Date of Award

Spring 1999

Document Type

Legacy Thesis

Degree Name

Bachelor of Science (BS)


Marine Science


College of Science

First Advisor

Eric T. Koepfler


Phytoplankton are important components of estuarine systems. They are responsible for most of the primary and secondary production that takes place in these systems. Grazing on phytoplankton has an obvious effect on phytoplankton populations. In this study, the effects of grazing on phytoplankton by both oysters and microzooplankton are investigated. Since phytoplankton is a primary food source for both oysters and microzooplankton, microzooplankton must find another food source when oysters are present filtering phytoplankton out of the water column. Fluorescently-labeled bacteria (FLB) uptake experiments were conducted with samples collected from an oyster flume to determine grazing on phytoplankton. A ciliate grazing parameters experiment was also conducted to determine grazing behaviors by a cultured benthic ciliate. Overall, it appeared that oysters do affect microzooplankton grazing in the presence of oysters, though the hypothesis was rejected, and ingestion rates of ciliates were highest in the highest concentration of FLB added.

Creative Commons License

Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.