Date of Award

Spring 5-5-2023

Document Type


Degree Name

Bachelor of Science (BS)


Marine Science


College of Science

First Advisor

Angelos Hannides


This research study examined the possible switch from benthic photosynthetic organisms to phytoplankton in the water column at White Point Swash, Long Bay, South Carolina, and what is causing this switch to occur. During Dr. Hannides’ and his group’s studies at this and other swashes in the past, they noticed this phenomenon of the benthic photosynthetic organisms taking over during a certain time and then the phytoplankton in the water column taking over during a different time. In this study, I measured the relative benthic macroalgal area coverage and sedimentary chlorophyll a concentration as measures of the abundance of benthic photosynthesizers, and I compared them to the water column chlorophyll a concentration as a measure of the abundance of phytoplankton. I also analyzed pore water samples for sedimentary nutrients which were compared to water-column nutrients. Finally, I compared the above with water depth levels to account for light reaching the benthic photosynthetic organisms to account for the role these have on this switch. The results show that as water level rises benthic photosynthesizers decrease in abundance and phytoplankton abundance increases. Sedimentary pore water nutrient concentrations are much higher than overlying water concentrations and this suggests that light is the main limiting factor to benthic photosynthesizer growth.