Term of Award

Fall 2024

Degree Name

Master of Science in Biology (M.S.)

Document Type and Release Option

Thesis (restricted to Georgia Southern)

Copyright Statement / License for Reuse

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.

Department

Department of Biology

Committee Chair

John Carroll

Committee Member 1

Shelby Ziegler

Committee Member 2

Stephen Greiman

Abstract

Ecosystem engineers play important roles within environments by modifying both the abiotic and biotic conditions and shaping overall community function. The Eastern oyster, Crassostrea virginica, is a critical ecosystem engineer for coastal habitats and communities. Some of the services they provide include filtering the surrounding seawater and increasing overall water quality, creating habitat as foraging and nursery grounds for many commercially and recreationally important species, and buffering wave energy to stabilize shorelines. In recent decades, however, oyster populations worldwide have been reduced to less than 15% of their previous abundance due to the pressure from overharvest, pollution, climate change, and disease. The loss of oyster reefs has had dramatic consequences for coastal communities, leading to declines in fisheries and ecosystem function. As a result, considerable investments have been put into management and restoration of oyster resources. For oyster management and restoration to be successful, it is important to investigate the factors that currently influence oyster demographics and disease to predict how those factors might change in the future. This study aimed to better understand the influence of water quality on oyster demographic metrics of recruitment, growth, survival, and condition as well as the prevalence and intensity of the disease-causing protozoan parasites Perkinsus marinus and Haplosporidium nelsoni. I utilized water quality data paired with various field surveys and experiments at Cabretta Creek, Dean Creek, Hunt Camp, and Ferry Dock that are part of the System-wide Monitoring Program at the Sapelo Island National Estuarine Research Reserve. Results indicate that my site with the highest temperature, salinity, DO, and pH, had oysters with the highest condition index, the greatest recruitment and growth, but the lowest survival and parasite infections. My site with the most variable water quality and lowest dissolved oxygen had oysters with the lowest condition index, the lowest recruitment and growth, but the greatest survival and high parasite infections. These results will inform current management, restoration, and aquaculture strategies and help to predict how climate change will impact oyster populations in the future.

OCLC Number

1478246957

Research Data and Supplementary Material

No

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