Discover Smith Mountain Lake
WINTER 2016
20
Almanac
Fisherman’s
December 13th-Full Moon
December 29th-New Moon
January 12th-Full Moon
January 27th-New Moon
February 10th-Full Moon
February 26th-New Moon
March 12th-Full Moon
March 27th-New Moon
April 11th-Full Moon
April 26th-New Moon
May 10th-Full Moon
May 25th-New Moon
June 9th-Full Moon
June 23rd-New Moon
July 9th-Full Moon
July 23rd-New Moon
August 7th-Full Moon
August 21st-New Moon
September 6th-Full Moon
September 20th-New Moon
October 5th-Full Moon
October 19th-New Moon
November 4th-Full Moon
November 18th-New Moon
December 3rd-Full Moon
December 18th-New Moon
MOON PHASES
FOR 2017
Fish Behavior and Weather
by Bob King
I have spent a great deal of effort within these
pages explaining how conditions such as water
temperature, light level and moon phase are
all important to consider when planning when,
where, and how to fish. Another factor that often
goes overlooked is barometric pressure. Unlike
the others, it can’t be predicted as accurately.
Nonetheless, it has a major influence on fish
behavior.
If you have ever marveled at getting a killer strike
right before an approaching storm or frontal
system, or watched the action suddenly shut
down when the weather turns foul, you have
witnessed the effect of barometric pressure
on fish. Many animals are keenly tuned into
changes in the weather. In particular, fish are
extremely sensitive to weather fronts and
pressure changes. The weather ahead of cold
fronts will lead to favorable fishing conditions
due to the lower pressure. Because fish are so
good at sensing changes in pressure, they will
often increase their activity in the days before a
cold front moves in, creating good conditions for
catching them.
Ahead of a cold front, as pressure is falling, air bubbles are
released in the water. They can take small particles and
organisms with them up to the surface, bringing fish up to feed on
them. After the front passes through and for a few days after, the
resulting conditions will cause a reverse effect. The high pressure
that follows behind cold fronts causes fish to become lethargic;
they won’t move as far as during low pressure conditions, or
come as near to the lake surface. In other words, during high
pressure conditions, fish are less likely to come up and feed as
frequently as they will when the pressure is lower.
Warm fronts also will create ideal fishing conditions. Lower
pressure and weaker winds will bring the fish closer to the
surface, and liven them up for swimming longer distances.
Rain can also affect how well the fish will be biting. Fishing during
a light rain makes casting lines more discreet. Insects are also
more likely to be out flying near the surface of the water during
or immediately following a light rain, which will bring fish closer
to the surface, and make them more susceptible to being caught.
Rain can also cause more organic matter to run into bodies of
water, and lure fish to the surface to eat.
You may well be wondering how fish can sense changes in
barometric pressure? The theory is that a fish senses pressure
changes through its air bladder, with far greater sensitivity than
humans. Fish that have small bladders aren’t affected as much by
barometric pressure as are those with large bladders. Fish with
small bladders have a body density that’s closer to the density of
the surrounding water. Therefore, pressure changes have a much
lesser affect on them. This does not mean that air pressure will
not predict their behavior, since a lot of the other fish that they eat
have air bladders. Thus it is the behavior of the food supply that
drives their behavior.
Fish with large bladders have are much more sensitive to
changes in air pressure. Under low pressure conditions,
their bladders will expand somewhat. This makes the fish
uncomfortable, prompting them to find relief by moving to deeper
water, or by absorbing extra gas into their bladders.
This physiological distress shifts their priority from feeding to
relieving their discomfort. This causes them to seek a water depth
that will equalize the pressure on their bladders so that they will
feel normal again. Some species will head for the lake bottom
until conditions improve. It usually doesn’t take very long for
