Phytoplankton samples were collected on May 3, 2023 at Bullock Reach and analyzed in the laboratory shortly after collection. Sondes data revealed the surface water temperature was 13.37⁰C, salinity was 6.62 psu, and chlorophyll a was 1.86 ug/L. The plankton tow net sample was filterable with a 20 micron mesh. The filtrate was a light brown color and had a quick filter time. There was lots of zooplankton activity in today’s sample. 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 214,000 cells per Liter. The micro flagellates were found at 7,000 cells/L. The most predominant phytoplankton genus was Skeletonema spp. at 87,000 cells/L. Representative genera in the tow net sample include Thalassionema spp., Leptocylindrus spp. and pennate diatoms.
200x phase contrast micrograph of Fragilaria spp.
