Living Environment Regents Practice Test

What evidence indicates that acid rain has adversely affected the Adirondack Mountains?

1. An increase in fish populations

2. A decrease in the variety of fish

3. Improvement in soil quality

4. An increase in amphibian species

The correct answer is: A decrease in the variety of fish

The choice indicating a decrease in the variety of fish serves as strong evidence that acid rain has negatively impacted the Adirondack Mountains. Acid rain results from the atmospheric deposition of pollutants, particularly sulfur dioxide and nitrogen oxides, which can significantly alter the pH of water bodies. In aquatic ecosystems, the diversity of fish species is often closely related to the quality of the water and the pH levels. When acid rain lowers the pH, it can lead to harmful conditions for many fish species, particularly sensitive ones. This change in water chemistry can cause a decrease in fish populations overall and diminish the diversity of species present. Specifically, certain fish may not be able to survive the increased acidity and thus either die off or be unable to reproduce, leading to a reduced variety of fish in affected lakes and streams. Consequently, the decline in fish variety directly points to the adverse effects of acid rain in this environment, highlighting significant ecological disruptions caused by pollution. In contrast, an increase in fish populations, improvement in soil quality, and an increase in amphibian species would suggest either a thriving ecosystem or recovery, which would not align with the detrimental impact expected from acid rain exposure.