Benthic carbon mineralization in hadal trenches

Assessment by in situ O2 microprofile measurements

Frank Wenzhöfer, Kazumasa Oguri, Mathias Middelboe, Robert Turnewitsch, Takashi Toyofuku, Hiroshi Kitazato, Ronnie N. Glud

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Abstract

Hadal trenches are considered to act as depo-centers for organic material at the trench axis and host unique and elevated biomasses of living organisms as compared to adjacent abyssal plains. To explore the diagenetic activity in hadal trench environments we quantified in situ benthic O-2 consumption rates and sediment characteristics from the trench axis of two contrasting trench systems in the Pacific Ocean; the Izu-Bonin Trench underlying mesotrophic waters and the Tonga Trench underlying oligotrophic waters. In situ oxygen consumption at the Izu-Bonin Trench axis site (9200 m; 746 +/- 103 mu mol m(-2) d(-1); n=27) was 3-times higher than at the Tonga Trench axis site (10800 m; 225 +/- 50 pmol m(-2) d(-1); n=7) presumably reflecting the higher surface water productivity in the Northern Pacific. Comparing benthic O-2 consumption rates measured in the central hadal Tonga Trench to that of nearby (60 km distance) abyssal settings (6250 m; 92 +/- 44 mu mol m(-2) d(-1); n=16) revealed a 2.5 higher activity at the trench bottom. Onboard investigations on recovered sediment furthermore revealed that the prokaryotic abundance and concentrations of phytopigments followed this overall trend (i.e minimum values at the abyssal site followed by higher values from the Tonga and lzu-Bonin Trenches axis, respectively). Excess Pb-210 profiles suggested that mass-wasting events contributed to the deposition of material enhancing the concentration of organic matter in the central trench as compared to the abyssal settings. Our results complement recent findings from the Challenger deep in the Mariana Trench area, which also revealed elevated diagenetic activity in the central trench underpinning the importance of hadal ecosystems for the deep sea carbon cycling.
Original languageEnglish
JournalDeep-Sea Research. Part 1: Oceanographic Research Papers
Volume116
Pages (from-to)276-286
ISSN0967-0637
DOIs
Publication statusPublished - Oct 2016

Cite this

Wenzhöfer, Frank ; Oguri, Kazumasa ; Middelboe, Mathias ; Turnewitsch, Robert ; Toyofuku, Takashi ; Kitazato, Hiroshi ; Glud, Ronnie N. / Benthic carbon mineralization in hadal trenches : Assessment by in situ O2 microprofile measurements. In: Deep-Sea Research. Part 1: Oceanographic Research Papers. 2016 ; Vol. 116. pp. 276-286.
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abstract = "Hadal trenches are considered to act as depo-centers for organic material at the trench axis and host unique and elevated biomasses of living organisms as compared to adjacent abyssal plains. To explore the diagenetic activity in hadal trench environments we quantified in situ benthic O-2 consumption rates and sediment characteristics from the trench axis of two contrasting trench systems in the Pacific Ocean; the Izu-Bonin Trench underlying mesotrophic waters and the Tonga Trench underlying oligotrophic waters. In situ oxygen consumption at the Izu-Bonin Trench axis site (9200 m; 746 +/- 103 mu mol m(-2) d(-1); n=27) was 3-times higher than at the Tonga Trench axis site (10800 m; 225 +/- 50 pmol m(-2) d(-1); n=7) presumably reflecting the higher surface water productivity in the Northern Pacific. Comparing benthic O-2 consumption rates measured in the central hadal Tonga Trench to that of nearby (60 km distance) abyssal settings (6250 m; 92 +/- 44 mu mol m(-2) d(-1); n=16) revealed a 2.5 higher activity at the trench bottom. Onboard investigations on recovered sediment furthermore revealed that the prokaryotic abundance and concentrations of phytopigments followed this overall trend (i.e minimum values at the abyssal site followed by higher values from the Tonga and lzu-Bonin Trenches axis, respectively). Excess Pb-210 profiles suggested that mass-wasting events contributed to the deposition of material enhancing the concentration of organic matter in the central trench as compared to the abyssal settings. Our results complement recent findings from the Challenger deep in the Mariana Trench area, which also revealed elevated diagenetic activity in the central trench underpinning the importance of hadal ecosystems for the deep sea carbon cycling.",
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Benthic carbon mineralization in hadal trenches : Assessment by in situ O2 microprofile measurements. / Wenzhöfer, Frank; Oguri, Kazumasa; Middelboe, Mathias; Turnewitsch, Robert; Toyofuku, Takashi; Kitazato, Hiroshi; Glud, Ronnie N.

In: Deep-Sea Research. Part 1: Oceanographic Research Papers, Vol. 116, 10.2016, p. 276-286.

Research output: Contribution to journalJournal articleResearchpeer-review

TY - JOUR

T1 - Benthic carbon mineralization in hadal trenches

T2 - Assessment by in situ O2 microprofile measurements

AU - Wenzhöfer, Frank

AU - Oguri, Kazumasa

AU - Middelboe, Mathias

AU - Turnewitsch, Robert

AU - Toyofuku, Takashi

AU - Kitazato, Hiroshi

AU - Glud, Ronnie N.

PY - 2016/10

Y1 - 2016/10

N2 - Hadal trenches are considered to act as depo-centers for organic material at the trench axis and host unique and elevated biomasses of living organisms as compared to adjacent abyssal plains. To explore the diagenetic activity in hadal trench environments we quantified in situ benthic O-2 consumption rates and sediment characteristics from the trench axis of two contrasting trench systems in the Pacific Ocean; the Izu-Bonin Trench underlying mesotrophic waters and the Tonga Trench underlying oligotrophic waters. In situ oxygen consumption at the Izu-Bonin Trench axis site (9200 m; 746 +/- 103 mu mol m(-2) d(-1); n=27) was 3-times higher than at the Tonga Trench axis site (10800 m; 225 +/- 50 pmol m(-2) d(-1); n=7) presumably reflecting the higher surface water productivity in the Northern Pacific. Comparing benthic O-2 consumption rates measured in the central hadal Tonga Trench to that of nearby (60 km distance) abyssal settings (6250 m; 92 +/- 44 mu mol m(-2) d(-1); n=16) revealed a 2.5 higher activity at the trench bottom. Onboard investigations on recovered sediment furthermore revealed that the prokaryotic abundance and concentrations of phytopigments followed this overall trend (i.e minimum values at the abyssal site followed by higher values from the Tonga and lzu-Bonin Trenches axis, respectively). Excess Pb-210 profiles suggested that mass-wasting events contributed to the deposition of material enhancing the concentration of organic matter in the central trench as compared to the abyssal settings. Our results complement recent findings from the Challenger deep in the Mariana Trench area, which also revealed elevated diagenetic activity in the central trench underpinning the importance of hadal ecosystems for the deep sea carbon cycling.

AB - Hadal trenches are considered to act as depo-centers for organic material at the trench axis and host unique and elevated biomasses of living organisms as compared to adjacent abyssal plains. To explore the diagenetic activity in hadal trench environments we quantified in situ benthic O-2 consumption rates and sediment characteristics from the trench axis of two contrasting trench systems in the Pacific Ocean; the Izu-Bonin Trench underlying mesotrophic waters and the Tonga Trench underlying oligotrophic waters. In situ oxygen consumption at the Izu-Bonin Trench axis site (9200 m; 746 +/- 103 mu mol m(-2) d(-1); n=27) was 3-times higher than at the Tonga Trench axis site (10800 m; 225 +/- 50 pmol m(-2) d(-1); n=7) presumably reflecting the higher surface water productivity in the Northern Pacific. Comparing benthic O-2 consumption rates measured in the central hadal Tonga Trench to that of nearby (60 km distance) abyssal settings (6250 m; 92 +/- 44 mu mol m(-2) d(-1); n=16) revealed a 2.5 higher activity at the trench bottom. Onboard investigations on recovered sediment furthermore revealed that the prokaryotic abundance and concentrations of phytopigments followed this overall trend (i.e minimum values at the abyssal site followed by higher values from the Tonga and lzu-Bonin Trenches axis, respectively). Excess Pb-210 profiles suggested that mass-wasting events contributed to the deposition of material enhancing the concentration of organic matter in the central trench as compared to the abyssal settings. Our results complement recent findings from the Challenger deep in the Mariana Trench area, which also revealed elevated diagenetic activity in the central trench underpinning the importance of hadal ecosystems for the deep sea carbon cycling.

KW - benthic carbon mineralization

KW - hadal trenches

KW - deep sea

KW - in situ

KW - lander technology

KW - O-2 microprofiles

KW - O-2 uptake

KW - organic matter

KW - marine sediments

KW - pacific ocean

KW - hydrostatic pressure

KW - triple junction

KW - oki earthquake

KW - sagami bay

KW - oxygen

KW - japan

U2 - 10.1016/j.dsr.2016.08.013

DO - 10.1016/j.dsr.2016.08.013

M3 - Journal article

VL - 116

SP - 276

EP - 286

JO - Deep-Sea Research Part I: Oceanographic Research Papers

JF - Deep-Sea Research Part I: Oceanographic Research Papers

SN - 0967-0637

ER -