High variability in organic carbon sources and microbial activities in the hadopelagic waters

Li, Xinxin1; Zhao, Xin1; Dang, Hongyue2; Zhang, Chuanlun1; Fernandez-Urruzola, Igor3; Liu, Zhiqiang1; Wenzhoefer, Frank4,5,6,7; Glud, Ronnie N.6,8

2023-06-01

10.1002/lno.12379

LIMNOLOGY AND OCEANOGRAPHY   影响因子和分区

0024-3590

1939-5590

Hadal sediments are recognized as organic carbon depocenters with intensified microbial activity compared to adjacent abyssal sites due to focusing of relatively labile organic materials. However, the sources and turnover of hadopelagic organic carbon and its linkages to microbial activities have not been studied. We present the first synergic research on particulate organic carbon, dark carbon fixation, and size-fractionated microbial community respiration proxy over the Atacama Trench. The results demonstrate that all parameters attenuate rapidly from surface to mesopelagic water (similar to 1000 m). Progressing deeper, values remain relatively stable throughout bathypelagic (similar to 4000 m) and abyssopelagic (similar to 6000 m) waters. However, in the hadopelagic zone (> 6000 m), highly variable values indicate dynamic organic carbon sources and microbial activities in the deepest trench. On average, 71% of the microbial community respiration proxy is attributable to particle-associated communities, indicating importance of particles for microbial metabolism. No apparent relationship was observed between the microbial community respiration proxy and microbial 16S rRNA gene abundance below the epipelagic depth, indicating variable supply and quality of organic carbon likely constrained heterotrophic activities rather than microbial abundances in the deep ocean. The depth-integrated dark carbon fixation (> 1000 m) accounts for 11.5% +/- 7.6% of the surface net primary production, of which 2.9% +/- 0.4% is from hadopelagic depth. Dark carbon fixation is thus an important in situ organic carbon source for hadal life. This study suggests that high variability in organic carbon sources and microbial activities in the hadopelagic trench cannot be simply extrapolated from findings in the shallower dark ocean (e.g., 1000-6000 m).

SCI

英语

第一 ; 通讯

National Science Foundation of China["42076029","42276045","41720104001","42076111","42141003","42188102","41861144018","DNRF145"] ; Danish National Research Foundation[669947] ; National Key Research and Development Program of China[11221079] ; null[41806085] ; null[2020YFA0608302]

Marine & Freshwater Biology ; Oceanography

Limnology ; Oceanography

WOS:001005099000001

WILEY

ENVIRONMENT/ECOLOGY

Web of Science

1.Southern Univ Sci & Technol, Dept Ocean Sci & Engn, Shenzhen, Peoples R China
2.Xiamen Univ, Coll Ocean & Earth Sci, State Key Lab Marine Environm Sci, Fujian Key Lab Marine Carbon Sequestrat, Xiamen, Peoples R China
3.Univ Concepcion, Millennium Inst Oceanog, Concepcion, Chile
4.Helmholtz Ctr Polar & Marine Res, Alfred Wegener Inst, HGF MPG Grp Deep Sea Ecol & Technol, Bremerhaven, Germany
5.Max Planck Inst Marine Microbiol, Bremen, Germany
6.Univ Southern Denmark, Dept Biol, Odense M, Denmark
7.Tokyo Univ Marine Sci & Technol, Tokyo, Japan
8.Univ Southern Denmark, Danish Inst Adv Study DIAS, Odense, Denmark

Li, Xinxin,Zhao, Xin,Dang, Hongyue,et al. High variability in organic carbon sources and microbial activities in the hadopelagic waters[J]. LIMNOLOGY AND OCEANOGRAPHY,2023.

Li, Xinxin.,Zhao, Xin.,Dang, Hongyue.,Zhang, Chuanlun.,Fernandez-Urruzola, Igor.,...&Glud, Ronnie N..(2023).High variability in organic carbon sources and microbial activities in the hadopelagic waters.LIMNOLOGY AND OCEANOGRAPHY.

Li, Xinxin,et al."High variability in organic carbon sources and microbial activities in the hadopelagic waters".LIMNOLOGY AND OCEANOGRAPHY (2023).