Very nice location and image, Richard
Would I be correct in identifying some iron deposits in the river bed in a few places?
I'm with you regarding the fishing vs. leaving well alone... though I will say, I've no issue with folks catching to eat, if there's a healthy population in the river or lake in question. We've a few reservoirs in my region of the country with managed stocks of freshwater trout, and we've had a couple of nice family meals from my catches on a couple of visits (I'm not a regular fisherman). In fact, those reservoirs have a strict "no release" policy - once you've caught it, you keep it. Frankly, with the day's fishing fees taken into account and the catch limits, it's probably cheaper to buy trout from the local fishmonger - but obviously it's the sport and enjoyment of a well-tended location that you're really paying for...