Pilot Branch IA 05-NSH-1424

Assessment Comments

Assessment is based on results of IDNR/UHL biological (biocriteria) monitoring in 2002: Fish IBI= 31 (fair), BM-IBI= 51 (fair).

Basis for Assessment

SUMMARY:  The general aquatic life uses are assessed (evaluated) as "fully supported / threatened" (minor impacts) based on results of IDNR/UHL biological (biocriteria) sampling in 2002.   The assessment type is considered "evaluated" (relatively lower confidence assessment) due to the uncertainty of using biological assessment methods developed for Class B(LR) and wadable Class B(WW) streams for assessing aquatic life conditions in general use-only stream segments.

EXPLANATION:  The assessment was based on data collected in 2002 as part of the DNR/UHL stream biocriteria project.  The 2002 Fish IBI score was 31 (fair) and the BM-IBI score was 51 (fair).  The aquatic life use support was assessed as fully supporting/threatened (=FS/T), based on a comparison of the F-IBI and BM-IBI scores with biological assessment criteria established for previous Section 305(b) reports.  The biological assessment criteria were determined from a statistical analysis of data collected at stream ecoregion reference sites from 1994-2001.