Phytoplankton samples were collected on February 23, 2023 at Bullock Reach and analyzed in the laboratory shortly after collection. Sondes data revealed the surface water temperature was 5.49⁰C, salinity was 26.72 psu, and chlorophyll a was 3.26 ug/L. The plankton tow net sample was filterable with a 20 micron mesh. The filtrate was a dark yellow/golden brown color and had a quick filter time. 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 7,824,000 cells per Liter. The most predominant phytoplankton genus was Skeletonema spp. at 7,408,000. Representative genera in the tow net sample include Thalassiosira spp., Asterionellopsis spp., and Leptocylindrus spp.
200x phase contrast image of diatomic phytoplankton.
