Pollution caused by phosphorus acumulated in the water of the Lake Erie in N America.
The Nitrogen being a gas ,leaves the water and goes into the atmosphere but phosphorus is a solid wich doesnt leave the lake.
The algae are verry good at taking the Nitrogen from the air and putting it in the lake if they have phosphorus.
Basically increasing level of phosphorus is drawing nitrogen from the air each year until the algae dies off in autumn and kills everything that breathes oxigen in that lake.
In order to stop this eutrophication the phosphorus needs to be locked by bonding it to calcium = calcium phosphate( bones).
There is the silver carp ( most hated chinese carp) wich its a filter feeder that eats planctonic algae and has big bone to weight ratio.
This carp is the only solution to fix this lake but unfortunatedly ,north american people dont have a ,,carp coulture,, to know this fish and respect it for its enviromental protection role .
This is an example of damage to the enviroment because of ignorance.