Residents in the Prince George, Smithers, Vanderhoof, Kitimat and Prince Rupert areas are being told not to consume clams, cockles and other bivalves from the North Coast.
The only exception is that it has been inspected and sold through a provincially and federally licensed facility,
According to a notice by the Department of Fisheries and Oceans, the entire North Coast area is closed to commercial shellfish harvesting and any sales occurring from the area are illegal.
It added that shellfish from the area are currently being sold on social media and if consumed could lead to serious disease, injury or possible death.
Symptoms of paralytic shellfish poisoning include tingling, numbness spreading from lips and mouth to face and neck, dizziness, arm and leg weakness, paralysis, respiratory failure and possibly death.
The symptoms can start with 30 minutes to three hours according to the DFO.
Anyone who feels ill after eating bivalve shellfish is being told to seek medical attention.
Anyone who recently purchased shellfish and is suspecting it is illegal is being advised to call the Fisheries and Oceans violation reporting line.