The Reference Codex contains data definitions and explanation of various aspects of the Fish Kill Database.
The locational information for some fish kills is an estimate only, and should not be accepted as the precise location of the kill. These are typically flagged on the event's description page.
The point of origin given for a fish kill is the (approximate) location of the start of the kill, not the entire extent of the kill.
Although these data and associated metadata have been reviewed for accuracy and completeness, no warranty expressed or implied is made regarding the display or utility of the data for other purposes, nor on all computer systems, nor shall the act of distribution constitute any such warranty.
Estimated Fish Killed
When a fish kill is enumerated, the number should be considered to be an estimate,since it is extremely difficult to count dead fish in flowing water conditions or when the kill is not reported immediately. When possible,the number of fish killed in a kill event is derived from procedures outlined in the American Fisheries Society Special Publication 30 and in the Iowa Administrative Code Chapter 113.
The reported number of fish killed in some cases is a rough estimate as determined by the field investigation staff, or by the account given by the person reporting the fish kill. Less accurate counts occur in the following cases:
- Fish kills that were reported several days after the event
- Unfavorable conditions for counting fish, such as high water levels or flows, ice, etc
- Events that are natural in origin
In these cases, the magnitude of the fish killed can provide an estimate of the size of the event.