Photo: We found at least one cell that looked like this (a euglenoid, Phacus) in the Twin Ponds
I talked to our summer Herbarium Interns about freshwater algae and then we wandered down to the Twin Ponds, the main pond and to 'Cunningham's Pond' (near the kiosk/restaurant) to collect some of the subject matter.
Twin Ponds looks very green, almost bluey-green, but it had a reasonable diversity of green algae - some swimming around (e.g. Chlamydomonas) and some staying still (e.g. Pediastrum) - just lots of them.
A sample from the edge of the froth in the brackish Main Pond contained only a few diatoms.
Around Cunningham's remains there was a rich and varied mix of diatoms and a few other freshwater algae, mostly attached to stems and leaves of aquatic plants. There were also some aggressive animals trying to eat the subjects.