Big difference between "contains salt because it's ocean based" and "salt added because humans love to eat more sodium than is healthy"
It's possible your stores don't carry to seasoned kinds, which would be good. Also, there are roasted and sun dried varieties, but I doubt that makes a huge difference. Even though I know I'm paying a retarded markup, I actually buy my nori from the LFS
. San Francisco Bay Brand fish foods.
If you're not noticed visible salt grains/deposits on your nori, then it's probably unsalted. I don't know about Canada, but in the US, I see people put salt on everything. Even things that are already heavily salted.