Argentina's Deep-Sea Canyons Gave Up 57 New Species in Two Weeks

Keypoints:

• Scientists identified 57 new marine species and five new genera
• The work took place at a two-week workshop in Buenos Aires
• Specimens came from Mar del Plata Canyon, nearly twice as deep as the Grand Canyon
• Only 10% of copepod samples were examined, and every one was new to science
• The Ocean Census Network led the effort

Scientists have identified 57 marine species and five genera new to science after examining deep-sea specimens from Argentina's submarine canyons at a two-week workshop in Buenos Aires. The Ocean Census Network ran the effort after a deep-sea expedition into the canyons.

The canyon is nearly twice as deep as the Grand Canyon. The Schmidt Ocean Institute's remotely operated vehicle SuBastian recorded an orange-red octocoral at 1,954 metres in Mar del Plata Canyon. A sea cucumber from 2,577 metres is one of up to 10 new sea cucumber species identified.

The copepods, tiny crustaceans, produced the most striking result. Taxonomists examined only 10% of the copepod samples, and every specimen proved new, which gave 20 new species and one new genus.

Corals added to the list. One colonial coral is among 14 new cnidarian species identified at the workshop. Some coral finds may represent two new genera and a new family, which await genetic analysis.

The expedition's wider work in the South Atlantic had already drawn attention. Researchers set out to study cold seeps, areas where methane and other chemicals from the seafloor sustain microbes that feed tube worms, clams and mussels. They flagged 28 possible new species, many living in the largest known Bathelia candida coral reef in the world, a colony nearly the size of Vatican City.

Dr Michelle Taylor, Ocean Census head of science, said the speed shows the power of collaborative taxonomy. The workshop brought Latin American expertise together with international experts and linked them to the open-access Ocean Census NOVA platform.

The census keeps growing. The Ocean Census reported 1,121 new species across 13 expeditions between mid-2025 and mid-2026. Off East Timor, researchers found striped ribbon worms they suspect may carry toxins that could yield new treatments. Less than 0.001 percent of the seafloor has ever been directly seen. The list of unnamed animals is likely far longer than the one scientists hold today.