Hi Joe, 

Your cold weather experience on the Blue is very interesting.  That
special local structure provides a good way to watch for negative effects
during C&R fishing.  As I remember, there are some pretty productive pools
right in town too!  

But on the subject of cold water, I've been scanning my bookshelves for
info and found some interesting stuff in the book by Robert Behnke "Trout
and Salmon of North America".  Apparently, only arctic char and Bear lake
cutthroat will remain active enough to put on weight during the winter. 
He doesn't address the topic of winter mortality, but there is a
suggestion that some info exists on low temp effects on trout activity.  


"Bear Lake cutthroat trout are the only
trout, except for Arctic char, known to
increase in weight during winter months
when water temperatures are below 39 degrees F.

  All experiments with brook trout,
brown trout, rainbow trout, and other forms
of cutthroat have demonstrated that when
water temperature falls to 39 degrees F and lower
(as occurs in most natural environments
where trout live), the fish stop growing and
eventually lose weight, even with unlimited
food. The reason Bear Lake cutthroat
trout can continue to gain weight during
winter is not known, but it may be the result
of evolutionary programming. The major
food source, especially in winter, of large
(16 inches/ 41 cm or larger) cutthroat trout in
Bear Lake is the Bear Lake cisco, which
spawns in winter, mainly in January. Since
the cutthroat trout most likely prey on
spawning aggregations of the cisco, it appears
that a life history of active feeding and
growth in winter allows the cutthroat to
capitalize on this opportunity."

I'll keep looking for more info on this.  Thanks very much to everyone
else who commented, especially with the advice not to expose fish to the
sub-freezing air, and to avoid putting them on streamside ice.  

Take care, 

Mark


--- [EMAIL PROTECTED] wrote:
>  I fished in Colorado outside of Breckenridge last winter.  Maybe as
> many as 25 days in the same area of small pools on the Blue River
> upstream from Dillon Lake.  If fish were dying after I caught them
> something was eating them quickly as I never saw a dead fish in the
> water.  They could not float downstream as there were several shallow
> pools where the water ran very slow and you could see the bottom easily.
>  The water slowly filtered out of these pools through small rock dams, a
> dead fish would not have been able to pass through them.
> 
> JoeL
> 


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