Pinto lake is ~8,000 years old and one of few naturally formed lakes in the Monterey Bay area. This shallow (27ft max depth), 100-acre, lake is fed by a surrounding watershed system that includes 4 creeks (Amesti, CCC, Pinto and Todos Santos). Seasonal cyanobacteria harmful algae blooms (cHABS) render this lake unsafe for public use with levels of a liver toxin called microcystin, reaching levels up to 10,000-fold the FDA recommended exposure limit. CALeDNA is currently using metabarcoding to monitor the Pinto Lake ecosystem over a cHAB bloom cycle. The main goal of this project is to look for early warning signs for cHABS, investigate the effect of a bloom on the surrounding ecosystem, and to provide data that will support efforts to effectively monitor potentially restore this public good.