Bad Beavers

I usually consider myself to be very pro wildlife and when beavers were reintroduced to our local area I thought it was a great thing. Lovely to see them on the river.
However, I'm beginning to wonder how good a thing it actually is. This is some of the damage caused to trees near Dunkeld, and I think I'm right in saying that because the bark has been stripped away all around the trunk, the trees will now die. That's a lot of damage in a small area and presumably it will just spread. It's a dilemma :(