Bear Creek IA 02-IOW-701

Assessment Comments

Assessment based on 1999 biocriteria data: Fish IBI= 49 (fair).

Basis for Assessment

The assessment was based on data collected in 1999 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 (F-IBI).   The index ranks the biological integrity of a stream sampling reach on a rising scale from 0 (minimum) to 100 (maximum).   The 1999 Fish IBI score was 49 (fair).   The benthic macroinvertebrate sampling results were incomplete, but the partial results suggested that benthic community integrity might be impaired.  Additional follow-up benthic sampling should be done to support a more complete assessment of aquatic life use status.   Until additional sampling data are available, the aquatic life use support is assessed as fully supporting / threatened (=FST), based on a comparison of the F-IBI score with biological assessment criteria established specifically for the 2002 Section 305(b) report.  The biological assessment criteria were determined from a statistical analysis of data collected at stream ecoregion reference sites from 1994-2001.