Question

Which of the following is an environmental indicator of acid deposition?

Decreased eutrophication of aquatic ecosystems
Increased photosynthesis from the breakdown of leaves
Decreased pH levels in lakes, rivers, or other bodies of water
Decreased concentrations of toxic metals, such as aluminum in soil

Answer 1

Acid deposition (sometimes referred to as "acid rain") refers to any form of precipitation with unusually high levels of acidity--in other words, low pH.

It seems to me that if the precipitation (like rain, snow, etc) is acidic, then the bodies of water where this precipitation falls would be acidic as well. So, perhaps the bodies of water affected by acid deposition would have unusually low pH levels?