That's a good question, and I don't know the full answer to that.
Obviously, Vancouver and increasingly Prince Rupert are both big trade hubs with Asia. I would say east coast hubs do ship out to Asia as well.
You'd have to look at particular companies and particular trade flows. The global shipping logistics chains are quite complex.
There is also air cargo. You have Vancouver airport, Edmonton airport and others that ship air cargo to Asia as well.