Are cyanobacteria out to hurt us?
Cyanobacteria, sometimes referred to as “blue-green algae”, are a common problem in freshwater reservoirs both in Australia and overseas. Cyanobacterial blooms, resulting from eutrophication (increased nitrogen and phosphorus concentrations) and water column stratification, have attracted attention worldwide. These blooms affect drinking water quality due to bad taste and odour and have caused fatalities in farm animals drinking directly from the water. Recorded human fatalities have thus far been limited to the drastic incident in Brazil where water contaminated with cyanobacteria was used in dialysis clinics. The reasons for these fatalities are attributed to secondary metabolites produced by a number of different cyanobacterial species. These include neurotoxins, such as saxitoxin produced primarily by species of Anabaena, and hepatotoxins such as microcystin produced by Microcystis and several other cyanobacterial genera. While the neurotoxins act directly on the central nervous sy
