College of Graduate Studies: Theses & Dissertations

Term of Award

Summer 2026

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

Risa Cohen

Committee Member 1

Lisa Brown

Committee Member 2

Stephen Greiman

Committee Member 3

Nathaniel Shank

Abstract

Imidacloprid is a widely used neonicotinoid insecticide in agriculture that enters surface waters through runoff, ultimately reaching the coast where it poses a risk to nontarget estuarine organisms such as oysters. Oysters are important both ecologically and economically, making it important to understand how pollutants influence them. In addition, it is also important to develop effective strategies for removing imidacloprid from the environment, such as bioremediation which uses bacteria already present in sediments to break down contaminants. To investigate the effects of imidacloprid on oysters, such as growth and immune response, post-settlement oysters were exposed to imidacloprid for 28 days before challenging them with Vibrio splendidus to measure the relative expression of an antimicrobial immune gene. To test the ability of estuarine bacteria to degrade imidacloprid for potential bioremediation, sediment samples were collected from six oyster reef sites distributed across approximately 140 km of the Georgia coastline. Bacteria capable of growth in the presence of imidacloprid were isolated from each sediment sample and six bacterial strains were selected for identification by sequencing the16S rRNA gene. All isolated strains were members of the Vibrionaceae family: four Vibrio parahaemolyticus, one Vibrio alginolyticus, and one Photobacterium ganghwense. Since the two Vibrio species identified are known human pathogens, they were excluded from further consideration. However, Photobacterium ganghwense was tested against a control for degradation of imidacloprid and was determined to not degrade imidacloprid (p = 0.33) and therefore is not likely a good candidate for bioremediation.

Research Data and Supplementary Material

No

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Available for download on Tuesday, June 29, 2027

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