Northwest Reel Life April 2023 Volume 2 Issue 9 - Flipbook - Page 31
watch
now
Sometimes you need to know
more about stuff than rod, hooks,
bait, corn, net and the smaller
words we kokanee dudes know
about. Let me introduce a couple
of words that could make the
difference between a fantastic day
on the water and just a boat ride.
free from predators, they can even
live up to 100 days. Their primary
source of food is phytoplankton.
They also carry out filter feeding
and consume bacteria, yeast,
detritus, and dissolved organic
matter – making them vital for a
healthy lake environment.
The first word is “Daphnia.”
Kokanee love Daphnia. Daphnia
make up to 90% of a kokanee’s
protein diet. Yes, your favorite
kokanee lake has Daphnia – likely
tons and tons of Daphnia.
Besides being a vital source of
protein for kokanee, one other
really important thing all kokanee
fishermen need to know about
Daphnia: Daphnia hate light. Hold
that thought.
Daphnia are small freshwater
crustaceans, commonly known
as water fleas. They are called so
due to the short, jerky flea-like
movement they make while
swimming. Their size ranges
from 0.5mm to 6 mm. Males
and females look similar, but the
males have a smaller body and
somewhat larger antennae.
The second word is “crepuscular.”
In this instance it describes the
rays of light when first hitting the
water. For the kokanee fisherman
this is usually early morning, when
the first rays of light come over
the mountain top and through
the trees to hit the water. When
crepuscular light hits the water, it
bends. Really !! The bending effect
polarizes the light as it goes down
the water column. Are you still
with me?
Daphnia have a lifespan of
approximately 10 to 30 days, but if
their environment is favorable and
As you just learned our friend
Daphnia hates light. So while
Daphnia have been happily
grazing all night on the
phytoplankton (the green stuff),
they close up their eating shop as
soon as that light hits the water.
They then proceed down the
water column to where it is dark.
Of course, to get to the dark water,
they have to do the gauntlet thing
where the kokanee are waiting to
slurp them up.
But the very cool (cruel?) thing is
the effect of crepuscular light on
the Daphnia. Daphnia have what
is called an exoskeleton – the outer
shell, so to speak, that supports
the anatomy of the creature.
When crepuscular light hits the
water, it bends and polarizes. That
polarized light then makes those
Daphnia exoskeletons shine like
the mid-day sun, making them
very easy for the kokanee to see
and target.
JULY 2023 | 31