This study aimed to analyze the fluctuations in diversity of phytoplankton during tidal cycle. The purpose of this experiment was to observe changes in phytoplankton diversity in the Duplin River. The hypothesis was that Mid Tide would have the highest diversity because of the increased movement of water that accompanies the ebb from high to low tide. Plankton tows were conducted during high tide, mid ebb (mid tide), and low tide from Marsh Landing on Sapelo Island, Georgia. The samples were then fixed with Lugol’s Iodine to help differentiate between detritus and phytoplankton cells. The resulting solution was plated on depression slides. The cells on the slides were then counted by type of algae. The hypothesis was rejected as high tide had the highest diversity followed by low tide (p < 0.0001). Mid tide had the lowest diversity due to the high dominance of the dinoflagellates and little brown balls in the samples.

Student paper for MARS 4510 as part of the 2015 Coastal Summer Semester.