Picture the water 4,500 meters (14,800 feet) below the surface off the coast of Western Australia. No light reaches down there. The temperature hovers just above freezing. The pressure is enough to collapse a steel drum in seconds. Nothing about this place invites a visitor. And yet, something has been moving through that dark for a very long time.

It is about 13 meters (43 feet) long. Its eyes are the size of dinner plates. It carries eight arms and two feeding tentacles studded with razor-edged suction rings, and it has spent its entire existence without ever encountering a human being. For all practical purposes, it was invisible to science. Then, in early 2026, a team of researchers aboard a vessel off the Ningaloo coast lowered a sampling bottle into that cold water and confirmed the giant squid’s presence without seeing a single living thing. The evidence that scientists found a sea monster came down to six small cups of seawater.

Scientists Found a Sea Monster Using Invisible Genetic Fingerprints

Every animal alive leaves a trail. On land, that trail looks like footprints, feathers, or fur. In the ocean, it is far more subtle: a constant, quiet release of shed skin cells, mucus, waste, and fragmented tissue that disperses into the surrounding water and drifts with the current. This genetic debris, called environmental DNA or eDNA, is present wherever animals have been. It is also almost impossibly faint, a signal so diluted by billions of liters of seawater that reading it requires filtering enormous volumes of ocean and decoding what clings to the membrane.

The science of doing exactly that has been developing for over a decade. The 2026 expedition to two previously unexplored submarine canyons off Western Australia stands as one of its most striking demonstrations yet. Dr. Georgia Nester, then a PhD candidate at Curtin University, led the study aboard the Schmidt Ocean Institute‘s research vessel R/V Falkor. The team’s targets were the Cape Range Canyon and the Cloates Canyon, located approximately 1,200 kilometers (745 miles) north of Perth, tucked in the shadow of Ningaloo Reef, one of the longest fringing coral reefs on Earth.

These canyons had never been biologically surveyed. Cape Range Canyon reaches roughly 4,900 meters (16,100 feet) at its deepest point. To put that in perspective, it is nearly six times the height of the world’s tallest building, stacked end to end. Cloates Canyon descends to around 4,400 meters (14,400 feet). Both are shaped by a productive mechanism: Antarctic Intermediate Water pushes upward against the Leeuwin Current at the canyon heads, generating cold, nutrient-rich upwellings that sustain dense concentrations of life. The team had reason to believe these were rich waters. The full picture exceeded their expectations.

Over the course of the expedition, researchers collected more than 1,000 water samples across five depth levels, reaching 4,510 meters (14,797 feet). Back in the laboratory, each sample was filtered through a cellulose membrane and processed using a technique called metabarcoding. DNA sequences captured in each sample are compared against a global species database to identify which animals had passed through that water, sometimes weeks before the sampling bottle even descended.

The results came back with 226 species across 11 major animal groups, and 83 of those had never been recorded in Western Australian waters before. Among the newcomers: a sleeper shark, the faceless cusk eel, and the slender snaggletooth fish. Researchers also detected two deep-diving whale species, the pygmy sperm whale and Cuvier’s beaked whale. And scattered across six separate samples drawn from both canyon systems independently, the team found the unmistakable genetic signature of Architeuthis dux: the giant squid.

The Invisible Giant: How Scientists Found a Sea Monster Without Ever Seeing It

To understand the weight of that detection, it helps to spend a moment with the animal itself. The giant squid is the largest invertebrate on Earth. Females reach total lengths of up to 13 meters (43 feet), tentacles included, and weigh close to 900 kilograms, nearly a ton. The mantle alone, the torpedo-shaped body housing all the animal’s organs, can exceed 2 meters (6.6 feet) in length. None of that is the most arresting detail. The eyes are. Giant squids possess the largest eyes of any animal on Earth, measuring up to 25 centimeters (10 inches) across, roughly the size of a dinner plate. Those eyes evolved for a world of near-total darkness, 300 to 1,000 meters (1,000 to 3,300 feet) below the surface. The faint bioluminescent glow of a passing creature, the kind of light a human eye would miss entirely, is enough for the squid to track, target, and strike.

Its arms carry hundreds of suction cups lined with rings of serrated chitin, a hard biological material structurally similar to a human fingernail, capable of slicing through flesh on contact. The beak at the center of the arm cluster is hard enough to sever bone. Two feeding tentacles, longer than the arms and coiled in wait, can be fired outward with explosive speed to seize prey before it reacts. The squid can also shift color patterns across its skin in an instant, a form of communication researchers are still working to decode.

For all that, humans have barely seen a living one. The first confirmed footage of a wild giant squid in its natural habitat came from a 2012 expedition by Japan’s National Museum of Nature and Science, which lured one to a camera using a bioluminescent decoy designed to mimic a jellyfish. Before that expedition, most of what science knew about the species came from carcasses washed onto beaches and partial remains tangled in fishing nets. The other main source of evidence has been the stomach contents of sperm whales, which dive to depths of around 2,000 meters (6,500 feet) to hunt the squid. Those encounters do not go one-sidedly. Circular scars left by squid suction rings appear regularly on sperm whale skin. Undigested squid beaks, hard enough to pass through an entire whale’s digestive tract intact, have been found packed by the dozens inside whale stomachs.

In Western Australia, documented records of the giant squid numbered exactly two in all of recorded scientific history, before this study.

How the eDNA Method Catches What Cameras Cannot

The traditional approach to deep-sea survey involves lowering cameras, nets, and remotely operated vehicles into the water column. The approach is expensive, slow, and limited to whatever passes in front of a lens during a narrow window of time. In an ocean covering 71 percent of Earth’s surface, at depths where the pressure would crush an unprotected human body in seconds, the probability of a camera capturing a giant squid on any given deployment is effectively zero.

Environmental DNA changes that calculation. Because every animal continuously sheds genetic material into its surroundings, a water sample collected weeks after an animal has passed through a location can still confirm the animal was there. No direct observation is needed. No cooperation from the animal is required. The only requirement is that some fragment of its biology persist long enough in the water column to be collected, filtered, and read.

Dr. Nester described the canyons as “incredibly rich ecosystems” that had been “largely unexplored because of the difficulty of working at such extreme depths.” eDNA analysis, she explained, allows a single water sample to simultaneously reveal hundreds of species, making it possible to produce the most thorough biodiversity assessment ever attempted in this remote stretch of the eastern Indian Ocean.
“You can’t protect what you don’t know exists,” said Dr. Lisa Kirkendale, Head of Aquatic Zoology at the Western Australian Museum and a co-author of the study. “The sheer number of discoveries, including megafauna, makes it clear that we still have so much to learn about what marine life lives in the Indian Ocean.”

The giant squid detection was not a sighting. When scientists found a sea monster through its forensic trace, what they recovered were molecular remnants circulating in cold, dark water four kilometers below the surface. Six independent samples across two separate canyon systems confirmed the signal and ruled out contamination or chance. Something very large had been in that water.

A Hidden World: What Else Scientists Found in Those Canyons

The giant squid made the headlines, but the rest of the species list from Cape Range and Cloates tells an equally compelling story. These two gorges sit beside one of the world’s most celebrated World Heritage reef systems. They had no biological record before this expedition. What the team found inside them suggests they have been quietly thriving, far from anyone’s attention.

Among the more striking finds was the faceless cusk eel (Typhlonus nasus), a fish so adapted to extreme depth that it has no functional eyes. Its diet, lifespan, and behavior remain largely unknown to science. Sleeper sharks were also detected in the samples, extending their confirmed range into these waters. Sleeper sharks grow slowly, reproduce rarely, and in certain species live for several centuries, which makes them particularly exposed to deep-sea trawling pressure.

Multiple unidentified DNA sequences in the dataset did not match any species currently in the global database. The team stopped short of declaring new species, since absence from a database does not equal novelty. The volume of unmatched sequences, however, points strongly toward animals that science has not yet formally described.

The study also revealed that life in these canyons is arranged vertically. Different depth bands host entirely different communities of animals. Two neighboring canyons, close in geography but distinct in their water dynamics, support noticeably different collections of species. The deep-sea floor is far more varied and locally structured than earlier broad-scale surveys had indicated.

Scientists Found a Sea Monster. Now Comes the Harder Work.

The Cape Range and Cloates canyons had no biological inventory before this expedition. They sit directly behind Ningaloo Reef, in waters facing increasing pressure from deep-sea trawling, oil and gas operations, and climate-driven warming. The 226 species now confirmed there form a starting point: the first written record of a community that has existed for millions of years without one.

The research team deposited all biological reference sequences recovered from the expedition into GenBank, the global open-access DNA database, available to any future survey. The original filtered water samples are archived in Perth under laboratory conditions, preserved for reanalysis as new species are formally described, and the reference library grows.

That is what the work leaves behind: a foundation others can build on.

Somewhere in those dark canyons, the giant squid carries on. Its dinner-plate eyes scan for the faint glow of passing prey. Its suction rings stay coiled and ready. The small ship that passed above it found its signature in a handful of water and confirmed what those depths had been holding all along. No one laid eyes on it. The trace was enough. That trace is now the starting point for protecting it.

Sources:
Nester, G.M., Wilson, N.G., Moore, G., Hosie, A.M., Przeslawski, R., Bunce, M., Kirkendale, L. and Richards, Z. “Environmental DNA Reveals Diverse and Depth-Stratified Biodiversity in East Indian Ocean Submarine Canyons.” Environmental DNA, 7 March 2026.
“Giant Squid Among Rare and Elusive Marine Life Detected off Western Australia’s Coast.” Curtin University Media Release, May 2026.
“Giant Squid Found in Western Australian Waters in eDNA Study.” Oceanographic Magazine, May 2026.
Schrope, M. “Giant Squid Filmed in Its Natural Environment.” Nature, January 2013.
“Sperm Whale and Giant Squid: Evidence of Conflict.” American Museum of Natural History, n.d.
“Caught on Video: Giant Squid.” Smithsonian Ocean, Smithsonian Institution, updated May 2023.