Air pressure

[severnfisher]

It would be interesting to hear views on the idea that salmon take best on a rising glass. This has recently been the subject of a book, but the general idea is much older.

Tom

[williegunn]

So if the glass is falling you will not bother going out?

Please give me a call if you ever have any decent fishing on the Spey I will happily fish your rod.


Pure rubish

[hadrian]

im quite new to salmon fishing but i was fascinated when a member of my local fishing club told me about watches you could buy that supposedly gave you a clue as to when it was best to go salmon fishing.he wasnt sure how accurate they were but felt there was something in it.
personally i think there are obviously better days for catching salmon than others but having said that i was working out last week that half of my fish this year have been caught in sunny conditions,none of them first thing in the morning.none of them last thing at night.most in low water,some with size 4 flies.
salmon constantly contradict theory.

hadrian.

[exerod]

Fishing on a chalkstream where there are practically no variations in flow to complicate matters I have had all my best catches on a falling glass. This may simply be because an approaching low usually brings cloud cover and an increase in wind to ripple the surface. Of course if the fish are very fresh they will take in any conditions but once they have been in a week or two they always seem more responsive when a change to fresher weather comes along.

So I think the idea is poppycock, but I could be wrong

The best thing to do is keep fishing and not worry about it.

Andy

[williegunn]

springer said:

Just the type of thought provoking constructive reply that will encourage members to post new threads, which without we would have no forum

And your response will encourage people to reply.............well .

If you bother to read between the lines of my response you will see I am deeply skeptical and unlike Graham will not buy a watch to prove it is all crap.

I once bought a ph meter, when the Spey rises it sometimes goes "black" and the salmon seldom take, 3 days later when the peat runs off they come back on. If you check the PH you can see it rising over the 3 days.

I stopped using it as I still fished anyway; the same with air pressure I assume

[jimthefish]

In our April week on the Dee, Paul Young appeared in the bar on the Sunday evening with said book and triple sensor watch. He was the subject of ridicule and severe legpulling. By the end of the week most of the rods had ordered a watch. Every springer but one out of 16 were caught when the pressure was rising.
There is something in it.
I have caught fish on a falling barometer since but they have been mainly sea liced and if you read the book, the author predicts that.
A falling pressure will not stop me fishing but a rising one concentrates my efforts. Just another interesting facet of our sport.

[tynetraveller]

I also think there is something in it. On the Thursday of my trip to Russia this month the wind direction changed at lunchtime and the barometer went through the roof. No fish was landed to 14 rods that afternoon when we had been catching twenty- plus per session up until then. My feeling is that whether rising or falling slowly, fish will still take but if there is a sudden move either way, things will get tough.

Like WG though, I will fish anyway so the watch is hardly a necessity.

[storlaks]

Guys, I've been using this type of watch now for the past 5 years and I'm afraid (WG) it's not all crap. Infact it's very close to the mark. I could quote many occassions where poor fishing conicided with falling or sustained low pressure and vice versa.

2 years ago, while fishing in Norway, we arrived at the start of are usual week. The previous week had some fantastic sport with many fish caught and high pressure prevailling. On the sunday my barometer started to drop and we were unfortunate to have low pressure on us all week. Our fishing was poor by comparison. However we did catch some fish, but what was evident about the fish we caught was that they took when the barometer rose by 1-2mb...just enought to envoke a take. On one occassion I was sitting in the hut watching the pool looking for inspiration (no fish showing, even though they were there) and then my watch shows a rise of 2mb. Before I got into the pool, my phone rang and my friend fishing another pool had landed a 12lber. Coincidental....don't think so! Another factor that week was the number of short takes, ruggs and pulls we had, but very few good solid takes.

Same happened at Orton this year in May. High pressure at start of the week produced good fishing. Falling, then low pressure for last 3 days produced nothing.

If you think about it logically. We as humans feel much more active when the pressure is rising or high, so why shouldn't salmon. Low pressure can make you feel lethargic and I'm sure it has the same effect on fish.

Obviously there will be occassions where we catch fish in low pressure....I've done it, but if I had a choice I'd prefer to fish on a rising barometer. I've also had some good fishing just as the barometer starts to fall i.e. a change. (same as it starts to rise) Once it continues to fall, the fish go down.

What I don't know and would like comments on, is whether fish will continue to enter a river on a falling or low pressure or will they stay at sea?? On this years evidence from Orton, they stopped running!

I don't stop fishing when by Barometer tells me I should, cause with salmon you just never know, but it does make you think more about when you fish hard or not.

You can however quickly lose fishing friends when you have one of these watches (-: After 3 days of low pressure and no fish, you're friends look for someone or something to blame and it's usually me!!!

Chuck that watch in the river is a common quote. No way!!!

[exerod]

jimthefish said:

I have caught fish on a falling barometer since but they have been mainly sea liced and if you read the book, the author predicts that.

That would seem a good enough reason to ignore the theory

storlaks said:

However we did catch some fish, but what was evident about the fish we caught was that they took when the barometer rose by 1-2mb...just enought to envoke a take.

Given that the air pressure is usually around 1000mb we are looking at a change of 0.1-0.2%. Is this really going to make a difference and how accurate are these watches anyway? Are you sure there was no change in air temperature (a rise from 10 degrees C to 11 is a 10% rise, surely more significant), or a slight rise or fall in the water level.
Also air pressure drops by around 1mb for every 8 meters of altitude. So you could leave a pool blank and walk uphill to the hut for lunch and say 'Oh look the pressure is falling, no wonder we blanked' and then walk back down in the afternoon catch a fish and say 'Oh look the pressure is rising, that's why they took'

I'm not saying there is nothing in it but I think you are better off spending your money on more fishing rather than more gizmos. Experience has got to be worth more than any amount of barometer tapping.

Does low pressure stopping fish entering a river? I've seen fish run in on lowish water levels as the air pressure drops and woken the next day to a spate so I would say no. But it may be different where you fish

Andy

[severnfisher]

Thanks for the comments so far. WG's post made me laugh, and reflects my own attitude to speculation about the impact of external factors such as air pressure, moonphases, black cats and other things on angling prospects.

However, there is another side to this. I'm less optimistic fishing on those days when the atmosphere is a bit heavy and oppressive. I am encouraged when I feel a breeze and that period in the evening when the atmosphere starts to soften a bit also make me more optimistic. I also find that the period after a storm breaks and the air clears finds me fishing harder. I think most anglers react to the same conditions in the same way, but maybe I'm wrong.

So although i've got the same basic attitude as WG - fish on regardless, I'm also aware that I'm more optimistic in certain conditions. The question is there a rational basis for this?

Those very limited records I have kept of air pressure and catches do tend to confirm the rising barometer theory. Our samples are small on the Severn, but for example of 12 salmon caught or hooked on my local stretch in the last four fishable weeks every one came on a rising glass: either on short blips during thundery conditions or on days where the general trend was up. They were caught at all times of day, weather conditions, water levels and wind directions.

I wouldn't buy a watch, but I do keep an eye on my local university weather centre web site.

Tom

[williegunn]

storlaks said:

Guys, I've been using this type of watch now for the past 5 years and I'm afraid (WG) it's not all crap. Infact it's very close to the mark. I could quote many occassions where poor fishing conicided with falling or sustained low pressure and vice versa.

Same happened at Orton this year in May. High pressure at start of the week produced good fishing. Falling, then low pressure for last 3 days produced nothing.

Chuck that watch in the river is a common quote. No way!!!

Are you fishing Orton next May? Give me a call when you leave the river as your watch tells you the fishing will be poor. I'll be there, I'll catch fish. I'll believe it's not crap when I see a salmon wearing one of the watches.

[dighty]

If salmon are that sensitive to air pressure, its not that amazing considering the migration they undertake and their even more outlandish olfactory capabilities.

Apparently the book mentioned proposes a link between rising air pressure and aquatic invertebrate activity - juveniles "learn" that such times are the most productive to go on the feed (and I suppose also sunrise and sunset, also times of increased insect activity no matter what the barometer is doing and well known times when salmon are more likely to take). Makes sense to optimise your feeding when its most profitable and hide from predators when its less worthwhile. Maybe over thousands of years of evolution this becomes less a learned response and more an hereditary instinct.

I wouldn't stop fishing either (surely we don't go fishing just to catch fish, certainly in my case!) but I don't think anyone can say its a crap theory until its been disproved, there does seem to be enough anecdotal evidence for us to at least speculate and anyway
its
supposed
to
be
fun!

[macsalmo]

I have to admit that I do like all the technical jargon Although I can't see myself buying the watch.
I think that the odds are stacked against you enough with these weird and wonderful creatures, so the thought of something telling you that they could be even harder than usual to catch is a sobering thought


Macsalmo

[severnfisher]

I don't think anyone can say its a crap theory until its been disproved

Trouble with disproving the theory is that rising air pressure occurs on most evenings (I reckon about 85% of the time on a rough guess) and often at dawn into early morning (perhaps 60%). This rise often happens even when the general trend is down. Unless it is a very steep fall.

There are plenty of other theories about why early and late are good times.

Tom

[storlaks]

I can understand some of you being a bit skeptical, but once you start looking at the signs then it becomes a little more obvious. Fly hatches and rising trout are another good example of when things are right or not. Just for WG, my trip to Orton in May had 2 days where the there was no hatch and thus no trout were rising...at all! Prior to that they were all over the place. Could it have been the low pressure.....possibly!

I also remember taking a drive to Aberlour that same week during the 3 blank days and funnily enough the guy in the tackle shop said that none of the beats were catching much at all....even Delfur, Rothes and Arndilly and association water were struggling! So what happened? We were catching at start of the week, low pressure came in and stayed, we had a rise in water but caught no fish for last 3 days.....and from what I heard the following week produced great fishing, when air pressure lifted.

So if we rule out air pressure as the controlling factor here, what happened to the catches during the later half of that week..on all the beats mentioned? Did all the fish migrate upriver and no fresh fish came in.....even on a 8inch rise of water. That would seem abit strange during primetime on Speyside unless they didn't run due to low pressure??

If someone can give a logical explanation to this I'd love to hear it.

[williegunn]

storlaks said:

I also remember taking a drive to Aberlour that same week during the 3 blank days and funnily enough the guy in the tackle shop said that none of the beats were catching much at all....even Delfur, Rothes and Arndilly and association water were struggling! So what happened? We were catching at start of the week, low pressure came in and stayed, we had a rise in water but caught no fish for last 3 days.....and from what I heard the following week produced great fishing, when air pressure lifted.

So if we rule out air pressure as the controlling factor here, what happened to the catches during the later half of that week..on all the beats mentioned? Did all the fish migrate upriver and no fresh fish came in.....even on a 8inch rise of water. That would seem abit strange during primetime on Speyside unless they didn't run due to low pressure??

If someone can give a logical explanation to this I'd love to hear it.

A rise in water......did you check the PH often the Spey goes acidic and this puts the fish off.

Nice to hear Hamish is still full of the joys, encouraging everyone with the catches up and down the river......................I hope you did not mention the internet.

[ceilidh]

Whether due to changes in barometric pressure or something else it is noticeable that salmon will often 'come on the take' at roughly the same time over widely separated beats on the same river, suggesting that they are all responding to the same stimulus.
It would be interesting to know if any one has compiled an analysis of the time when fish have been caught on a particular river. Obviously this wiill vary with the conditions, however, I would guess that the graph of quiet and active times for a particular day will be similar over a fairly wide area.

[wilbert]

I am unsure about air pressure as it is something that i have never looked at when going fishing, my main checks are water height, colour and temp. One thing I have noticed is that the last Thursday in the month seems to be a lucky day for me. I caught my first fish and my biggest ever fish on this day plus a few others so the rest of the fishing club committee think i am a fishing god as I quite often arrive at the meeting having just had a fish. Looks like rain this week and if the river is right I will be going fishing this Thurs, lets see if my lucky day works!!

[macd]

Atmospherics really have an impact on the Thurso. Low pressure puts the fish down- its like they have disapeared, but i would never dream of staying home. lots of other things- the dreaded east wind, acidity etc. can screw it up too.

But I cant imagine there is a books worth in this subject. Low pressure so what? Im going fishing.

R

[storlaks]

WG, you maybe right about the PH change after a rise in water......this can definately put fish off the take, but I'm still convinced salmon (and other fish) react to changes in atmospheric pressure. Why wouldn't they?

I'm sure many of us have experienced fishing after a thunderstorm has passed over and the humidity starts to clear and the air freshens. This can be a good taking time and the reason is that the atmospheric pressure has gone up.

Anyway, I'm convinced and if Michael Frodin wears one of these watches then I'll keep it for now (-: