Missouri Fish Kills

The Missouri Department of Conservation's (MDC) Fish Kill and Pollution Program was initiated in the 1940s to protect aquatic resources and maintain high-quality fishing and recreational opportunities. To accomplish this, the program conducts fish kill and water pollution investigations and reports incidents to increase awareness about water pollution and its effect on aquatic life. Fish kills should be reported by calling the nearest MDC office. You can find your nearest office by visiting www.mdc.mo.gov/regions. Alternatively, you can call Emergency Environmental Response at the Missouri Department of Natural Resources (573-634-2436) and they will report the incident to MDC.Missouri Fish Kills

After receiving your call, an agent from MDC may follow up with you about visiting the site to conduct an investigation. If the MDC agent determines that a fish kill is from natural causes, no investigation will be conducted. If an investigation is warranted, the agent will visit the site to determine the size of the affected area, contain the pollution (if possible), conduct some basic water chemistry tests, and perhaps collect water samples for later analysis. During an investigation, the agent will estimate the number of organisms killed. Each organism will have an associated monetary value, and the cumulative value of all the dead organisms will be charged to the polluter, if identified.
In its recently released its summary of fish kill data from 2012 and 2013, the MDC estimated a value of $61,876 for organisms lost to either regulated or unknown causes. The value of fish lost to unregulated causes (natural causes or nonpoint source pollution) is not estimated because doing so is expensive and there is no mechanism in place for the reimbursement of MDC's costs.

Non-regulated causes of fish kills are often, but not always, natural. High temperatures and low water levels resulted in approximately 253 fish kills during Missouri's record drought in the summer of 2012. Non-regulated fish kills may also be the result of nonpoint source pollution (polluted runoff) where chronic nutrient inputs lead to algae blooms. High concentrations of algae contribute to wide fluctuations in dissolved oxygen concentrations, which causes stress to fish. One high-profile example of a non-regulated fish kill is the death of 16,000 common carp in Blue Springs Lake. The cause was determined to be Koi herpesvirus (KHV), a virulent pathogen that is carried by goldfish and transmitted to carp.

Regulated causes of mortality fall into 5 categories: agricultural, industrial, municipal, transportation and other. There were 44 regulated causes of mortality in 2012 and 2013, accounting for the loss of an estimated 41,365 animals, valued conservatively at $44,564. Municipal sources of pollution accounted for just 31% of the lost animals, but their monetary value was $34,628 or 78% of the total value lost to regulated pollution sources. The most expensive fish kill occurred below Truman Dam on May 29, 2013, when approximately 2,700 fish (valued at $15,197) were killed by a combination of trauma from the turbines and low dissolved oxygen. Seventeen incidents were resolved during 2012 and 2013 with settlement funds totaling over $23,000. The remaining cases are either still pending or were closed for lack of evidence, a pollutant, or a responsible party.

There are 3 ways MDC can impose monetary charges on polluters:

  1. Fish Damages. Once received, 90% of these funds are allocated to aquatic resource projects, like Hydrilla eradication or lake aeration. The remaining 10% of the funds are placed in a Chemical Emergency Preparedness Fund.
  2. Investigation Costs: These are simply reimbursement costs for MDC activities, so that fewer tax dollars are spent cleaning up polluters' messes.
  3. Penalties: These are typically managed by the Missouri Department of Natural Resources (DNR) under provisions of the Clean Water Act and Missouri Clean Water Law. All of the penalty money collected is given directly to the school system in the county where the offense occurred.

MDC investigated more fish kills on streams than any other habitat type during 2012 and 2013. Most causes of mortality in streams were regulated, meaning MDC could pass fees on to violators. Fish kills on lakes during the same period were due to primarily unregulated causes.

The full report can be found online here.

Total # of Investigated Pollution/Water Quality Incidents (2012-2013)




Regulated (agriculture, industry, etc.)

44 (36%)


60 (56%)


10 (8%)



Occurred in Summer

60 (49%)

Occurred in Winter

4 (3%)



Occurred in Streams

58 (47%)

Occurred in Lakes

39 (32%)

Occurred in Ponds

14 (11%)

Occurred in Backwaters

10 (8%)



Involved Fish Kills

112 (91%)

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