The Maryland Department of Natural Resources (DNR) Algal Monitoring Program identified a potentially harmful algae, Dinophysis accuminata, from water samples collected from the lower Potomac River on Tuesday, 2/12 and analyzed on Thursday, 2/14/2002. On Friday, 2/15/2002, the Maryland Department of the Environment (MDE) and the Academy of Natural Sciences of Philadelphia (ANSP) conducted additional water sampling and testing in conjunction with DNR and confirmed Dinophysis at densities above normal for our region. Please refer to our webpage on Dinophysis for additional information about the algae. There is more information on the Maryland Department of Environment press release regarding the temporary closing of shellfish waters.  MDE, ANSP and DNR will be testing Potomac waters again on Thursday, 2/21.  Virginia has also found this alga in their tributaries to the lower Potomac Estuary and have also moved to close their waters to shellfish harvesting.