CSIRO Expedition Discovers More Than 120 New Species in Australia's Coral Sea, Including a Ghost Shark and New Rays
A 36-day voyage aboard CSIRO's RV Investigator surveyed 61 deep-water sites in Australia's Coral Sea Marine Park, collecting over 6,000 fishes and 80,000 invertebrates and identifying more than 120 species new to science at depths reaching 3,600 meters.
A Deep-Water Survey of Volcanic Seamounts and Ancient Reefs
Australia’s national science agency CSIRO has announced the discovery of more than 120 species new to science following a 36-day expedition into the Coral Sea Marine Park, one of the largest and least explored marine protected areas on Earth. The voyage aboard research vessel RV Investigator departed Brisbane in October 2025 and surveyed 61 sites across depths of 200 to 3,600 meters, exceeding the planned 55 survey locations.
The expedition, conducted in partnership with the Nippon Foundation-Nekton Ocean Census, Parks Australia, and Bush Blitz, focused on two previously understudied ecological features: the Marion Plateau reefs and the northern Tasmantid Seamount Chain, a series of extinct volcanic peaks that had never received a modern deep-water survey.
A Haul of Unprecedented Scale
Over the course of the voyage, 38 scientists and 23 crew members collected more than 6,000 fishes and 80,000 invertebrates. Taxonomists working through the specimens at a series of workshops across Australia have so far confirmed more than 120 species as new to science, a figure the research team expects to surpass 200 as additional cryptic species are identified through DNA sequencing.
The discoveries span a wide range of marine life. Chief Scientist Dr. Will White, a shark expert at CSIRO, personally identified four new species: two rays in the genera Dipturus and Urolophus, one deepwater catshark in the genus Apristurus, and one chimaera in the genus Chimaera. The chimaera, commonly known as a ghost shark, is a cartilaginous fish related to sharks and rays, characterized by a plump nose, a dorsal spine, and a long rat-like tail. White described observing “plenty of unique, deep-sea creatures in locations from seamounts and atolls to unexplored deep reefs” during the voyage. The expedition also documented brittlestars, crabs, sea anemones, sponges, jellyfish, and polychaete worms previously unknown to science.
Mapping the Unknown
One of the expedition’s notable achievements was the complete mapping of Mellish Seamount, where researchers discovered a previously unknown mesophotic coral ecosystem. Mesophotic reefs exist in the ocean’s twilight zone, typically between 30 and 150 meters deep, where reduced light supports coral communities distinct from those found in shallow waters. The Coral Sea Marine Park spans nearly one million square kilometers east of the Great Barrier Reef, yet the vast majority of its deep-water habitats remain unsurveyed.
White noted that the deep ocean contains “some of the most interesting and least known species” and described observing unique creatures at locations ranging from seamounts and atolls to unexplored deep reefs during the voyage.
Conservation Context
The discoveries arrive as ocean warming intensifies pressure on marine ecosystems. The Coral Sea has warmed nearly half a degree over the past 30 to 40 years, with record temperatures documented in recent years. Dr. Candice Untiedt of CSIRO noted that “voyages like the Coral Sea Frontiers expedition are essential for uncovering biodiversity in our marine parks” and emphasized the importance of securing specimens in national museum collections for future study.
The expedition included two Indigenous students through the Indigenous Time at Sea Scholarship program, part of CSIRO’s effort to broaden participation in marine research.
A Global Effort to Catalog Ocean Life
The Coral Sea expedition contributes to the broader Nippon Foundation-Nekton Ocean Census, an international initiative launched in 2023 to accelerate the discovery and documentation of marine species. The program operates on the premise that more than 90 percent of ocean species remain undiscovered. Specimens from the voyage have been lodged in collections across Australia, including CSIRO’s Australian National Fish Collection and state museums. Taxonomic data has been entered into the Ocean Census Biodiversity Data Platform, the world’s first open-access digital gateway for newly discovered marine species, making the findings immediately available to researchers worldwide.