Temporal variation in P. shumwayae abundance at the five stations in Neuse River, N.C. P. shumwayae cell concentration was measured with PSCOB primers for natural seawater before (Natural) and after (Fed) fed incubation using Rhodomonas sp. as prey. UPP, FB, FHM, MBM, and MM, Union Point Park, Flanners Beach, Fairfield Harbour Marina, Minnesott Beach Marina, and Matthews Marina stations, respectively.