Abstract
Purpose
Diagenetic modelling, the mathematical simulation of the breakdown of sedimentary organic matter and subsequent fate of associated nutrients, has progressed to a point where complex, non-steady state environments can be accurately modelled. A genetic algorithm has never been used in conjunction with an early diagenetic model, and so we aim to discover whether this method is viable to determining a set of realistic model parameters, which itself is often a difficult task.
Materials and methods
A range of sensitivity analyses were conducted to establish the parameters for which the model was most sensitive before a micro-genetic algorithm (μGA) was used to fit an output from a previously published diagenetic model (OMEXDIA) to observational data, taken at the North Dogger site from a series of cruises in the North Sea. Profiles of carbon, oxygen, nitrate and ammonia were considered. The method allows a set of parameters to be determined in a manner analogous to natural selection. Each iteration of the genetic algorithm within each experiment decreases the variance between the observed profiles and those calculated by OMEXDIA.
Results and discussion
Despite some of the observed profiles, particularly for carbon, showing unusual patterns, the genetic algorithm was able to generate a set of parameters which was able to fit the observations. The genetic algorithm can therefore help to determine the values of other parameters used in the model, for which observational values are difficult to measure (e.g. the flux of organic matter to the sediment from the overlying water column and the rates of degradation of organic matter). We also show that the values of the parameters determined by the μGA technique are able to be used in a potentially temporally predictive manner.
Conclusions
The μGA used is a viable method to fit carbon and nutrient sedimentary profiles observed in complex, dynamic shelf sea systems, despite OMEXDIA originally being designed for a different sedimentary environment. The results therefore show that this novel use of a genetic algorithm is a suitable method for both model calibration and validation and that the technique may help in explaining processes which are poorly understood.
Similar content being viewed by others
References
Aller RC (1980) Quantifying solute distributions in the bioturbated zone of marine sediments by defining an average microenvironment. Geochim Cosmochim Acta 44:1955–1965
Andersen FØ (1996) Fate of organic carbon added as diatom cells to oxic and anoxic marine sediment microcosms. Mar Ecol Prog Ser 134:225–233
Anton KK, Liebezeit G, Rudolph C, Wirth H (1993) Origin, distribution and accumulation of organic carbon in the Skagerrak. Mar Geol 111:287–297
Arndt S, Regnier P (2007) A model for the benthic–pelagic coupling of silica in estuarine ecosystems: sensitivity analysis and system scale simulation. Biogeosciences 4:331–352
Baptist MJ, van Dalfsen J, Weber A, Passchier S, van Heteren S (2006) The distribution of macrozoobenthos in the southern North Sea in relation to meso-scale bedforms. Estuar Coast Shelf Sci 68:538–546
Beck M, Köster J, Engelen B, Holstein J, Gittel A, Könneke M, Riedel T, Wirtz K, Cypionka H, Rullkötter J, Brumsack H-J (2009) Deep pore water profiles reflect enhanced microbial activity towards tidal flat margins. Ocean Dynam 59:371–383
Berg P, Rysgaard S, Thamdrup B (2003) Dynamic modeling of early diagenesis and nutrient cycling. A case study in an Arctic marine sediment. Am J Sci 303:905–955
Boon AR, Duineveld GCA (1998) Chlorophyll a as a marker for bioturbation and carbon flux in southern and central North Sea sediments. Mar Ecol Prog Ser 162:33–43
Bottrell SH, Mortimer RJG, Davies IM, Harvey SM, Krom MD (2009) Sulphur cycling in organic-rich marine sediments from a Scottish fjord. Sedimentology 56:1159–1173
Boudreau BP (1996) A method-of-lines code for carbon and nutrient diagenesis in aquatic sediments. Comput Geosci 22:479–496
Boudreau BP (1997) Diagenetic models and their implementation: modelling transport and reactions in aquatic sediments. Springer, New York
Burdige DJ (2006) Geochemistry of marine sediments. Princeton University Press, Princeton
Canfield DE, Lyons TW, Raiswell R (1996) A model for iron deposition to euxinic Black Sea sediments. Am J Sci 296:818–834
Cefas (2011) Cefas: marine ecosystem connections. http://cefas.defra.gov.uk/our-science/ecosystems-and-biodiversity/marine-ecosystem-connections.aspx. Accessed 8 Apr 2011
de Haas H, Boer W, van Weering TCE (1997) Recent sedimentation and organic carbon burial in a shelf sea: the North Sea. Mar Geol 144:131–146
de Haas H, van Weering TCE (1997) Recent sediment accumulation, organic carbon burial and transport in the northeastern North Sea. Mar Geol 136:173–187
Dhakar SP, Burdige DJ (1996) A coupled, non-linear, steady-state model for early diagenetic processes in pelagic sediments. Am J Sci 296:296–330
Emerson S, Jahnke R, Heggie D (1984) Sediment-water exchange in shallow water estuarine sediments. J Mar Res 42:709–730
Epping E, van der Zee C, Soetaert K, Helder W (2002) On the oxidation and burial of organic carbon in sediments of the Iberian margin and Nazaré Canyon (NE Atlantic). Prog Oceanogr 52:399–431
Froelich PN, Klinkhammer GP, Bender ML, Luedtke NA, Heath GR, Cullen D, Dauphin P, Hammond D, Hartman B, Maynard V (1979) Early oxidation of organic matter in pelagic sediments of the eastern equatorial Atlantic: suboxic diagenesis. Geochim Cosmochim Acta 43:1075–1090
Gargas E, Mortensen E, Ærtjeberg-Nielsen G (1980) Production and photosynthetic efficiency of phytoplankton in the open Danish waters 1975–1977. Orphelia 1(Suppl):123–144
Gattuso J-P, Frankignoulle M, Wollast R (1998) Carbon and carbonate metabolism in coastal aquatic ecosystems. Annu Rev Ecol Syst 29:405–434
Goldhaber MB, Aller RC, Cochran JK, Rosenfeld JK, Martens CS, Berner RA (1977) Sulfate reduction, diffusion, and bioturbation in Long Island Sound sediments; report of the FOAM Group. Am J Sci 277:193–237
Greenwood N, Parker ER, Fernand L, Sivyer DB, Weston K, Painting SJ, Kröger S, Forster RM, Lees HE, Mills DK, Laane RWPM (2010) Detection of low bottom water oxygen concentrations in the North Sea; implications for monitoring and assessment of ecosystem health. Biogeosciences 7:1357–1373
Henrichs SM (1992) Early diagenesis of organic matter in marine sediments: progress and perplexity. Mar Chem 39:119–149
Huettel M, Cook P, Janssen F, Lavik G, Middelburg JJ (2007) Transport and degradation of a dinoflagellate bloom in permeable sublittoral sediment. Mar Ecol Prog Ser 340:139–153
Iversen N, Jørgensen BB (1993) Diffusion coefficients of sulfate and methane in marine sediments: influence of porosity. Geochim Cosmochim Acta 57:571–578
Jensen MM, Holmer M, Thamdrup B (2005) Composition and diagenesis of neutral carbohydrates in sediments of the Baltic-North Sea transition. Geochim Cosmochim Acta 69:4085–4099
Joassin P, Delille B, Soetaert K, Harlay J, Borges AV, Chou L, Riebesell U, Suykens K, Grégoire M (2011) Carbon and nitrogen flows during a bloom of the coccolithophore Emiliania huxleyi: modelling a mesocosm experiment. J Mar Syst 85:71–85
Kamiyama K, Okuda S, Kawai A (1976) Studies on the release of ammonium nitrogen from the bottom sediments in fresh water bodies. Part 1: a preliminary experiment using an annular channel. Jpn J Limnol 37:59–66
Krom MD, Berner RA (1980) The diffusion coefficients of sulfate, ammonium, and phosphate ions in anoxic marine sediments. Limnol Oceanogr 25:327–337
Li Y-H, Gregory S (1974) Diffusion of ions in sea water and in deep-sea sediments. Geochim Cosmochim Acta 38:703–714
Mackin JE, Aller RC (1984) Ammonium adsorption in marine sediments. Limnol Oceanogr 29:250–257
Mouret A, Anschutz P, Lecroart P, Chaillou G, Hyacinthe C, Deborde J, Jorissen F, Deflandre B, Schmidt S, Jouanneau J-M (2009) Benthic geochemistry of manganese in the Bay of Biscay, and sediment mass accumulation rate. Geo-Mar Lett 29:133–149
Revsbech NP, Sorensen J, Blackburn TH, Lomholt JP (1980) Distribution of oxygen in marine sediments measured with microelectrodes. Limnol Oceanogr 25:403–411
Rusch A, Huettel M, Forster S (2000) Particulate organic matter in permeable marine sands—dynamics in time and depth. Estuar Coast Shelf Sci 51:399–414
Rutgers van der Loeff MM (1980) Time variation in interstitial nutrient concentrations at an exposed subtidal station in the Dutch Wadden Sea. Neth J Sea Res 14:123–143
Smits JGC (1980) Microbial decomposition of organic matter and nutrient regeneration in natural waters and sediments (report on literature study). In: Report no. R1310-5. Delft Hydraulics, Delft, pp 1–117
Soetaert K, Herman PMJ, Middelburg JJ (1996a) Dynamic response of deep-sea sediments to seasonal variations: a model. Limnol Oceanogr 41:1651–1668
Soetaert K, Herman PMJ, Middelburg JJ (1996b) A model of early diagenetic processes from the shelf to abyssal depths. Geochim Cosmochim Acta 60:1019–1040
Sun M, Aller RC, Lee C (1991) Early diagenesis of chlorophyll-a in Long Island Sound sediments: a measure of carbon flux and particle reworking. J Mar Res 49:379–401
Upton AC, Nedwell DB, Parkes RJ, Harvey SM (1993) Seasonal benthic microbial activity in the southern North Sea: oxygen uptake and sulphate reduction. Mar Ecol Prog Ser 101:273–281
Van Cappellen P, Wang Y (1996) Cycling of iron and manganese in surface sediments: a general theory for the coupled transport and reaction of carbon, oxygen, nitrogen, sulfur, iron, and manganese. Am J Sci 296:197–243
van der Zee C, van Raaphorst W, Helder W (2002) Fe redox cycling in Iberian continental margin sediments (NE Atlantic). J Mar Res 60:855–886
van Raaphorst W, Kloosterhuis HT, Cramer A, Bakker KJM (1990) Nutrient early diagenesis in the sandy sediments of the Dogger Bank area, North Sea: pore water results. Neth J Sea Res 26(1):25–52
van Raaphorst W, Malschaert JFP (1996) Ammonium adsorption in superficial North Sea sediments. Cont Shelf Res 16:1415–1435
Van Weering TCE, Berger GW, Kalf J (1987) Recent sediment accumulation in the Skagerrak, northeastern North Sea. Neth J Sea Res 21:177–189
Vanderborght J-P, Billen G (1975) Vertical distribution of nitrate concentration in interstitial water of marine sediments with nitrification and denitrification. Limnol Oceanogr 20:953–961
Ward BA, Friedrichs MAM, Anderson TR, Oschlies A (2010) Parameter optimisation techniques and the problem of under determination in marine biogeochemical models. J Mar Syst 81:34–43
Wilson RFD (2011) Comparative assessment of a two-layered and multi-layered sediment model. Unpublished MSc thesis. Dalhousie University, Halifax
Westrich JT, Berner RA (1984) The role of sedimentary organic matter in bacterial sulfate reduction: the G model tested. Limnol Oceanogr 29:236–249
Wollast R (1991) The coastal organic carbon cycle: fluxes, sources, and sinks. In: Mantoura RFC, Martin J-M, Wollast R (eds) Ocean margin processes in global change. Wiley, Chichester, pp 365–381
Acknowledgments
The authors acknowledge the use of the IRIDIS High Performance Computing Facility and associated support services at the University of Southampton, in the completion of this work. Ruth Parker and Naomi Greenwood from the Centre for Environment, Fisheries and Aquaculture Science and Gary Fones and Fay Couceiro from the University of Portsmouth are thanked for providing observational data, as are Phil Owens, Ian Droppo and Katja Fennel for their constructive comments on the manuscript. The project was funded by the UK Natural Environment Research Council (NERC NE/F003552/1) as part of the Marine Ecosystem Connections project. The code used in the experiments is available by contacting the authors.
Author information
Authors and Affiliations
Corresponding author
Additional information
Responsible editor: Ian G. Droppo
Rights and permissions
About this article
Cite this article
Wood, C.C., Statham, P.J., Kelly-Gerreyn, B.A. et al. Modelling macronutrients in shelf sea sediments: fitting model output to experimental data using a genetic algorithm. J Soils Sediments 14, 218–229 (2014). https://doi.org/10.1007/s11368-013-0793-0
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11368-013-0793-0