Managed some freshwater fishing in Scotland, mostly pike and trout. Many of the waters are not too fertile so have low stocks of coarse fish.
Lake of Menteith is the only "lake" in Scotland. It is quite rich in coarse fish but is also a well stocked trout fishery. In the winter the pike associations get limited access to fish the lake. Here are a couple I was lucky to catch, the 18 pounder on a large floating plug and the 27 pounder on a launce deadbait.
Loch Earn has some rainbow trout farms. Purist trout fishing techniques (swimfeeder, double maggot!) fishing near the farms, brought good brown trout and char.
My daughter with a handsome brown trout of 4.5 lb
Ruth was not pleased I went solo when she was in school and got this 5.75 lb trout.
My friend had a boat with a dodgy engine on Loch Earn. His daughter fished whilst we struggled with the engine. She had a string of good brown trout and char, again on swimfeeder and maggot bait.
For a few years after the fish farms started on Loch Earn the fishing was brilliant. The char that normally only reached about 12ozs grew to over 10lbs! Then more and more rainbow trout escaped into the loch and the fishing became rainbow hell! Fish method feeder and you will get dozens of stunted, tatty finned rainbow trout - and they taste horrible!