Pond Boss Forums GENERAL QUESTIONS Muddy water Bruce ignorantly comments on barometric pressure.

Does barometric pressure affect fishing?

Here's my comment on http://www.bigbluegill.com

A lot more people will see it here, so I thought I'd throw it out there for general discussion.

I've got nothin' to back this up....

But it won't stop me from commenting anyway.

I think that barometric pressure is signficant primarily in it's relationship to other weather events that are occurring simultaneously. i.e. cold front or warm front comes through with change in pressure also means other changes.

I think that the following factors that I can be more certain of their effect on fishing.

1. Light levels. Sudden increases and decreases in light, in the way of cloud cover have a significant effect on fish patterns and feeding. So many fish rely on sight advantages over prey, that a sudden change in light often triggers feeding activity, just like dawn and dusk.

2. UV. Ultraviolet rays have a clear identifiable effect on fish location in the water column. Weather patterns that create change in barometric pressure also effect UV. Low atmospheric humidity after the passage of a cold front means LOTS of UV penetration, and the associated changes in fish location due to UV sensitivity. Some fish simply won't stay shallow if there is lots of UV penetration.

3. Wind. Once again, wind changes can be tied directly to passage of a weather front. Wind affects like levels significantly, and it also lifts nutrients and small organisms, both plant and animal off the bottom, which triggers the sequence of events often referred to as the food chan.

I think all of these factors are so intertwined that it would be futile to try to say something as simple as "The barometric pressure changed, so my fishing success changed". Possibly too many things changing right along with it to ever be able to make the direct correlation.

Makes perfect sense! Never thought of it!

Here's a weird observation on wind/barometric pressure.

South wind, falling pressure, fish get hooked in the lip.
North wind, rising pressure, fish get hooked in the gullet.

True! I can go fishing 3-4 times in a row, and never once gullet hook a fish. Then the wind switches to northerly/rising pressure, and I can catch 4-5 foul hooked fish in a row. Same gear, same bait, yet fish obviously bite differently. And that's the honest truth. I couldn't make that up if I tried.


Don't know if it's peculiar to my pond or generally true.

I've never been a total believer in it and, like you, think there is something else going on.

A fairly good sized change in barometric pressure is equivalent to a change in depth of about a foot and a half of water. It seems like most fish change the depth they are at a lot more than a foot and a half, a lot quicker than even the most rapid change in the weather can occur. So the effect on fish of an atmospheric pressure change alone, without regard to associated affects like temperature, precipitation, and sunlight vs. clouds, would seem to be pretty small.

Theo has an eyeball under his post.

see if you can decide if the eyeball movement is synchronous, asynchronous, or random.

Randinchronous

The eye creeps me out. I feel like it's watching me. Judging my typing skills.

Theo, that is exactly how I have always viewed the effects of barometric pressure on fish...neglible because of the small magnitude of the change. In the act of everday swimming fish subject themselves to pressure changes in seconds, or fractions of a second, that dwarf almost any barometric change possible.

Good job Theo.

I wonder if this is a chicken or egg (or a cause and effect) question. Ask Bill Dance if he thinks BP has a bearing on fishing (or go to his web site).

I suppose that would depend on how barometric pressure is "weighted" in the fish's brain. If the fish have a sophisticated way of sensing pressure (which the lateral line is purported to be), they could sense barometric pressure independently of depth.

Fish response to pressure change could be weighted high, because it is linked to ancient survival instincts. Or maybe not. I really have no idea, just saying that tiny changes can trigger radical behavior changes depending on weighting.

It would be a very interesting to do behavior studies on fish vis a vis barometric pressure changes. I would like to know with some certainty whether fish key on pressure change itself, or things that go along with it, such as light, wind, and temperature changes. Fish may even be sophisticated enough to key on several conditions at once.

Sounds like a good research project idea, bobad.

Yea, I was hoping you would handle it!

It does seem to be an engineering sort of challenge, Theo. You know like someone that's good with pirate graphs and such.

Well, I could fake the data for money any time, burger - kind of like in Physics class. But to do it for real, I'd need a hyperbaric chamber.

Hey guys, In 2002 or 2003 I was around Lincoln Nebraska and was fishing at a lake 30 miles from there when a tornado came through. The pressure went from 30 to around 10 in a matter of minutes. WE had not caught much all day and we were trolling with mr. twister grubs. All the sudden as the storm approached we caught Walleye after Walleye. We caught like 30 or so in 10 minutes. We had to get off the lake in a hurry because the lightning was hitting the water or so it appeared. When we arrived home in lincoln we learned the tornado went right through that area and tore up a small town. Anyways, I was told the pressure affected the fish so much because of the air bag inside the fish that they use to stay right side up. Apparently the pressure dropping relieves a lot of pressure on the fish in this way and causes them to feel good in a sense and makes them go into a feeding frenzy. I have no scientific data to back this up ,but it makes sense to me. I have always done better when the pressure was dropping steadily or quickly as in before a storm.

The temp dropped 20' in about 30 minutes yesterday afternoon and the fish didnt eat much at all last nite.They were eating fine the day before.I forgot to ck but the water temp couldnt have dropped that fast so I figured it was the front.More info for the knowledge pool.

During ice fishing I prefer low barometer fishing. Light penetration and wind effects negligable under the ice. High pressure pushes down on the ice pack and gives the fish an ear ache, causing them to bite less.

My question would be, "How do we know this?" Are we just speculating?

I'm not doubting you. It's just that my intuition tells me that there may be other factors at work.

I think fish eat when they're hungry, when there's food available, and particularly when they have some type of advantage to exploit.

I don't personally believe that variations in barometric pressure have such a profound effect. But that doesn't mean I'm right.

Yes we are, but I catch more fish on a low barometer under the ice.

Do you fish more when the pressure is low? Are you more confident when the pressure is low?

When pressure is high, for example 30.10 inches, then drops precipitously, say to 29.80 inches, isn't that only a change in magnitude of less than 1%?

I ice fish when ever I get the time. I may have more confidence on a low barometer. Do you agree that a fish may be able to sense a pressure change of less than one percent in their underwater world?

I agree fully with that.

Remember the name of the thread.

I have kept fishlogs for 20 years, with pressure, lunar phase,
wind, water temp, air temp, cloud cover, etc. It turns out that
they are more a reminder of good or bad patterns. The only real
weird think I have noticed, is that I have never been out fishing on a full moon day that I have not caught fish. I don't
even know if that is "lunar" or confidence.