Assessment Comments
Assessment based on results of IDNR/UHL biological (biocriteria) monitoring in 1999: FIBI = 27 (fair), BMIBI = 45 (fair). FIBI BIC = 36, BMIBI BIC = 51.
Basis for Assessment
SUMMARY: The Class B(LR) aquatic life uses are assessed (evaluated) as "partially supported" based on results of IDNR/UHL biological (biocriteria) sampling in 1999. This assessment is the same as that developed for the 2004 reporting cycle except the data are now more than five year old and the assessment has changed from monitored to evaluated.
EXPLANATION: This assessment was based on data collected in 1999 as part of the IDNR/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 1999 FIBI score was 27 (fair) and the BMIBI score was 45 (fair). 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 FIBI BIC for this ecoregion is 36 and the BMIBI BIC for this ecoregion is 51.
