Toxicity testing of shellfish meats collected from the Potomac River shellfish waters of Maryland and Virginia by the U.S. Food and Drug Administration showed only trace amounts of toxin from the algae, far below public health standards associated with shellfish borne disease. In response to these findings the Maryland Department of the Environment (MDE) and Virginia Department of Health (VDH) have reopened the waters of the Potomac River to shellfish harvesting.

MDE sampled the lower Potomac River on Wednesday, March 13, 2002. The Route 301 Bridge and Ragged Point were also sampled on March 11^th by Maryland Department of Natural Resources (MD DNR). Samples processed by the MD DNR generally show declining trends in concentrations of Dinophysis accuminata in surface and bottom waters of the main stem Potomac from Nanjemoy Creek (Marker 11) downstream to Point Lookout. During the last week, however, concentrations were higher in surface samples at Swan Point, Route 301 Bridge and Cobb Island as well as bottom samples at Route 301 Bridge, Lower Cedar Point and Point Lookout. The MD DNR will continue to monitor the area through its Water Quality Monitoring Program throughout the year.