I believe that indigenous peoples are guaranteed the right to hunt and fish for food and spiritual reasons, but I'm not certain that the right to a commercial fishery is guaranteed.
-k
As far as I understand, that's been decided in a court case:
In 1999, the Supreme Court of Canada (SCOC) released the Marshall Decision. The court did not give the Mi’kmaq the right to fish – but recognized and upheld that right enshrined in the Treaties.
The judges created the term Moderate Livelihood so the Mi’kmaq can make money, but not get rich. Then the court issued a second decision with a clarification that this right can be regulated by Canada.
https://www.aptnnews.ca/national-news/the-facts-behind-mikmaw-fishing-rights/