I also physically drove them across, and from what customs told me, If i were to try and ship them across, that would be a whole different story. There are some US online stores that apparently can and will ship to Canada. Some people have said they have bought from these places and had them shipped with no issues. I have no experience in that, so I have no comment or knowledge of this method. It is my understanding that if the coral is cultured in the US it is way less complicated to import.
http://ec.gc.ca/Publications/0D42F8E...Trade_e_v6.pdf