Just received official word from the Ministry (they replied in one day!):

Hello James:

Thank you for your inquiry.

Only barbless hooks and artificial bait are permitted in Quetico Provincial Park.  Barbed hooks may be in a tackle box but must not be on the fishing line. Barbed hooks must be pinched before being attached to a fishing line.

If you require further assistance, please contact the Natural Resources Information and Support Centre at 1-800-667-1940 or 1-800-387-7011.

Regards,

NRISC web reader - AC