Kirt:
I think the added salt is traditional. In the old days of canning foods,
salt was added as a preservative. Nowadays, I think most people just
prefer their canned meats to taste a little salty. I'm sure that the high
temperatures of the autoclaves are enough to kill any bacteria that might
be present in the fish, but I think it's just habit. Who knows, maybe some
day there will really be a no salt added canned salmon.
Liz