Toxic Chemicals: Page 8 Endangered Species Handbook

Aquatic Ecosystems

Toxic Chemicals: Page 8

Acid rain is another threat posed to lakes, streams and ponds. Large power plants in Europe and the United States and, most recently, in China, which burn fossil fuels such as coal, have affected forests and aquatic systems hundreds and even thousands of miles away from the source of pollution. In the 1970s, tall stacks were mandated as pollution control to dispel soot particles, sulphur dioxide and nitrogen oxides. Rather than control the problem, they merely spread it by dispersing these pollutants vast distances on the wind. The pollutants combine with atmospheric water and fall to the ground hundreds or thousands of miles away as diluted sulphuric and nitric acids. Coal-fired power plants in England and central Europe have poisoned the lakes and rivers of Scandinavia, while plants in the US Midwest and southern Ontario, Canada, have rendered lakes in New England and Quebec lifeless. In Scandinavia, 20,000 lakes are now lifeless as a result of acid rain (Mason and Macdonald 1986), and in northeastern North America, thousands more have become totally barren (Durrell 1986). Acid rain increases acidity in water to levels toxic to many types of wildlife. In lakes with clear water and few nutrients, acid rain can eliminate all life forms. Acid rain's effects on aquatic species have been catastrophic, eliminating water birds, salamanders, otters, many types of fish, frogs and other temperate wildlife in entire regions.

Coal mines contribute to acidification of aquatic ecosystems as well by exuding acids that poison streams and rivers in their drainage. Thousands of streams in Appalachia in eastern North America have been rendered sterile from coal mines that continue to poison waterways, even when no longer being mined, until they are sealed off. In October 2000, a coal mine sludge retention pond in eastern Kentucky gave way, spilling 200 million gallons of toxic waste into streams feeding the Ohio River (NYT 2000). The state's governor declared a state of emergency in the northeast as water supplies for the entire region were threatened with contamination (NYT 2000).