Assessment Comments
Assessment based on 2002 REMAP data: Fish IBI= 10 (poor), BM-IBI= 35 (fair).
Basis for Assessment
The assessment was based on data collected in 2002 as part of the DNR/UHL REMAP 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) and a benthic macroinvertebrate index (BM-IBI). The indexes rank the biological integrity of a stream sampling reach on a rising scale from 0 (minimum) to 100 (maximum). The 2002 Fish IBI score was 10 (poor) and the BM-IBI score was 35 (fair). The aquatic life use support was assessed as not supporting (=NS), 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.
As part of the 2002 REMAP sampling project, stream physical habitat assessment found adverse conditions that are thought to contribute to the biological impairment. These include, bank instability, excessive silt deposition, lack of instream cover, stream channelization and incision. Stream temperature exceeded 36C (97F) during continuous d.o. and temperature monitoring in June 2002. Channel alterations resulting in wide, shallow, and sluggish stream flow conditions probably contribute to elevated stream temperature.
