Temperature Trends

[Guest muddy]

I catch as many fish mid summer these days as spring and fall, all my bigger fish however do come in the fall. This happened once i moved away from the shore line and stayed away from where a lot of the other boats were fishing, I have confidence that vertical jigging will furthur improve things as i get more proficient in it.

[Paul Roberts]

Muddy: Yes, I see an offshore movement even in my small waters by summer too. Fascinating that it happens even on small waters. It seems to be an orientation to the main basin. Ralph Manns and I have had some discussion as to why this might be. He wonders, purely speculation (not research backed), if it isn't in part a result of early entrainment from when they were fry, and moving to open water to feed on zooplankton. Not sure what to do with that but it is interesting.

The mid-summer slump I see appears to be in part temperature related (surface temps >85F). But there may be more to it. This summer I'm going to spend some time on waters that might not heat so high, and see what comes. I can always hope for a Godsend -a cool summer! Interestingly, I've been in contact with a couple anglers in southern Canada and they claim they do not see this slump, and water temps don't surpass 75F.

But, what confuses me a bit, is Keith Jones' (Knowing Bass) research in a thermally graded tank that showed bass had no upper temperature avoidance! They continually sought heat in the laboratory. I'm wondering if the summer slump in natural systems has to do with oxygen levels, food availability (dense vegetation), and...?? This would likely show great variations across waters. Thus, I'm going to dabble in what possible variation there is here this summer. I don't have very deep water though. I'm eyeing an 18 foot deep lake for some of this, and I'll be comparing temperature profiles with this lake and my shallower summer slump waters.

So, Muddy, what are your good summer lakes like? Sounds like you are fishing deep, with jigging spoons?

[Guest muddy]

Hey Paul: I fish Mauch Chunk primarily small 339 flood /water suppl lake. Lots of boulders and weed beds on one part the other shallow with tons of stumps and a lot of pads. When it really starts getting into the summer the water really gets over the 80 degree mark then those large boulders and the submerged weed beds ( Coon tail and some type of grass) all found in water around 10 to 18 feet really jump to life. Over those same weedbeds at night the top water bite is tremndous

  Of the many naturally occuring small lakes and ponds here, once they get warm, I belive the oxygen dissolved in the shallow ater is not enough for bass surival, but most of these have some kind of underwater run off or spring, the presence of very healthy and green weeds and a sudden drop in temp will usually tip off their location. EVEN THOUGH THE WATER IS VERY MUCH COOLER there  THE BITE IS WAY BETTER  than the rest of the lake at this summer time period

I am just starting to put all this together

Another great pattern that works in the dog days: We all know that before a thunderstorm, around these parts the falling barometer triggers insane bite. If a Tstorm drops a lot of rain and there is a lot of runoff, you know you can see where they are easily. A weightless t rigged worm of your choice really works I beleive the fresh water and wind helps the oxygen leveel and I have seen how the fish key in on those spots and devour anyting edible that wahes in

[Paul Roberts]

Muddy,

One of my summer slump waters has a spring, and it's the hot-spot in that water during mid-summer.

I think what you are describing are what we all look for -the situations when the fish are on fire. It's a combination of proper conditions AND available food.

The summer T-storm thing: Is it the falling barometer, or the associated sky conditions and stable to warming temps that matter here?

[roadwarrior]

On large rivers, temperature trends, barometric pressure, moon phases and other variables have no noticable impact. River fish are all about current, baitfish migration and the "general" temperature (hot or cold).

Species congregate and spawn at various times and those periods are important. However, the daily bite within any time and temperature frame is only efffected by water flow. Specific examples on the Tennesse River (north of Guntersville) are the congregation and spawn period for smallmouth bass and sauger in January and February (45-55 degrees); white bass and crappie currently (+/- 60 degrees) and in a few weeks, Kentucky bass (70+). However, when water temperatures vary outside these ranges, the concentration of fish is still present whether they are actually spawning at that exact time or not.

So, my observation is that the effects of many variables may come into play, but the only constant is water flow. When we have good water, we catch fish. Without current, you might as well stay home!

8-)

[Guest muddy]

Muddy,

One of my summer slump waters has a spring, and it's the hot-spot in that water during mid-summer.

I think what you are describing are what we all look for -the situations when the fish are on fire. It's a combination of proper conditions AND available food.

The summer T-storm thing: Is it the falling barometer, or the associated sky conditions and stable to warming temps that matter here?

There is a small lake close by, in a public park. On the west side of the lake is a mountain ( by Eastern standards, not like you guys out west) the T storms come from that direction most the time. The water is beat to death by trout fishermen, but it is full of some nice size bass. This lake turns on big time with an appoaching storm. There is a weather sataion there, and now my curisoity is up, about checking the falling barometer.

 I can tell you that before there is anynoticable change in the sky( To human eyes) as the storm is approcahing the fish are already on a stronger more aggressive bite.

[Paul Roberts]

Muddy, keep tabs on that. I'm going to venture a guess that the real effects are more immediate (clouds and temp trend) than early barometric pressure movement. But that's my guess at this point. Lemme know what you see. I'm not sure, for myself, I can discern barometric effects from sky and water conditions in terms of angling results, since sky and water conditions factor in SO heavily in terms of angling success.

roadwarrier,

I agree, current has an enormous effect on fish location, and activity I think in large part because of the advantages larger predators over prey fishes in current. But also because concentrations of activity are easier to discern for anglers. On the flipside, current also affects lure presentation enormously, and low slow water can be tough. (In general, water and sky conditions can affect angling presentation to the point that it can overshadow environmental effects, when one is sampling by angling.)

Water level itself (rising or falling) is very important to fish. It's one major factor that can cause bass to abandon nests, or incite movements to spawn (when other factors are met). This sensitivity to water level appears to be ingrained in many fishes. It's my holdout explanation for any sensitivity to the moon that might exist for freshwater fishes, although I'm leaning more and more towards skepticism here from a one-time moon believer! We'll see new moon coincides with spawn times here this year. I'll be watching closely.

My experience with warmwater rivers is limited at least with taking down any really useful information. But I have a lot of experience with coldwater stream fisheries, and this is where I came to where I am with bass. Temperature rules in trout streams, and not just during summer when temps are marginal. Food factors in huge of course, but hour by hour, I've come to believe, temperature is of enormous importance. But stream levels had a notable impact too, and I believe it factored into brown trout's nocturnal shift in late spring/early summer. However, interestingly, when surface water fed streams warmed and levels dropped and the browns went nocturnal, in nearby (as close as 100 yards in one particular case!) groundwater fed stream sections the browns were NOT nocturnal and rising freely during the daylight hours! Fascinating.

[RoLo]

Roger, I'd really like to get that IF article. Do you have any specifics on it? Was it in the magazine? I'll go ahead and contact them and see if it's available. Any info would be helpful though.

What do you attribute the vertical movements you see to? Slowly rising surface temperature?

The study team at In-Fisherman correlated "vertical positioning" with "stable weather" conditions.

It might be presumptuous to single out water temperatures as being solely responsible.

In any event, we do know a couple things for sure. We do know that bass are cold blooded creatures,

so water temperature tends to dictate their disposition (bass lack free-will).

We also know that warm fronts are accompanied by a "temperature uptrend".

You're not the first person to request that specific article, and now you've got me looking for it too.

Actually In-Fisherman published TWO reports: the first in an early Study Report regarding the vertical positioning of bass,

and another article several years later in their ad-laden magazine discussing lateral migration (both pre-Primedia).

The staff did telemetry tracking on several largemouth bass in a natural lake.

Their findings in this test-case (ex-reservoirs) effectively exploded Buck Perry's theory

regarding daily or twice-daily horizontal shuttles between deep and shallow water.

That's when I began to realize that bass are comfortable wherever they may be,

but react differently under different sets of conditions (meteorological and limnological).

In this same In-Fisherman article was a diagram showing the color-coded migration tracks of each largemouth bass.

For the most part, all lateral movement clung to the same depth line (contour line) essentially paralleling the shoreline.

Differently put, the bass were looking for a change in scenery without a change in depth.

There were also one or two renegade bass that swam across the lake from one shore to the opposite shore, but again

not in the interest of depth change. The study team offered no explanation for the random migration of those wayward bass.

For Roger:

Was this phenomenon strictly thermal or is it a combination of weather conditions; barometric pressure, cloud cover, wind direction ECT.

I wish I could tell you

As you know Tom, warm-fronts are comprised of a bundle of similar circumstances,

while cold-fronts demonstrate an opposing set of conditions.

Although we understand the "thermal" implications of weather fronts, I'm sure we have a whole lot more to learn

regarding the impact of all other elements of weather (air & water).

Roger

[Guest muddy]

Wow what a thread thanks to all the fellas this is why I don't watch TV Fishing shows too much, IT"S ALL HERE     and then some

[CJ]

I agree Muddy! It may take me awhile to soak it all in... with the help of a dictionary.  :-/

[roadwarrior]

My experience with warmwater rivers is limited –at least with taking down any really useful information. But I have a lot of experience with coldwater stream fisheries, and this is where I came to where I am with bass. Temperature rules in trout streams, and not just during summer when temps are marginal. Food factors in huge of course, but hour by hour, I've come to believe, temperature is of enormous importance. But stream levels had a notable impact too, and I believe it factored into brown trout's nocturnal shift in late spring/early summer. However, interestingly, when surface water fed streams warmed and levels dropped and the browns went nocturnal, in nearby (as close as 100 yards in one particular case!) groundwater fed stream sections the browns were NOT nocturnal and rising freely during the daylight hours! Fascinating.

I fish the White River below Bull Shoals in north central Arkansas. The water coming through the dam is taken from the bottom of the lake and is a constant 52 degrees year-around. Although an occasional big brown is caught during the day, the majority of 10+ pound browns are caught at night. The only exception is after a shad kill when the trout lose all inhibition!

Current trumps all other factors on this river, too. Rising water is good, falling water is terrible.  If you can "catch the release" as generators are open and water moves downstream, fishing improves by at least a factor of 10X!

8-)

[Paul Roberts]

Roger,

I'm familiar with the horizontal movement stuff. It's the bass rooted into the vegetation following a cold front I'd like to see.

roadwarrior,

Very cool. Thanks. My ponds don't fluctuate too much, but my small reservoirs do. I'll keep that in mind.

Catt,

Are you Ken or Tom?

Thanks All.

Those listening in. If you have observations along these lines you can share, as your season progresses, please do. No one person is going to figure this stuff out alone. I do think we can refine what we know a lot further.

[RoLo]

Roger,

I'm familiar with the horizontal movement stuff. It's the bass rooted into the vegetation following a cold front I'd like to see.

In searching for the unabridged article, I did find something in a 1978 In-Fisherman that addresses vertical positioning.

As my scanner isn't currently hooked up, I photograghed the page in macro mode.

Text>        http://64.226.208.65/scans/vertpos-text.jpg

Diagram> http://64.226.208.65/scans/verticalpositioning.jpg

Roger

[Paul Roberts]

Roger,

Thanks so much.

I do wonder, How do they know what the bass are actually doing?

I have some thoughts and questions about supposed cold front behavior. Another post someday.

[Catt]

Me? I'm Thomas (catt) Thibodeaux

The Email is from Ken Cook:

Graduate Oklahoma State University with a B.S. in Zoology he worked for the Oklahoma Department of Wildlife Conservation as a Fisheries Biologist.

1991 BASSMASTER CLASSIC Champion

Fourteen Time BASSMASTER CLASSIC Qualifier

Chosen among Top 35 Anglers of All Time by BASS in 2005

Named one of the top ten most fan popular anglers by Bassmaster Magazine.

Top 50 on B.A.S.S. All-time Money Winner's List

SIX-Time B.A.S.S. Champion

Three Time World Champion Angler

U.S. Bass World Champion, 1985

American Angler Grand American Champion, 1980

[HesterIsGod]

I heard Doug Hannon say once that there was a test done where bass were put in a long tank. In one side of the tank was 40 degree water, and the water temp. gradually increased until it got to the other end and topped out at 90 degree water. No other factors like food or oxygen, just temp. The bass chose 82.5 degree water.

I personally believe that bass will not move across the lake for warmer water, but I always look for warmer water in the colder months not because that is where all the bass are but because those bass are mostly, but not always, a little more active than the bass in the colder water.

In the summer I absolutely love spots where a small creek or some sort of a spring or runoff comes in. I have personally found in my experiences of the last few years that in early summer when the bass are holding at or near where this current they always will hold at some sort of current break, being a laydown, big rock, whatever. But in the middle and late summer when the temps. get a little higher than 82.5 degrees they will begin to stray from these current breaks during midday and position themselves in the mid to heavy current of the creeks running in much like smallmouth do. So I am a believer that when the water surpasses 82.5 or around there the largemouths will stop seeking out warmer water. Since there metabolism is in high gear they just put themselves in the middle of this current and eat whatever happens to float/swim by. I do really well at this time with heavy jigs/ soft plastics that are heavy enough to not get swept away by the current.

My 2 cents on the issue.

[RoLo]

Roger,

Thanks so much.

I do wonder, How do they know what the bass are actually doing?

You're welcome Paul.

Well, we may not know what bass are doing, but their vertical position in the weed bed discloses a lot about their current disposition.

In the unabridged report, post-frontal bass were observed firsthand with their noses against the bottom

and their tail sections angled upward. Even without the article in front of me, and even though it was many years back,

it's not something you could ever forget (at least I won't). The position and attitude of bass during a warm-front

was described in detail, day-by-day (Day-1 - Day-2 - Day-3 - Day-4). Ditto for a cold-front. However, a full-blown warm-front

is generally living on borrowed time after around the 4th or 5th day. With each passing day, the sky grows hazier and hazier

due to the cumulative buildup of moisture, then around the 4th or 5th day a thunderstorm is generally in the offing,

the death knell of the warm front.

The wind direction ultimately shifts into the northern hemisphere and cold winds will usher in dry air and cloudless skies.

This takes us back to Day-1 of a cold-front with bass ON the bottom, and the beginning of a new vertical cycle.

I should indicate that vertical positioning is basically (but not exclusively) a summer pattern

that applies essentially to the vegetative zone (littoral zone).

It goes without saying, anyone who's been bass fishing for more than one season already knows that nothing is etched in stone.

Nonetheless, I've found that an understanding of vertical positioning as it relates to frontal conditions

continually unlocks important pieces of the ongoing "fishing puzzle"

Roger

[WRB]

Bass are in sunfish family and water temperature controls nearly every aspect of their lives. The largemouth bass in Florida are a different specie than the bass located outside of Florida, unless transplanted. The reason FLMB didn't spread naturally beyond Florida is water temperatures north of that region drops below 45 degrees and the FLMB can't tolerate the colder water.

There is a lot of opinions stated about bass and water temperature. Try to keep in mind that the bass we a trying to catch have a prefered water temperature zone of 70 degrees*, if availble. During the winter 70 degree water isn't available many places where bass live, so they move to where ever the warmest water is that contains good levels (7 to 9 mg/L) of dissolved oxygen (DO) and food, because they must breath and eat. DO limits are somewhere between 3 to 12 mg/L for most fish.

During the summer largemouth bass will try to stay near the cooler 70 degree water temperature if possible and they still need to breath and eat, so they may move to warmer water if neccessary. The lower temperature that largemouth bass can survive in is about 40 degrees, the upper limit is about 85 degrees. The reason that bass can't survive colder water is the fact that at 39.4 degrees the water changes dramatically, the density gets lighter, the DO levels are too high for bass to servive, so the bass go deeper to stay in warmer water or locate springs that keep the water warmer. At 85 degrees the water doesn't hold enough DO, so the bass go deeper to find cooler water.

It doesn't matter where the largemouth bass are living, the water is the temperature affects them the same in California or Ohio.

The problem is today's bass fisherman look at their surface temperature guage to determine the lakes core water temperature. I don't know if anyone has ever swam in a lake, if you have you would know that the water gets cooler the deeper you go down. The bass don't live in the first foot of surface water, they live down deeper several feet where the water temperaure is confortable, the DO levels are good and food is availble.

You will see bass swimming near the surface as the water column is warming following the cold water period to seek the warmest water possible, they are sunfish and don't forget bass are a predator fish looking for food and hopefully our lures.

WRB

* ideal water temerature for bass survival when DO levels are between 7 to 9 mg/L.

[Guest muddy]

Even though the lake I fish is only 339 acres, i have never witnessed this going to 70 degree water temp Migration. In the summer the bass in the warmer water areas are usually found in the same area and the bass in the cooler parts of the lake generally seem to stay on that side. I do not think what you are seeing is for every body of water.

  I think, I am not sure yet but as long as there is a good food source and enough oxygen , that temp becomes less important when stacked up with all the otehr factors.

[Raul]

For me talking about temperature trends lacks of any value to almost everybody, down here water temp seldomly drops to the 60 's even in the middle of the "winter", it can rise up to 90 in the middle of the summer specially in the shallow lakes ( shallow means 45 ft at the deepest part ) most lakes I fish are deep and water temps remain in the 80 's well into the year, yeah, imagine yourself living in a place where the water temp is 80 in January ( jealous ?   ).

So for me it 's relatively easy:

1.- When can I expect the fish to be active ? all year round

2.- Even though the methabolic rate and the degree of agressiveness go hand in hand ( warmer water means more active fish ) water temp trend does not apply per se to my case,

3.- Weather patterns on the other hand do apply and have a greater impact on what I can expect when I go to fish.

4.- Full or almost full pool lakes, nice warm weather usually mean pretty lousy fishing, not because the fish aren 't active, because the level of human activity in the lake skyrockets; all them water skiers, jet skiers n ' pleasure boaters come out from their lair when the wether is nice and run up and down all over the lake at warp speed all day long !  >

[WRB]

As long as the temperature is within the basses confort zone, the DO levels are good, the PH is OK and food supply is there, the optimum temperature isn't a primary factor. If the bass are there, then the conditions are right for them.

DO comes from 3 natural sources; aquatic green weeds producing oxygen during the day light hours (via photosynthesis), incoming aeriated water from a stream or river and wind generated wave action. DO is consumed by the same weed growth at night, decaying organic animal or vegetation and underwater DO breathing animals like fish. Man made oxygen pumps are sometimes added to lakes to help increase DO levels below the thermocline. Both fertilizers and pesticides deplete DO levels.

If the small lake is located near residential or commerical areas, then the man made affects should be considered.

Spring water is normally a constant 60 degrees, unless heated and has very low DO levels. Springs are usually surriunded by weed growth that adds DO and that is where the bass like to hold in both summer warm water and winter cold water periods, because the water tepmerature is confortable and aquatic life is good around a spring.

WRB

[Paul Roberts]

Hester,

Yes, the low to mid 80sF is generally agreed upon as the "thermal preferentia" for LMB, from a bunch of studies.

First, let me say this about lab studies cause I can hear the grumbling already. Lab studies are useful in that they can offer glimpses toward what bass' limitations or capabilities are. My take home message is: Use them in your fishing to make your educated guesses, and then check em out. But don't assume too much going in. Natural systems are complex.

Something fascinating about bass comes from Keith Jones in his book "Knowing Bass". He found that LMB, over time, would keep re-acclimating higher and higher, until they hit the limit of his tank (not sure highest temp but it was above the accepted preferentia values). I found this fascinating. But it hasn't panned out into anything useful on the water, as yet.

I see a reduction in activity when my ponds hit the mid-80's. Not sure what to make of Jones' observations, beyond that natural systems are more complex: actual temperature distribution and fluctuation, oxygen, prey availability, and the fact that wild bass are mobile (what we're presently interested in short range vertical is what we've come to here mostly it seems).

There's another value used to assess the metabolic engines of fish that may help shed some light on some of what we see in the wild though the upper (and lower) avoidance temperatures. At a certain high temperature a given species must move away or die. These values are highly dependent on the individual fish's present acclimation temperature. Here's one example I have: A group of largemouth bass acclimated to 68F all die at 87F, 50% die at 84F, and none die at 77F. Now, rarely will you have bass in 68F water near 84F water in the wild, but that 16 degree difference KILLED half the bass! You can imagine that even a 10F difference might make a bass mighty uncomfortable. The take home is that there are limits to what bass can tolerate, at least within a period of time.

Interestingly, there's a growing body of research indicating that fish grow best by digesting meals at lower temps (below metabolic optimum). Further, this has been demonstrated in the wild, from sharks to salmon, through vertical water column movements: They feed high and warm and digest low and cooler. (Roger?? What do you think?) The latest IF magazine has an article showing this very thing in king salmon in the great lakes. I don't think they understood why the salmon were doing this.

Hester, your bass in river current observation is very neat. And I'll venture a guess as to what could be happening there: Heat challenged stream trout, (not at all uncommon in the many marginal streams and seasons throughout the country), approaching an upper temperature limit suffer oxygen stress and will move into stronger current in order to increase their oxygen uptake efficiency. They do this through what's called ram-jet ventilation, in which water can flow freely over the gills, rather than the trout having to pump it through. Thus, heat stressed trout move out of pools and into riffles. I've seen this myself in hot summers on marginal streams. I've never seen such a thing in bass, but, it's not unlikely. Bass can't go into too fast water because they aren't built for it. Just as different trout species have different capabilities in current: browns hold below the rainbows which can nose right up into the whitewater.

Of course it could just be a movement toward food, but the temperature values you've offered may indicate something more physiological in nature.

Phew! No my head doesn't hurt yet. It's my fingers. Hey if anyone (besides my wife) is wondering why I'm bothering to type so much, I'll say that discussions like this allow me to organize my thoughts better. That's how I keep from being overwhelmed by it all, and my head hurting. In my fishing I'm not just after the where and how, but the why. The why is more exportable to other waters and fish, and worth the effort.

Roger,

The problem I have with cold front stuff is that I for one have a hard time separating the effects of sky and water conditions on angling effectiveness from what might be real bass behavior. The cold front thing is a tough nut. I'm not sold on anything yet, but I do have some ideas.

Raul,

Excellent stuff. Temperature is more important where it matters LOL! Further north, that is.

[Raul]

Paul, in my experience post cold front conditions have little to do with the sudden drop in air temperature, the water temp remains for practical terms the same than before the front, but the weather pattern associated to the passing of the cold front ( cloudless bluebird skies ) have a great impact, it 's the light penetration increase which causes the fish to either go deeper or bury into cover, it 's not that de fish develop a severe case of shutmouthitis, it 's just that most anglers continue to fish the same places at the same depth and the fish ain 't around there no more, in other words, instead of adapting their baits, presentations and locations they continue to fish when the fish aren 't there.

It 's a common mistake, they fish "the history" instead of fishing "the conditions". If the greatest bug is the light penetration then fish deeper or fish the conditions where the light penetration bug has less effect, like windblown areas or where there 's muddy water n 'such.

[WRB]

Pual, bass are not suicidal, fisherman catch them and store the bass in surface temperature water pumped into the livewells. It's not uncommon for bass in the summer to locate near the thermocline in water in the 70's, in deeper large reserviors, that is the temperature they prefer and the surface water can be over 85 degrees. The thermal shock of water exceeding 10 degree differential will lead to high mortality rates, if the bass can't return to the cooler water temepratures. To acclimate to warmer or colder water that exceed more than 10 degrees, takes the bass several hours with the water temperature changing a few degrees in steps.

reference; Gene Giililand, biologist OK DWC

http:www.stse.tn.us'twra/fish/Reservior/blaclbass/livebass2.pdf

Not trying to hijack the thread, just trying to keep things somewhat accurate. Doug Hannon bases his experiences on FLMB in Florida and his view points rarely agree with bass behavior outside of Florida.

For example it was stated that bass don't school to feed on prey fish. That goes agianst the experiences most bass fishermen. Bass that target threadfin shad schools on large reserviors are school fish. Big bass, out west, school to target trout in open water, it's a common tactic.

The eccosystem in a small natural lakes are different than a large reservior and that is why you need to classify the type of water the bass live in.

WRB

[Guest muddy]

WRB: Thank you for adding I know very little about Bass Bio, I got the bug b/c when Glenn was asked for the most underutilized part of the site his answer was Bass Biology.

Bass however do not have schooling activity. They do sometimes exhibit traveling in groups, usually of the same size They do njot have organized shool activity: Like traveling and using organized escape patterns, reproducing in " school family " groups and oraganized feeding patterns, every bit of research I have read clearly states this