Final answer:
Nutrients enter the reservoir of surface waters through run-off and atmospheric dissolution. Fertilizers and atmospheric gases can contribute to nutrient enrichment.
Step-by-step explanation:
The ways nutrients enter the reservoir of surface waters include run-off and atmospheric dissolution. Run-off occurs when rainwater or melted snow flows over the surface of the land and carries nutrients into bodies of water. Atmospheric dissolution is when nutrients are dissolved in the air and then fall into surface waters through precipitation.
For example, when fertilizers that contain nutrients such as nitrogen and phosphorus are applied to agricultural fields, excess nutrients can enter nearby rivers and streams through run-off. Additionally, gases such as carbon dioxide in the atmosphere can dissolve into rainwater and contribute to nutrient enrichment in surface waters.
Learn more about Nutrient entry in surface waters