HCNSO Student Theses and Dissertations

Defense Date


Document Type


Degree Name

M.S. Marine Environmental Sciences

First Advisor

D. Abigail Renegar, Ph.D.

Second Advisor

David Gilliam, Ph.D.

Third Advisor

Beth Smith, M.S.


Microplastics have been found in large quantities in marine water samples and biota around the world. These microplastics, when present in the marine environment, decrease water quality and negatively impact marine life. This research quantified and classified marine plastic pollution along the Southeast Florida Reef Tract (SEFRT), in order to understand how this plastic is entering the ocean and the scope of the microplastic contamination in the northern SEFRT. Surface and bottom water samples were collected at 7 sites along the SEFRT for 6 months, filtered, and microscopically analyzed for microplastic content and composition using Fourier-transform infrared spectrophotometry (FTIR). Classification groups were created, and included pieces, shards, clusters, and fibers of 9 colors; fibers were the most common, as was the color blue. Data regarding total plastics at depth, sites, and months was analyzed. There were significantly more total plastics in surface samples than in bottom samples, but no significant difference in plastic totals from month to month or between sites. Overall, there was no significant difference between depth, location, and month combined. FTIR polymer analysis was used to evaluate the source of this plastic pollution, and seven plastic polymers were successfully identified. Five contaminants adsorbed to the plastic particles were also identified. Based on composition of observed polymers, it is likely that these plastics entered the ocean as both primary and secondary microplastics. A multi-faceted approach is necessary to halt the insertion of microplastics into the ocean; preventing microplastics from entering the drain and sewage systems as well as eliminating larger plastic debris.

Creative Commons License

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