Biogeosciences www.biogeosciences.net 1726-4170 1726-4189 7 2 2010 10.5194/bg-7-469-2010 http://www.biogeosciences.net/7/469/2010/ http://www.biogeosciences.net/7/469/2010/bg-7-469-2010.html http://www.biogeosciences.net/7/469/2010/bg-7-469-2010.pdf 469 480 2010-02-03 Benthic phosphorus and iron budgets for three NW African slope sediments: a balance approach K. Küster-Heins snoepje@uni-bremen.de G. J. de Lange M. Zabel Department of Geosciences, University of Bremen, Klagenfurter Strasse, 28359 Bremen, Germany Department of Earth Sciences – Geochemistry, Faculty of Geosciences, Utrecht University, 3508 TA Utrecht, The Netherlands Marum – Center for Marine Environmental Sciences, University of Bremen, Leobener Strasse, 28359 Bremen, Germany Despite intensive research on the different domains of the marine phosphorus (P) cycle during the last decades, frequently discussed open questions still exist especially on controlling factors for the benthic behaviour of P and its general distribution in sediment-pore water systems. Steady state or the internal balance of all relevant physical and (bio)geochemical processes are amongst the key issues. In this study we present and discuss an extended data set from surface sediments recovered from three locations on the NW African continental slope. Pore water data and results from sequential sediment extractions give clear evidence to the well-known close relationship between the benthic cycles of P and iron. Accordingly, most of the dissolved phosphate must have been released by microbially catalyzed reductive dissolution of iron (oxhydr)oxides. However, rates of release and association of P and iron, respectively, are not directly represented in profiles of element specific sediment compositions. Results from steady-state based transport-reaction modelling suggest that particle mixing due to active bioturbation, or rather a physical net downward transport of P associated to iron (oxyhydr)oxides, is an essential process for the balance of the inspected benthic cycles. This study emphasizes the importance of balancing analytical data for a comprehensive understanding of all processes involved in biogeochemical cycles. Alperin, M. J., Martens, C. S., Albert, D. B., Suayah, I. B., Benninger, L. K., Blair, N. E., and Jahnke, R. A.: Benthic fluxes and pore water concentration profiles of dissolved organic carbon in sediments from the North Carolina continental slope, Geochim. Cosmochim. Ac., 63, 427–448, 1999. Anderson, L. D., Delaney, M. L., and Faul, K. L.: Carbon to phosphorus ratios in sediments: Implications for nutrient cycling, Global Biogeochem. Cy., 15, 65–79, 2001. Anderson, L. G., Turner, D. R., Wedburg, M., and Dyrssen, D.: Determination of total alkalinity and total dissolved inorganic carbon, in: Methods of Seawater Analysis, 3 Edn., edited by: Grasshoff, K., Kremling, K., and Ehrhardt, M., Wiley-VCH, Weinheim, 127–148, 1999. Anschutz, P., Zhong, S., Sundby, B., Mucci, A., and Gobeil, C.: Burial efficiency of phosphorus and the geochemistry of iron in continental margin sediments, Limnol. Oceanogr., 43, 53–64, 1998. Barusseau, J. P., Giresse, P., Faure, H., Lezine, A. M., and Masse, J. P.: Marine sedimentary environments on some parts of the tropical and equatorial Atlantic margins of Africa during Late Quaternary, Cont. Shelf Res., 8, 1–21, 1988. Baturin, G. N.: Phosphorites on the sea floor. Origin, composition and distribution, Elsevier, Amsterdam, 343~pp., 1982. Borggard, O. K.: Effect of surface area and mineralogy of iron oxides on their surface charge and anion-adsorption properties, Clays Clay Min., 31, 230–232, 1983. Boudreau, B. P. and Jørgensen, B. B.: The benthic boundary layer: transport processes and biogeochemistry, Oxfort University Press, US, 404~pp., 2001. Burns, S. J.: Early diagenesis in Amazon Fan sediments, in: Proc. ODP Sci. Results, edited by: Flood, R. D., Piper, D. J. W., Klaus, A., and Peterson, L. C., College Station, Texas, 497–504, 1997. Crosby, S. A., Glasson, D. R., Cuttler, A. H., Butler, I., Turner, D. R., Whitfield, M., and Millward, G. E.: Surface areas and porosities of Fe(III)-Fe(II)-derived oxyhydroxides, Environ. Sci. Technol., 17, 709–713, 1983. De Lange, G. J., Cranston, R. E., Hydes, D. H., and Boust D.: Extraction of pore water from marine sediments: A review of possible artifacts with pertinent examples from the North Atlantic, Mar. Geol., 109, 53–76, 1992. De Lange, G. J.: Distribution of various extracted phosphorus compounds in the interbedded turbiditic/pelagic sediments of the Madeira Abyssal Plain, eastern North Atlantic, Mar. Geol., 109, 115–139, 1992. Dickens, G. R., Koelling, M., Smith, D. C., Schnieders, L., and Scientists: Rhizon Sampling of Pore Waters on Scientific Drilling Expeditions: An Example from the IODP Expedition 302, artic coring expedition (ACEX), Scientific Drilling, 4, 22–25, 2007. Fagel, N., Alleman, L. Y., Granina, L., Hatert, F., Thamo-Boszo, E., Cloots, R., and André, L.: Vivianite formation and distribution in Lake Baikal sediments, Global Planet. Change, 46, 315–336, 2005. Feely, R. A., Massoth, G. J., Baker, E. T., Cowen, J. P., Lamb, M. F., and Krogslund, K. A.: The effect of hydrothermal processes on midwater phosphorus distributions in the northeast Pacific, Earth Planet. Sci. Lett., 96, 305–318, 1990. Föllmi, K. B.: The phosphorus cycle, phosphogenesis and marine phosphate-rich deposits, Earth-Sci. Rev., 40, 55–124, 1996. Froelich, P. N., Klinkhammer, G. P., Bender, M. L., Luedtke, N. A., Heath, G. R., Cullen, D., Dauphin, P., Hammond, D., Hartman, B., and Maynard, V.: Early oxidation of organic matter in pelagic sediments of the eastern equatorial Atlantic: suboxic diagenesis, Geochim. Cosmochim. Ac., 43, 1075–1090, 1979. Froelich, P. N., Arthur, M. A., Burnett, W. C., Deakin, M., Hensley, V., Jahnke, R., Kaul, L., Kim, K.-H., Roe, K., Soutar, A., and Vathakanon, C.: Early diagenesis of organic matter in Peru continental margin sediments: Phosphorite precipitation, Mar. Geol., 80, 309–343, 1988. Hagen, E.: Mesoscale upwelling variations off the West African coast, in: Coastal and Estuarine Sciences, Coastal Upwelling, 1 Edn., edited by: Richards, F. A., AGU, Washington DC, 72–78, 1981. Hagen, E.: Northwest African upwelling scenario, Oceanol. Acta, 24, 113–128, 2000. Hall, P. O. J. and Aller, R. C.: Rapid, small-volume, flow injection analysis for $\delta $CO₂, and NH$_4^+$ in marine and freshwaters, Limnol. Oceanogr., 37, 1113–1119, 1992. Hammond, D. E., Giordani, P., Berelson, W. M., and Poletti, R.: Diagenesis of carbon and nutrients and benthic exchange in sediments of the Northern Adriatic Sea, Mar. Chem., 66, 53–97, 1999. Hansen, H. P. and Koroleff, F.: Determination of nutrients, in: Methods in Seawater Analysis, 3rd edition, edited by: Grasshoff, K., Ehrhardt, M., and Kremling, K., Wiley-VCH, Weinheim, 159–228, 1999. Hartmann, M. P., Müller, P. J., Suess, E., and Van der Weijden, C. H.: Chemistry of Late Quaternary sediments and their interstitial waters from the NW African continental margin, \textitMeteor Forschungsergebnisse Ser. C, Hamburg, 24, 1–67, 1976. Helmke, P., Romero, O., and Fischer, G.: Northwest African upwelling and its effect on offshore organic carbon export to the deep sea, Global Biogeochem. Cy., 19, 1–15, doi:10.1029/2004GB002265, 2005. Hensen, C., Landenberger, H., Zabel, M., Gundersen, J. K., Glud, R. N., and Schulz, H. D.: Simulation of early diagenetic processes in continental slope sediments off southwest Africa: the computer model CoTAM tested, Mar. Geol., 144, 191–210, 1997. Hensen, C., Landenberger, H., Zabel, M., and Schulz, H. D.: Quantification of diffusive benthic fluxes of nitrate, phosphate and silicate in the South Atlantic Ocean, Global Biogeochem. Cy., 12, 277–300, 1998. Ingall, E. D. and Van Cappellen, P.: Relation between sedimentation rate and burial of organic phosphorus and organic carbon in marine sediments, Geochim. Cosmochim. Ac., 54, 373–386, 1990. Ingall, E. D. and Jahnke, R.: Evidence for enhanced phosphorus regeneration from marine sediments overlain by oxygen depleted waters, Geochim. Cosmochim. Ac., 58, 2571–2575, 1994. Inthorn, M., Wagner, T., Scheeder, G., and Zabel, M.: Lateral transport controls distribution, quality, and burial of organic matter along continental slopes in high-productivity areas, Geology, 34, 205–208, 2006. Jahnke, R. A., Emerson, S. R., Cochran, J. K., and Hirschberg, D. J.: Fine scale distributions of porosity and particle excess $^210$Pb, organic carbon and CaCO₃ in surface sediments of the deep equatorial Pacific, Earth Planet. Sci. Lett., 77, 59–69, 1986. Jahnke, R. A., Emerson, S. R., Reimers, C. E., Schuffert, J., Ruttenberg, K. C., and Archer, D.: Benthic recycling of biogenic debris in eastern equatorial Atlantic Ocean, Geochim. Cosmochim. Ac., 53, 2947–2960, 1989. Jensen, H. S., Mortensen, P. B., Andersen, F. O., Rasmussen, E., and Jensen, A.: Phosphorus cycling in a coastal marine sediment, Aarhus Bay, Denmark, Limnol. Oceanogr., 40, 908–917, 1995. Kim, D., Schuffert, J. D., and Kastner, M.: Francolite authigenesis in california continental slope sediments and its implications for the marine P cycle, Geochim. Cosmochim. Acta, 63, 3477-3485, 1999. Koroleff, F. and Kremling, K.: Determination of trace elements - Analysis by spectrophotometry, in: Methods of Seawater Analysis, 3 Edn., edited by: Grasshoff, K., Kremling, K., and Ehrhardt, M., Wiley-VCH, Weinheim, 340–344, 1999. Krom, M. D. and Berner, R. A.: Adsorption of phosphate in anoxic marine sediments, Limnol. Oceanogr., 25, 797–806, 1980. Krom, M. D. and Berner, R. A.: The diagenesis of phosphorus in a nearshore sediment, Geochim. Cosmochim. Ac., 45, 207–216, 1981. Latimer, J. C., Filippelli, G. M., Hendy, I., and Newkirk, D. R.: Opal-associated particulate phosphorus: Implications for the marine P cycle, Geochim. Cosmochim. Ac., 70, 3843–3854, 2006. Lerman, A.: Geochemical Processes: Water and sediment environments, Wiley-VCH, New York, 481~pp., 1979. Li, Y.-H. and Gregory, S.: Diffusion of ions in sea water and in deep-sea sediments, Geochim. Cosmochim. Ac., 38, 703-714, 1974. Lijklema, L.: Interaction of orthophosphate with iron(III) and aluminum hydroxides, Environ. Sci. Technol., 14, 537–541, 1980. Lutze, G. F. and Coulbourn, W. T.: Recent benthic foraminifera from the continental margin of northwest Africa: Community structure and distribution, Mar. Micropaleontol., 8, 361–401, 1984. März, C., Hoffmann, J., Bleil, U., De Lange, G. J., and Kasten, S.: Diagenetic changes of magnetic and geochemical signals by anaerobic methan oxidation in sediments of the Zambesi deep-sea fan (SW Indian Ocean), Mar. Geol., 255, 118–130, 2008. McMaster, R. L. and Lachance, T. P.: Northwestern African continental shelf sediments, Mar. Geol., 7, 57–67, 1969. Mittelstaedt, E.: The upwelling area off Northwest Africa - A description of phenomena related to coastal upwelling, Prog. Oceanogr., 12, 307–331, 1983. Mollenhauer, G., Inthorn, M., Vogt, T., Zabel, M., Sinninghe Damste, J. S., and Eglinton, T. I.: Aging of marine organic matter during cross-shelf lateral transport in the Benguela upwelling system revealed by compound-specific radiocarbon dating, Geochem. Geophys. Geosyst., 8, Q09004, doi:09010.01029/02007GC001603, 2007. Mulitza, S., and cruise participants: Report and preliminary results of Meteor cruise M65/1, Dakar – Dakar, 11.06.–1.07.2005, Berichte FB Geowissenschaften der Universität Bremen, Bremen, 252, 149~pp., 2006. Mulitza, S., Prange, M., Stuut, J.-B., Zabel, M., Dobeneck, T. v., Intambi, C., Nizou, J., and Schulz, M.: Sahel megadroughts triggered by glacial slowdowns of Atlantic meridional overturning, Paleoceanogr., 23, doi:10.1029/2008PA001637, 2008. Nadeau, M. J., Schleicher, M., Grootes, P. M., Erlenkeuser, H., Gottdang, A., Mous, D. J. W., Sarnthein, J. M., and Willkomm, H.: The Leibniz-Labor AMS facility at the Christian-Albrechts University, Kiel, Germany, Nucl. Instrum. Methods Phys. Res. Sec. B, 123, 22–30, 1997. Poulton, S. W. and Canfield, D. E.: Co-diagenesis of iron and phosphorus in hydrothermal sediments from the southern East Pacific Rise: Implications for the evaluation of paleoseawater phosphate concentrations, Geochim. Cosmochim. Ac., 70, 5883–5898, 2006. Redfield, A. C., Ketchum, B. H., and Richards, F. A.: The influence of organisms in the composition of sea-water, in: The composition of seawater. Comparative and descriptive oceanography, 1st edition, edited by: Hill, M. N., Interscience, New York, 26–77, 1963. Ruttenberg, K. C.: Development of a sequential extraction method for different forms of phosphorus in marine sediments, Limnol. Oceanogr., 37, 1460–1482, 1992. Sarnthein, M., Winn, K., Jung, S. J. A., Duplessy, J.-C., Labeyrie, L., Erlenkeuser, H., and Ganssen, G. M.: Changes in east Atlantic deepwater circulation over the last 30,000 years: Eight time slice reconstructions, Paleoceanography, 9(2), 209–267, 1994. Sarnthein, M.: Sedimentology on sediment core GIK 13239-1, http://doi.pangaea.de/ 10.1594/PANGAEA.134606, 2004. Schenau, S. J. and De Lange, G. J.: A novel chemical method to quantify fish debris in marine sediments, Limnol. Oceanogr., 45, 963–971, 2000. Schenau, S. J., Slomp, C. P., and De Lange, G. J.: Phosphogenesis and active phosphorite formation in sediments from the Arabian Sea oxygen minimum zone, Mar. Geol., 169, 1–20, 2000. Schenau, S. J. and De Lange, G. J.: Phosphorus regeneration vs. burial in sediments of the Arabian Sea, Mar. Chem., 75, 201–217, 2001. Schlichting, A. and Leinweber, P.: Effects of pretreatment on sequentially-extracted phosphorus fractions from peat soils, Commun. Soil Sci. Plant Anal., 33, 1617–1627, 2002. Schulz, H. D. and Schulz, H. N.: Large Sulfur Bacteria and the Formation of Phosphorite, Science, 307, 416–418, 2005. Schulz, H. D.: Quantification of Early Diagenesis: Dissolved Constituents in Pore Water and Signals in the Solid phase, in: Marine Geochemistry, 2 Edn., edited by: Schulz, H. D. and Zabel, M., Springer-Verlag, Berlin, Heidelberg, New York, 75–124, 2006a. Schulz, H. D.: Conceptual Models and Computer Models, in: Marine Geochemistry, 2 Edn., edited by: Schulz, H. D. and Zabel, M., Springer-Verlag, Berlin, Heidelberg, New York, 513–547, 2006b. Seeberg-Elverfeldt, J., Schlüter, M., Feseker, T., and Kölling, M.: Rhizon sampling of porewaters near the sediment-water interface in aquatic systems, Limn. Oceanogr. Methods, 3, 361–371, 2005. Slomp, C. P., Epping, E. H. G., Helder, W., and Van Raaphorst, W.: A key role for iron-bound phosphorus in authigenc apatite formation in North Atlantic continental platform sediments, J. Mar. Res., 54, 1179–1205, 1996. Slomp, C. P., Malschaert, J. F. P., and Van Raaphorst, W.: The role of adsorption in sediment-water exchange of phosphate in North Sea continental margin sediments, Limnol. Oceanogr., 43, 832–846, 1998. Strickland, J. D. H. and Parsons, T. R.: A practical handbook of seawater analysis, Fisheries Research Board of Cananda, Ottawa, 293~pp., 1968. Summerhayes, C. P.: Sedimentation of organic matter in upwelling regimes, in: Coastal upwelling – Its Sediments Record Part B: Sedimentary records of ancient coastal upwelling, 1 Edn., edited by: Suess, E., and Thiede, J., Plenum Press, New York, 29–72, 1983. Sundby, B., Gobeil, C., Silverberg, N., and Mucci, A.: The phosphorus cycle in coastal marine sediments, Limnol. Oceanogr., 37, 1129–1145, 1992. Takahashi, T., Broecker, W. S., and Langer, S.: Redfield Ratio based on chemical data from isopycnal surfaces, J. Geophys. Res., 90, 6907–6924, 1985. Van Cappellen, P. and Ingall, E. D.: Benthic phophorus regeneration, net primary production, and ocean anoxia: A model of the coupled marine biogeochemical cycles of carbon and phosphorus, Paleoceanography, 9, 677–692, 1994. Van der Zee, C., Slomp, C. P., Rancourt, D. G., De Lange, G. J., and Van Raaphorst, W.: A Mössbauer spectroscopic study of the iron redox transition in eastern Mediterranean sediments, Geochim. Cosmochim. Ac., 69, 441–453, 2005. Wenzhöfer, F. and Glud, R. N.: Benthic carbon mineralization in the Atlantic: a synthesis based on in situ data from the last decades, Deep-Sea Res. Pt I, 49, 1255–1279, 2002. Zabel, M., Dahmke, A., and Schulz, H. D.: Regional distribution of diffusive phosphate and silicate fluxes through the sediment-water interface: the eastern South Atlantic, Deep-Sea Res. Pt I, 45, 277–300, 1998. Zabel, M., Bickert, T., Dittert, L., and Haese, R. R.: The significance of the sedimentary Al/Ti ratio as indicator for reconstructions of terrestrial input to the equatorial Atlantic, Paleoceanography, 14, 789–799, 1999. Zabel, M. and Schulz, H. D.: Importance of submarine landslides for non-steady state conditions in pore water systems – lower Zaire (Congo) deep-sea fan, Mar. Geol., 176, 87–99, 2001.