Northwest Fishing Magazine September 2025 Volume 5 Issue 1 - Flipbook - Page 16
At night, no photosynthesis
takes place, so algae stop
taking in carbon dioxide
from water and go into a
respiratory stage. During
this respiratory stage,
algae consume oxygen
that was produced during
photosynthesis and release
carbon dioxide into the
water. This increased
production of carbon
dioxide decreases the pH
levels in the water at night.
DUDE: There’s more?
KOKANEE: Algae are a very
welcome part of a lake’s
ecosystem. They form the
base of the food chain
and are thus vital. They
provide a source of food,
energy, and shelter for the
zooplankton, fish, and other
aquatic organisms. Algae
also play a strong role in the
ability of an ecosystem to
absorb nutrients and heavy
metals.
DUDE: Temperature?
KOKANEE: If the water is too
cold, green algae cannot
sustain growth. This is the
situation in the cold months
of late fall, all of winter, and
early spring. If the winter
produces abundant snow in
the high country feeding a
lake, the rate at which that
snowpack melts and flows
to the lake determines,
in part, how fast a lake
will warm up after winter.
Remember too that in
winter the angle of the
sun to a lake is lower than
when the days get longer
in spring and summer.
Water has a great capacity
to absorb infrared radiation
(from sunlight) and to
retain that gained heat.
And sunlight drives the
growth of green algae. So,
snowpack inflows and the
angle of the sun on the lake
work together to make the
lake’s temperature what it
is.
DUDE: Let me see if I can
apply this. Fishing in the
early spring for kokes can
be frustrating because the
water is too cold and there
