The streams fell into four categories. Minimally disturbed or degraded streams were those that are unaffected by acidity or other pollutants. Episodically acidified streams experience temporary episodes of high acidity and high aluminum in the spring when rains and melting snow greatly increase stream flow. In the summer and fall, these same streams are not as acidic.

Streams suffering from acid mine drainage (AMD) are abundant in Pennsylvania and the Appalachians and occur when coal-bearing rock is exposed to water and air. This produces sulfuric acid and releases a number of metals such as iron, aluminum and manganese into streams.

AMD streams are always acidic and contain metals that are toxic to many aquatic animals, including amphibians. The fourth stream type is not acidic but flows through a watershed fragmented by urbanization or agriculture. The researchers sampled each study stream by searching 4 square meter plots that included both wet and dry bank area. "Three of the seven species were very rare in the samples, but this is probably due to our sampling techniques," says Rocco. "The northern red salamander prefers slow areas of streams and we sampled faster moving water; the longtail salamander ranges farther from the stream and our terrestrial area may not have been large enough; and the seal salamander needs to have very rocky banks, which we did not have."

However, the researchers found the remaining four species abundant enough for stream quality monitoring.

"The mountain dusky salamander was found in most of the study streams and appears fairly insensitive to environmental chan
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Contact: A'ndrea Elyse Messer
aem1@psu.edu
814-865-9481
Penn State
25-Jun-1999