Cyanobacteria (blue-green algae) bloom, Clear Lake, California
A bloom of the cyanobacterium, Aphanizomenon flos-aquae, covers the water of Clear Lake, California. This lake is probably naturally eutrophic, but agriculture and urban development increases nutrient loading to the system. Blooms of several species of algae reach nusiance proportions. The high productivity, however, fuels a highly productive warm water fishery.