Scientists surveying deep-sea canyons off Western Australia have found evidence of a giant squid and 225 other species in waters that have been largely out of reach until now. The study, published recently in the journal Environmental DNA, used seawater samples from the Cape Range and Cloates canyons off Nyinggulu, also called Ningaloo, about 1,200km north of Perth.
Some of the samples came from depths of up to 4,510m, where researchers said they detected marine animals not by sight but through environmental DNA, or eDNA, left behind in the water. The finding is one of the biggest surprises in the study because giant squid had not been recorded in Western Australian waters for more than 25 years.
The research team said it found evidence of 226 species in the deep waters around the canyons, including pygmy sperm whales, Cuvier’s beaked whales and bony-eared assfish. It also recorded sleeper sharks, slender snaggletooths and faceless cusk eels in Western Australian waters for the first time, while other species detected may be new to science.
Georgia Nester said the canyons are “incredibly rich ecosystems” that had been largely unexplored because working at such extreme depths is so difficult. She said eDNA means a single water sample can reveal hundreds of species at once, expanding what scientists can learn about deep-water environments in a way that had not been possible before.
That matters because the result is not just a rare sighting; it is a broader map of life in a part of the ocean few people have been able to study. Giant squid can grow to more than 13m long and have eyes the size of dinner plates, and Dr Lisa Kirkendale said this was the first giant squid record off Western Australia’s coast using eDNA protocols and the northernmost record of the species A. dux in the eastern Indian Ocean.
The tension in the study is that the most striking discoveries came from water, not from direct observation. Scientists still do not know how many of the organisms identified are new to science, but the team said a large number of species did not neatly match anything now on the record. For the deep canyons off Nyinggulu, that leaves the clearest answer from this survey: the ecosystem is richer, stranger and less charted than anyone had shown before.
