Hadal trenches are dynamic hotspots for early diagenesis in the deep sea

Hadal trenches, the deepest parts of the ocean, are considered depocenters for organic material. This study investigates sediment characteristics and in-situ benthic oxygen uptake in the Kermadec and Atacama trenches, which have contrasting surface primary productivity. Benthic oxygen consumption varied significantly between sites but was consistently higher in trenches than adjacent abyssal plains, reflecting surface production differences and local deposition dynamics. Respiratory activity correlated with organic carbon and phytodetrital material inventories. The findings suggest hadal trenches are dynamic hotspots for early diagenesis, more diverse and active than previously understood.

Ronnie N. Glud, Peter Berg, Bo Thamdrup, Morten Larsen, Heather A. Stewart, Alan J. Jamieson, Anni Glud, Kazumasa Oguri, Hamed Sanei, Ashley A. Rowden, Frank Wenzhöfer