Assessment Comments
Assessment based on results of IDNR/UHL biological (biocriteria) monitoring in 2001: FIBI = 52 (good), 38 (fair); BMIBI = 52 (fair), 54 (fair). FIBI ave = 45, BMIB ave = 53. Riffle site FIBI BIC = 65, natural substrate BMIBI BIC = 70.
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 2001.
EXPLANATION: The assessment was based on data collected in 2001 as part of the DNR/UHL stream biocriteria project. 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 2001 FIBI scores were 52 (good) and 38 (fair), and the BMIBI scores were 52 and 54 (good). The FIBI average was 45 and the BMIBI average was 53. 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 riffle site FIBI BIC for this ecoregion is 65 and the natural substrate BMIBI BIC for this ecoregion is 70.
