Presence of oxygen and aerobic communities from sea floor to basement in deep-sea sediments

The depth of oxygen penetration into marine sediments differs considerably from one region to another. In areas with high rates of microbial respiration, O2 penetrates only millimetres to centimetres into the sediments, but active anaerobic microbial communities are present in sediments hundreds of metres or more below the sea floor. In areas with low sedimentary respiration, O2 penetrates much deeper but the depth to which microbial communities persist was previously unknown. The sediments underlying the South Pacific Gyre exhibit extremely low areal rates of respiration. Here we show that, in this region, microbial cells and aerobic respiration persist through the entire sediment sequence to depths of at least 75 metres below sea floor. Based on the Redfield stoichiometry of dissolved O2 and nitrate, we suggest that net aerobic respiration in these sediments is coupled to oxidation of marine organic matter. We identify a relationship of O2 penetration depth to sedimentation rate and sediment thickness. Extrapolating this relationship, we suggest that oxygen and aerobic communities may occur throughout the entire sediment sequence in 15–44% of the Pacific and 9–37% of the global sea floor. Subduction of the sediment and basalt from these regions is a source of oxidized material to the mantle.

Full Text

FilePagesSizeAccess
Author's final draft
211 Mo
Publisher's official version
61 Mo
Supplementary information
262 Mo
How to cite
D'Hondt Steven, Inagaki Fumio, Zarikian Carlos Alvarez, Abrams Lewis J., Dubois Nathalie, Engelhardt Tim, Evans Helen, Ferdelman Timothy, Gribsholt Britta, Harris Robert N., Hoppie Bryce W., Hyun Jung-Ho, Kallmeyer Jens, Kim Jinwook, Lynch Jill E., McKinley Claire C., Mitsunobu Satoshi, Morono Yuki, Murray Richard W., Pockalny Robert, Sauvage Justine, Shimono Takaya, Shiraishi Fumito, Smith David C., Smith-Duque Christopher E., Spivack Arthur J., Steinsbu Bjorn Olav, Suzuki Yohey, Szpak Michal, Toffin Laurent, Uramoto Goichiro, Yamaguchi Yasuhiko T., Zhang Guo-liang, Zhang Xiao-Hua, Ziebis Wiebke (2015). Presence of oxygen and aerobic communities from sea floor to basement in deep-sea sediments. Nature Geoscience. 8 (4). 299-304. https://doi.org/10.1038/NGEO2387, https://archimer.ifremer.fr/doc/00255/36658/

Copy this text