Walking along the shoreline at the northern end of Kāpiti Island, Dave Banks saw something strange on the gravel beach.

“On inspection it turned out to be a very unusual barely alive octopus.”

A closer inspection revealed it was a female blanket octopus.

“A rare find but most definitely as a consequence of the warmer water we are experiencing at present with the marine heatwave elevating water temperatures.

 “Lots of what appeared to be skin or part of its mantle were lying over the stones but were brilliantly iridescent.

“Much of this skin was detached with the animal in a very sorry state.

“It was helped back into deeper water but I doubt that it was going to survive.

Blanket octopus. Photo / Dave Banks

“The octopus, weighing about 1.5kg, would have been a very tasty meal for the seal swimming by in the locality.”

Banks, who was on the island with Kāpiti Island Nature Tours, said blanket octopus were rarely seen but some spearfishers saw a live one in the Marlborough Sounds last year.

“The long streamer-like appendages hide the eight tentacles from view most of the time and can contain some stinging cells.

“The female is the striking individual while the male remains very small.”

Meanwhile, Banks noted that before and during the Christmas period thousands of paper nautilus octopus washed up on Kāpiti Island beaches.