Q.
I primarily fish two Utah rivers - the Provo
and the Green. On my last outing on the Provo,
I caught several large brown trout. While
handling these trout I noticed two things about
their markings which contrast to the browns I
have caught on the Green. First, the Provo
browns seemed to be a very faded color of green.
Second, these browns seemed to have scarlike
markings all over their body.
The markings could be a result of the browns being
frequently snagged due to the large amount of nymph
fishing done on the Provo. I also do most of my
winter and fall fishing on the Provo, while devoting
the summer to the Green. Perhaps this could have
something to do with the coloration differences. Thanks.
A.
I called Dr. Robert Behnke at Colorado State U.
to see if he had any experience with the trout
from the Provo and Green. He didn’t, specifically,
but suggested that color variations can be
influenced by various factors including both
stocking history and heredity. Brown trout stocks
originated in both Germany and Scotland, but you
would have to study the stocking and rearing records
of the strains planted in your two rivers to see of
the color differences might be traced to different
stocks. Environmental factors can also influence
color variations; the old “nature vs nurture” argument.
Hatchery folks will tell you that diet can affect
color; also, hatchery fish tend to be lighter in color
than wild fish. That’s about the best I can come up
with on the color variations you’ve observed.
As to the scarlike markings, neither Bob nor I
think it could have anything to do with nymph
fishing. It is highly unlikely that accidental
snagging by nymphs could be as extensive as you
indicate. A more likely source would be scarring
by rocks tumbled downstream during high flow periods,
and even this is unusual.
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 July 26, 2004 on Fly Anglers Online by Dr. Robert Behnke at Colorado State U..