East Okoboji Lake IA 06-LSR-1652

Assessment Comments

Assessment is based on results of monitoring in 1990 by ISU as part of the Clean Lakes Classification study (1994) and results of U.S. EPA/IDNR fish tissue monitoring in September 1992.

Basis for Assessment

Assessed as FST for the 1994 report for the following reasons:  (1) BPJ of DNR field staff in 1990 showed swimmable uses FST; no new information; (2) BPJ of DNR Fisheries (1994) agree with FST assessment; (3) results of monitoring in 1990 show that average levels of secchi depth, chl-a, total-P, and TSS are better than overall average levels for the 116 SPOLs sampled in 1990 and 1992; all averages were within the overall means + 1 SD.   Lake does, however, have summerkill in approximately 12 percent of years.   Average levels of chl-a and total-P in 1990 approach overall averages for the 116 SPOLs, and nutrient enrichment may be occurring; high productivity may also be due to rel.  shallow mean depth (3.2 m) and the tendency for the lake not to completely stratify (Bachmann et al.  1994).   The few fish contaminants detetected in the 1992 RAFT sampling (composite, channel catfish fillets) were all less than 1/2 the respective FDA action levels.