When trees are big and strong enough, they sometimes show their roots outside the ground. That's when it often dawns on us that, underneath all the dazzling things we see on the outside, there is a strong structure that is not only feeding it but also anchoring it firmly to the earth. Talking to Tavish Scott, CEO of Salmon Scotland, we had the feeling that we were looking at one of those magnificent trees whose roots, increasingly visible, are firmly rooted in the Shetland Islands . . .