It has been known by scientists for several years that phosphorus and nitrogen given off from fertiliser applied to farm fields and lawn can promote algae growth in lakes. It results in the toxic blooms of the pea soup colour.
When 139 lakes in Iowa where studied over a 13-year period, it was discovered by scientists from the University of Duluth and the Sea Grant of Minnesota that the water is surprisingly clear when the lakes attain extremely high nutrient.
Chris Filstrup commented that it was shocking,Filstrup is the lead author and researcher at Large Lakes Observatory and Minnesota Sea Grant of UMD.
“This is shocking because prior research has indicated the growth of algae is supported by more nitrogen and phosphorus concentration” he stated.
Phosphorus levels ten times higher than what was anticipated in northern Minnesota lake were discovered by the Researchers after the study and Nitrogen levels more than 30 times higher too.
Also in their investigation, they discovered that rather than result in the growth of the algae into more massive blooms, the extreme nutrient concentration killed the algae. Quite akin to how too much fertiliser applied on the soil can deter the progress of plant life by inhibiting growth.
Water Monitoring agencies called to caution
Researchers on the study concluded that elevated levels of nitrates in water could essentially cause the cells of algae to burst apart, quite similar to how pouring hydrogen peroxide on a cut effects the fizzling out of the bacteria.
According to Filstrup, a possible danger would be the chance that people may consider these clear lakes to be of improved water quality.
He mentioned that water agencies estimate the purity and quality of water by the degree of clarity of the water body.