Question

Rain may wash fertilizers into bodies of water, such as ponds. How might fertilizer affect a pond?

Answer 1

Fertilizers contain tremendous amounts of Nitrogen and Phosphates which can affect the algal growth in ponds and lakes.
This in turn can lead to algal bloom and the release of toxins that can affect freshwater ecosystems.

Explanation:

Fertilizers contain tremendous amounts of Nitrogen and Phosphates which can affect the algal growth in ponds and lakes.
This in turn can lead to algal bloom and the release of toxins that can affect freshwater ecosystems.

http://news.psu.edu/story/361695/2015/06/25/research/project-reduce-risk-harmful-algal-blooms-ponds-and-lakes