EVERYDAY SCIENCE

Detailed explanation-1: -As the acidity of a lake increases, the water becomes clearer and the numbers of fish and other water animals decline. Some species of plant and animal are better able to survive in acidic water than others.

Detailed explanation-2: -PH 5 or lower. As a lake becomes more acidic, fish are harmed not only by the acidity but also by substances that leach out of the soil into the water. Which of toxic substance is leached when conditions are acidic? Aluminum.

Detailed explanation-3: -At pH 5, most fish eggs cannot hatch. At lower pH levels, some adult fish die. Some acidic lakes have no fish. Even if a species of fish or animal can tolerate moderately acidic water, the animals or plants it eats might not.

Detailed explanation-4: -As acid rain flows through soils in a watershed, aluminum is released from soils into the lakes and streams located in that watershed. So, as pH in a lake or stream decreases, aluminum levels increase. Both low pH and increased aluminum levels are directly toxic to fish.