Phytoplankton samples were collected on July 26, 2023 at Bullock Reach and analyzed in the laboratory shortly after collection. Sondes data revealed the surface water temperature was 25.586⁰C, salinity was 16.22psu, and chlorophyll a was 19.77 ug/L. It was a hot and humid day with calm conditions on Narragansett Bay. The plankton tow net sample was filterable with a 20 micron mesh. The filtrate was a light tan color and had a quick filter time. Some small comb jellies were detected. The tow net sample was analyzed qualitatively for microorganisms using phase contrast microscopy. The whole water sample was analyzed quantitatively under 200x phase contrast microscopy. A Hensen Stempel pipette was used to accurately deliver 1ml of sample to a Sedge-wick Rafter chamber. This analysis revealed a total of 462,000 cells per Liter. The micro flagellates were found at 376,000 cells/L. The most predominant phytoplankton genus was Heterocapsa spp. at 38,000 cells/L. Other representative genera include Guinardia spp., Thalassiosira spp., and Eutreptiella spp.
200x phase contrast micrograph of Eucampia spp.
