Question

A farmer converted a forest to a cornfield. The farmer applied a nitrogen fertilizer to the corn. Over nearby stream increased. Later, several fish populations decreased.

Which statement is a reasonable inference, instead of a fact, about the human impact on this stream
A. Nitrogen from the fertilizer led to the decrease in the fish populations.
B. Fewer fish lived in the stream after the farmer converted the forest to farmland.
C. Converting a forest to farmland increases runoff of surface water into nearby streams.
D. The addition of fertilizer decreased the ability of the fish populations to process nitrogen.

Answer 1

The most reasonable inference about the human impact on the stream, following the application of nitrogen fertilizer and the decrease in fish populations, is that the fertilizer led to eutrophication and reduced dissolved oxygen levels, negatively affecting the fish.

Step-by-step explanation:

The statement that is a reasonable inference about the human impact on the stream after a farmer applied nitrogen fertilizer to a cornfield, and nearby fish populations decreased is: A. Nitrogen from the fertilizer led to the decrease in the fish populations. This inference is based on the known environmental effects of nitrogen-rich fertilizer runoff, which can lead to eutrophication of water bodies. Eutrophication causes excess growth of algae and depletion of dissolved oxygen, which can be detrimental to aquatic life such as fish.