Surely Beavers and salmonids co-existed in the same rivers for thousands of years before Beaver were exterminated?
Yes, but co-existence does not mean species not impacting on each other – all Predators and Prey “co-exist”, for example. Where there are fewer Salmon fry upstream of a Beaver dam than below because access by spawning adults is restricted, the species are “co-existing” but salmon are being impacted nevertheless. Of course the extent of that co-existence so long ago is not known. What we do know is that Salmon in particular are an important feature of our river ecosystems and rural economies and that they are under great pressure out at sea so require very careful management, where this is possible, which is during their fresh water phase.
