Humans have drastically increased the amount of ammonia (NH₃) that is generated from nitrogen gas (N₂), and NH₃ can be utilized by organisms to build organic compounds, But there are both positive and negative effect of using ammonia:
Positive effect:
Ammonia based fertilizers can be used for plant growth and to increase the crop yield.
Negative effect:
It can accumulate in the body of aquatic animals and disrupts the aquatic life.