Bodies of water affected by acid rain include the streams and lakes surrounding the Adirondacks and Catskill Mountains, the highlands of the mid-Appalachian region and the Upper Midwest. A survey conducted by the Environmental Protection Agency indicates that over 75 percent of all 1,000 freshwater bodies larger than 10 acres are acidified.
The situation is particularly dire in areas where soil-buffering capacity is poor, as this leads to the buildup of soil acidity when acid rain falls continuously. Little Echo Pond in Franklin, N.Y., is a prime example, registering a pH of 4.2. Streams that flow through regions with a low soil-buffering capacity soak up soil acidity, gaining acidity of their own. Other sources of stream acidity include acidic runoff from deluges and snowmelt.
Acid rain also causes ecological problems, including fish population reduction due to the eradication of roe and fry. Acid rain stunts tree growth, upsetting the ecological balance of forest biomes. The release rate of ions of metals, such as aluminum, into the ecosystem is accelerated in an acidic environment. These metal ions are toxic, causing extensive damage to fish and aquatic animals. The destruction of plant and animal life due to acid rain results in a cascade effect, in which the compromised ecosystem biodiversity causes complications of its own.