Canadian passenger lists

After a discussion with a cousin, we are thinking that our ancestors might have come though Canada to get to Minnesota. Anybody know how to find and search efficiently through passenger lists from Canada? I am looking for Karl Tapio(b 1859), his wife Hilda (b1866)and two children Christian (b 1884) and Clara (b 1887). I know that they came over when Clara was a baby. So we are thinking late 1887 or early 1888 they came over. Anybody know how to help me? thanks, Steph