Fish Are Excellent
Listeners
By Lawrence Gunther Euteneier /
Feel the Bite!
In my April article, “Fish Hear
Amazingly Well”, we focussed on
how fish hear using their ears.
In this article, the focus will
be on how they listen through
their lateral lines.
People take hearing for granted
until it stops working, and then
they realize just how important
a role it plays in almost
everything we do. The point
being, our own marginal
understanding of the role of
hearing makes it even harder to
comprehend the different ways
fish hear and how they combine
their different hearing senses
to survive.
After I lost my ability to use
sight to carry out daily
activities, I began using my
hearing more. It never got any
stronger, I just got better at
using it. Now, if I drop a coin
on the floor in a store while at
the cash, I can not only tell
what denomination the coin is
based on the sound of the coin
hitting and then rolling along
the floor, but place my hand
exactly on the spot on the floor
where the coin came to rest.
Sighted people think they
perform these same tasks using
their eye sight exclusively, but
put these same people in the
forest with a gun and their
first instinct is to aim an
shoot in the direction from
which they hear the sound of
what they believe to be a
potential life-threatening
animal or their intended pray.
It’s exactly this reflex
response that hunter safety
courses are intended to repress,
and it’s precisely this response
that predatory fish spend their
entire lives honing.
On
average, fish can see well
between 5 and 10 feet, depending
on water clarity and light
penetration. Contrast this with
a fish’s ability to hear higher
frequency sounds with their ears
originating from as far away as
30 feet, and under ideal
conditions, low frequency sounds
using their lateral lines that
originate from much further, and
it’s no wonder then that the
primary sense fish depend on for
first detecting the presents of
food or danger is hearing.
Lateral lines on a fish can
detect sound vibrations (cycles
/ hertz) from 80 all the way
down to one vibration (Hertz)
per second. A human with typical
hearing detects sound waves or
vibrations from as low as 20 per
second all the way up to 20,000
per second.
A sub woofer in a typical
Surround sound system outputs
between 20 and 200 cycles or
vibrations or Hertz per second.
The lowest frequency still
considered a musical tone is
about 12 Hertz. Humans can
detect by touch tones between 4
and 16 hertz, compared with a
fish that can hear tones as low
as one cycle per second with
their lateral line.
Whales produce high and low
frequency sounds from 40 up to
8,000 hertz. High frequency
sound waves can best be
described as many tall pointed
mountain peeks close together,
where as low frequency sound
waves can be described more as
low hills spread far apart.
Scientists believe that whales
can detect low frequency sound
waves (40 hertz) originating up
to 10,000 miles away.
Fish can detect unseen sources
of low frequency sounds such as
those produced by wobbling
crankbaits from quite far off.
They can also use their lateral
lines to determine a baits
trajectory fairly accurately,
which explains how Walleye are
able to swim upwards
considerable distances and
intercept vibrating baits being
trolled.
Fish use their lateral lines
much the same way I now use my
ears. They can not only
determine in what direction to
venture forth to find that ball
of bait, but move in with
precision on pray under no light
conditions. Yes, even blind fish
can find food. What this means
for us fishers is that negative
sounds need to be limited as
much as possible since they give
away both our presents and
location, and positive sounds
need to be exploited in ways
that suit the conditions we are
fishing.
A bait making too much noise
under ideal visibility
conditions will draw a fish’s
attention, but this may work to
your disadvantage if it means a
fish now has ample time to
determine that your offering is
artificial. Reaction baits
depend on the element of
surprise causing fish to respond
compulsively, which is why they
don’t need to offer exact visual
reproductions of pray.
For example, willow leaves on a
spinner bait transmit maximum
visual flash and almost no
sound, which is why we use them
for burning in water with
moderate to high clarity. A
single large Colorado painted
blade offers almost no visual
flash, but instead emits a
throbbing low frequency sound
intended to provide fish with an
audible target.
Using sound to alert fish that
pray is in the area is the
premise of tools such as the
“Hydro Wave”. Other less
technical ploys involve
rhythmically thumping the bottom
of the boat, revving an outboard
motor, slapping the surface of
the water, adjusting the
throttles on boats equipped with
dual engines to create harmonic
resonance, etc. More
specifically, we can bounce jigs
off the bottom, crash crankbaits
into structure, drop soft
plastics through the water
column, or select baits with
internal noise makers. The
important distinction to
remember when determining just
how much noise you want your
bait to make depends on what
point fish will actually see
your offering. If the idea is to
draw fish in so they will either
react impulsively, or visually
target your bait at between five
to ten feet out, then minimal
erratic sound is best. If
conditions call for deploying
baits that allow fish to target
your bait using hearing alone,
such as in heavily stained water
or at night, then baits that
emit steady sounds fished in a
predictable (non-erratic)
fashion offer the most
appropriate target.
Fish living in the crystal clear
waters of the south Pacific can
see extremely long distances,
just as their pray can. There’s
also remarkably little cover.
Consequently, large predatory
tropical fish need to swim miles
each day to find food, and the
way they find those humungous
bait balls surrounded by every
living thing in the sea for
miles around is by listening.
Even in our waters many species
of predatory fish migrate from
one feeding opportunity to
another based on what they hear.
.
Fish would not survive if they
had to depend on sight alone to
locate pray. Their dependency on
sound is what distinguishes us
from fish as our own
environments become increasingly
cluttered with noise – a
relatively recent phenomena in
terms of human evolution.
.
Ontario Ice
Fishing