The accumulation and cycling of biogenic silica in the Southern Ocean: revisiting the marine silica budget

DeMaster, David J.

doi:10.1016/s0967-0645(02)00076-0

Cited by 209 publications

(205 citation statements)

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“…1) to the localization of opal burial mostly in the equatorial Pacific, in the eastern boundary current upwelling systems, and in the Southern Ocean. The latter accounts for 17 -37% of the global opal burial [3], a somewhat conservative estimate compared to previous studies, which attributed up to two-thirds of the opal burial to the Southern Ocean [4]. This observa-tion places a particular stress on the importance of opal deposition on continental margins, which might account for the difference [5].…”

Section: Introductionmentioning

confidence: 87%

“…In our opinion, the amount of weathering from the continents sets the primary control on the availability of DSi to the ocean, as river runoff represents the main source of DSi to the present-day ocean [4]. The first nutrient screening occurs at continental margins, which are today considered as the site of the missing BSi sink, as the importance of the Southern Ocean opal accumulation has been revised downward [3]. Since the Middle Miocene, the extent of continental margins has not drastically varied, as the breakup of Pangaea, which probably increased the importance of margins in the overall BSi accumulation, was basically completed by then (see also Section 4.4).…”

Section: The Conveyor Belt and Silica: Todaymentioning

confidence: 99%

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Opal sedimentation shifts in the World Ocean over the last 15 Myr

Cortese

Gersonde

Hillenbrand

et al. 2004

Earth and Planetary Science Letters

149

130

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Biogenic silica (opal) accumulation records were used to trace mechanisms, consequence, and geographic pattern of shifts in the main locus of opal deposition of the World Ocean over the last 15 Myr. Over this time interval, the main opal ''sink'' seems to have moved from the North Atlantic, to the Pacific, equatorial Pacific, eastern equatorial Pacific, eastern boundary current upwelling systems (California, Namibia, Peru), and finally to the Southern Ocean. The interplay between opal deposition and a series of climatic, tectonic, oceanographic, and biologic events has been analyzed and discussed. These events include the Cenozoic global cooling trend, intensified glaciation in Antarctica, Late Miocene -Early Pliocene biogenic bloom, development of Northern Hemisphere Glaciation (NHG), closing of the Panama Seaway, transition of the climate system from a monopolarto a bipolar-glaciated world, Mid-Pleistocene Revolution (MPR), nutrient availability, evolution of diatoms and C4 plants, and changes in continental weathering rates. While the observed shifts are mostly traceable to oceanic reorganizations and global climatic evolution, conditions favorable to opal deposition involve the above-mentioned complex mix of processes. For this reason, the interpretation of opal deposition records might not always be straightforward. We, however, believe that it can still provide clear indications of large-scale oceanographic reorganizations in the geological past. D

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Section: Introductionmentioning

confidence: 87%

Section: The Conveyor Belt and Silica: Todaymentioning

confidence: 99%

Opal sedimentation shifts in the World Ocean over the last 15 Myr

Cortese

Gersonde

Hillenbrand

et al. 2004

Earth and Planetary Science Letters

149

130

View full text Add to dashboard Cite

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“…Therefore, the remineralisation and dissolution of particles in the water column during the transfer to the seafloor should be rather low, when compared with continental margins or the open ocean (e.g. DeMaster, 2002;Tréguer and De La Rocha, 2013). Assuming sedimentation rates of 0.0026 m yr À 1 (Hebbeln et al, 2003) we calculated the mass accumulation of biogenic silica (Eq.…”

Section: Recycling Efficiency Of Silicic Acid Into the Bottom Watermentioning

confidence: 99%

“…For example, biogenic silica contents of more than 70%, silicic acid fluxes of 0.095-0.767 mol m À 2 yr À 1 (Deep Sea) and burial rates of 40.84n10 12 mol yr À 1 were reported for the Southern Ocean (Schlüter et al, 1998;DeMaster, 2002;Geibert et al, 2005). Although for coastal regions like the Amazon Shelf or Monterey Bay high fluxes of 0.46 mol m À 2 yr À 1 or 2.28 mol m À 2 yr À 1 were observed (Tréguer and De La Rocha, 2013), still little is known about the benthic silica cycle in temperate coastal, shallow water environments.…”

Section: Introductionmentioning

confidence: 99%

Seasonal dynamics of the biogenic silica cycle in surface sediments of the Helgoland Mud Area (southern North Sea)

Oehler

Schlüter

Schückel

2015

Continental Shelf Research

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a b s t r a c tIn coastal waters and the ocean silicic acid (Si(OH) 4 ) is a key nutrient for primary producers (e.g. diatoms) and other siliceous organisms, because it is required for the formation of frustules and other hard parts made of biogenic silica (bSi). Especially in shallow waters like the southern North Sea, dissolution of bSi in surface sediments and the reflux of silicic acid from sediments into the water column is an important feedback mechanism for sustaining primary production. We investigated the temporal variability of benthic silicic acid fluxes and the recycling efficiency of bSi in surface sediments of the Helgoland Mud Area (southern North Sea). For this purpose we used different methods including a benthic chamber lander system for in situ flux studies of Si(OH) 4 , ex situ sediment incubations, pore water studies and sediment analysis. . The relevance of biological mediated transport for the recycling of Si(OH) 4 was underlined by comparing in situ and ex situ sediment incubations, pore water studies, as well as depth profiles of benthic macrofauna. Mass budget calculations indicate that about 1.7-2.2 mol bSi m À 2 settle annually at the seafloor, off which about 60-81% are recycled within surface sediments and transported back into the water column.

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“…The dissolution of biogenic silica (BSi) starts immediately after the death of the organisms. Regionally very different, about 10 to 100% is immediately recycled within the euphotic zone, whereas the remnant is transferred to greater depths and to the seafloor (DeMaster, 1981(DeMaster, , 2002Nelson et al, 1995;Tréguer et al, 1995). Within the sediment, pore water profiles usually develop asymptotic (or quasi-asymptotic) Si concentrations within the upper 5 to 20 cm of sediment (e.g., Berelson et al, 1987;Van Cappellen and Qiu, 1997a;Rabouille et al, 1997;Zabel et al, 1998;Dixit and Van Cappellen, 2003).…”

Section: Introductionmentioning

confidence: 99%

Microbial mediation of benthic biogenic silica dissolution

Holstein

Hensen

2009

Geo-Mar Lett

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Pore water profiles from 24 stations in the South Atlantic (located in the Guinea, Angola, Cape, Guyana, and Argentine basins) show good correlations of oxygen and silicon, suggesting microbially mediated dissolution of biogenic silica. We used simple analytical transport and reaction models to show the tight coupling of the reconstructed process kinetics of aerobic respiration and silicon regeneration. A generic transport and reaction model successfully reproduced the majority of Si pore water profiles from aerobic respiration rates, confirming that the dissolution of biogenic silica (BSi) occurs proportionally to O 2 consumption. Possibly limited to well-oxygenated sediments poor in BSi, benthic Si fluxes can be inferred from O 2 uptake with satisfactory accuracy. Compared to aerobic respiration kinetics, the solubility of BSi emerged as a less influential parameter for silicon regeneration. Understanding the role of bacteria for silicon regeneration requires further investigations, some of which are outlined. The proposed aerobic respiration control of benthic silicon cycling is suitable for benthic-pelagic models. The empirical relation of BSi dissolution to aerobic respiration can be used for regionalization assessments and estimates of the silicon budget to increase the understanding of global primary and export production patterns.

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The accumulation and cycling of biogenic silica in the Southern Ocean: revisiting the marine silica budget

Cited by 209 publications

References 46 publications

Opal sedimentation shifts in the World Ocean over the last 15 Myr

Opal sedimentation shifts in the World Ocean over the last 15 Myr

Seasonal dynamics of the biogenic silica cycle in surface sediments of the Helgoland Mud Area (southern North Sea)

Microbial mediation of benthic biogenic silica dissolution

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