Question

1. which human activity contributes most to excess phosphorus in aquatic ecosystems? fossil fuel combustion use of synthetic fertilizers overharvesting forests industrial emissions

Explanation:

Synthetic fertilizers are rich in phosphorus. When they are used in agriculture, runoff can carry excess phosphorus into aquatic ecosystems. Fossil - fuel combustion mainly releases carbon - related pollutants and some heavy metals. Overharvesting forests affects soil stability and biodiversity but not directly a major source of excess phosphorus in water. Industrial emissions are more associated with sulfur, nitrogen compounds and heavy metals rather than being the main contributor of excess phosphorus in aquatic systems.

Answer:

Use of synthetic fertilizers