The Academy of Natural Sciences Estuarine Research Center (ANSERC) in coordination with Maryland DNR continues to track a persistent algal bloom of Karlodinium micrum on the Lower Patxuent River. On July 28th, ANSERC reported a bloom concentration area containing 78,000 cells/ml on the main stem of the Lower Patuxent between Jack Bay and St. Leonard. This bloom is near the same region where ANSERC monitored a "Black Tide" event, an extremely dense bloom of K. micrum on St. Leonard Creek during June (see HAB News from June 24, 2003: "Black Tide" on St. Leonards Creek, Calvert County.").

An historical overview of the algal bloom conditions this year on the lower Patuxent River can be found at Eyes on the Bay and in the monitoring story "Lower Patuxent River Experiences Algal Blooms/High Chlorophyll Levels in May/June 2003".