December is finally here, and so is the end of Fall and beginning of Winter. With extreme cold temperatures coming (around freezing point), I thought it would be very interesting to bring you guys a topic on "fish hibernation," and finally be the first angler in the net to scientifically connect the sport with this term and unveil this interesting "secret" to you: freshwater fish do not hibernate.
The truth is that biologically speaking, they just can't do it. It's against science. Therefore, fish hibernation is a myth. Emphasizing, freshwater fishes do not hibernate (note that I classified them as "freshwater," meaning that there are a couple exceptions for saltwater fish -- more details later).
According to science nowadays: the weather gets colder and the fishes bite less. However, science wasn't that advanced a couple centuries ago. In other words, what is obvious today certainly wasn't obvious back then. I mean...there was a point when we believed that the Earth was flat and the horizon was a cliff. There was a period of time in history when we did not understand how thunder and lightning worked (many myths in the ancient times associated this phenomenon with Gods: Thor and its Hammer, Zeus and its Spear, etc). And so on.
The human knowledge was very limited back then, and people couldn't help themselves but to make up theories based on observations and experiences. As a matter of fact, this same "phenomenon" happens at any time in history: our future society will certainly be looking at us, maybe 20 years from now on, and be laughing at how much we lacked in terms of knowledge when it comes to certain fields. Science is beautiful because it's a never ending process packed with discoveries and advancements!
Anyways...time for a story/example:
Knowing about the presence of fish, the residents of this small village soon start to practice fishing. They use worms and other insects to fish, and they eventually succeed! The catches are good during the Summer, but the size of their catches is limited since their equipment's durability is also limited. Also, surprisingly, the caught ones were all of the same Species -- the darker ones. Families are happy, hence they have more than enough fish meat to consume. Soon, the residents start to hunt and plant as well, but they fail as they realize that they don't have the basic skills for those arts. They try their best and they accomplish little.
With their current skills and technology, they are not able to survive the harsh Winter. Food runs out often, and they are forced to search for more. Part of the males die from hypothermia while trying to hunt or fish. Another part of the population die from winter starvation. And finally, another part leaves with their kids in search of aid. And so, the Winter of 1670 passes, leaving dozens of bodies in an abandoned little village, somewhere in the colony of Pennsylvania.
The little village prospers in a short amount of time, and soon Winter arrives.
If you are familiar with the history of Pennsylvania (or even the USA), you may be able to notice that this example is not totally fictional. I based this example on my knowledge of the history of this country, and I left many "ifs" and "hows" for the reader to think about.
By now, you should have a better idea of where myths come from. =)
It's not totally wrong to say that fishes do "sleep" more during Winter time. Although they don't enter a state of hibernation, they do enter a state of dormancy during low water temperatures. Fish often go into a state of torpor -- "a state of physical or mental inactivity; lethargy;" However, that doesn't last more than a couple hours a day. For example, Northern Snakeheads enter a state of torpor for about 8-9 hours a day during Winter time. During those hours, they are totally unaware of their surroundings and they do not move at all. As a matter of fact, torpid fishes barely respond to any stimuli!
Therefore, it's not wrong to say that fishes are lethargic during Winter time; however, it's wrong to say that they are hibernating. Scientifically speaking, hibernation is basically an extended form of torpor (dormancy); however, dormancy and hibernation are triggered very differently: dormancy is triggered by ambient temperature and food availability whereas hibernation is triggered by the length of the day and hormonal changes in the living organism.
Here's a summary of Hibernation Vs. Dormancy, in general (not only restricted to fishes, which are ectothermic, poikilothermic):
Dormancy/Torpor (in general):
-- Living organisms go into the state of torpor once they are in their natural habitats (refuges).
-- Living organisms in a state of torpor barely respond to external stimuli, not to mention that they cannot perform coordinated movements.
-- The metabolic rate of torpid organisms is very low; therefore, they are able to save a lot of energy in that state.
-- The time to awake from a state of torpor varies from organism to organism, sometimes taking even 1-2 hours to get out of it.
Hibernation (in general):
-- Living organisms go into the state of hibernation once they select a special "hibernacula" (i.e. nest).
-- Body temperatures drop a lot lower for hibernation than for torpor; therefore, external stimuli is non-existent.
It's within these guidelines that fishing slows down during Winter time:
So, fishing during Winter time is truly tougher than other seasons. It's at this point that a fish temperature chart turns out to be pretty handy, guys!