Technical Abstract: As part of an EPA sponsored state of knowledge symposium on toxic cyanobacteria, six workgroups were established to assess published literature. A review of ARS research on harmful algal blooms was made by the incumbent. Aquaculture systems have had four types of freshwater toxic algal blooms. Detection methods have been developed for HAB identification. Remote sensing using the cyanobacterial specific phycobilin proteins appears to be a useful rapid diagnostic procedure.