Reports of algal blooms at the end of August in the upper Bay on the Back River (western shore), and the Sassafras, Elk, Bohemia and Northeast Rivers (Eastern Shore) continue to be followed and investigated. Blooms are often related to Microcystis. There were no toxic Microcystis samples collected this year. A culture from a sample in 2000 identified elevated levels of phycotoxins from Microcystis in the Sassafras River during a summer bloom.

Blue-green algal blooms are recurring summer season events on the Potomac River and in many freshwater regions of Chesapeake and Coastal Bays. During the 1980s there were significant blooms of algae on the Potomac River before nutrient management for phosphorus went into effect. Blue-green algae declined in abundance during the late 1980s and early 1990s. Fluctuations in the duration and abundance of the blooms each summer partly relate to rate of nutrients being delivered to the river by the amount of freshwater flowing into the system each year.

An interagency press release was issued on August 9^th regarding blue-green algal blooms in Maryland waters. For more information please visit: https://dnrweb.dnr.state.md.us/dnrnews/pressrelease2001/081001a.html