Data-Collection and Processing Methods

Watershed characteristics were determined by using methods described in greater detail in Falcone and others (2007). Characteristics were determined for each of the study watersheds in the nine EUSE study areas. Continuous stream stage and stream temperature data were collected at or near the biological sampling reach for approximately a 1-year period in coordination with the biological data-collection effort. Streamwater chemistry samples were collected at or near the biological sampling reach two to six times at each stream, with at least one sample representing a period of high base flow and one sample representing a period of low base flow. The exception was the Birmingham study, in which a high base-flow sample could not be obtained because of a drought that occurred during the study. Passive samplers, called semipermeable membrane devices (SPMD), were deployed near the biological sampling reach for several weeks preceding biological data collection to detect hydrophobic organic contaminants. Habitat measures were developed for the stream segments and reaches where the biological sampling occurred. Samples of macroinvertebrate, algal, and fish communities were collected once during low-flow conditions.