Q.
From LSHEH: What are the water temperature
ranges that best facilitate the optimum feeding
cycle for the most popular trout, e.g., rainbow,
cutthroat and brown.
A.
This is very difficult to answer and
what I say probably won’t entirely satisfy you.
The problem is that optimum temperature ranges
for any activity can vary from species to
species and among different populations of the
same species. This is because optimum temperatures
for spawning, feeding, etc. are largely determined
by the temperature to which the particular
population has been acclimated. A population of
rainbows living in a relatively warm stream or
lake will have different optimal feeding
temperatures than a population acclimated to
a cold environment. In general, warmer
temperatures increase metabolic activities up
to a point; then it adversely affects growth,
movement, feeding, etc.
Thus, it is virtually impossible to answer your
question with any degree of precision. I talked
to a local fishery biologist to confirm the above
and he agreed with me. There are data available
showing the temperatures and ranges at which
various species of trout grow best, preferred
spawning temperatures, etc., but this doesn’t
address your question. Let me know
(streamdoctor@aol.com) if you want to pursue
this further.
If you have a question, please feel free to contact me.
~ C. E. (Bert) Cushing, aka Streamdoctor
105 W. Cherokee Dr.
Estes Park, CO 80517
Phone: 970-577-1584
Email: streamdoctor@aol.com
The ‘Stream Doctor’ is a retired professional stream ecologist and
author, now living in the West and spending way too much time
fly-fishing. You are invited to submit questions relating to
anything stream related directly to him for use in this Q & A Feature
at streamdoctor@aol.com.
Originally published March 8th, 2004 on Fly Anglers Online by Robert Younghanz.