show Abstracthide AbstractCyanobacterial blooms are an increasing scourge in freshwater lakes and reservoirs across the world. They can be toxic and represent ecological disfunction. This project determines the genome sequences of the standing populations of such bloom-forming cyanobacteria, mainly from the Pacific Northwest region of the US. The sequences obtained allow the deduction of gene content (such as toxin biosynthetic genes), relationships across geographic areas, and population structures within blooms. They also provide taxonomic clarification among bloom-forming cyanobacteria. Genomes of bacteria associated with these blooms are also being sequenced. These bacteria may have synergistic, commensal or predatory relationships with cyanobacterial blooms. An understanding of these relationships will provide insight into the development and turnover of cyanobacterial blooms.