what causes an algae bloom in a lake
Record torrential spring rains washed fertilizer into the lake, promoting the growth of microcystin producing cyanobacteria blooms. An algal bloom is a rapid increase or accumulation in the population of algae in freshwater or marine water systems, and is recognized by the discoloration in the water from their pigments. Cyanobacteria were mistaken for algae in the past, so cyanobacterial blooms are sometimes also called algal blooms.