If it wasn’t for toxic Cyanobacteria, eutrophication would not be much more than an unsightly cosmetic issue.
But the inevitable end-point of the eutrophic process is toxic CyanoHABs that result from Cyanobacteria dominating nutrient uptake in eutrophic conditions. These toxic blooms are known by a variety of terms; toxic bluegreen algae, BGA, toxic HABs (Hazardous Algae Blooms), CyanoHABs.
They render the water body unusable for recreational activities such as swimming, water skiing, fishing, kayaking, etc. They cause mass fish-kills. And they can make it impossible to purify the water to produce safe drinking water, resulting in lethal toxins in a town or city’s drinking water and “do not drink the water” alerts on radio, TV, and newspapers describing the situation as a “water shortage”.
For years billions of dollars have been spent on herbicides and algaecides to kill weeds and algae that die off and sink into the sediments and on alum to precipitate phosphorus into the sediments.
History may well view the decades that we have spent applying these various chemicals as a self-inflicted catastrophe because it has only served to make the situation more and more favorable for CyanoHABs. And this is evidenced by the fact that these toxic CyanoHAB blooms are occurring earlier in the summer, lasting longer, are more intense and more widespread every year.
Until both the public and professionals get a better understanding of how Cyanobacteria exploit eutrophic conditions, and how conventional “treatments” make eutrophication worse and thus are driving the worsening of CyanoHABs every year, we will be doomed to a worsening Global Water Crisis.
It is time that we understand the futility of these interventions and stop being the engineers of our own demise.