Archive for the ‘ichthyology’ Tag

Fish Activity and Water Temps   6 comments

OK all you biologists out there. I have a theory.

The graph below shows water temps at a monitoring station in Black Earth Creek, with the last data point being taken at 8:00am. In my opinion the ideal water temp for trout activity is in the range between 59-degrees and 64-degrees F. The temp of the water goes through that range twice a day in the spring and summer.

Overnight and early this morning it has dropped from the high 60’s and has come down through that range. Later today it will climb again and will go up through that range.


Stream Temps on BEC at Black Earth, WI


So, my theory: Trout are more likely to actively feed as the temps increase through the ideal temp range.

Counter-theories would be that…


  1. Trout are more likely to actively feed as the temps decrease through the ideal temp range, or
  2. As long as the water is within the ideal temp range, Trout don’t care if it’s increasing or decreasing, they’re equally active in either scenario.


Does anybody out there have ideas or perhaps even data to support any of these theories?