13. a nutrient whose supply is negatively impacting an ecosystem's productivity 22. result of stormwater runoff which carries large amounts of nutrients into aquatic ecosystems

22. Storm runoff and irrigation runoff carrying elevated nutrients from fertilizer application can have indirect effects on aquatic ecosystems. ... Fertilizer and nutrient concentrations, not directly toxic to biota, can cause eutrophication in lakes, impoundments, bays, and estuaries and indirectly affect ecosystem structure.

common management practices in dairy and poultry farming are: (i) proper shelter facilities and their regular cleaning. (ii) some basic hygienic conditions such as clean water, nutritious food, etc. (iii) animals are kept in spacious, airy, and ventilated place.

there are so many examples for that in different areas, like biology experiment carried out in our lab recently.

here's one link: