Pfiesteria shumwayae

Pfiesteria shumwayae is a dinoflagellate that was recently found in Taskinas Creek, a tributary of the York River in James City County, Virginia. The toxicity of P. shumwayae is unknown, although it is considered potentially dangerous. A recent Nature article suggests that P. shumwayae kills fish not by secreting an exotoxin but by micropredation. One implication is that the fears about possible human health risks may be overblown.