Spawning stress fish kill in Tama County


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More than 1,000 black crappies were reported dead at Lake Casey yesterday due to spawning stress. (Georgia Aquarium
Jenna Ladd |June 8, 2017

A fish kill has been reported at Casey Lake in Tama County. More than 1,000 black crappies were reported dead at the Hickory Hills Park Lake yesterday. Crappies are a North American freshwater sunfish that are indigenous to Iowa. Fish kills can be caused a number of factors including pesticide contamination, high temperatures, algal blooms and more.

“When we get calls about one species of dead fish during the spawning season, it is usually caused by spawning stress,” said Dan Kirby, fisheries management biologist for the Iowa Department of Natural Resources (DNR). Like many freshwater fish, crappies move closer to the shoreline to spawn in the late spring and early summer. Spawning activities require fish to expend a lot of energy, leaving them susceptible to infections and illness. It is common for spawning fish to sustain abrasions from jagged rocks and debris at the water’s edge. These cuts and scrapes are vulnerable to infection that can cause death. Typically, spawning stress fish kills occur slowly over the course of weeks. It is unclear how long the fish at Casey Lake were piling up near shore.

“Fish surveys conducted this week on Casey Lake showed that largemouth bass and bluegills are doing well, and black crappies are abundant,” Kirby added.

Iowa DNR encourages residents to call their 24-hour phone line at 515-725-8694 if they notice dead fish accumulating in lakes or rivers.

Environment Iowa’s “10 Scary Facts Plaguing Iowa’s Waterways”


Photo by BLW Photography, Flickr.

For Halloween, Environment Iowa released a list of ten discouraging facts about how Iowa’s waterways are being harmed.

The list includes the increasing number of fish kills in Iowa, the large amounts of phosphorous and nitrogen entering the waterways and the small percentage of animal feeding operations with the required environmental permits.

Read the whole list here.

Dry fall means increased risk of runoff damage


Photo by eutrophication&hypoxia, Flickr

Iowa’s unusually dry fall could lead to an increase in agricultural runoff. Because of the low stream flows across the state, any spill has increased effects – including a greater chance of fish kills and water quality issues.

The Iowa Department of Natural Resources offers tips to reduce the risk of spills:

  • Watch pumps and hoses, monitoring closely for leaks and pressure losses.
  • Keep a spill kit handy with emergency equipment, phone numbers and tools.
  •  Think about how to move dirt quickly in case you need to create a small dam.
  • Make sure all manure is injected or incorporated into the field, or follow required separation distances from vulnerable areas like streams, wells and lakes.

Open feedlots are the most likely to have problems with runoff. Make sure lots are scraped and cleaned. It’s a good time for stockpiles to be land applied too.

Massive fish kills in South Skunk River


Photo by Towboat Garage, Flickr

Last week a manure spill caused the death of more than 30,000 fish in Hamilton County. This was the South Skunk River’s second fish kill of the week.

Iowa’s Department of Natural Resources reports:

A fish kill on the South Skunk River near the Hamilton and Story County line last week affected five miles of stream and killed an estimated 27,456 fish valued at $38,056. Continue reading