Phytoplankton samples were collected on September 17, 2025 at Bullock’s Reach and analyzed in the laboratory shortly after collection.
The water temperature was 20.99 °C, the salinity was 31.07 psu, and the chlorophyll a was 13.57 ug/L.
The qualitative tow net sample had a quick filtration time. The filtrate was reddish brown and murky.
The analysis of the quantitative whole water sample revealed a total of 1,014,000 cells/L. The microflagellates were found at 374,000 cells/L. The most predominant phytoplankton genera were Chaetoceros spp. at 303,000 cells/L, Prorocentrum spp. at 168,000 cells/L, and Heterocapsa spp. at 46,000 cells/L.
Gymnodinium is a genus of marine and freshwater dinoflagellates. They have two flagella used for locomotion and they are one of the few dinoflagellates that appear ‘naked’ due to their lack of armored cellulosic plates. Some species produce saxitoxins which can cause paralytic shellfish poisoning.