Honors Theses
Date of Award
Spring 5-8-2026
Document Type
Undergraduate Thesis
Department
Biology
First Advisor
Colin Jackson
Second Advisor
Ryan Garrick
Relational Format
Dissertation/Thesis
Abstract
Bacterial communities are important to ecosystem function in coastal environments, but the response of these communities to short term increased salinity conditions is understudied. This study utilized a microcosm setup to investigate the response of coastal seawater bacterial communities to three treatments: an unamended seawater control, a reference treatment that received reverse osmosis (RO) water, and an elevated salinity treatment that received artificial seawater dissolved in RO water. Microcosms were sampled four times over a five-day period to analyze the effects of time under different salinity conditions on the seawater bacterial community. 16S rRNA gene sequencing was used to analyze bacterial community composition and diversity. Day and treatment type were found to be statistically significant determinants of bacterial community composition. The proportion of Gammaproteobacteria in the seawater bacterial community increased while proportions of other phyla, such as Cyanobacteria, decreased throughout the experiment. Evenness and richness of the bacterial community differed based on sample day but not treatment type. Overall, the response of the bacterial community to the RO water reference treatments was similar to that to the elevated salinity treatment, suggesting that a bottle effect of being in microcosms was influencing the bacterial community. These results suggest that while bacterial community composition may change with increased salinity, such treatment-based differences maybe be difficult to detect in microcosms because of this bottle effect.
Recommended Citation
Wade, Clifton C., "Effects of Increased Salinity on Mississippi Coast Bacterial Community Composition and Diversity" (2026). Honors Theses. 3589.
https://egrove.olemiss.edu/hon_thesis/3589
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