Best depth?

[no-one in particular]

Not sure where I am going with this, it's just an idea in my mind really. I seem to catch most fish at a depth of about 6ft. Two rivers I fish are not wide maybe 30ft and are about 12-15ft in the middle, Occasionally I try the middle but hardly ever a bite, the best place is in about 6ft just beyond the weed margin. Weed margin or not this is usually where I catch the most fish. Its generally the same on most lakes I have fished as well and I am only generalizing. I was fishing in about 10-12ft of water last time, far bank had over growing trees so I couldn't get to six ft. I had a few bites but missed them, as soon as I went to about 6 ft; fishing mid water; I had a good bite and a nice chub. What I am wondering is water pressure anything to do with it, is their an ideal water pressure that fish like to feed in or are there other factors, or is it just in my imagination.

 

[markcw]

There is the thermocline,
On cool days when the sun is starting to show ,I fish the shallowest part of the water because this will warm up the fastest.

 

[no-one in particular]

There is the thermocline,
On cool days when the sun is starting to show ,I fish the shallowest part of the water because this will warm up the fastest.

But is there their natural fear of shallow water but natural liking of warmth but dislike of too dark too much water pressure mean that about 6ft is their happy medium. That's if they dislike water pressure - I don't know, just thinking aloud really.

Where do you catch most fish, perhaps the better question.

 

[rayner]

Not too sure about deep water. I generally am against fishing deep. The deeper the water the thinner my confidence
I look for four feet of water in warmer months, I try to keep less than eight feet in winter just because that depth seems more productive for me.
I have never thought about water pressure, similar to Mark in winter fish will search for temperature differences to be more comfortable.
Water pressure will alter with moon phases, I never pay much heed to moon phases or pressure maybe that is a fault of mine. It is a little too late for me to change now.

 

[markcw]

But is there their natural fear of shallow water but natural liking of warmth but dislike of too dark too much water pressure mean that about 6ft is their happy medium. That's if they dislike water pressure - I don't know, just thinking aloud really.

Where do you catch most fish, perhaps the better question.

One of the best places to catch on a commercial is against the island if there is one or if on a snake lake the far bank,
The margin on the far bank is usually shallow with the odd mud line which can be shallower, sometimes this can be around 12" deep. Same as nearside margins, another good spot is around between 3 and 5 metres out where the margin slopes away . Similar to fishing down the track on a canal.
I would say as long as there is cover , it may be died down weed in the winter,or under the hull of a boat on a canal.The fish will be there in the shallower water.

 

[108831]

Personally I find depths of 28-30ft poor,similarly depths under 18ins,I find fish feed well in any depths in between,but imo the richest waters for fish life are up to 4ft deep,on rivers these have to gave a good flow,but ive caught quite a few hundred pound catches in around 18ft,roach,or bream,fish feed where they are comfortable feeding in depths where they want,not where I want them to unfortunately....lol.

 

[rayner]

It is over 25 years since I last fished in deep water, notably Dam Flask. the deepest I would fish was 16 feet deep there was deeper water for those that preferred. Wind dictated feeder or slider. For roach shallower water around 6 feet max, bream in deeper water.
I am not saying fish don't get caught in deeper water, they do just not by me. I used to find my preferred depths improved my catch rate deeper and I would always struggle.

 

[108831]

Most deep lakes I know are clear and shelve quickly,the fish are often scared to be near the shelves because Mr.Snapper waits there,so often it is 11ft plus,or 4-6ft of danger filled water,where catching them could be extremely difficult,unless it was a tench or carp your after,I catch fish where they are,so if it is 18ft,so be it,very rarely did I catch them up in the water either,on the drop in the last few feet,yes,at times,nothing is written in stone in angling and each venue is different....

 

[steve2]

When I fished the London docks depths could be 30 ft or more the problem we had was the depth could affect the swim bladders espically of perch if reeled in fast.

 

[Philip]

It’s a giant question as there are so many permutations.

One thing I have come to realize is that “deep” is relative. On a shallow park lake that’s 3 foot on average then 6 foot might be deep but on a dammed moutain lake with depths dropping to over 100 feet then 15 foot might be shallow..that sort of thing.

Its almost impossible to say one depth is best as pressure, temperature, wind, light levels, predation, species and 1001 other things will have an impact.

I guess the “best” depth will be the one the fish are feeding at on a given day.

 

[no-one in particular]

I think what I am trying to think about is water pressure, the weight of the water on their bodies, does this affect their feeding pattern. There are no rules but we can generalize. Do fish feed less in deeper water. They may hang up in dep water, over wintering or when idle and not feeding but is it more conducive for them to feed in less water pressure. Not sure I am explaining this well, it is just vague thoughts.

 

[sam vimes]

It's been part of many anglers' thinking that periods of high pressure and the associated light winds are not conducive to good angling results. The exact opposite, low pressure and stronger winds, is generally associated with good results. The snag is that many anglers aren't overly keen on sitting through the wind and rain usually associated with low pressure systems. I've yet to see or hear of any theory that suggests that any particular pressure reading will result in fish being at a certain depth. However, there are hordes of variables that trying to be anywhere near definitive about fish behaviour is nigh on impossible.

I have little doubt that air pressure affects fish behaviour. However, I'm usually more concerned with wind direction, water temperatures (though not enough to take readings!), and light levels, than I am air pressure. I've had a few too many good days during high pressure systems to worry about it. Besides, a nice summers day by the water is an absolute joy, even if it might not be the best time to fish.

 

[John Aston]

Yes , what passes for conventional wisdom in every Angling Times article I read (on the odd occasion when I buy it ) wazzes on about low pressure triggering fish to feed, while high pressure is a Bad Thing . Good job the grayling , perch and pike I have catching in numbers recently don't read AT , as it's been high pressure for weeks . As Sam says, light (especially ), temperature and wind are far more important .

 

[no-one in particular]

I kept records for a few years which included air pressure, the results did show I caught more fish during low pressures but it, varied from species to species. it was a general thing, not a rule, I caught some good fish in high pressures still do, but quite a lot less than in low pressures. I used to published some of the results on here but don't bother anymore. I always thought it was more to do with the weather patterns, cloud, rain, low light levels, cooler temperatures etc. with low pressure and more or less the opposite with high pressures; not the actual air pressure itself but I am not a scientist. However, I did at the time try to understand the science, it even prompted me to write to a couple of universities at the time. But how much "air" pressure fish feel under the water, I don't know but I doubt it is very much. Then again there is the case of salmon and sea trout in estuaries who seem to "sense" when rain is imminent and congregate ready to go up rivers, is this air pressure sensing, I do not know.
However, in this question I am talking about water pressure which is a different thing, think of the weight of water like divers have to measure, that will cause a submersible to collapse if it dives too deep etc.; nothing to do with air pressure. How much "water pressure" do fish experience, how much does this affect their behavior, as to what depths they will feed, "hibernate", lay up, become inactive. I ask the question as I said in my OP because I fish rivers that slope deeply from 0-15ft in the middle and in memory have never caught anything in the middle; I do try now and again but nothing. The last 3 chub I caught were all caught in about 6ft of water, this is usually the case. This got me thinking about water pressure, not air pressure.

 

[peterjg]

Markg, you are yet again raising some very interestingly points. Does air pressure actually make a difference to a fish when all they have to do is swim at a slightly different depth to experience a far bigger difference? - Well yes I do think the actual air pressure does alter fish behaviour because air pressure effects our weather and temperature patterns. I have also noted that in still waters in low air pressure you see more gas (probably methane?) bubbles. In high pressure in stillwaters I think that I have had better results in shallower water and conversely in low pressure. It's all very well to have these theories but because there are so many variables how does one prove or disprove them? More questions than answers.

 

[108831]

High air pressure does however make a massive difference in whether they feed or not,especially in winter,as if fish rise up in the water to avoid the pressure they are forced into areas of cooler,more dangerous water,where it pays to stay still,as most fish feed on or near the bottom until we bring their competetive natures into play by regular feeding...

 

[fishface1]

Generally, high pressure means clearer water due to stiller conditions with little rain, so better for your sight feeders such as perch, grayling and pike (and salmonids if you are of that persuasion)

Other fish, generally, prefer a bit of cover be that from a wind chopped surface, or additional rain. I think this is more important that the pressure itself.

 

[Philip]

I would agree...i think its the associated conditions more than the air pressure itself that influence feeding.

I would not think that water pressure plays a big part in anything but the deepest of lakes.

 

[rayner]

Do you find that in high pressure the fish will feed in the upper layers, low pressure fish will feed deeper. In summer especially I do not bother with a plummet.

 

[barbelboi]

Do you find that in high pressure the fish will feed in the upper layers, low pressure fish will feed deeper.

Carp and tench certainly........................

We know that fish are susceptible to the change in air pressure but why? Hydrostatic pressure is much more intense than air pressure due to water being considerably denser than air. So, if a fish changes its depth even a couple of feet up or down it will go through more of a pressure change in seconds than any of us will ever experience on dry land. How could the barometric pressure above the surface affect a fish that goes through equal to a surface pressure change if they move only a few inches up, or down in the water.

The only reason I can think of is that air pressure will affect the oxygen level in the water. High pressure usually means a warm spell in summer so oxygen levels will be low, i.e. it doesn't replace enough oxygen that is being used up by fish, plants, etc. Low pressure often means wind and/or rain which will oxygenate the water.