....I wonder how the carp got in there?
A few years back - many Welsh hill-farms with a patch of water on them were tempted to create 'fisheries' as part of the 'diversification' programme and even received some grant-aid for the set-up. A lot of these were trout-pits stocked with rainbows - but the pH and water quality was not always suitable for trout - so some were stocked with carp.
Years go by and the farm continues to be less than profitable for the family running it - and is eventually sold-off to meet debts - with the result that the farm goes back to being open-grazing land - with a pond of uncared-for carp in the middle - some of these survive to breed - usually the 'commons' - but, with the dearth of food, never flourish and grow to the size of previous generations.
I'm guessing that most of their high-protein food is fly and wind-blown insect life - which is why they respond so well to pellets splashing onto the water.
If you find one of these pools - give it a go - but keep it secret!