We argue that deep trenches, some of the most remote, extreme, and scantly explored habitats, are hotspots of deposition and mineralization of organic material.
Therefore, we aim to provide the first detailed, combined analysis of benthic diagenesis and microbial ecology and diversity of some of the deepest oceanic trenches.
Global carbon cycle
We want to investigate unexplored trenches and their specialized bacterial communities to understand how they function and what role they play in the global carbon cycle.
Equipment reaching the bottom of Kermadec Trench at 9,994 m. Credit: NIWA.
Comparing trenches from contrasting oceanic settings the project provides a novel general analysis of hadal biogeochemistry and the role of deep trenches in the oceans, as well as fundamental new insights to the composition and functioning of microbial communities at extreme pressure.
What are our hypotheses?
We hypothesize that:
- Hadal trenches represent sites of intensified deposition and mineralization of organic material and act as unexplored hot-spots for the deep ocean carbon and nitrogen cycle.
- Hadal conditions select for unique piezophilic (high pressure loving) and hyperpiezophilic microbial communities that remain almost completely unstudied with respect to both composition and function.
- Viruses play an important role for microbial mortality and biogeochemical cycling in these environments.
- Microbial diversity in hadal sediments is much greater than revealed by previous surveys and that unique hadal components of the communities can be identified.
A hadal rosette getting ready for the deep. Photo: Ashley Rowden.
Novel equipment and instruments
To overcome large sampling artifacts from decompression and heating during recovery, we will develop new autonomous instrumentation that can quantify process rates and can fix microbial communities directly at the seabed.
The investigations of how hydrostatic pressure affect microbial performance flexible pressure chambers will be developed and established at the university campus.