Scientists have confirmed the presence of the giant squid — one of the ocean's most elusive and mythologised animals — in deep-sea submarine canyons off the coast of Western Australia, the first record of the species in these waters in more than 25 years.¹⁵ The discovery was made not by direct sighting or underwater camera, but through environmental DNA analysis: traces of genetic material shed by the animals into the water column, collected and identified by researchers from the Western Australian Museum and Curtin University during an expedition aboard the Schmidt Ocean Institute's research vessel R/V Falkor.²⁶

The expedition explored the Cape Range and Cloates submarine canyons, located approximately 1,200 kilometres north of Perth, collecting 178 water samples at five different depths reaching as deep as 4,540 metres.⁵⁷ Giant squid DNA — from the species Architeuthis dux — was identified in six separate samples across both canyon systems, making this the first record of the species in Western Australian waters using eDNA protocols and the northernmost confirmed record of Architeuthis dux in the entire eastern Indian Ocean.³⁴

What is environmental DNA and why does it matter

Environmental DNA, or eDNA, refers to genetic material that organisms shed into their surroundings — through mucus, skin cells, waste, or other biological products — which can be collected from water or soil samples and used to detect the presence of species without physically observing them.⁶⁸ eDNA metabarcoding, the technique used in this study, analyses these samples for short DNA sequences that serve as biological barcodes, allowing researchers to identify which species were present based on the genetic signatures in the water.²

For deep-sea research, eDNA represents a transformational tool. Physically observing animals in submarine canyons at depths of thousands of metres requires expensive submersibles and long dive operations, and many deep-sea species are so rare or behaviourally cryptic that they are almost never caught on camera even when vehicles are present.⁵⁹ Collecting water samples and sequencing them onboard allows researchers to survey biodiversity across entire water column depths without needing to see a single animal, and at a fraction of the cost of traditional deep-sea observation campaigns.⁶⁷

The broader biodiversity survey

The giant squid detection was one highlight of a much broader survey that documented extraordinary deep-sea biodiversity in the Cape Range and Cloates canyons. Across the 178 water samples, the expedition identified evidence of 226 species spanning 126 families — and crucially, 83 of those records represent possible new species records or range extensions for their taxa, meaning animals documented for the first time in these waters or found significantly further from their known ranges than previously recorded.⁵⁷

The canyons are located in a remote stretch of the eastern Indian Ocean that has received relatively little scientific attention compared to other deep-sea environments globally. The expedition's findings suggest this is a biologically rich and largely unexplored ecosystem, home to diverse assemblages of fish, cephalopods, crustaceans, and other invertebrates living in conditions of perpetual darkness and extreme pressure.⁴⁸

The giant squid: context and significance

Architeuthis dux is the largest known invertebrate on Earth, capable of reaching lengths of up to 13 metres including tentacles, and was for centuries known almost entirely from carcasses washed ashore or found in the stomachs of sperm whales.³⁹ The first confirmed photographic evidence of a live giant squid in its natural deep-sea habitat was not obtained until 2004, and video footage of a living specimen in the wild did not emerge until 2012.¹¹⁰ The animal's extreme depth range, elusive behaviour, and the logistical challenges of deep-sea observation mean that its population size, distribution, and biology remain poorly understood.⁶

The Western Australia eDNA detection is therefore significant not just as a local biodiversity record, but as a demonstration of what eDNA methods can achieve in documenting the presence of animals that conventional methods have consistently failed to observe directly.²⁵ Researchers expect that applying eDNA surveys more broadly across under-sampled deep-sea regions will substantially expand our knowledge of giant squid distribution — and of the deep ocean's biodiversity more generally.⁷⁹

#marine biology

Giant Squid Detected in Western Australian Deep-Sea Canyons for First Time in 25 Years, Using Environmental DNA