Randy,
Our salmon runs have not just been declining "in the last few years." They have been declining every since the late 1800's. Salmon runs have DEFINITELY been affected by dams, in fact the wild coho on the Columbia were made extinct primarily by the effect of the dams. For those who think that salmon runs have only been shrinking in recent years, a great book to become educated is "Salmon Without Rivers" by Jim Lichatowich.

Kevin