Question

How does the flow of acid rain water into a river makes the survival of aquatic life in the river difficult?

Answer 1

Answer: Acid rain water, if mixed with river water, lowers its pH below 5.6, i.e., makes river water acidic. ... That's why flow of acid rain water to river makes the survival of aquatic life in the river difficult.

Answer 2

When acid rain flows into the rivers, it lowers the pH of the river water. Living organisms can survive  only in a narrow range of pH change. So flow of acid rain water into rivers is dangerous to the survival of  aquatic life. These acids have free ions that conduct electric current.