Utilizing environmental DNA (eDNA) from depths exceeding 4 km off the coast of Western Australia’s Ningaloo, researchers have identified an astounding 226 species spanning 11 major animal groups. This includes remarkable finds like the giant squid, which hasn’t been previously documented in the region, as well as species believed to be new to science.
When a giant squid, measuring 10 to 12 feet long, approaches Medusa’s e-jelly lure, it realizes the e-jelly is not bait and retreats. Image credit: Edie Widder and Nathan Robinson.
“Our findings underscore the vast unknowns within Australia’s deep sea ecosystems,” stated Dr. Georgia Nester, the lead researcher from Curtin University, now enrolled at the University of Western Australia.
Dr. Nester and her team from the Schmidt Ocean Institute’s R/V Falco conducted a survey of the Cape Ranges and Croats submarine canyon, roughly 1,200 km north of Perth, collecting over 1,000 samples from depths as deep as 4,510 m.
Employing eDNA techniques, they documented the species inhabiting these deep-sea environments without direct observation or capture.
Among their significant discoveries was evidence of the giant squid (Architeuthis dux), detected across six separate samples from both the Cape Mountains and Cloetes Valley, alongside pygmy sperm whales (Kogia breviceps) and beaked whales (Ziphius cavirostris).
“Only two previous records of giant squid exist in Western Australia, with no sightings for over 25 years,” noted Dr. Lisa Kirkendale from the Western Australian Museum.
“This marks the first detection of a giant squid using the eDNA protocol along the coast of Western Australia and represents the northernmost record of Architeuthis dux in the eastern Indian Ocean.”
Overall, researchers recorded a total of 226 species from 11 major animal groups, which included rare deep-sea fish, cnidarians, echinoderms, squid, marine mammals, and many more.
They also identified numerous species in Western Australian waters, such as the sleeper shark, previously unrecorded, as well as the faceless cask eel (Typhronus) and thin snaggletooth (Ladinastes demus).
“While the discovery of giant squid captivates public imagination, it’s part of a broader ecological puzzle,” explained Dr. Nester.
“We found numerous species that don’t align with existing records, indicating a significant scope of deep-sea biodiversity that remains to be uncovered.”
Curtin University researcher Dr. Zoe Richards noted, “eDNA has the potential to revolutionize how scientists explore and conserve deep-sea environments.”
“These ecosystems are vast, remote, and costly to study, yet they confront increasing threats from climate change, fishing, and resource extraction.”
“eDNA offers a scalable, non-invasive method to gain essential insights into the organisms residing there, crucial for informed conservation efforts.”
“You can’t protect what you don’t know exists. The sheer volume of discoveries, including megafauna, emphasizes that we have much to learn about marine life in the Indian Ocean.”
The team’s findings are published in the journal Environmental DNA.
_____
Georgia M. Nester et al. 2026. Environmental DNA reveals diverse and expanding biodiversity in underwater canyons in the eastern Indian Ocean. Environmental DNA 8 (2): e70261; doi: 10.1002/edn3.70261
Source: www.sci.news
