Upper Klamath Lake, where Cell Tech harvests its algae, is a shallow eutrophied lake full of nitrogen and phosphorus from animal feces. Klamath Lake lies along a migratory bird flyway, and large colonies of pelicans poop there year-round in a protected sanctuary. The August 1995 issue of Vegetarian Times describes the lake as pretty polluted. Three epidemic fish kills have occurred there recently, due to algal blooms. Toxins may also come from bacterial contaminants.
Pathogenic bacteria luxuriate in water with a slightly basic pH, like water found in Klamath Lake.
The mucilaginous sheath encasing A. flos-aquae and Spirulina spp. Most Spirulina cultivators recognize this problem and pasteurize their product. 6a A. flos-aquae also produces hepatotoxins and neurotoxins. Some of these are carcinogenic. Others are acutely lethal.