Researchers exploring the deep Southern Ocean have uncovered at least 30 previously unknown species, including a bizarre carnivorous sponge that expedition teams have nicknamed the “death ball.” The discoveries come from surveys of volcanic calderas, the South Sandwich Trench and the seafloor around Montagu and Saunders Islands.
Two research vessels conducted the missions, which probed some of the least-studied waters on Earth. Just north of Montagu Island, roughly 3.5 kilometres beneath the surface, scientists recorded an unusual sponge with white stalks topped by ball‑like tips covered in microscopic hooks.
The sponge is carnivorous: tiny animals — mainly small crustaceans — that contact the hooked tips become entangled and are slowly digested by the sponge’s tissues.
'They're doomed, unfortunately. To be absorbed slowly over time is a grim way of going,' said Michelle Taylor of the University of Essex, who led part of the expedition.
The “death ball” was only one highlight among roughly 2,000 samples collected. Teams also recovered an iridescent worm, at least one previously undocumented sea star, and several new crustaceans. So far, about 30 percent of the specimens have been examined; from that subset scientists have already confirmed 30 new species.
These voyages were part of the Ocean Census program, a global collaboration of more than 500 institutions. Across 13 expeditions the program has identified more than 800 new species, and it aims to continue expanding our knowledge of deep‑sea biodiversity.
Currently about 240,000 marine species are formally described, but researchers estimate the true total may be between one and two million. The newly collected specimens were sent to the University of Magallanes in Punta Arenas, Chile, where international taxonomists are working together to verify and classify the finds.
'By coupling expeditions with species discovery workshops, we compress what often takes more than a decade into a faster pathway while maintaining scientific rigor,' said taxonomist Tina Bolstad.
These discoveries highlight how much of the deep Southern Ocean remains unexplored and how expeditions combined with rapid taxonomic collaboration can accelerate our understanding of life in Earth’s most remote oceans.
