Northwest Fisheries Science Center

Marine Microbes and Toxins Research Activities

Marine Microbes and Toxins Research Topics


Dr. Linda Rhodes
Program Manager
Staff Directory

Illness and tidal trends of Vibrio parahaemolyticus in Puget Sound

Oyster harvest and consumption is a favorite pastime for many people living in the Pacific Northwest. Most cases of gastroenteritis by consumption of raw oysters are caused by the bacterium, V. parahaemolyticus, and occur during the summer season when the weather is warmer and when oyster harvest is optimal during the daytime low tides.

Appearance of this bacterium in the water column varies by day, season, and hour. This project investigates when (temporal) and where (spatial) this bacterium appears within oyster harvesting waters of two bays in the south Puget Sound, and looks at tidal patterns of clinical illness caused by this bacterium over the last 16 years.

Project Staff

Anne Baxter
Bar graph showing seasonal and tidal variations of illness (n= 331 cases) caused by Vibrio parahaemolyticus from oysters harvested in Washington State. The average number of cases/day were calculated over a 16 year period (1997-2012) for corresponding spring (light grey bars) and neap (dark grey bars) weekly tidal cycles.
(click to enlarge)

Important prior research