Development and validation of two fish-based indices of biotic integrity for assessing perennial coolwater streams in Wisconsin, USA

摘要: Abstract Perennial coolwater streams (maximum daily mean water temperature 20.7–24.6 °C; 90th percentile annual exceedence flow ≥ 0.0283 m 3 /s) are common in the Laurentian Great Lakes region of North America, including state Wisconsin, but they lack specific and effective bioassessment tools. I used landscape-scale ecological modeling geographically referenced data on stream location, valley slope, watershed surficial geology, air temperatures, riparian land cover, road population densities, nutrient wastewater inputs to classify Wisconsin sites based temperature, flow, degree environmental degradation. Fish from classified as perennial were then analyzed with objective standardized procedures develop indices biotic integrity (IBI). Because substantial differences their fish assemblages, separate IBI's formulated for cool-cold transition (20.7–22.5 °C) cool–warm (22.6–24.6 °C) streams. The cool–cold IBI had five metrics: numbers darter, madtom, sculpin species, intolerant percentages individuals tolerant species generalist feeders. Scoring criteria differed between northern southern (boundary at 44.6°N latitude) metric. also native minnow, intolerant, benthic invertivore omnivores. small large 200 km 2 area) percentage tolerants metrics. In validation tests, scores both significantly related independent measures human disturbance, indicating that would be useful tools assessing quality However, any given level varied substantially, suggesting multiple samples needed provide a reliable evaluation particular segment.