Fish Kill Event - Upper Iowa River
East of Kendallville at Cattle Creek Road Bridge
- Event ID
- 1043
- Date of Kill
- 8/21/2023
- Waterbody Type
- River/Stream
- Cause Origin
- Natural
- Cause
- Environmental
- Mode
- N/A
- Magnitude
- 3 (1001 - 5000 fish killed)
- Estimated Fish Killed
- 1,383
- Kill Length
- 74.00 miles
- Investigation Expenses
- $1,655.45
- County
- Winneshiek
- ESD Field Office
- FO 1
- Fisheries Office
- Decorah State Hatchery
- LongDD
- -91.95842
- LatDD
- 43.41500
- Created Date
- 9/6/2023 8:16:54 AM
- Last Update
- 9/6/2023 8:16:54 AM
Highlighted river segments indicate those impacted in part or whole by this fish kill event. It is not meant to represent the actual extent of the kill.
This kill was most likely caused by lower than average stream flows and warm temperatures. Northeast Iowa is currently experiencing severe drought conditions. Water clarity was also lower than normal for drought conditions, with a secchi depth reading of only 2 ft on the lower river during the kill period. The water had a brown coloration, suggesting a possible diatom bloom, that could have contributed to the fish kill.
The fish kill covered over 74 river miles of the Upper Iowa River. Species above lower dam included Brown Trout, Rainbow Trout, darters, and minnows whereas Redhorse spp. and Mooneye accounted for the majority of dead fish on the lower reaches of the river. A total of 1383 dead fish were counted on 9.6 river miles of the lower Upper Iowa River (Avg 144 fish/river mile)