STILLWATERS
LOCATING
TROUT
IN LAKES
By Brian Chan
Determining where trout live in lakes and, in
particular, where they feed is critical to fly-fishing
success. It is definitely worth the time to learn some
basic facts about lake morphometry, biology and
water chemistry. This knowledge relates directly
to understanding the life-cycles of important
aquatic food sources, including significant insect
emergences. So let’s take a more detailed look
at the stillwater trout environment, where these
fish live, their preferred feeding habitats, and the
impacts of changing water chemistry.
STRUCTURE OF LAKES
Big OK or Island Lake, located southwest of the city
of Kamloops, British Columbia, is a near perfectly
designed trout lake. A large table-top shaped
shallow water area covers much of the middle
portion of the lake, while a deep-water trough
that reaches almost 12 meters in depth rings the
outer edges towards shore. The lake has abundant
shallow feeding areas with nearby deeper water
for the rainbow trout to escape predators as well
as provide refuge from warm summer water
temperatures. All productive trout lakes, regardless
of geographic location, have one physical feature
in common—they typically have a large littoral
or shoal zone, which is defined as water less
than six meters deep. This means energy from
the sun penetrates to the lake bottom and allows