On a brisk Sunday morning at the end of November 2025, a quiet stretch of sand at Forvie National Nature Reserve in Collieston, Aberdeenshire, became the scene of a marine mystery that has left scientists and beachgoers alike scratching their heads. A local walker, taking in the wintry calm, stumbled upon something utterly out of the ordinary: a large, fleshy tentacle with rows of suckers, washed up by the North Sea’s relentless tides. It was a find that would soon draw in marine biologists, spark widespread speculation, and provide a rare window into the deep, unseen world beneath the waves.
According to BBC News, the discovery was first reported to reserve staff at Forvie, a sprawling 2,471-acre sanctuary known for its seals and Scotland’s largest tern and black-headed gull colony. Catriona Reid, the NatureScot manager for the reserve, remembered the moment her team was alerted: “We were first made aware that there was something odd on the beach over the weekend, when a local walker spotted part of the octopus on the beach. However, we couldn’t get out until after the next high tide, when only sections of the tentacles could be found.”
The tentacle was like nothing the staff had seen before—its diameter and the size of its suckers were far greater than those of the common curled octopus typically found in these waters. Speculation ran wild. Could it be the remains of a giant squid, a creature that has inspired sea monster legends for centuries? The idea wasn’t far-fetched; after all, a giant squid had washed up dead at nearby Newburgh in 1998. But as Reid explained, “The suckers didn’t have teeth, which giant squid suckers do—a real mystery!”
In search of answers, the team reached out to marine experts far and wide, including Aberdeen University’s zoology department and the Natural History Museum. It was local marine biologist Dr. Lauren Smith, of the East Grampian Coastal Partnership, who ultimately helped crack the case. With the help of colleagues and a network of marine scientists, the remains were identified as belonging to the giant gelatinous octopus, Haliphron atlanticus—better known as the seven-arm octopus or, more whimsically, the blob octopus.
Despite its name, the seven-arm octopus actually has eight arms like all octopuses, but in males, one arm is modified as a reproductive organ and is typically hidden from view, which led to its misleading moniker. According to Dr. Smith, “Seven-arm octopus are a remarkable and rarely documented species.” They are among the largest octopuses known to science, with females capable of growing up to 13 feet (4 meters) in length and weighing as much as 165 pounds, as reported by Aberdeen Live and BBC News. The largest recorded specimen stretched an astonishing 11 feet long.
What makes this find truly extraordinary is the creature’s typical habitat. The seven-arm octopus is a deep-sea dweller, usually found at depths below 500 meters (1,640 feet)—well beyond the reach of sunlight and, generally, far from the shallow waters of the North Sea. “These are a deep-water species—usually found below 500m—so it’s a puzzle how it came to be here, as most of the North Sea is shallower than that,” Reid told reporters. “Washed up by deep water currents? Trawled up by fishers? We’ll probably never know, but it’s a fascinating find nonetheless and yet again serves to illustrate how little we know about deep-water creatures.”
The discovery has prompted a flurry of scientific activity. Dr. Smith noted that the recovered remains have been frozen for further study, with the potential for some parts to be preserved as museum specimens. She emphasized the scientific value of such a rare event: “This is an extraordinary find, to have a deep-water species like Haliphron atlanticus appear here is incredibly rare and offers a valuable opportunity for further study.” Dr. Smith also credited Dr. Steve O’Shea, another marine biologist, for helping to verify the species identification.
The process of identification was a true exercise in scientific detective work. The tentacle’s large size and the lack of teeth on the suckers quickly ruled out the giant squid, and the distinctive features matched those of Haliphron atlanticus. As reported by Aberdeen Live, the team at Forvie had “never seen anything like it before.” The find, they said, was “far too big for the common curled octopus we see around the shore here.”
Forvie National Nature Reserve itself is no stranger to wildlife wonders. Nestled between the North Sea and the estuary of the River Ythan, its dunes and heathlands are alive with birdlife and marine mammals. But the sudden appearance of a deep-sea giant on its shores was an event of a different magnitude—one that has captured the imagination of locals and scientists alike.
As Live Science reported in their weekly roundup, the washed-up arms of the rare seven-armed octopus have raised “questions as to how they got there.” The mystery is compounded by the geography of the North Sea, which is mostly too shallow for such deep-sea creatures except for the Norwegian Trench, which reaches depths of about 700 meters (2,296 feet). Whether the octopus was carried by unusual currents, fell victim to fishing activity, or found its way to shallower waters for reasons unknown, remains an open question.
For now, the remains of the giant gelatinous octopus are being preserved and studied, offering a rare chance for scientists to learn more about a species that is seldom encountered and poorly understood. As Dr. Smith put it, “The discovery highlights both the scientific value of community wildlife reporting and the enduring mysteries of the deep ocean.”
It’s a sentiment echoed by Reid and her team at Forvie, who see the event as a reminder of how much remains undiscovered in the world’s oceans. “It’s a fascinating find nonetheless and yet again serves to illustrate how little we know about deep-water creatures,” she said. In a time when the world sometimes feels thoroughly mapped and catalogued, the North Sea’s mysterious visitor is a humbling reminder that the deep still holds secrets—and that sometimes, those secrets wash up right at our feet.
