Are cyanobacterial blooms toxic?
Alberta’s nutrient-rich lakes support an abundance of cyanobacteria, which can make the lake appear green and murky. When weather conditions are right, cyanobacteria may congregate at the water’s surface in what is known as a cyanobacterial bloom. Bloom-forming species of cyanobacteria produce many compounds, some of which have toxic properties. In Alberta’s lakes, the most common are the liver toxins called microcystins. Microcystins have been responsible for illness and death of livestock, pets, and wildlife following the consumption of cyanobacteria-infested water. Microcystins have also been linked to incidences of gastrointestinal illness in humans. Less common are the neurotoxins (nerve toxins), including anatoxin-a, anatoxin-a(s), and saxitoxin. Although neurotoxic blooms tend to be more potent than those containing only microcystin, they occur less frequently. Neurotoxins have been linked to sporadic die-offs of ducks, shorebirds, and bats, as well as pets and livestock. Lastly
