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Journal ArticleDOI

Production and accumulation of calcium carbonate in the ocean: Budget of a nonsteady state

01 Dec 1993-Global Biogeochemical Cycles (John Wiley & Sons, Ltd)-Vol. 7, Iss: 4, pp 927-957
TL;DR: In this article, it was shown that the oceans are not presently in a steady state, suggesting that outputs have been overestimated or inputs underestimated, that one or more other inputs have not been identified, and/or that one of the missing calcium sources might be groundwater, although its presentday input is probably much smaller than that of rivers.
Abstract: Present-day production of CaCO3 in tne world ocean is calculated to be about 5 billion tons (bt) per year, of which about 3 bt accumulate in sediments; the other 40% is dissolved. Nearly half of the carbonate sediment accumulates on reefs, banks, and tropical shelves, and consists largely of metastable aragonite and magnesian calcite. Deep-sea carbonates, predominantly calcitic coccoliths and planktonic foraminifera, have orders of magnitude lower productivity and accumulation rates than shallow-water carbonates, but they cover orders of magnitude larger basin area. Twice as much calcium is removed from the oceans by present-day carbonate accumulation as is estimated to be brought in by rivers and hydrothermal activity (1.6 bt), suggesting that outputs have been overestimated or inputs underestimated, that one or more other inputs have not been identified, and/or that the oceans are not presently in steady state. One “missing” calcium source might be groundwater, although its present-day input is probably much smaller than that of rivers. If, as seems likely, CaCO3 accumulation presently exceeds terrestial and hydrothermal input, this imbalance presumably is offset by decreased accumulation and increased input during lowered sea level: shallow-water accumulation decreases by an order of magnitude with a 100 m drop in sea level, while groundwater influx increases because of heightened piezometric head and the diagenesis of metastable aragonite and magnesian calcite from subaerially exposed shallow-water carbonates.
Citations
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Journal ArticleDOI
TL;DR: The potential for marine organisms to adapt to increasing CO2 and broader implications for ocean ecosystems are not well known; both are high priorities for future research as mentioned in this paper, and both are only imperfect analogs to current conditions.
Abstract: Rising atmospheric carbon dioxide (CO2), primarily from human fossil fuel combustion, reduces ocean pH and causes wholesale shifts in seawater carbonate chemistry. The process of ocean acidification is well documented in field data, and the rate will accelerate over this century unless future CO2 emissions are curbed dramatically. Acidification alters seawater chemical speciation and biogeochemical cycles of many elements and compounds. One well-known effect is the lowering of calcium carbonate saturation states, which impacts shell-forming marine organisms from plankton to benthic molluscs, echinoderms, and corals. Many calcifying species exhibit reduced calcification and growth rates in laboratory experiments under high-CO2 conditions. Ocean acidification also causes an increase in carbon fixation rates in some photosynthetic organisms (both calcifying and noncalcifying). The potential for marine organisms to adapt to increasing CO2 and broader implications for ocean ecosystems are not well known; both are high priorities for future research. Although ocean pH has varied in the geological past, paleo-events may be only imperfect analogs to current conditions.

2,995 citations

Journal ArticleDOI
16 Jul 2004-Science
TL;DR: The in situ CaCO3 dissolution rates for the global oceans from total alkalinity and chlorofluorocarbon data are estimated, and the future impacts of anthropogenic CO2 on Ca CO3 shell–forming species are discussed.
Abstract: Rising atmospheric carbon dioxide (CO 2 ) concentrations over the past two centuries have led to greater CO2 uptake by the oceans. This acidification process has changed the saturation state ofthe oceans with respect to calcium carbonate (CaCO3) particles. Here we estimate the in situ CaCO3 dissolution rates for the global oceans from total alkalinity and chlorofluorocarbon data, and we also discuss the future impacts of anthropogenic CO2 on CaCO3 shell– forming species. CaCO 3 dissolution rates, ranging from 0.003 to 1.2 micromoles per kilogram per year, are observed beginning near the aragonite saturation horizon. The total water column CaCO 3 dissolution rate for the global oceans is approximately 0.5 0.2 petagrams ofCaCO 3-C per year, which is approximately 45 to 65% ofthe export production ofCaCO 3 . Atmospheric CO 2 concentrations oscillated be

2,140 citations

Journal ArticleDOI
21 Sep 2000-Nature
TL;DR: It is suggested that the progressive increase in atmospheric CO2 concentrations may slow down the production of calcium carbonate in the surface ocean, as the process of calcification releases CO2 to the atmosphere.
Abstract: The formation of calcareous skeletons by marine planktonic organisms and their subsequent sinking to depth generates a continuous rain of calcium carbonate to the deep ocean and underlying sediments1 This is important in regulating marine carbon cycling and ocean–atmosphere CO2 exchange2 The present rise in atmospheric CO2 levels3 causes significant changes in surface ocean pH and carbonate chemistry4 Such changes have been shown to slow down calcification in corals and coralline macroalgae5,6, but the majority of marine calcification occurs in planktonic organisms Here we report reduced calcite production at increased CO2 concentrations in monospecific cultures of two dominant marine calcifying phytoplankton species, the coccolithophorids Emiliania huxleyi and Gephyrocapsa oceanica This was accompanied by an increased proportion of malformed coccoliths and incomplete coccospheres Diminished calcification led to a reduction in the ratio of calcite precipitation to organic matter production Similar results were obtained in incubations of natural plankton assemblages from the north Pacific ocean when exposed to experimentally elevated CO2 levels We suggest that the progressive increase in atmospheric CO2 concentrations may therefore slow down the production of calcium carbonate in the surface ocean As the process of calcification releases CO2 to the atmosphere, the response observed here could potentially act as a negative feedback on atmospheric CO2 levels

1,449 citations


Cites background from "Production and accumulation of calc..."

  • ...jpg" NDATA ITEM> ]> The formation of calcareous skeletons by marine planktonic organisms and their subsequent sinking to depth generates a continuous rain of calcium carbonate to the deep ocean and underlying sediment...

    [...]

Book Chapter
01 Jan 2001
TL;DR: Contributing Authors D.R.A. Archer, M.M.P. Keeling, D.D.F. Weirig, T. Whorf, A.C. Sitch, R.J. Rayner, S.Q. Tans, H. Yool.
Abstract: Contributing Authors D. Archer, M.R. Ashmore, O. Aumont, D. Baker, M. Battle, M. Bender, L.P. Bopp, P. Bousquet, K. Caldeira, P. Ciais, P.M. Cox, W. Cramer, F. Dentener, I.G. Enting, C.B. Field, P. Friedlingstein, E.A. Holland, R.A. Houghton, J.I. House, A. Ishida, A.K. Jain, I.A. Janssens, F. Joos, T. Kaminski, C.D. Keeling, R.F. Keeling, D.W. Kicklighter, K.E. Kohfeld, W. Knorr, R. Law, T. Lenton, K. Lindsay, E. Maier-Reimer, A.C. Manning, R.J. Matear, A.D. McGuire, J.M. Melillo, R. Meyer, M. Mund, J.C. Orr, S. Piper, K. Plattner, P.J. Rayner, S. Sitch, R. Slater, S. Taguchi, P.P. Tans, H.Q. Tian, M.F. Weirig, T. Whorf, A. Yool

1,275 citations


Cites background from "Production and accumulation of calc..."

  • ...Further, deep ocean concentrations of major nutrients and DIC are tightly correlated, with the existing ratios closely (but not exactly, see Section 3.2.3.3) matching the nutritional requirements of marine organisms (the “Redfield ratios”: Redfield et al., 1963)....

    [...]

  • ...Part of this is returned to DIC through autotrophic respiration, with the remainder being net primary production, estimated on the basis of global remote sensing data 197The Carbon Cycle and Atmospheric Carbon Dioxide Box 3.3: The varying CO2 uptake capacity of the ocean....

    [...]

  • ...These mechanisms, often referred to as the biological pump, maintain higher DIC concentrations at depth and cause atmospheric CO2 concentrations to be about 200 ppm lower than would be the case in the absence of such mechanisms (Sarmiento and Toggweiler, 1984; Maier-Reimer et al., 1996)....

    [...]

  • ...Export of CaCO3 to the deep ocean is a smaller flux than total export production (0.4 PgC/yr) but about half of this carbon is buried as CaCO3 in sediments; the other half is dissolved at depth, and joins the pool of DIC (Milliman, 1993)....

    [...]

  • ...Milliman (1993) estimated a global production of CaCO3 of 0.7 PgC/yr, with roughly equivalent amounts produced in shallow water and surface waters of the deep ocean....

    [...]

Journal ArticleDOI
TL;DR: In this paper, the primary production, respiration, calcification, carbon burial and exchange with adjacent systems, including the atmosphere, are reviewed for the major coastal ecosystems (estuaries, macrophyte communities, mangroves, coral reefs, and the remaining continental shelf).
Abstract: The coastal zone is where land, ocean, and atmosphere interact. It exhibits a wide diversity of geomorphological types and ecosystems, each one displaying great variability in terms of physical and biogeochemical forcings. Despite its relatively modest surface area, the coastal zone plays a considerable role in the biogeochemical cycles because it receives massive inputs of terrestrial organic matter and nutrients, is among the most geochemically and biologically active areas of the biosphere, and exchanges large amounts of matter and energy with the open ocean. Coastal ecosystems have therefore attracted much attention recently and are the focus of several current national and international research programs (e.g. LOICZ, ELOISE). The primary production, respiration, calcification, carbon burial and exchange with adjacent systems, including the atmosphere, are reviewed for the major coastal ecosystems (estuaries, macrophyte communities, mangroves, coral reefs, and the remaining continental shelf ). All ecosystems

974 citations

References
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Journal ArticleDOI
01 Dec 1989-Nature
TL;DR: In this paper, a global oxygen isotope record for ocean water has been calculated from the Barbados sea level curve, allowing separation of the ice volume component common to all isotope records measured in deep-sea cores.
Abstract: Coral reefs drilled offshore of Barbados provide the first continuous and detailed record of sea level change during the last deglaciation. The sea level was 121 ± 5 metres below present level during the last glacial maximum. The deglacial sea level rise was not monotonic; rather, it was marked by two intervals of rapid rise. Varying rates of melt-water discharge to the North Atlantic surface ocean dramatically affected North Atlantic deep-water production and oceanic oxygen isotope chemistry. A global oxygen isotope record for ocean water has been calculated from the Barbados sea level curve, allowing separation of the ice volume component common to all oxygen isotope records measured in deep-sea cores.

4,483 citations

Journal ArticleDOI
TL;DR: In this article, a computer model has been constructed that considers the effects on the CO/sub 2/ level of the atmosphere, and the Ca, Mg, and HCO/sub 3/ levels of the ocean, of the following processes: weathering on the continents of calcite, dolomite, and calcium-and-magnesium-containing silicates; biogenic precipitation and removal of CaCO 3/from the ocean; removal of Mg from the ocean via volcanic-seawater reaction; and the metamorphic-magmatic decarbon
Abstract: A computer model has been constructed that considers the effects on the CO/sub 2/ level of the atmosphere, and the Ca, Mg, and HCO/sub 3/ levels of the ocean, of the following processes: weathering on the continents of calcite, dolomite, and calcium-and-magnesium-containing silicates; biogenic precipitation and removal of CaCO/sub 3/ from the ocean; removal of Mg from the ocean via volcanic-seawater reaction; and the metamorphic-magmatic decarbonation of calcite and dolomite (and resulting CO/sub 2/ degassing) as a consequence of plate subduction. Assuming steady state, values for fluxes to and from the atmosphere and oceans are first derived for the modern ocean-atmosphere system. Then the consequences of perturbing steady state are examined by deriving rate expressions for all transfer reactions. These rate expressions are constructed so as to reflect changes over the past 100 my. Results indicate that the CO/sub 2/ content of the atmosphere is highly sensitive to changes in seafloor spreading rate and continental land area, and, to a much lesser extent, to changes in the relative masses of calcite and dolomite. Consideration of a number of alternative seafloor spreading rate formulations shows that in all cases a several-fold higher CO/sub 2/ level for the Cretaceous atmosphere (65-100 mymore » BP) is obtained via the model. Assuming that CO/sub 2/ level and surface air temperature are positively correlated via an atmospheric greenhouse model, they authors predict Cretaceous paleotemperatures which are in rough general agreement with independent published data. Consequently, their results point to plate tectonics, as it affects both metamorphic-magmatic decarbonation and changes in continental land area, as a major control of world climate.« less

2,003 citations

Journal ArticleDOI
01 Oct 1987-Nature
TL;DR: In this article, direct evidence of past atmospheric CO2 changes has been extended to the past 160,000 years from the Vostok ice core, showing an inherent phenomenon of change between glacial and interglacial periods.
Abstract: Direct evidence of past atmospheric CO2 changes has been extended to the past 160,000 years from the Vostok ice core. These changes are most notably an inherent phenomenon of change between glacial and interglacial periods. Besides this major 100,000-year cycle, the CO2 record seems to exhibit a cyclic change with a period of some 21,000 years.

1,473 citations

Journal ArticleDOI
23 Nov 1984-Science
TL;DR: Dense biological communities of large epifaunal taxa similar to those found along ridge crest vents at the East Pacific Rise were discovered in the abyssal Gulf of Mexico.
Abstract: Dense biological communities of large epifaunal taxa similar to those found along ridge crest vents at the East Pacific Rise were discovered in the abyssal Gulf of Mexico. These assemblages occur on a passive continental margin at the base of the Florida Escarpment, the interface between the relatively impermeable hemipelagic clays of the distal Mississippi Fan and the jointed Cretaceous limestone of the Florida Platform. The fauna apparently is nourished by sulfide rich hypersaline waters seeping out at near ambient temperatures onto the sea floor.

548 citations

Journal ArticleDOI
TL;DR: The biogeochemical properties of an extensive bloom (∼250,000 km2) of the coccolithophore, Emiliania huxleyi, in the north east Atlantic Ocean were investigated in June 1991.
Abstract: The biogeochemical properties of an extensive bloom (∼250,000 km2) of the coccolithophore, Emiliania huxleyi, in the north east Atlantic Ocean were investigated in June 1991. Satellite (NOAA-AVHRR) imagery showed that the bloom was centered initially at 60°–63°N by 13°–28°W and lasted approximately 3 weeks. Spatial variations in satellite-measured reflectance were well correlated with surface measurements of the beam attenuation coefficient, levels of particulate inorganic carbon, and coccolith density. Rates of both photosynthesis and calcification were typically relatively low within the coccolithophore-rich waters, suggesting the population was in a late stage of development at the time of the field observations. Levels of dimethyl sulphide (DMS) in surface waters were high compared to average ocean values, with the greatest concentrations in localized areas characterized by relatively high rates of photosynthesis, calcification, and grazing by microzooplankton. The estimated spatially averaged flux of DMS to the atmosphere was 1122 nmol m−2 h−1, somewhat greater than that determined for the same region in June-July 1987. Coccolith production (1 × 106 tonnes calcite-C) had a significant impact on the state of the CO2 system, causing relative increases of up to 50 μatm in surface pCO2 in association with alkalinity and water temperature changes. Gradients in pCO2 were as great as 100 μatm over horizontal distances of 20–40 km. The environmental implications of these findings are discussed in relation to the spatial and temporal distributions of E. huxleyi.

530 citations