Greenlake is a small lake in seattle, wa that sometimes experiences blooms of cyanobacteria, photosynthetic nitrogen-fixing bacteria that typically grow as filaments. these blooms are especially likely to occur during warm summer weather and result in the production of large quantities of biomass that then dies off and decomposes, leading to unpleasant odors. in addition to the looking bad, some strains make toxins that can be dangerous when ingested; for this reason, the lake is closed when blooms occur. treatment of the water with alum (aluminum sulfate) to remove phosphorus from the water has to limit growth of cyanobacteria. how would you classify the cyanobacteria from greenlake in terms of their carbon and energy sources?