What the NUS–OceanX expedition found at Monsoon Rise

The Monsoon Rise expedition gave researchers a first detailed look at biodiversity around a little-studied seamount complex in the eastern Indian Ocean. Its findings combine a new seabed map with direct observations, physical specimens and environmental DNA—but the most striking species identifications remain preliminary. 211

What did the expedition find?

The team mapped 6,050 sq km of seabed and brought back more than 2,000 specimens. Early assessments suggest that at least 20 species could be new to science. That is a count of possible new species, not a declaration that 20 have been formally identified and described. 2

Researchers observed corals and other cnidarians on seamount slopes and crustaceans on the seabed. Sea cucumbers illustrate why the identification work matters: of 20 collected specimens discussed in reporting on the expedition, four could be confidently identified to species, 10 may belong to previously encountered but unresolved species, and six may represent organisms not previously observed by researchers. Those six are intriguing candidates, not six confirmed new species. 4

How did the team explore Monsoon Rise?

The research vessel OceanXplorer served as a base for seabed mapping and onboard research, with sonar systems and laboratories alongside its underwater vehicles. Sonar supplied the broad view needed to map the seafloor; crewed submersibles let researchers inspect habitats directly. The remotely operated vehicle Chimera, equipped with cameras, sensors and sampling gear, could investigate and collect material at depths beyond 6,000 metres. 1413

Physical collection was only part of the survey. Researchers are also analysing environmental DNA from water and sediment samples—genetic traces that can indicate organisms absent from the specimens brought aboard. Preliminary analysis has pointed to organisms not represented in the physical collection, expanding the picture beyond what cameras and sampling alone captured. 34

Why does the baseline matter?

Together, the maps, observations, specimens and DNA records establish an initial account of habitats and organisms at Monsoon Rise. Future surveys could compare their findings with this baseline to look for ecosystem change. The evidence could also inform decisions about fishing and other uses of the area, although it does not show that any particular management measure has been adopted. Confirming the candidate species will require further examination and comparison. 2413