The Maryland Department of Natural Resources water quality monitoring program continues to find Dinophysis accuminata in the Potomac River at densities below levels observed in February 2002.  Since the end of the Potomac River shellfish closure by Maryland Department of the Environment on March 19, 2002 after tests by the U.S. Food and Drug Administration could detect only trace amounts of okadaic acid in shellfish tissues, sampling has been conducted on March 26th and April 8th.  Dinophysis accuminata was recorded in the surface waters at low densities between 1000-5000 cells/Liter and up to 7000 cells/Liter in bottom waters at the Route 301 Bridge and Ragged Point locations (see graphs below).

The Maryland DNR Water Quality Monitoring will continue to monitor these regions throughout the year.