Ocheyedan River IA 06-LSR-1641

Assessment Comments

Assessment is based on results two October 1990 IDNR stream use assessments conducted in Clay county and also fish surveys conducted by staff/students at Lakeside Laboratory in June 1998.

Basis for Assessment

Reviewed field sheets from the two October 1990 DNR stream use assessments and incorporated results of a fish survey conducted by Neil Bernstein and his students from Lakeside Laboratory in June 1998 to upgrade the assessment of support of the Class B(LR) aquatic life uses from PS to FST due to the following:  (1) comments from the 1990 DNR field sheets such as "good pool/riffle areas," "very diverse habitat, rocky, weeds, and sand/gravels," and "good numbers of fish."  Although frequent channelization was identified as the main impact to habitat quality, the assessors noted the re-meandering of the channel and the resultant improvement in habitat quality.   The June 1998 fish survey by Bernstein and his students from Lakeside Lab showed a moderately diverse fish community (14 species from 5 families) for the NW Iowa Loess Prairies (47a) subecoregion and the presence of nearly all the expected fish taxa (8 of 9) for streams in the subecoregion.   These results indicate that the Class B(LR) aquatic life uses are fully supported.   The primary threat to the continued support of these uses is the impact of past channelization activities.