Storm Lake IA 04-RAC-1143

Assessment Comments

Assessment is based on results of (1) ISU lake survey, (2) surveys by IDNR Fisheries Bureau (3) ISU report on lake phytoplankton communities, and (4) results of U.S. EPA/IDNR fish tissue monitoring.

Basis for Assessment

The assessment from the 1992 report ("fully supported / threatened") was changed to "partially supported." This assessment is based on BPJ of DNR Fisheries and on monitoring conducted by ISU in summer 1990.   Average levels of secchi, total-P, chl-a, and TSS were all within the overall mean +/- 1SD for the 116 lakes sampled in 1990 and 1992 for the Clean Lakes Classification study.   The level of TSS (42 mg/l) was near the upper range of the overall mean + 1SD (46 mg/l), thus suggesting some type of turbidity problem.   DNR Fisheries reports good populations of game fish in the lake.   Water, fish, and sediment were analyzed for toxic organics, pesticides, and metals as part of Clean Lakes Program Phase I study (info in Hoyman et al.  (1994)); all levels of contaminants were well- below MCLs, FDA action levels, and state WQ criteria for ammonia and toxic metals.   DNR Fisheries believes organic enrichment from natural shallowness could lead to a fishkill; thus assess as PS.