Hadal topography incubates hidden microbial hotspots in the deepest ocean.

Hadal topography creates microbial hotspots in the Mariana Trench, with concave features hosting higher biomass and activity than convex areas, influencing global carbon cycling.

• Why it matters: Understanding how topographic features shape microbial ecosystems in the deepest ocean regions is crucial for predicting organic carbon flux and biogeochemical processes on a planetary scale.
• What they did: The study combined high-resolution topographic mapping with metagenomic, metaproteomic, and geochemical analyses across 6-11 km water depths in the Mariana Trench, revealing topography as a key factor.
• The result: Concave slope sites harbor dense microbial communities and hotspots that may facilitate genetic exchange and upward dispersal, significantly impacting organic carbon turnover and global ocean biogeochemistry.