Not sure about in St. John's or the province but Cabela's Canada has traps and other supplies: http://www.cabelas.ca/store/?section=1190§ion2=1326#product...
Here is the current list of traps to use by species: http://www.fur.ca/TRS_certified_traps.php
Click the links for Certified under 2007 requirement (Phase 1) and Certified ahead of requirements (Phase 2) for the complete list. Hope this helps.
heres a guy in st.john's, he doesn't have a big stock but he can get pretty much anything you want.very knowledgeable and friendly man. http://www.redindianrivertrappingsupplies.ca/ you made a comment on one of my pics,it's my dads backyard in St.lunaire, up here on the northern pen, if ever up this way drop in he loves to show off his pond.
www..longcreektrappingsupplies.ca or dot com
I got my traps there and its great price on the shipping and the tax are included