Expedition describes 31 new deep-sea species off Brazil

An international team of scientists aboard a Schmidt Ocean Institute research vessel has described 31 new species from the ocean depths off the coast of Brazil. The survey was carried out in the tropical mid-depths of the South Atlantic, in the layer of water below the sunlit surface, and the results rest on a combination of remote imaging and laboratory analysis. This is one of the less-studied parts of the ocean, where almost every dive can turn up organisms that science has never formally described.

According to the institute, the crew used several advanced imaging technologies alongside genome sequencing to confirm the new species. That approach lets researchers describe an organism not only by its appearance but also by its genetic material, which lowers the risk of mistaking an already-known species for a new one. Genome sequencing has become a standard tool in modern marine biology, since many deep-sea animals have body shapes that are hard to tell apart by eye.

What does it actually mean to describe a new species?

Describing a new species does not mean the organism has just come into existence, or that it recently drifted into those waters. It means the species has now been formally documented, sampled, and placed within the existing classification system. Many of these organisms have probably lived in the same stretch of ocean for thousands of years, but stayed beyond the reach of research because the deep ocean is technically difficult to access and expensive to survey in a systematic way.

It is also worth keeping the limits of these results in mind. The figure of 31 species reflects what the team managed to collect and analyze during a limited expedition window, at a limited number of sites. It does not tell us how many species live in that part of the Atlantic in total, nor how many are under threat. Estimating the real diversity and the state of those populations will require further expeditions, repeated sampling, and independent confirmation from other teams.

Why this discovery is part of a bigger picture

During the same expedition, the team also set a marine record with the first three-dimensional imaging of a living microbe’s cell structure at such depth. That technical step matters as much as the species catalogue itself, because it shows how deep-sea biology increasingly relies on tools that record organisms in their natural setting, without necessarily hauling them to the surface, where shifts in pressure and temperature can damage delicate tissue.

The find off Brazil is not an isolated one. Earlier in 2026, in the Pacific’s Clarion-Clipperton Zone, scientists described 24 new species of amphipods, small crustaceans that live on the seabed. Taken together, these results reveal unfamiliar branches of life and serve as a reminder that much of the deep ocean is still unexplored. Most researchers consider the number of formally described deep-sea species to be only a small fraction of what really exists.

For now, it remains an open question how these new species catalogues will shape the protection of deep waters, especially in zones where seabed mining is under discussion. In your view, how much should discoveries like this determine where, or whether, mining of the ocean floor should be allowed at all?