A long stretch of Canterbury coast has been closed to shellfish gatherers because the shellfish there are not rated safe to eat.
The Canterbury District Health Board says that diarrhetic toxins have been detected in bivalve or filter-feeding shellfish from Pigeon Bay on Banks Peninsula to Leithfield Beach in North Canterbury.
The board warns that cooking the shellfish does not remove the toxins, though crayfish, crabs, paua and finfish can be eaten if the gut is removed.