For centuries, tales of sea monsters turned sailors’ fear of the unknown into legends of giant tentacled beasts. On March 9, 2025, a real-life encounter finally caught up with the myths when researchers quietly filmed a colossal squid at about 600 meters without startling it, during a Schmidt Ocean Institute expedition. That success has now helped scientists explain why giant squids have been so good at avoiding us in the first place, and the answer lies in how they see our lights in the dark.
The Elusive Giant Squid
The giant squid, Architeuthis dux, lives far below the reach of sunlight, in a band of deep water where human visits are rare and fleeting. A Primary peer-reviewed study documenting the first wild images of Architeuthis and its behavior at depth stressed that the species inhabits a zone where light is scarce and pressure is intense, which naturally limits encounters with people. Researchers in that work relied on specialized cameras and long deployments because the animals simply did not show themselves near conventional submersibles.
Those early deep-sea expeditions also revealed how unpredictable the squid can be, appearing briefly on camera before vanishing into the dark. In later analysis of the same fieldwork, biologist Edith Widder described how past efforts struggled because traditional vehicles and bright lights seemed to empty the water column of large animals. As she explained in coverage cited by a Primary Architeuthis and report, the historical challenge was not just finding the squid, but learning how to be present in its world without announcing our arrival with a blaze of white light.
Breakthrough Footage
The recent leap forward came from a different approach to filming, one that treated the deep sea more like a darkroom than a stage. During the Nippon Foundation–Nekton Ocean Census expedition aboard Schmidt Ocean Institute’s ship Falkor (too), the team relied on the ROV SuBastian and a specialized Medusa camera system that used low-intensity red illumination. A detailed account of how the crew captured landmark giant squid video explains that the Medusa system was designed with very sensitive cameras so it could operate with dim red lights instead of the harsh white beams typical of deep-sea vehicles.
That same strategy guided the encounter with a live colossal squid, Mesonychoteuthis hamiltoni, filmed by ROV SuBastian near the South Sandwich Islands at roughly 600 m. Reporting on the expedition, carried out under the Nippon Foundation–Nekton Ocean Census umbrella, makes clear that the researchers saw the low-light setup as their best chance to record a relaxed animal. The Nippon Foundation and Nekton Ocean Census team had already concluded that bright white lights might scare elusive creatures away, so they treated the Medusa’s red glow as a kind of visual whisper in the dark.
The Chilling Reason Revealed
The emerging explanation for why giant squids avoid humans so effectively is simple and unsettling: our lights look dangerous to them. A Peer-reviewed methods and observations paper on deep-sea squid behavior argues that these animals can detect and actively avoid disturbances from vehicles, especially when those platforms blast the water with intense white or blue illumination and mechanical noise. In that work, scientists found that low-intensity or red light, combined with passive platforms, sharply reduced avoidance responses, suggesting that the animals interpret bright light as a threat worth fleeing.
Primary research focused on light conditions has gone further, examining how squid eyes respond to different wavelengths. One Primary study on visual sensitivity in cephalopods reports that deep-sea squid show strong behavioral changes under artificial white and blue light, while red light is far less disruptive because it barely penetrates their native habitat. Edith Widder, quoted in Mainstream coverage of the new footage, linked this sensitivity directly to past failures: she argued that the glaring beams of earlier submersibles likely caused giant squids to keep their distance, creating the eerie impression that the ocean was empty whenever humans arrived.
Why It Matters
Understanding that giant squids may interpret our lights as danger changes how scientists approach the deep sea. A Reputable science explanation of the first successful giant squid filming made clear that the key was avoiding bright white lights and instead using dim red illumination with low-light cameras. That insight now guides expedition planning, from how ROVs are lit to how long they remain still, shifting the goal from simply seeing animals to seeing them behave naturally.
The rarity of these encounters is stark when set against historical records. A Guinness World Records entry on the first video of a giant squid in its natural habitat notes how long scientists had to wait for such footage despite decades of collecting dead specimens. A Detailed explainer comparing giant and colossal squids points to specimen history such as an intact 2007 Ross Sea individual held at Te Papa, underscoring that for years researchers knew these creatures mostly from carcasses. The new light-sensitive methods promise more frequent, less intrusive observations, which could inform conservation decisions before growing human activity in the deep ocean affects species we have barely met.
What We Still Don’t Know
Even with better footage, the behavior of giant and colossal squids remains largely mysterious. The original Primary Architeuthis paper that captured wild images at depth could only document a narrow slice of activity, leaving open questions about migration patterns, social behavior and how often the animals approach the surface. Later Reputable magazine reporting on those images highlighted how hard it was to interpret a few fleeting clips as a full behavioral profile, especially for a species that spends its life in darkness.
The line between giant squid and colossal squid behavior is also thinly drawn. A Major-accountability report on the new colossal squid video notes that scientists are still sorting out how Mesonychoteuthis differs ecologically from Architeuthis dux, beyond size and anatomy. Coverage described as Useful for understanding concealment and avoidance emphasizes that many deep-sea animals rely on transparency, counter-illumination and careful use of light to stay hidden from predators, but the specific predators and prey that shape giant squid behavior remain poorly documented and thinly supported by direct observation.
Future Expeditions
The March 9, 2025 encounter has become a template for how future deep-sea missions might proceed. A Reputable science report on the precise capture date and the role of ROV SuBastian under the Nippon Foundation–Nekton Ocean Census program describes how Schmidt Ocean Institute plans to keep refining low-impact technology. That includes quieter vehicles, more sensitive cameras and lighting tuned to wavelengths that deep-sea animals either cannot see or do not interpret as threatening.
Other coverage points to how this technology could spread beyond one ship or one project. A Quick reference on the milestone of filming a giant squid at depth, along with Additional expert verification, frames the new methods as a model for future ocean observatories that watch without blinding their subjects. As more expeditions adopt dim red lights, passive platforms and Census-style long deployments, the chilling reason giant squids have stayed out of sight for so long may also become the key to finally watching them live their lives in the dark.
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*This article was researched with the help of AI, with human editors creating the final content.
