Publication Date:
2018-03-13
Description:
Hadal trenches have been proposed as depocenters of organic material and hotspots for organic matter mineralization. In this study, we for the first time quantified the total benthic O 2 uptake in hadal trenches using in-situ chamber incubations. Three trenches in the tropical Pacific were targeted and exhibited relatively high diagenetic activity given the great water depths, i.e., the Mariana Trench (2.0×10 2 μmol O 2 m -2 d -1 , 10,853 m), the Mussau Trench (2.7±0.1×10 2 μmol O 2 m -2 d -1 , 7,011 m), and the New Britain Trench (6.0±0.1×10 2 μmol O 2 m -2 d -1 , 8,225 m). Combined with the analyses of total organic carbon (TOC) and δ 13 C of TOC in the sediments and previously published in-situ O 2 microprofiles from hadal settings, we suggest that hadal benthic carbon mineralization partly is governed by the surface production but also is linked to the distance from land. Therefore, we highlight that terrestrial organic matter can be of importance in sustaining benthic communities in some hadal settings.
Print ISSN:
0094-8276
Electronic ISSN:
1944-8007
Topics:
Geosciences
,
Physics
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