Another question for John and others

[Steve Craig]

The other thread was getting pretty long, so I thought I would ask these questions here.

Now......another question?
What causes the fish to move from their summertime structure locations, to the steeper wintertime locations?

And the second half question ties in with it.....when, in the fall, do they make the change?

Mr. Perry talked alot about the when and why for the springtime seasonal movements but he said very little about this subject.
I am pretty sure I know the answer, but want to get more input from others here, so that we all put our thinking caps on again, as this is what this board is all about!

[david powell]

My 3 cents.
What causes the fish to move from their summertime structure locations, to the steeper wintertime locations?

I don't think anyone knows why the fish do it ,and we don't really need to understand why they do it.All we need to know is that it happens,and adjust our fishing accordingly.


And the second half question ties in with it.....when, in the fall, do they make the change?

Just off the top of my head it should start to happen after the first big frost.

[jwt]

,,,and we don't really need to understand why they do it.All we need to know is that it happens,and adjust our fishing accordingly.

Agreed David. But, on the other hand, some people with a curious nature might just wonder why they do it. Which is OK as long as it doesn't interfere with their adherence to the guidelines.

As David said, the "Why" may not be known, but the breakdown of the stratification allows fish to move through the entire water column. Specifically, there is no longer a temperature gradient, density becomes uniform throughout, and mixing of nutrients and DO is possible from top to bottom. Because fish are sensitive rapid changes in temperature of 8º or more, my thoughts are the fish use the more gradual slopes during the period when the lake is stratified to allow time to become acclimated to the change in temperature when moving from deep to shallow, but during the cold season with the uniform conditions fish can use the steep slopes to move from deep to shallow.

[Steve Craig]

"it should start to happen after the first big frost."

What if it doesnt frost, say.....in Phoenix Az.? Or Southern Calf.? Southern NM? South Texas?

Jim,
Pretty good answer. But this doesnt apply in the Spring time, as research has shown that in the spring when the fish move to the shallower areas, that temperature doesnt play ANY part in the when they go.
I read a study that had the fish in 3 different water temps, (normal for the time of year,very high temps, and very cold temps)and they ALL moved at the same time to the shallower areas. So temperature is only a part of the answer. Something else is causing them to go. Temperature ONLY determines when the eggs will hatch.

So wouldnt it be safe to say that something else is causing them to change in the fall as well?

I am one of those fellows that always wants to know the why's of things. It helps me become a better hunter/fisherman.

[Bink]

"it should start to happen after the first big frost."

What if it doesnt frost, say.....in Phoenix Az.? Or Southern Calf.? Southern NM? South Texas?

.

Hours of daylight, as the days get shorter they begin to transition.

[jwt]

Steve,
You don't need frost. The breakup of stratification begins when the water temperature reaches about 50º and continues until the entire water column is about uniform 39º except for a thin layer when there is ice. As far as springtime, how fast do fish move up from the deep water to the spawning areas? Do they go up the steep side or the gradual side?

[david powell]

this is why Mr.Perry gave us guidelines,you can never tell a fish where it is suppose to be or when.You have to check it out,as stated earlier this is part of summing up the fishing situation.JWT where did you get the info on 8 degrees.

[jwt]

David - Chip Long, Fisheries biologist for the Virginia Department of Game and Inland Fisheries.

The body temperature of a largemouth bass is the same as the water where it lives. As a result, its metabolism and body chemistry change as water temperature changes. An abrupt decrease or increase in temperature of 8º F or more can cause internal chemical imbalances in fish. It’s important to realize that when largemouth bass experience changes in temperature, they may become inactive until their bodies can reach equilibrium at a new temperature. It may take largemouth bass several days to recover from a decline in temperature, whereas they can recuperate from an increase in temperature in only a few hours. Therefore, cold fronts have a greater effect on fishing than warm fronts.

Sounds like something Buck Perry wrote doesn't it; except for the part about the chemical imbalance? Only Buck didn't go into all the details. He simplified it by saying fish are inactive after a cold front.

We need David Erdly to jump in here. He is a fisheries biologist and a spoonplugger from IN. Protege of the one and only John Bales.

[Steve Craig]

Dead on Bink! At least as far as I am concerned. So my opinion only.

Hours of daylight..........
It is what causes the geese/birds to migrate. The furbearer's pelts to prime, even in very warm climates, and the ungulates to start their rutting.

So it only makes sense to assume that hours of daylight affect the seasonal movements of fish.

[jwt]

Makes sense to me. Also starts the chemical change in trees that causes fall color.

[The Fisherman]

This is only my opinion here. We know that all of a fish's movements are determined in all likelihood by a light condition of sorts. In the spring the weather is normally a few more overcast days. Depending on the weather and how much cloud cover you get on a particular year, decides when they move up. On the other hand if we go really big on the thinker; some fish are ready to spawn and migrating north before the ice is off. The sunlight is at a direct enough angle to the surface of the lake that the light condition has triggered the spawn or pre-spawn. The same condition except reverse occurs in the fall. The angle of the earth/sun relationship changes in such a way that the sunlight begins to have less penetration into the water. The fish at this point are triggered into using structures that offer a quicker route to sanctuary depth water and safety. Although it seems odd, less light normally means better fishing. The lesser light conditions in the summer are still at a more perpendicular angle allowing a certain amount down, then it changes angle. Even though it is still bright to us, the light is not traveling downward towards the fish. This could be seen as a "changing" light condition. hmmmm. I completely agree with Bink here on the light being the cause of transition. I do not know exactly why or at what point he is triggered. This is why we have different ideas on when to switch. I have always seen a slow transition. At least a transition that I was able to notice. Today I caught 50 bass on a good summer structure. Next day 35 with no weather change. so on and so fourth. During this time going to check my winter structures and begin to find more fish there every day. It is not a power switch. I don't think that this can be answered in any way other than a light condition. Just like...what is shallow water? Steve Craig will probably fish shallow water that is much deeper than anything we fish in GA, due to the water color.

Josh

[jwt]

Maybe the excerpt below from an article by Wayne Gustaveson(Fisheries Management at Lake Powell) will shed some light on the subject. To elaborate on his statement "Bass are really adept at finding even the slightest change in temperature.", Chip Long, fisheries biologist with VDGIF, states "A largemouth bass can detect changes in water temperature less than one half of a degree using its lateral line."

Fish first become aware of impending spring by the changing angle of the sun as the seasons change, bringing first a few more minutes and then a few more hours of daylight. Sometimes Phil, the weather guy, has the weather so fouled up that we think it is the dead of winter in early March. But our finny friends the fish know that the strength of the sun is increasing and longer days mean it will soon be time to spawn.

Fish spawning behavior is hormone driven. Flowing juices cause different behavior in male and female bass. Males are nest builders. They need a place to entertain before they can even think about scoring with a great green fish lady. The big green mommas are not nearly as retentive about the whole scene. They are content to move near the spawning shallows while still eating tasty small sunfish in the brush or crayfish on the rocks. Males cannot really be bothered with eating because first they have to find the perfect spot to build. Then there's nest construction, and then nest maintenance following windy turbulence and WOW, before you know it, it's time to spawn.

The actual spawning event is temperature driven. Bass are really adept at finding even the slightest change in temperature. It's not brain surgery. You may recall swimming in really brisk water and then encountering a warm pocket that allows half of the goose bumps to melt. Same thing for bass. They can feel the warmer temperatures.

[The Fisherman]

It kind of seems that we have two different studies or at least people saying two similar but still different things. I have not doubt that the light condition controls all of a fish's movements in some fashion. We see that one study says all the fish moved at the same time to spawn with different temperatures. The other says the spawn is determined by temperature. The only way for me to understand something is to see it in some way. The guy that said temperature doesn't matter, actually watched or noted the fish all moving at the same time. This can only be explained by the fact that there had to be an overall controlling factor, light. While the temperature may affect how fast the fish moves, velocity, on his way there. He will not actually spawn because the temperature rose one half of a degree. I do believe that he can notice it and that goes back to previous discussions. The study that said temperature is what actually causes the spawn; it would be very difficult I think to conclude that when fish spawn in different temps. Also to go back to the basics, Mr. Perry made strong warnings to not worry about water temps, he kind of made fun of those people that were running around looking for an ideal temp. He did however stress the importance of observing light conditions on a given day.

Josh