In North America, the Europeans initially found a profitable commodity when fishermen began to barter with natives for:

North America, the Europeans initially found a profitable commodity when fishermen began to barter with natives for Fur.

Explanation:

Before any type of settlement in Canada, the fisherman of Europe, namely: France, Spain and England used to bring metal cooking instruments, glass jewellery and types of armory to Northern America and trade them for exotic animal furs the natives would hunt and catch.