Extraordinary Photos Show Octopus ‘Riding’ a Dolphin

Image by Bill Coulson, Risso’s Dolphin Project South West volunteer, courtesy of the Marine Biological Association

Remarkable photographs show an octopus seemingly “riding” a dolphin in the waters off the South West coast of the U.K.

Bill Coulson, a volunteer with the Risso’s Dolphin Project South West, was taking photographs off Berry Head in Devon, U.K., when he captured something extraordinary across the back of a Risso’s dolphin. His images reveal a common octopus (Octopus vulgaris) wrapping its arms around the dolphin’s dorsal fin and clinging to it like a passenger aboard.

According to a news release by the U.K.’s Marine Biological Association, Coulson’s photographs come as researchers investigate how warming seas are affecting marine life and contributing to unusually high numbers of common octopuses along the South West coastline of the U.K. There has been an unprecedented surge in common octopus numbers in the region, described as the largest such bloom in at least 75 years.

Risso’s dolphins (Grampus griseus) are reportedly among the U.K.’s least-understood cetaceans and are known to feed primarily on squid and other cephalopods. The recent abundance of octopus, however, may be creating new feeding opportunities for these distinctive dolphins.

Josh Symes, an MSc researcher at the University of Exeter who uses photo identification to study Risso’s dolphins, said the photographs provide insight into more than just a rare encounter.

“These photographs offer a fascinating glimpse into the feeding ecology of Risso’s dolphins and the changing marine environment around our coasts. Risso’s dolphins are closely associated with cephalopods, and sightings like this help us understand how they are responding to changing prey availability,” Symes says in a statement to the Marine Biological Association. “The images also highlight the value of citizen science, as observations from volunteers are helping us build a clearer picture of marine wildlife across the Southwest.”

Although native to U.K. waters, the common octopus is usually rare. Evidence suggests that the octopus population likely originated from breeding grounds near the Channel Islands and northern France, with currents carrying young octopuses into U.K. waters. Warmer sea temperatures appear to have played a key role in the increase, raising concerns that similar events could become more common as the climate changes.