of MSX and Dermo in the original ocean samples. Since the samples were sent in over the course of February-August ‘21 the presence over time was also able to …

Disease Prevalence And The Population Genetic Structure Of Crassostrea Virginica Along The Georgia Coast, Sarah Batchelor

Electronic Theses and Dissertations

The Eastern Oyster, Crassostrea virginica, is an ecologically important species that plays a role in protecting shorelines, water filtration, and providing habitat and food for various fish species. Perkinsus marinus and Haplosporidium nesloni are two pathogens currently affecting oyster populations. These pathogens have both been documented as causes of mass mortality events along the East coast. They greatly diminish the health of oysters, resulting in the degradation of oyster tissue, reduction in growth and reproductive ability, and may cause death. In this study, wild oysters were collected from eleven locations along the Georgia coast to investigate the presence, intensity, …

Examining The Effect Of Interstitial Space On Eastern Oysters (Crassostrea Virginica): Applications Of Photogrammetry And Three-Dimensional Modeling, Bailie Lavan

Masters Theses, 2010-2019

Global oyster populations have decreased by as much as 99% in the past century. Oysters are known ecosystem engineers, providing benthic habitat for macrofauna, linking benthic and pelagic food webs, improving water quality, and mitigating shoreline erosion. Restoration efforts are critical in re-establishing native oyster populations. In the Chesapeake Bay, where oyster loss is primarily due to severe over harvest, artificial substrates with geometric shapes are widely used in restoration efforts. However, natural oyster reefs form emergent shapes with a high degree of aggregation and many interstitial spaces (three-dimensional volumetric spaces between oysters within a reef). The lack of interstitial …

Efficacy Of Magnesium Enriched Artificial Substrate For Oyster Restoration, Matthew Elder

Masters Theses, 2010-2019

The eastern oyster, Crassostrea virginica, is a keystone species that has undergone a large (> 95%) population decline due to overharvest, pollution, and disease. Restoration efforts focus on alternative larval attachment substrates such as concrete, to supplement the loss of natural oyster shell. Magnesium is a component of bivalve shells and its presence in the environment has shown to be important to the growth of mussels, but the same relationship has not been studied in oysters. Assuming that magnesium can be assimilated from the substrate on which the organism is growing, or that ions of magnesium are leached into …

Detrital Protein Contributes To Oyster Nutrition And Growth In The Damariscotta Estuary, Maine, Usa, Cheyenne M. Adams

Electronic Theses and Dissertations

Oyster aquaculture is an expanding industry that relies on identifying and utilizing natural estuarine conditions for the economically viable production of a filter-feeding crop. The eastern oyster, Crassostrea virginica, is the principal species currently cultured in Maine. In addition to preferentially consumed phytoplankton, various detrital complexes (non-algal and/or non-living organic matter) may provide some nutrition to C. virginica between times of phytoplankton abundance. Here I investigated the importance of detrital proteins in supporting the growth of oysters cultured in the upper Damariscotta Estuary. Oyster aquaculture in this area is highly successful and previous reports indicate that labile detrital protein …

The Effect Of Calcium In Artificial Substrates For Oyster Restoration: Implications For The Mitigation Of Oyster Population Decline, Jessie Mandirola

Masters Theses, 2010-2019

Oyster populations in the Chesapeake Bay have declined by 99% over the past 150 years due to overharvesting, disease, ocean acidification, and poor water quality. Restoration efforts are needed to reestablish native oyster populations. Current restoration efforts utilize natural oyster shells but these methods are expensive and unsustainable. Therefore, restoration is starting to use artificial substrates instead. Concrete has been successfully used in previous research; spat will attach and oysters will grow. However, there is a lack of knowledge about how the composition of concrete effects oyster larval recruitment. We tested concrete made with limestone sand (“special concrete”) to increase …

Social And Ecological Factors Affecting The Adoption Of Aquaculture, Karen Pianka

Electronic Theses and Dissertations

Commercial fishermen in Maine are increasingly dependent upon the American lobster fishery, and this reliance on a single species poses a threat to working waterfronts. Aquaculture represents a potential opportunity for commercial fishermen to diversify their income. Literature on the adoption of innovation suggests that factors such as age, education level, fishing experience, diversification, and leadership are important predictors of early adoption of innovation. However, few studies have examined whether such factors affect the adoption of aquaculture by commercial fishermen. Our marine policy research studied fishermen enrolled in two pilot shellfish and seaweed aquaculture classes held in 2013 in Harpswell …

Management Recommendations For Restoration Of The Degraded Olympia Oyster, Ostrea Lurida Carpenter 1864 In Tomales Bay, Ca, Carolyn M. Gibson

Master's Projects and Capstones

This research addresses the effective restoration of Olympia oyster populations in Tomales Bay, Marin County, California. Chapter 2 provides background information on the Tomales Bay estuary, regional history, and ecology of the Olympia oyster. Following this background discussion, each of the three aforementioned degraders of Olympia oyster populations in Tomales Bay is presented: ocean acidification (Chapter 3), sedimentation (Chapter 4), and invasive species (Chapter 5). Each of these issues creates numerous barriers that require the attention of resource protection managers. Chapter 6 presents overall Research Conclusions and Chapter 7 identifies management recommendations to effectively begin the restoration of the Olympia …