Winter Bass - What They Do
wonders what bass do in the winter? Curiosity got
the best of me too, and I researched the issue. Here is a little
more about it. It primarily pertains to bass in colder northern
Biologically, bass and many other game fish are programmed to
fatten up during late fall in instinctive anticipation of a
scarcity of food as winter arrives.
waters drop in temperature in winter, there is
less food available to eat. For example, a surprising number of
species of crustaceans, mollusks, reptiles, amphibians and
insects all vanish into the mud or elsewhere underground until
spring. Other prey sources become less dispersed and less
available to predators as winter approaches as well. This reduces
the total "energy content" available in the water - and
consequently less incentive for bass to pursue food. Instead the
bass will swim less, eat less and otherwise conserve the
"energy budget" it has stockpiled within its own body.
As the water gets downright colder, food gets even scarcer, and
the bass tend to fast for long periods of time in cold water.
This inactivity happens gradually day by day and eventually
causes its muscle composition and body chemicals to change so
that in deep winter, it could not swim fast or otherwise act as a
quick swimming predator in cold water. Even if it wanted to, it
would be impossible to swim quickly to pursue bait such as a
A small item of interest is that a few minnow species are
known to have an actual "anti-freeze" chemical in their
blood which allows them to remain slightly more active, and
therefore more elusive to consistently avoid being caught by the
slowed-down predators during the winter.
In extremely cold water, bass even
tend to lose their balance and may even have difficulty in
propping themselves upright on the bottom. Keep in mind that this
loss of swimming ability is a gradual process over an entire
season of winter in cold climates. The bait has to become scarce
over time, the bass has to become inactive and stop pursuing bait
over time, the water has to increasingly become colder over
time...all these changes take place over time. So, if there is a
quick chill and quick water drop in early winter, you can
continue to find plentiful bait and plenty of feeding bass in
chilled waters in early winter. But, given time, the whole cycle
of reduced energy content (less food in the water), energy
budgeting by bass (less incentive to feed), and consequent
reduced swimming ability will happen to bass in colder climates
by deep winter time.
In a late winter, when the water
stays open (no ice) longer than usual, fish may continue to
follow the instinct to feed later into the season than usual.
This is generally not good because the low water temperatures
restricts the rate of food absorption which also limits the
energy intake derived by even a "well-fed" bass. Often,
gastric evacuation results (puking) rather than digesting the
food and unlocking its energy. In this way, the energy
"cost" of maintaining a high metabolism for continued
feeding is far more costly than the energy gained from it.
Therefore, such continued feeding only begins to deplete its
stored body reserves in order to "pay for" the
continued loss of energy from the fruitless continued feeding.
This breaks down the condition of the fish and compromises its
ability to endure throughout the still long winter ahead.
This affect is especially serious
in young of year fish that simply do not have the body mass to
"budget" large quantities of energy that will carry
them over the winter. They will, however, be fine if a normal,
cold winter slows their metabolisms to a very low level that
allows them to subsist in a sort of suspended animation. For
young of year fishes, a good cold winter is generally survivable.
In fact, it has been reported that young of year of some species
have been known to endure being frozen solid within ice at times
during the winter...and they apparently thaw out with no problem.
This resiliency is only present in the smaller young of
year...and larger fish that are frozen do not have the same
durability to thaw out and swim away so happily.
However it's probably an extreme case for them to get frozen -
I think that they mostly go into something like a suspended
animation-like state to winter-over. I think this is a good way
to think of it. This is a common pattern in nature, for animals
to endure and in a certain sense "cheat" winter by
going into a "deep sleep" and not waking up until
spring. Besides, if you have ever seen bass during other adverse
times of weather (cold front, hot water), they are definitely
prone to "zone out" not just in winter, but they often
become inactive and drop into a stupor-like state at any time of
the year when conditions are not favorable to them, not just
winter. Anglers generally say the bass are "inactive"
then - whether it's for a few hours, a few days or even weeks. No
doubt, the bass have shut down their high-maintenance body
systems in order to budget their energy and wait for more
favorable periods of time. This is not a conscious thought or
decision made by the bass, but Mother Nature at work controlling
their metabolisms to ensure their short-term vigor and long-term
survival of the species.