Cragg, Barry A. et al. (2006): Bacterial populations in deepwater low-sedimentation-rate marine sediments and evidence for subsurface bacterial manganese reduction (ODP Site 1149, Izu-Bonin Trench)
Leg/Site/Hole:
Related Expeditions:
ODP 185
Identifier:
ID:
2006-060880
Type:
georefid
ID:
10.2973/odp.proc.sr.185.008.2003
Type:
doi
Creator:
Name:
Cragg, Barry A.
Affiliation:
University of Bristol, Department of Earth Sciences, Bristol, United Kingdom
Role:
author
Name:
Wellsbury, Peter
Affiliation:
Boston University, United States
Role:
author
Name:
Murray, Richard W.
Affiliation:
Ocean Drilling Program, United States
Role:
author
Name:
Parkes, R. John
Affiliation:
University of North Carolina, United States
Role:
author
Identification:
Title:
Bacterial populations in deepwater low-sedimentation-rate marine sediments and evidence for subsurface bacterial manganese reduction (ODP Site 1149, Izu-Bonin Trench)
Year:
2006
Source:
In: Ludden, John N. (editor), Plank, Terry (editor), Escutia, Carlota (editor), Abrams, Lewis J., Alt, Jeffrey C., Armstrong, Robin N., Barr, Samantha, Bartolini, Annachiara, Cairns, Graeme, Fisk, Martin R., Guerin, Gilles, Haveman, Shelley A., Hirono, Tetsuro, Honnorez, Jose, Kelley, Katherine A., Larson, Roger L., Lozar, Francesca M., Murray, Richard W., Pletsch, Thomas K., Pockalny, Robert A., Rouxel, Olivier, Schmidt, Angelika, Smith, David C., Spivack, Arthur J., Staudigel, Hubert, Steiner, Maureen B., Valentine, Robert B., Proceedings of the Ocean Drilling Program; scientific results, Izu-Mariana Margin; covering Leg 185 of the drilling vessel JOIDES Resolution; Hong Kong, People's Republic of China, to Yokohama, Japan; Sites 801 and 1149; 12 April-14 June 1999
Publisher:
Texas A&M University, Ocean Drilling Program, College Station, TX, United States
Volume:
185
Issue:
Pages:
Abstract:
Bacterial distributions were determined at Site 1149 in the Izu-Bonin Trench, which is a deepwater (5818 m) low-sedimentation-rate area. This was the first Ocean Drilling Program (ODP) leg where contamination checks were conducted for microbiology. These demonstrated that the inner portion of cores, where the microbiological samples were taken, were free from any potential sampling contamination. Bacterial populations were present in all samples (deepest at 171.2 meters below seafloor [mbsf]). The highest numbers were near the surface (1.4 mbsf; 7.2X10 (super 6) cells/cm (super 3) ), but these declined rapidly within the upper 10 mbsf. Below this, numbers decreased at a more gradual rate to 7.2X10 (super 5) cells/cm (super 3) at 172 mbsf, a 10-fold reduction. This two-stage bacterial depth distribution has been observed at several other ODP sites (e.g., Amazon Fan and Santa Barbara Basin). Bacterial depth distributions at this site were well below those predicted by the general equation for global deep-sediment bacteria and predominantly below the lower 95% prediction limits. These low bacterial populations were thought to reflect the low sedimentation rates and low input of bioavailable organic matter that is characteristic for deepwater sites. Consistent with this trend is that there was only limited removal of pore water sulfate and, thus, bacterial sulfate reduction. Most of this removal was in the top approximately 5 mbsf, coinciding with the highest bacterial populations, the presence of small amounts of methane, and an increase in pore water manganese and ammonia. In the deeper sediments, however, there was still indirect evidence of continuing low bacterial activity, with increases in pore water ammonia, soluble manganese, bioavailable acetate, and decreasing sulfate. Interestingly, manganese reduction, sulfate reduction, and a limited amount of methanogenesis seemed to be occurring simultaneously at depth in this low-organic matter site, and the coincident detection of bacterial populations provides further support for the universal presence of a deep biosphere in marine sediments.
Language:
English
Genre:
Serial
Rights:
URL:
Coverage: Geographic coordinates: North:31.2030 West:143.2100 East:
143.2100 South:31.2030
Keywords: Oceanography; General geochemistry; bacteria; biogenic processes; chemical reactions; deep-water environment; geochemistry; geomicrobiology; hydrochemistry; Izu-Bonin Arc; Leg 185; manganese; marine sediments; metals; North Pacific; Northwest Pacific; Ocean Drilling Program; ODP Site 1149; Pacific Ocean; pore water; reduction; sea water; sedimentation; sedimentation rates; sediments; West Pacific;
.