Answer:
The use of fertilizers
Step-by-step explanation:
Eutrophication simply implies the increase in nutrient or nutrient enrichment.
Commonly, waterways are connected to other water bodies. When water from farmlands washes fertilizers into them, there is an increase the available nutrient. Overtime, the water can be oversaturated with nutrients and this would lead to eutrophication. We can attribute eutrophication to human activities.