The word “eutrophy” is derived from the Greek “eutrophos” which means “well nourished”. The term was coined around 1930 to describe water bodies experiencing prolific algae blooms that were associated with high levels of the nutrients Nitrogen (N) and Phosphorus (P) in the water.
Over the next 30 years eutrophication became a more prevalent and high-profile issue as more and more lakes, dams and reservoirs became plagued with algae blooms. In the 1970’s veterinarians, particularly in Australia and South Africa, started reporting numerous incidents of dead sheep that farmers were finding at watering holes where bright green algae blooms were present.
It was Professor Wayne Carmichael, then a graduate student at the University of Alberta, who determined that it was Cyanobacteria that formed these “hazardous algae blooms” or CyanoHABs and produced the toxins responsible for the fatalities.
One may well ask why “well nourished” should be a bad thing. The answer lies in the process of “eutrophication” by which nutrients are misappropriated into the production of algae and cyanobacteria, rather than a productive “Food Chain”.
Eutrophication is thus a distortion of the Nutrient Cycle that allows algae and cyanobacteria to dominate an aquatic biome to the detriment of the productive Food Chain needed to maintain the level of quality of water resources necessary to ensure sustainable food production and the modern lifestyle required by a global urbanized population that has ballooned since the Industrial Revolution.
High levels of algae and cyanobacteria first make it more difficult and expensive to produce potable water, and then as cyanobacteria begin to dominate, toxin levels rise to make it impossible.
Eutrophication is a systemic transformation of the aquatic biome, that superficially manifests in a variety of symptoms. These are usually labeled “causes” and “effects” of eutrophication but this characterization fails to consider the systemic nature of the problem or the Systems Theory paradigm that governs it.
These “causes and effects” include stratification and deoxygenation of the water column, accumulation of anaerobic, nutrient rich organic sediments, high levels of N and P in the water column, and a proliferation of invasive aquatic weeds, algae and cyanobacteria culminating in toxic cyanobacteria blooms or “CyanoHABs”.
But the key to understanding eutrophication lies in the name – “well nourished”. The problem is that it is the algae and cyanobacteria that become well nourished by dominating the uptake of the available nutrients, not the biodiverse organisms that make up a productive Food Chain and are synonymous with the sustainable Water Cycle and Nutrient Cycle that we need to ensure Renewable Water on a global scale.