[en] The RIVERSTRAHLER model, an idealized biogeochemical model of the river system,
has been coupled to MIRO-CO2, a complex biogeochemical model describing diatom and
Phaeocystis blooms and carbon and nutrient cycles in the marine domain, to assess the
dual role of changing nutrient loads and increasing atmospheric CO2 as drivers of air–sea
CO2 exchanges in the Southern North Sea with a focus on the Belgian coastal zone (BCZ).
The whole area, submitted to the influence of two main rivers (Seine and Scheldt), is
characterized by variable diatom and Phaeocystis colonies blooms which impact on the
trophic status and air–sea CO2 fluxes of the coastal ecosystem. For this application, the
MIRO-CO2 model is implemented in a 0D multibox frame covering the eutrophied
Eastern English Channel and Southern North Sea and receiving loads from the rivers
Seine and Scheldt. Model simulations are performed for the period between 1951 and
1998 using real forcing fields for sea surface temperature, wind speed and atmospheric
CO2 and RIVERSTRAHLER simulations for river carbon and nutrient loads. Model
results suggest that the BCZ shifted from a source of CO2 before 1970 (low eutrophication)
towards a sink during the 1970–1990 period when anthropogenic DIN and P loads
increased, stimulating C fixation by autotrophs. In agreement, a shift from net annual
heterotrophy towards autotrophy in BCZ is simulated from 1980. The period after 1990 is
characterized by a progressive decrease of P loads concomitant with a decrease of
primary production and of the CO2 sink in the BCZ. At the end of the simulation period,
the BCZ ecosystem is again net heterotroph and acts as a source of CO2 to the atmosphere.
R-MIRO-CO2 scenarios testing the relative impact of temperature, wind speed, atmospheric
CO2 and river loads variability on the simulated air–sea CO2 fluxes suggest that
the trend in air–sea CO2 fluxes simulated between 1951 and 1998 in the BCZ was mainly
controlled by the magnitude and the ratio of inorganic nutrient river loads. Quantitative
nutrient changes control the level of primary production while qualitative changes
modulate the relative contribution of diatoms and Phaeocystis to this flux and hence
the sequestration of atmospheric CO2.
Disciplines :
Aquatic sciences & oceanology
Author, co-author :
Gypens, N.
Borges, Alberto ; Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Océanographie chimique
Lancelot, C.
Language :
English
Title :
Effect of eutrophication on air-sea CO2 fluxes in the coastal Southern North Sea: a model study of the past 50 years
Andersson AJ, Mackenzie FT (2004) Shallow-water oceans: A source or sink of atmospheric CO2? Frontiers in Ecology and the Environment, 2, 348-353.
Billen G, Garnier J, Ficht A, Cun C (2001) Modeling the response of water quality in the Seine river estuary to human activity in its watershed over the last 50 years. Estuaries, 24, 977-993.
Billen G, Garnier J, Hanset P (1994) Modelling phytoplankton development in whole drainage networks: The RIVERSTRAHLER model applied to the Seine river system. Hydrobiologia, 289, 119-137.
Billen G, Garnier J, Rousseau V (2005) Nutrient fluxes and water quality in the drainage network of the Scheldt basin over the last 50 years. Hydrobiologia, 540, 47-67.
Billen G, Servais P, Wargnies S (1991) Modélisation du transport des polluants par l'Estuaire de l'Escaut. Cas du Phosphore. Etude réalisée pour le compte de l'Unitéde Gestion du Modèle Mathématique de la Mer du Nord et de l'Estuaire de l'Escaut. Ref BH/90/37, Rapport d'avancement, 33 pp, Brussel, Belgium.
Borges AV (2005) Do we have enough pieces of the jigsaw to integrate CO2 fluxes in the Coastal Ocean? Estuaries, 28, 3-27.
Borges AV, Delille B, Frankignoulle M (2005) Budgeting sinks and sources of CO2 in the coastal ocean: Diversity of ecosystems counts. Geophysical Research Letters, 32, L14601.
Borges AV, Frankignoulle M (1999) Daily and seasonal variations of the partial pressure of CO2 in the surface seawater along Belgian and southern Dutch coastal areas. Journal of Marine Systems, 19, 251-266.
Borges AV, Frankignoulle M (2002) Distribution and air-water exchange of carbon dioxide in the Scheldt plume off the Belgian coast. Biogeochemistry, 59, 41-67.
Borges AV, Frankignoulle M (2003) Distribution of surface carbon dioxide and air-sea exchange in the English Channel and adjacent areas. Journal of Geophysical Research, 108, 3140.
Borges AV, Schiettecatte L-S, Abril G, Delille B, Gazeau F (2006) Carbon dioxide in European coastal waters. Estuarine, Coastal and Shelf Science, 70, 375-387.
Cai W-J, Dai MH, Wang YC (2006) Air-sea exchange of carbon dioxide in ocean margins: A province-based synthesis. Geophysical Research Letters, 33, L12603.
Cai W-J, Guo X, Chen CTA et al. (2008) A comparative overview of weathering intensity and HCO3 2-flux in the world's major rivers with emphasis on the Changjiang, Huanghe, Zhujiang (Pearl) and Mississippi Rivers. Continental Shelf Research, 28, 1538-1549.
Chen CTA, Borges AV (2008) Reconciling opposing views on carbon cycling in the coastal ocean: Continental shelves as sinks and near-shore ecosystems as sources of atmospheric CO2. Deep-Sea Research, Part II, in press.
Chen CTA, Liu KK, Macdonald R (2003) Continental margin exchanges. In: Ocean Biogeochemistry: The Role of the Ocean Carbon Cycle in Global Change (ed Fasham MJR), pp. 53-97. Springer-Verlag, Berlin, Germany.
Cloern JE (2001) Our evolving conceptual model of the coastal eutrophication problem. Marine Ecology Progress Series, 210, 223-253.
Cohen JE, Small C, Mellinger A, Gallup J, Sachs J (1997) Estimates of coastal populations. Science, 278, 1211-1212.
da Cunha LC, Buitenhuis ET, Le Quéré C, Giraud X, Ludwig W (2007) Potential impact of changes in river nutrient supply on global ocean biogeochemistry. Global Biogeochemical Cycles, 21, GB4007.
Dickson AG (1990) Thermodynamics of the dissociation of boric acid in synthetic sea water from 273.15 to 298.15 K. Deep-Sea Research, Part A, 37, 755-766.
Dickson AG, Goyet C (eds) (1994) Handbook of Methods for the Analysis of the Various Parameters of the Carbon Dioxide System of Sea Water (2nd edn). ORNL/CDIAC-74, US Department of Energy (DOE, 1994), 36 pp.
Frankignoulle M, Abril G, Borges AV et al. (1998) Carbon dioxide emission from European estuaries. Science, 282, 434-436.
Frankignoulle M, Borges AV (2001) Direct and indirect p CO2 measurements in a wide range of p CO2 and salinity values (the Scheldt estuary). Aquatic Geochemistry, 7, 267-273.
Frankignoulle M, Bourge I, Canon C, Dauby P (1996) Distribution of surface seawater partial CO2 pressure in the English Channel and in the Southern Bight of the North Sea. Continental Shelf Research, 16, 381-395.
Garnier J, Billen G, Coste M (1995) Seasonal succession of diatoms and chlorophyecae in the drainage network of the River Seine: Observations and modelling. Limnology and Oceanography, 40, 750-765.
Garnier J, Billen G, Hannon E, Fonbonne S, Videnina Y, Soulie M (2002) Modeling transfer and retention of nutrients in the drainage network of the Danube River. Estuarine, Coastal and Shelf Science, 54, 285-308.
Garnier J, Billen G, Palfner L (1999) Understanding the oxygen budget and related ecological processes in the river Mosel: The RIVERSTRAHLER approach. Hydrobiologia, 410, 151-166.
Gattuso JP, Frankignoulle M, Wollast R (1998) Carbon and carbonate metabolism in coastal aquatic ecosystems. Annual Review of Ecology and Systematics, 29, 405-434.
Gypens N, Lacroix G, Lancelot C (2007) Causes of variability in diatom and Phaeocystis blooms in Belgian coastal waters between 1989 and 2003: a model study. Journal of Sea Research, 57, 19-35.
Gypens N, Lancelot C, Borges AV (2004) Carbon dynamics and CO2 air-sea exchanges in the eutrophied coastal waters of the Southern Bight of the North Sea: A modelling study. Biogeosciences, 1, 147-157.
Hannon E, Boyd PW, Silvoso M, Lancelot C (2001) Modelling the bloom evolution and carbon flows during SOIREE: Implications for future in situ iron-experiments in the Southern Ocean. Deep-Sea Research, Part II, 48, 2745-2773.
Heip C, Goosen NK, Herman PMJ, Kromkamp J, Middelburg JJ, Soetaert K (1995) Production and consumption of biological particles in temperate tidal estuaries. Oceanography and Marine Biology: An Annual Review, 33, 1-149.
Howarth RW, Marino R (2006) Nitrogen as the limiting nutrient for eutrophication in coastal marine ecosystems: Evolving views over three decades. Limnology and Oceanography, 51, 364-376.
Kaul L, Froelich P (1984) Modelling estuarine nutrient biogeochemistry in a simple system. Geochimica et Cosmochimica Acta, 48, 1417-1433.
Kemp WM, Smith EM, Marvin-DiPasqual M, Boynton WR (1997) Organic carbon-balance and net ecosystem metabolism in Chesapeake Bay. Marine Ecology Progress Series, 150, 229-248.
Lancelot C (1995) The mucilage phenomenon in the continental coastal waters of the North Sea. The Science of the Total Environment, 165, 83-102.
Lancelot C, Gypens N, Billen G, Garnier J, Roubeix V (2007) Testing an integrated river-ocean mathematical tool for linking marine eutrophication to land use: The Phaeocystis-dominated Belgian coastal zone (Southern North Sea) over the past 50 years. Journal of Marine Systems, 64, 216-228.
Lancelot C, Spitz Y, Gypens N et al. (2005) Modelling diatom and Phaeocystis blooms and nutrient cycles in the Southern Bight of the North Sea: The MIRO model. Marine Ecology Progress Series, 289, 63-78.
Ludwig W, Amiotte-Suchet P, Probst JL (1996) River discharges of carbon to the world's oceans: Determining local inputs of alkalinity and dissolved and particulate organic carbon. C.R. Academy of Science, Paris, t. 323, Serie II a, pp. 1007-1014.
Mackenzie FT, Lerman A, Andersson AJ (2004) Past and present of sediment and carbon biogeochemical cycling models. Biogeosciences, 1, 11-32.
Mackenzie FT, Ver LM, Lerman A (2002) Century-scale nitrogen and phosphorus controls of the carbon cycle. Chemical Geology, 190, 13-32.
Mehrbach C, Culberson CH, Hawley JE, Pytkowicz RM (1973) Measurements of the apparent dissociation constants of carbonic acid in seawater at atmospheric pressure. Limnology and Oceanography, 18, 897-907.
Middelburg JJ, Duarte CM, Gattuso JP (2005) Respiration in coastal benthic communities. In: Respiration in Aquatic Ecosystems (eds del Giorgio PA, Williams PJLB), pp. 206-224. Oxford University Press, Oxford.
Middelburg JJ, Soetaert K (2004) The role of sediments in shelf ecosystem dynamics. In: The Global Coastal Ocean: Multiscale Interdisciplinary Processes (eds Robinson AR, Brink K), pp. 353-374. Harvard University Press, Cambridge.
Nightingale PD, Malin G, Law CS et al. (2000) In situ evaluation of air-sea gas exchange parameterizations using novel conservative and volatile tracers. Global Biogeochemical Cycles, 14, 373-387.
Nixon SW (1995) Coastal marine eutrophication: A definition, social causes, and future concerns. Ophelia, 41, 199-219.
Officer CB, Ryther JH (1980) The possible importance of silicon in marine eutrophication. Marine Ecology Progress Series, 3, 83-91.
Rabouille C, Mackenzie FT, Ver LM (2001) Influence of the human perturbation on car -carbon, nitrogen, and oxygen biogeochemical cycles in the global coastal ocean. Geochimica et Cosmochimica Acta, 65, 3615-3639.
Sabine CL, Feely RA, Key RM et al. (2004) The oceanic sink for anthropogenic CO2. Science, 305, 367-371.
Schiettecatte L-S, Gazeau F, Van der Zee C, Brion N, Borges AV (2006) Time series of the partial pressure of carbon dioxide (2001-2004) and preliminary inorganic carbon budget in the Scheldt plume (Belgian coast waters). Geochemistry, Geophysics, Geosystems (G3), 7, Q06009.
Smith SV (1995) Net carbon metabolism of oceanic margins and estuaries. In: Biotic Feedbacks in the Global Climatic System: Will the Warming Feed the Warming? (eds Woodwell GM, Mackenzie FT), pp. 251-262. Oxford University Press, Oxford, UK.
Smith SV, Hollibaugh JT (1993) Coastal metabolism and the oceanic carbon balance. Reviews of Geophysics, 31, 75-89.
Smith SV, Mackenzie FT (1987) The ocean as a net heterotrophic system: implications from the carbon biogeochemical cycle. Global Biogeochemical Cycles, 1, 187-198.
Smith SV, Swaney DP, Talaue-Mcmanus L et al. (2003) Humans, hydrology, and the distribution of inorganic nutrient loading to the ocean. Bioscience, 53, 235-245.
Soetaert K, Middelburg JJ, Heip C, Meire P, Van Damme S, Maris T (2006) Long-term change in dissolved inorganic nutrients in the heterotrophic Scheldt estuary (Belgium, the Netherlands). Limnology and Oceanography, 51, 409-423.
Takahashi T, Sutherland SC, Feely RA, Wanninkhof R (2006) Decadal change of the surface water p CO2 in the North Pacific: A synthesis of 35 years of observations. Journal of Geophysical Research, 111, C07S05.
Takahashi T, Sutherland CS, Wanninkhof R et al. (2008) Climatological mean and decadal change in surface ocean p CO2, and net sea-air CO2 flux over the global oceans. Deep-Sea Research, Part II, in press.
Taylor KE (2001) Summarizing multiple aspects of model performance in a single diagram. Journal of Geophysical Research, 106, 7183-7192.
Thomas H, Bozec Y, Elkalay K, de Baar HJW (2004) Enhanced open ocean storage of CO2 from shelf sea pumping. Science, 304, 1005-1008.
Van Beusekom JEE, de Jonge VNN (2002) Long-term changes in Wadden-Sea nutrient cycles: Importance of organic matter import from the North Sea. Hydrobiologia, 475/476, 185-194.
Ver LM, Mackenzie FT, Lerman A (1999) Carbon cycle in the coastal zone: effects of global perturbations and changes in the past three centuries. Chemical Geology, 159, 283-304.
Vitousek PM, Aber JD, Howarth RW et al. (1997) Human alteration of the global nitrogen cycle: Sources and consequences. Ecological Applications, 7, 737-750.
Weiss RF (1974) Carbon dioxide in water and seawater: The solubility of a non-ideal gas. Marine Chemistry, 2, 203-215.
Wollast R (1998) Evaluation and comparison of the global carbon cycle in the coastal zone and in the open ocean. In: The Sea: The Global Coastal Ocean, Processes and Methods (eds Brink KH, Robinson AR), pp. 213-252. John Wiley and Sons Inc., New York, NY.