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Posts: 2691
Location: Pewaukee, Wisconsin | Personally I do not like hot humid days. The night bite after dark is very good. Does humidity play a roll in this? Can muskies detect humidity under the surface? |
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Location: Illinois | I don't think it does. IMO it's more to do with high barometric pressure and lack of cloud cover that make those muggy days the pits. Muskies cannot detect the humidity of air above the surface, but they do feel the barometric pressure changes or lack thereof.
Fishing's been better for me when it's muggy + windy/prtly cldy, than bluebird and calm. Seems like 3 out of 4 times if it's muggy, it's bluebird. On those days I think it's best just to hit it during low light and after dark.
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Posts: 433
Location: Cedarburg, Wisconsin | Humidity may very well have an effect on light penetration with the associated haze you get. I do know my very best surface bait fishing happens when there is dew forming all over the boat just after the sun goes down and swarms of mosquitoes attacking. |
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Posts: 676
Location: Wisconsin | Fish can't feel barometric pressure either. |
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| You're right Muskiemetal., they can't feel atmospheric pressure; they can feel water pressure, which changes with barometric pressure. Water pressure at a point exactly 4'-0" below surface with atmospheric pressure at 29.50 in. Hg is exactly equivalent to the water pressure of a point 5'-1 1/2" below surface with atmospheric pressure at 28.50 in. Hg.
So barometric pressure is felt by fish. |
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Posts: 1906
Location: Oconto Falls, WI | Don’t think they can feel humidity. I am sure it is the weather that comes with the humidity that makes the difference, and to me humidity is good. Typically you have a bit more cloud cover, and the whole ecosystem is firing on all cylinders. Bugs seem to be at their worst which means things are going, and often times makes for the best fishing day or night. I think the simple fact of the bugs being crazy (often times meaning they are near the surface) brings the food chain up in the water column making muskies more accessible. They are no longer buried in the weeds or suspended way down in the water column out deep.
Often high humidity also brings about instability in an otherwise stable weather pattern.
Barometric pressure…I don’t think there will ever be agreement on how it truly affects fish and if they feel it at all. An interesting discussion on it here.
http://muskie.outdoorsfirst.com/board/forums/thread-view.asp?tid=28...
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Posts: 676
Location: Wisconsin | No, they can't...
http://midcurrent.com/science/the-pressure-myth/ |
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Posts: 1753
Location: Mt. Zion, IL | Water is an incompressible fluid so no fish do not feel pressure increases because you can't increase the pressure in a liquid. This is why hydraulics use fluids. A small ram is used to move a larger ram. |
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Posts: 1906
Location: Oconto Falls, WI | RyanJoz - 6/22/2012 7:55 AM
Water is an incompressible fluid so no fish do not feel pressure increases because you can't increase the pressure in a liquid. This is why hydraulics use fluids. A small ram is used to move a larger ram.
From Wikipedia.
"The compressibility of water is a function of pressure and temperature. At 0 °C, at the limit of zero pressure, the compressibility is 5.1×10-10 Pa-1.[28] At the zero-pressure limit, the compressibility reaches a minimum of 4.4×10-10 Pa-1 around 45 °C before increasing again with increasing temperature. As the pressure is increased, the compressibility decreases, being 3.9×10-10 Pa-1 at 0 °C and 100 MPa.
The bulk modulus of water is 2.2 GPa.[29] The low compressibility of non-gases, and of water in particular, leads to their often being assumed as incompressible. The low compressibility of water means that even in the deep oceans at 4 km depth, where pressures are 40 MPa, there is only a 1.8% decrease in volume.[29]"
So in essence correct as it is very minimally compressed. However thematter below the water is compressible.
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Posts: 676
Location: Wisconsin | A fish going from 5 feet of water to 15 feet of water would experience the same atmospheric pressure change equivalent of the greatest high pressure on record to the lowest recorded in a hurricane. To a fish, it just doesn't matter..... |
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Posts: 1753
Location: Mt. Zion, IL | CiscoKid - 6/22/2012 8:04 AM
From Wikipedia.
"The compressibility of water is a function of pressure and temperature. At 0 °C, at the limit of zero pressure, the compressibility is 5.1×10-10 Pa-1.[28] At the zero-pressure limit, the compressibility reaches a minimum of 4.4×10-10 Pa-1 around 45 °C before increasing again with increasing temperature. As the pressure is increased, the compressibility decreases, being 3.9×10-10 Pa-1 at 0 °C and 100 MPa.
The bulk modulus of water is 2.2 GPa.[29] The low compressibility of non-gases, and of water in particular, leads to their often being assumed as incompressible. The low compressibility of water means that even in the deep oceans at 4 km depth, where pressures are 40 MPa, there is only a 1.8% decrease in volume.[29]"
So in essence correct as it is very minimally compressed. However thematter below the water is compressible.
How can you measure 1x10^(-10) pascals?
By comparison to air and if using fluid dynamics or you have taken any class on compressible flow, the compression of water is so small, that is is ignored. Compressible by definition in fluid dynamics is any material that can be compressed to a point at which it changes state. If you increase the pressure of water can you turn it to ice (solid) or steam (gas). Hold the temperature steady. Let's pick 50 degrees Farenheit for a hold temperature.
Edited by RyanJoz 6/22/2012 9:11 AM
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Posts: 1906
Location: Oconto Falls, WI | RyanJoz - 6/22/2012 9:01 AM
CiscoKid - 6/22/2012 8:04 AM
From Wikipedia.
"The compressibility of water is a function of pressure and temperature. At 0 °C, at the limit of zero pressure, the compressibility is 5.1×10-10 Pa-1.[28] At the zero-pressure limit, the compressibility reaches a minimum of 4.4×10-10 Pa-1 around 45 °C before increasing again with increasing temperature. As the pressure is increased, the compressibility decreases, being 3.9×10-10 Pa-1 at 0 °C and 100 MPa.
The bulk modulus of water is 2.2 GPa.[29] The low compressibility of non-gases, and of water in particular, leads to their often being assumed as incompressible. The low compressibility of water means that even in the deep oceans at 4 km depth, where pressures are 40 MPa, there is only a 1.8% decrease in volume.[29]"
So in essence correct as it is very minimally compressed. However thematter below the water is compressible.
How can you measure 1x10^ (-10 ) pascals?
By comparison to air and if using fluid dynamics or you have taken any class on compressible flow, the compression of water is so small, that is is ignored. Compressible by definition in fluid dynamics is any material that can be compressed to a point at which it changes state. If you increase the pressure of water can you turn it to ice (solid ) or steam (gas ). Hold the temperature steady. Let's pick 50 degrees Farenheit for a hold temperature.
I agreed with you Ryan. |
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Posts: 8840
| Not trying to be a jerk here, but... They're under water. Is that a trick question??
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Posts: 13688
Location: minocqua, wi. | it got crazy wet and humid around here the last week ... all of a sudden ants, bees, skeets, spiders and bugs all over the #*^@ place!! the circle of life got a shot of adrenaline ... :0)
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Posts: 209
| RyanJoz - 6/22/2012 7:55 AM
Water is an incompressible fluid so no fish do not feel pressure increases because you can't increase the pressure in a liquid. This is why hydraulics use fluids. A small ram is used to move a larger ram.
You can certainly feel the change in pressure when more pressure is applied to the boundaries of a fluid. Say a balloon is in a sealed container full of water with a piston. You push the piston down (adding pressure). The water then pushes on the balloon. The pressure inside the balloon pushes back against the water pressure. The balloon will shrink until the two pressures balance out.
Now, this is obviously just semantics, because the fish still can't feel the pressure changes. The pressure change caused by them swimming up or down a few feet is more than the barometric pressure is likely to ever swing either direction, so your point is still correct.
To answer the original poster's question, I don't think humidity affects anything. I think humidity can be a good sign of other weather changes that may actually cause a change in fish behavior, but I don't think humidity is what's actually causing the behavior.
Edited by MuskieMark01 6/22/2012 1:58 PM
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| RyanJoz - 6/22/2012 9:01 AM
How can you measure 1x10^(-10) pascals?
By comparison to air and if using fluid dynamics or you have taken any class on compressible flow, the compression of water is so small, that is is ignored. Compressible by definition in fluid dynamics is any material that can be compressed to a point at which it changes state. If you increase the pressure of water can you turn it to ice (solid) or steam (gas). Hold the temperature steady. Let's pick 50 degrees Farenheit for a hold temperature.
RyanJoz, you're going to talk about taking classes on compressible flow after stating that you can't change the pressure in a liquid? Ever go to class? How do hydraulics work? Why do you think your head hurts when you swim deeper in water? What happens when you press the piston of a syringe but plug the end? You increase the pressure. True, water is [effectively] incompressible, but that has nothing to do with pressure. Maybe what you were thinking of was density.
Sorry, but don't use the jargon if you don't have a clue about the concepts.
If atmospheric pressure increases, and air temperature and water temperature both stay constant, the PRESSURE at some defined point below water surface will increase. Period. And keeping in mind the level to which fish are in tune with pressure, they can undoubtedly detect the changes. They can sense movement or vibration from a great distance via very slight pressure waves at some frequency (otherwise known as sound), so they can surely sense pressure changes on the order of thousands of Pascals.
True, they'll shoot up 15 ft in the water column on attack, but no doubt they can feel it. I'm not saying high pressure shuts off the bite though. |
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Posts: 4343
Location: Smith Creek | I think the article refers to saltwater fish living in an environment with severe fluctuations based on tide, waves, etc. in depths exceeding 100's of feet. It's naive to think in a small environment like a 300 acre 20ft deep lake surrounded by trees (sheltered by the wind) that a fish can't detect a change in pressure. I think that's why in the last two paragraphs the author states it's UNLIKELY under normal OCEANOGRAPHIC conditions.
There's been too many times when a feeding window has opened and we had no clue why... then looked at barometer history and the drop in pressure coincided with the feeding period. |
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Posts: 200
Location: Minnesota | esoxaddict - 6/22/2012 9:44 AM
Not trying to be a jerk here, but... They're under water. Is that a trick question??
It's like, 100% humidity under water all the time. Maybe even more. |
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Posts: 676
Location: Wisconsin | And In-Fisherman FTW....
Weather Effects In-Fisherman researcher Ralph Manns downplays the direct effect of barometric pressure on fish behavior. “A fish with a gas bladder needs only to swim up or down a foot or two to experience as great or greater a pressure change as that created by all but the largest natural pressure changes—say, a hurricane. “A fish might notice itself floating or sinking a few inches in response to a change in air pressure, but it experiences larger pressure changes as it shifts depth several feet while hunting prey, escaping predators, or changing location.
“Black bass and other species with closed gas bladders use their bladders to achieve neutral density and thereby hold at constant depths. This weightlessness conserves energy by reducing the need to swim to hold position. If air pressure or depth changes, a fish with a gas bladder slowly and naturally adjusts bladder pressure to re-establish equilibrium.”
Weather expert Irvin Decker adds, “Freshwater fish, including largemouth bass and crappies, shift depths from the surface to 15 feet or more in their feeding activities. This difference in depth represents a pressure change many times greater than the maximum barometric pressure change ever recorded on earth. “I believe that barometric pressure changes associated with fronts bring with them secondary effects—wind, thunderstorms, cloud cover, changes in temperatures, and changes in light intensity—that do affect fishing success. Actual pressure changes alone do not have any direct effect on fishing, as is so often stated.”
Manns concludes: “Biologists have never identified physical mechanisms or sensory systems that would specifically allow fish suspended at neutral density to sense relatively small changes in water pressure associated with barometric pressure shifts. Biologists have, however, long postulated that clouds, waves, and changes in lighting affect hunting success by predators, by favoring species with eyes sensitive to low light levels, such as crappies.”
Research into bioenergetics suggests that fish conserve energy by not foraging when their likelihood of success is reduced, then begin actively feeding when conditions are more promising. How they know this remains unstudied. |
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Posts: 4343
Location: Smith Creek | "A fish might notice itself floating or sinking a few inches in response to a change in air pressure, but it experiences larger pressure changes as it shifts depth several feet while hunting prey, escaping predators, or changing location."
So what that tells me is that they do notice, more so if they are in a neutral mood (not moving around).
And they wouldn't notice when they are aggressively feeding.
The last paragraph says it all.
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Posts: 719
| Lots of humidity=lots of air moisture=better filtration of UV rays=happy thin skinned surface plankton= betterfeeding opportunities for minnows and up the food chain. When the air gets crisp and dry it may be harmful to tiny little surface riding creatures or even small minnows and feeding opportunities may fall....sounds good anyways. Anybody agree??? |
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Location: Illinois | Bondy - 6/22/2012 7:01 PM Lots of humidity=lots of air moisture=better filtration of UV rays=happy thin skinned surface plankton= betterfeeding opportunities for minnows and up the food chain. When the air gets crisp and dry it may be harmful to tiny little surface riding creatures or even small minnows and feeding opportunities may fall....sounds good anyways. Anybody agree??? I agree plankton sets the tone, but prefer low or falling pressure which makes them more buoyant, sending minnows up high to feed upon them. I'd think the high skies days would be when you go deep and slow, through and around the suspended baitfish, chasing the minnows feeding on the less buoyant plankton. |
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Posts: 2691
Location: Pewaukee, Wisconsin | Very good stuff here. Another question to the humid weather day pattern: Why do the muskies seem to purpose on these days but do not even chase a lure? I just have a lower follow and catch ratio on hot humid days. The nights are extremely good. Hard to figure out why the muskies are up high and playing but not aggressively feeding until it gets dark or a front drops the humidity.
Very good info everyone. Love the various responses and detailed data.
OutdoorsFirst Rocks!!! |
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