Sable Island, off the coast of Nova Scotia, is home to the world's largest gray seal breeding colony — and the site of a gruesome, decades-old mystery that's finally been solved.
Reports of traumatically injured seals have plagued Sable Island since at least 1980. Gray seal (Halichoerus grypus) pups were found with strange spiral-shaped lacerations that tore to the bone, starting at the seals' mouths and winding down to their chests. The oddly shaped injuries led scientists to guess the culprit might be sharks or ship propellers. However, there was no direct evidence to confirm either of those theories.
