Official State of Iowa Website Here is how you know

Search for a News Release

Press/Media inquiries:

DNR News Releases

Be careful, late summer is prime time for fish kills

  • 8/24/2016 2:22:00 PM
  • View Count 5605
  • Return

Unfortunately the end of summer is the worst time for underwater dwellers. In August and September, temperatures are often high, oxygen levels tend to be low and if stream levels are low, fish and other water critters can be especially vulnerable. 

Add to that the occasional cloud burst or algal bloom and a fish kill is more likely. 

“Historically we see more fish kills this time of year,” said Ken Hessenius, supervisor at DNR’s Spencer field office. “We investigated five fish kills in the first three weeks of August. So we want to encourage farmers, pesticide and manure applicators, and homeowners to be extra careful when applying chemicals, fertilizers and manure.”

Take these simple precautions to protect our waters:

• Follow pesticide labels and manure management plans. Watch application rates and required setbacks from streams. “Some aerially sprayed chemicals are toxic to fish at concentrations of less than one part per billion, which is like adding a pinch of salt to a 10-ton bag of potato chips,” he said. 

• Divert water from chemical mixing stations and livestock holding areas to prevent runoff from carrying off pollutants. Keep open lots scraped and clean to avoid polluted runoff.

• Check for pollutant trails below mixing stations and livestock facilities. If there is runoff, immediately contain it to keep pollutants out of streams.

• Finally, report spills, runoff and fish kills as soon as possible to the 24-hour spill line at 515-725-8694. DNR specialists have seen hundreds of spills – they can help you find the best way to contain a spill and reduce impacts downstream. Check the DNR Environmental Reporting Hotline Guide for situations that must be reported and the reporting deadlines. 

For more information, contact Ken Hessenius at 712-262-4177 or