It is prohibited, under the Marine Mammal Protection Act of 1972, to export from Canada, any art or artifact created from a marine mammal, including whale bone, ivory walrus tusks, ivory narwhal tusks, baleen and sealskin. Inuit art containing caribou bone, skin or antler does not fall under this Act and is eligible for export.
In addition to Canadian restrictions, each country has its own specific regulations regarding the import of specific animal materials. It is recommended you check with customs officials prior to purchasing art containing any of these materials, as fines or penalties can be very severe. Written export clearance must be obtained prior to shipping internationally, and is the responsibility of the consumer.