Maryland Department of the Environment (MDE) sampled the lower Potomac River on Wednesday, March 6, 2002. Samples processed by the Maryland Department of Natural Resources and MDE generally show declining concentrations of Dinophysis accuminata in surface and bottom waters of the main stem Potomac from Nanjemoy Creek (Marker 11) downstream to Point Lookout. The Wicomico River, tributary to the Potomac River, declined from peak levels measured on 2/21/02 but remains at levels greater than other monitoring sites. Samples of shellfish were collected in Maryland and, combined with samples from Virginia waters, are being processed for toxin testing by the U.S. Food and Drug Administration. The temporary closure to harvesting oysters on the Potomac River and tributaries below the 301 Bridge remains in effect. Monitoring will continue until it is safe to remove the closure.