Assessment Comments
Assessment based on 2003 REMAP data: FIBI = 51 (good), 51 (good); BMIBI = 48 (fair), 43 (fair) and 2003 Biocriteria data: FIBI = 60 (good); BMIBI = 78 (excellent). FIBI riffle BIC = 65, non-riffle BIC = 44; BMIBI Hess sample BIC = 70.
Basis for Assessment
SUMMARY: This segment is partially supporting its aquatic life uses because the BMIBI scores from the REMAP site failed to meet the BMIBI BIC for this ecoregion and sample type. All of the FIBI scores and the BMIBI score from the biocriteria site met the applicable BICs.
The assessment was based on data collected in 2003 as part of the DNR/UHL stream REMAP and biocriteria projects. 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 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 2003 biocritera riffle site FIBI score was 60 (good) and the benthic macroinvertebrate hess sample BMIBI score was 78 (excellent). The 2003 REMAP non-riffle FIBI scores were 51 (good); 51 (good) and the 2003 benthic macroinvertebrate hess sample BMIBI scores were 48 (fair) and 43 (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 riffle BIC for this ecoregion is 65 and the non-riffle BIC is 44. The BMIBI hess sample BIC for this ecoregion is 70.
