How Does Acid Rain Affect Lakes?

pH Levels

• According to the EPA, most lakes have a pH level between 6 and 8. When acid rain falls into these bodies of water their pH levels decrease and they become more acidic. Some soils next to the lake cannot form a barrier against acid rain. This could trigger a rise in acid levels and promote the release of aluminum from soil into lakes. Aluminum is a metallic substance and an element that causes harm to aquatic plants and organisms. Seventy-five percent of the lakes classified as acidic are the result of acid rain, says the EPA.

Marine Life

• Marine life suffers from the effects of acid rain through increased pH and aluminum levels. Low acidic levels and aluminum are toxic to fish and other water-related organisms. Aluminum also causes chronic problems to fish such as lowering body weight and limiting their ability to obtain food and shelter. Some plant and marine organisms can adjust to the low acidic conditions posed by acid rain but many cannot -- and in some instances marine life doesn't exist in lakes that are highly acidic.

Ecosystems

• Ecosystems are affected by acid rain because it has the ability to eliminate some organisms and plants from the aquatic food web. With the increase in acidity, certain organisms could be removed from the food chain. Remaining creatures will have to compete over the limited number of food sources that are available. Increased acidic levels will naturally decrease the number of aquatic plants and animals that live in or near a lake.

Nitrogen Levels

• Acid rain raises nitrogen levels within lakes and it also plays a role in episodic acidification, which results from storm runoff and snow melt. Nitrogen is an important factor in depleting oxygen from bodies of water, states the EPA. Large blooms of algae and the health decline of marine life are contributed to the effects of oxygen depletion. When nitrogen levels are increased within lakes activities such as boating and swimming are affected. People who rely on marine life as a source of food will also be negatively impacted with the increase in nitrogen levels.