What is the significance of the Maumee River in relation to HABs?

• A. It has no relation to HABs.
• B. It is a minor contributor of nitrogen to the lake.
• C. It provides most of the dissolved oxygen in the basin.
• D. It is a major source of phosphorus entering the Western Lake Erie Basin.

Answer: (D)

The key idea is that phosphorus loading drives harmful algal blooms in Lake Erie. The Maumee River brings a large amount of phosphorus from agricultural lands into the Western Lake Erie Basin, especially during spring runoff when fertilizer and soil wash into streams. Phosphorus is the nutrient that fuels rapid algal growth in freshwater systems, and when it enters Lake Erie in large amounts, it promotes the blooms that can produce toxins and degrade water quality. This makes the Maumee River a major contributor of phosphorus to the basin, which is why it’s closely tied to HABs. It’s not primarily about nitrogen, it doesn’t supply most of the dissolved oxygen, and those ideas don’t capture its real influence.