Lick Creek IA 04-LDM-1027

Assessment Comments

Assessment is based on 1997 Biocriteria sampling: Fish IBI=48(fair), BM-IBI=42(fair).

Basis for Assessment

The DNR/EPD stream assessment project data collected in 1991 were not used to determine the degree of aquatic life use support for this waterbody segment because the data are more than five years old, and no longer considered current.   The assessment was based on data collected in 1997 as part of the DNR/UHL stream biocriteria development 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)-100 (maximum).  

The F-IBI score was 48(fair), and the BM-IBI score was 42(fair).   The aquatic life use support status 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 specifically for the 2000 Section 305b report (IDNR 2000).   The biological assessment criteria were determined from a statistical analysis of data collected at stream ecoregion reference sites from 1994-1998.  

The majority of the watershed is in Shimek State Forest.  Land use impacts, if any, are slight.   It is suspected that low flow stability and/or extreme fluctuations in flow are the primary threat to the aquatic community.  The stream where sampled is moderately incised, and fairly wide and shallow.   Some channelization in headwater reaches was observed, as well as straightening at several bridge approaches.   These are most likely not recent modifications to the stream channel, but historical impacts.