Good holding pool/poor taking pool

[Sawyer]

Just wondering if anyone has come across the phenomenon of a pool that holds large quantities of fish in all heights of water but in which you rarely catch (relative to the numbers of fish present).
The pool I have in mind on the face of it seems a picture perfect pool for both salmon/seatrout. It has depth, cover (both bankside & underwater lies), fast water at the head with plenty of oxygen, middle section that runs over a mixture of gravel/boulders, nice wide tail running out over a weir plus because of the long trek over some unpleasant bogs it is very rarely fished!
I make the trek at least 3 times a month (bonus run upstream that does fish well) & have done for nigh on 30 years, probably longer as I used to cycle to the farm on my bike. Over the years it has become a bit of an obsession & I must have spent hours flogging away with only perhaps 3/4 fish a year. there are nearly always fish moving but they are very reluctant to take.
Any theories/thoughts? (beauty of a forum such as this is that having spent so long fishing the night away rarely seeing/speaking to another soul now I can pick my peers brains).

[T7]

It might sound stupid but are there any fish in it? Have you seen them/heard them jump?

[moonlighter]

I did fish a beat with a pool that sounds similar,the pool always had plenty of fish in showing and splashing around enticingly but very few fish came from the pool.this pool was very deep in parts and was the nearest deep pool downstream of a major spawning tributary to the main river .The Ghillie held the view that fish due to spawn in that tributary ran up to that pool and just held there until making a final push up the tributary,I do not know enough about sea trout to know if that is correct but it was certainly his theory on why the pool both held large stocks of fish for a large part of the season which seemed to be poor takers,I know spring salmon can run upriver to certain lies and stay there for months but as i said I do not know enough about sea trout -still trying to figure them out after 30 years thats part of the appeal of sea trout fishing for me moonlighter

[Sawyer]

It might sound stupid but are there any fish in it? Have you seen them/heard them jump?

Hi T7 definately stacked full of fish after about the second or third rise of water, after dark there are fish moving pretty much the full length of the pool, the biggest splashes coming from just off the run by the white water at the head of the pool. In lower water if you know where to look, have a pair of polaroids & can climb a tree you can see fish lying through the middle of the pool.
Its an enigma, I have come across pools that will only yield fish on certain heights of water or to certain combinations depth/size of fly or at certain times of the year, even pools where the moon plays a part.
Bizarrely there is one lie I fish where fish only come if you cast left handed, a combination of trees behind you & the angle your fly comes round with a left handed cast (took years to figure that one out, only when I realised that the angler who always made a beeline for that lie was left handed did it dawn).

[T7]

If the pool is high up the river, moonlighter could be right - the fish just get in there and basically shut down.

I saw an amazing video of a guy scuba diving in a pool in one of the scottish salmon rivers. Basically he sees a salmon on the bottom of the river, swims down towards it and it doesn't move. He gets closer and closer and still nothing. Then he even touches the fish and it doesn't move. Eventually it wakes up when he gives it a bit of a grab and it swam off. Fascinating stuff.

Seems like when the fish find a pool they are happy with they basically shut down and go into a kind of sleep (presumably similar for sea trout as well). No wonder we can't catch them!!!