Assessment Comments
Assessment is based on results of IDNR/UHL biological (biocriteria) monitoring in 2000: FIBI = 39 (fair), 29 (fair); BMIBI = 45 (fair), 32 (fair). FIBI ave = 34, BMIBI ave = 38.5. FIBI non-riffle BIC = 32, BMIBI BIC = 62.
Basis for Assessment
SUMMARY: The Class B(LR) aquatic life uses are assessed (monitored) as "partially supported" based on results of IDNR/UHL biological (biocriteria) sampling in 2000. This is the same assessment as that developed for the 2004 reporting cycle.
EXPLANATION: This assessment was based on data collected at two sites in 2000 as part of the DNR/UHL stream biocriteria project: near Goodell and near Belmond. A series of biological metrics which reflect stream water quality and habitat integrity were calculated from the biocriteria sampling data. The biological metrics are based on the numbers and types of benthic macroinvertebrate taxa and fish species that were collected in the stream sampling reach. The biological metrics were combined to make a fish community index of biotic integrity (FIBI) and a benthic macroinvertebrate index (BMIBI). The indexes rank the biological integrity of a stream sampling reach on a rising scale from 0 (minimum) to 100 (maximum). The 2000 FIBI scores were 39 (fair) and 29 (fair); the BMIBI scores were 45 (fair) and 32 (fair). FIBI average was 34 and BMIBI average was 38.5. The aquatic life use support was assessed as partially supporting (=PS), based on a comparison of the FIBI and BMIBI scores with biological impairment criteria (BIC) established for previous Section 305(b) reports. The biological impairment criteria were determined from a statistical analysis of data collected at stream ecoregion reference sites from 1994-2004. The non-riffle FIBI BIC for this ecoregion is 32 and the BMIBI BIC for this ecoregion is 62.
