"You've ruled that out."
Did I ??? - I said that the Lower Severn is not stocked.
"The water quality, conditions, and appropriate food supply is such that there is a fantastic survival rate of the prey fish. It must be an exceptional stretch of water if that's the case."
Not at all - you will find that many rivers are in healthy positions with certain fish stocks but the angling traffic has significantly dropped and anglers are unaware of this.
"The predators are mainly preying on their own young and juveniles. Possible, but unlikely if the pred numbers are increasing, as suggested.
or
It could be a temporary situation that as I said in my earlier post, is not sustainable, and at least one of the elements is likely to 'crash' eventually.!"
Fact or your presumption-please explain where you are getting this from?
I personally do not fish one water where there is a prey/predator stock imbalance.
In reference to your post relating to large predators I made a point that you should look at Barbel stock crashes and the correlation to otters.
Would still be interested for you to do this as I don't think you understand the eating preferences of our freshwater Predators and the main non-aquatic predators that have an impact on the fish stocks.
I don't recall singling out large preds, or making reference to their eating preferences, Lee, just the predation levels in general, and questioned how an increase in overall predation, could lead to an increase in prey fish levels? A situation that I personally haven't encountered/noticed lasting long term. I put forward a few theories I had, (not presented as facts), and invited others to offer theirs.
Maybe it's me, (could be 'an age thing'
), but I took your answer of,
"As for fish restocking,doesn't tend to happen much on the Severn and yet the Lower fish stocks are improving every year.", to mean the stocking on the Severn in general, and not just the lower sections, that's why I ruled out my theory.
I've read your many posts on otter predation, and the effects on the barbel population in your area, and realise that you are passionate about the subject, and hold strong views on it, but I wasn't questioning that at all.
I didn't put forward anything as fact, just a few theories that came to mind based on my past experience.
Over the years I have known waters that have had a prey, pred imbalance, usually due to either a very good prey fish survival year, followed by an increase in the pred numbers over the following years, or a reduction in prey numbers, causing an eventual fall in pred numbers due to the reduction in the numbers of food fish. The two natural examples that stand out in my area, are the disappearance of the roach following the disease in the 60s leading to an eventual fall in pred numbers after an initial fall in other prey species stocks, that had filled the gap in the food chain created by the reduction of the main prey fish, ie roach. The other was the hot dry summers of the mid 70s, resulting in a fantastic fry survival rate, that eventually resulted in a boom in all pred numbers. Neither of these situations lasted, and nature eventually created a 'new' balance, with different species being at the fore. I have also known several other more localised situations on individual 'natural' waters, where the imbalance has been caused usually by the introduction of a species alien to the water, again a kind of balance was eventually created, but different to the initial one.
I apologise for the 'long winded' reply, but I felt that we were discussing two different aspects of the same situation. Yours a specific one, mine a more general one, and I wanted to clarify my own posts, I hope I have now done that.
John.
