Natural environment is what we make it.
Look at some of Colins photos of huge trout, from lochs that historically only had half pounders!
Just to clarify - the big trout from Arkaig and Lochy are ferox - have always been there and always been big - feed mostly on char - but you can catch the occasional one on an intermediate line and a Kate muddler or a goat's toe! However, the char may be benefitting from the presence of cages, and passing it on up the food chain.
The big trout from Loch Shiel come about from a change to the balance of seatrout and brown trout due to the sea cages reducing seatrout numbers and freshwater cages in the loch increasing nutrient levels for the increased numbers of stay-at-home brown trout. I don't know if this situation is even repeated anywhere else?
Even then, Mark Hirst reckons there have always been some big browns in Loch Shiel. It's just that I used to fish it in the 1970s, and back then a 1 pound brownie was a good one. Mark has personally had some absolute lumps off it in recent years - well into the teens. In the times he has taken some of us out, we have had several big browns up to 12 lb. He has seen what happens when they clean the smolt cages. A big roller machine pulls them up to clean them and masses of crud comes off them, and there are billions of sticklebacks bouncing out of it. Well, put 2 and 2 together... the bigger of the 2 large brownies I had in the times I was out with Mark on Shiel went 8 lb 12 oz, and I caught it on a 2 inch minkie. Match the hatch!
Back in the day.I won the Daily Record fish of the week.with a 3lb 2oz brown out of a local stream that trout averaged 1/2-3/4lb.It too had been working on a stickleback diet.it had dozens of the armour plated spikes in its belly.(supposed to protect the S/back from predators,failed miserably in the case of this trout)
Trutta Lacustra, the Lake trout
Yep, with the addition of scuds that about covers it for natural conditions.I mind the English Reservoir boys saying that they reckoned there are only really 2 food sources that allow trout to pack on the pounds at the fastest rate: Daphnia and fish.
Short answer is yes. Loch Damph immediately springs to mind, however the situation is a little more complex when smolt cages a sited on the lochs. Aside from opportunistic fish taken advantage of feed that either misses or makes it way through the cages, you have the effects of eutrophication in what are mostly deep, dark oligotrophic waters. A change in water chemistry, however localised, will result in a change in the ecology.
What we are seeing is a disruption in the tropic structure of large lochs as a result of fish farming activity and large fish caught as a consequence shouldn’t be seen as much a trophy.
Aye well, I would much rather the cages were all removed, saltwater and fresh, and we got back to fishing for seatrout. But hey-ho... it's still a blummin' big challenge to go out on a 17 mile long loch and catch a 10 lb totally wild brown trout on intermediate line and wet fly. Plenty have tried and failed. I haven't had one myself yet.
I prefer the challenge of a 10lb total wild trout on a small loch on a floating line and a dry fly. Now that, my friend, is a challenge.
But overall, I prefer the challenge that a 17 mile long loch presents.