Barometric Pressure Effects

[Leighton]

How much effect does it really have?
Barometric pressure this morning was about 1000hpa and falling and I had a lousy day fishing. My best trips have been when the barometric pressure has been rising.
How many people take note on the barometric pressure and is it that important to?

[reidy]

Good day,
Know this as a fact that trout in Tassies highland lakes tend to come on the bite as the barometric pressure drops.Snow=fish.May be they sence the pressure change and start foraging ?
sorry about the poor spelling
Cheers
Reidy

[Leighton]

hello, anybody??

[BigE]

1020 fish aplenty ,,,,,, that was my grandads mantra


BigE

[baychaser]

G'day !

I've heard that anything under 1010 and its not really worth going out.
Something about the pressure in the fish's bladder contracting and then they dont feel like feeding ? :-/

[artesian]

I don't know that fish are measuring the change in air pressure, as it is insignificant compared to water pressure and changes in water depth.

Lots of people accept that there is a connection, so maybe the fish are detecting something else

[baitwaster]

I have also heard 1020 fish aplenty.

I don't know why though. Since they live in water , which cannot be compressed. I paid attention to the barometer on a few trips and there did seem to be more action. Maybe I should do a fishing log with pressure readings.

I would never miss a day out because of a barometer though ;D

[Wahoo]

C/S
up this way, the coral trout go nuts when it falls below 1000, have always had a good run when there is a tropical low hanging about


Daz

[Leighton]

I have also heard 1020 fish aplenty.

I don't know why though. Since they live in water , which cannot be compressed. I paid attention to the barometer on a few trips and there did seem to be more action. Maybe I should do a fishing log with pressure readings.

I would never miss a day out because of a barometer though ;D


Been keeping a log for some time now, there are some patterns in barometric pressure. But yeah, I wouldnt cancel a trip for a falling barometer

[nick-o83]

Hay mate where were u fishing today? location / inside or outside coz I had a red hot sesh on the trevally at tweed this mornin!

Never really pay any attention to the barometric pressure, maybe I should!!

[Leighton]

In the Bay, awesome weather. Light SW, rising tide, plenty of bait but no fish. Just trying to narrow it down as to why no fish.

[tunaticer]

Im very curious as to what effect barometric pressure has on waters??
I mean has anybody tested say 1m under the surface of the water for pressure on both high and low pressure days?
I am wondering if barometric pressure does in fact make a discernable difference in underwater measured pressure?
For every 10 feet of depth you gain another 13.8 psi. or 1 bar. It does not take much movement up or down in the water column to equate to 20 heptapascals in pressure.

What is the actual variation in depth for 10hpa anyway? That should remain a constant whether you are 10 feet down or 1000 feet down.

The way I am thinking a fish will without thinking move to his/her comfort zone or altitude to feel good or adjust his swim bladder......do fish have a comfort zone sense?

Jack.

[Flex]

You cannot compress water. Its physically impossible. So I doubt very much air pressure plays big part in it. I'd say the factors contributing are the other weather patterns affected by pressure. I.e Temperature, wind, cloud cover etc.

I could be wrong, but I cannot see how a animal living in water can possibly detect pressure. Since water cannot be compressed

[John_R]

Flex - you can't compress water, but you can put pressure on it. You can feel the difference in pressure at the deep end of a swimming pool.

When the barometer is high, there is a heavier column of air on top of the water and this would increase water pressure at a given depth by some minor amount.

The amount would be pretty small and be less than a fish would experience by moving down by 3 metres - so the effect of fish biting is a bit doubtful.

They do shut down the bite - mostly (but not always) at times of low or dropping pressure. The barometric pressure may play a part, but I don't think anyone can fully explain it.

[artesian]

G'day Jack and Flex,

It's a long time since I got my C (diving) card, and even longer since school, but hope this helps and is right.

air pressure at sea level is 1 atmosphere. At about 33 feet another atmosphere of pressure is added by the water, at 66 feet, 3 atmospheres and so on.

I had a go at the sums a few years ago, and from memory the diffence between 1000 hpascals and 1030 hpa is about 100mm of water.

Fish swim bladders are filled with gas. When the pressure reduces, they expand, as does other gasses in the body -hence bends in divers, where nitrogen bubbles out of the blood, and pop eyes, bulgy bellies and protuding guts (hang on, sounds like me) for fish brought up quickly from depth.

What puzzles me is that if a fish feels full, because it's swim bladder has puffed up due to low pressure, then it would feel the same when swimming towards the surface a very small amount. And it is hard to line that theory up with the hot bite that some say happens before a storm - which is usually accompanied by a drop in air pressure.

But, enough people see a connection to make me wonder, and since some fish navigate by detecting the earth's magnetic fields, or by 'smelling' the creek of their birth from 100s of ks of open ocean..........I for one can't say.

[Flex]

Yeah its a tough one to answer I think. I have no doubt that varying air pressure co-insides with fish coming on the bite. I have seen it a thousand times myself. I have fished many a reef before a storm and its been the best fishing I have had. i.e low pressure.

Then I've also had awesome fishing during a constant high pressure aswell. We've all no doubt experience good fishing in varying pressure scenarios.

But, I think its to hard to say what role pressure plays.

As I mentioned earlier. Maybe its the other prevailing weather conditions caused by the change in pressure that bring the fish on, who knows?

But I dont think anyone really knows for sure.