What does Eutrophication, Hypoxia & Cyanobacteria have to do with Nitrite? Eutrophication happens when artificial or natural substances are introduced into waterways, like nitrates and nitrites, from fertilizers (farm run-off) or untreated sewage. Large blooms of algae (cyanobacteria) can grow due the increased levels of nutrients in the water, which can lead to hypoxia.
https://www.h2odistributors.com/pages/contaminants/contaminant-nitrite.asp

