The photos of the great Pacific octopus were taken March 24 by Ginger Morneau but first publicized Thursday.
Morneau, her husband and brother were walking along the shore near Victoria when they spotted a seagull behaving oddly, Postmedia News reported.
"It was a stunning moment, to be sure," Morneau said. "I saw the bird in the water and it looked like he was pecking at something underwater."
She said her first thought was to try to rescue the bird, but realized it was too late and too dangerous.
"It's that horrible situation to watch, like a car wreck -- it was so primal and gut-wrenching," Morneau said. "The hair was standing up on the back of my neck."
Her series of photographs spanned a 53-second period before the octopus submerged with the seabird, she said.
Morneau said afterwards, the group went for lunch and ordered calamari.