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Estuaries

, Volume 27, Issue 6, pp 977–985 | Cite as

Ecosystem metabolism and carbon fluxes of a tidally-dominated coastal lagoon

  • Rui Santos
  • João Silva
  • Ana Alexandre
  • Nuria Navarro
  • Cristina Barrón
  • Carlos M. Duarte
Article

Abstract

The metabolism and carbon flux in the western sector of the highly dynamic coastal lagoon Ria Formosa (south Portugal) were assessed to elucidate the relative importance of the contribution of the main communities, the treated sewage inputs from the adjacent city of Faro, and the exchange with the adjacent coastal waters to the ecosystem metabolism. The results depict the Ria Formosa as being a highly productive ecosystem dominated by the seagrassZostera noltii. The community dominated by the seagrassCymodocea nodosa had half of the gross production ofZ. noltii, followed by bare sediments and phytoplankton. The net contribution of seagrasses to community metabolism was negligible, as bothZ. noltii andC. nodosa showed a production: respiration ratio close to 1. Benthic microalgae emerge as the most important components of the net metabolism. The western sector of Ria Formosa was in metabolic balance during the summer when the study was done. Even though the total net ecosystem production was 7.22 Kmol C d−1, the error associated with this estimate was 8.38 Kmol C d−1, so ecosystem net production was not significantly different from zero. The Ria Formosa ecosystem is shallow and rapidly flushed by the tides, which force an important exchange of dissolved organic carbon (DOC) and particulate organic carbon (POC) with the adjacent coastal waters. The daily net export rate to the adjacent coastal waters, 0.98 Kmol d−1, represented 7.6% of the net ecosystem production, suggesting that the bulk of the net ecosystem production accumulates within the ecosystem. The organic carbon retention in the western sector of the Ria Formosa is higher than net production, because the allochthonous carbon inputs from urban sewage enter the carbon mass balance with about 40% of the autochthonous processes, at about 1.6 Kmol d−1 of DOC and 2.8 Kmol d−1 of POC. The western sector of Ria Formosa has an organic carbon sink of about 46.4 tons per year. Most of this is harvested in the form of molluscs (clams, cuttlefish, etc.) and fish (sea bream, sea bass, etc.). The total carbon harvested every year in the form of bivalves is about 40 tons, rendering the Ria Formosa the most productive seafood area in Portugal.

Keywords

Particulate Organic Matter Particulate Organic Carbon Gross Primary Production Dissolve Organic Carbon Concentration Coastal Lagoon 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Literature Cited

  1. Andrade, C. 1990. O ambiente barreira da Ria Formosa, Algarve, Portugal. Ph.D. Dissertation, Faculty of Sciences, University of Lisbon, Algarve, Portugal.Google Scholar
  2. Coelho, H., R. Neves, M. White, P. Leitão, andA. Santos. 2002. A model for ocean circulation on the Iberian Coast.Journal of Marine Systems 32:153–179.CrossRefGoogle Scholar
  3. Duarte, C. M. andS. Agustí. 1998. The CO2 balance of unproductive aquatic ecosystems.Science 281:234–236.CrossRefGoogle Scholar
  4. Duarte, C. M. andC. L. Chiscano. 1999. Seagrass biomass and production: A reassessment.Aquatic Botany 65:159–174.CrossRefGoogle Scholar
  5. Falcão, M. 1996. Dinâmica dos nutrientes na Ria Formosa: Efeitos da interacção da laguna com as suas interfaces na reciclagem do azoto, fósforo e sílica. Ph.D. Dissertation, University of Algarve, Algarve, Portugal.Google Scholar
  6. Gattuso, J.-P., M. Frankignoulle, andR. Wollast. 1998. Carbon and carbonate metabolism in coastal aquatic ecosystems.Annual Review of Ecology and Systematics 29:405–434.CrossRefGoogle Scholar
  7. Hansen, H. P. andF. Koroleff. 1999. Determination of nutrients, p. 170–174.In K. Grasshoff, K. Kremling, and M. Ehrhardt (eds.), Methods of Seawater Analysis. Wiley-Verlag Chimica Helvetia Verlag, Weinheim, Germany.Google Scholar
  8. Hansen, J. W., B. Thamdrup, andB. B. Jørgensen. 2000. Anoxic incubation of sediment in gas-tight plastic bags: A method for biogeochemical process studies.Marine Ecology Progress Series 208:273–282.CrossRefGoogle Scholar
  9. Heip, C. H. R., N. K. Goosen, P. M. J. Herman, J. Kromkamp, J. J. Middelburg, andK. Soetaert. 1995. Production and consumption of biological particle in temperature tidal estuaries.Oceanography and Marine Biology—An Annual Review 33:1–149.Google Scholar
  10. Hemminga, M. A. andC. M. Duarte. 2000. Seagrass Ecology, 1st edition. Cambridge University Press, Cambridge, U.K.Google Scholar
  11. Hemminga, M. A., F. J. Slim, G. M. Ganssen, J. Nieuwenhuize, andN. M. Kruyt. 1994. Carbon outwelling from a mangrove forest with adjacent seagrass beds and coral reefs (Gazi Bay, Kenya).Marine Ecology Progress Series 106:291–301.CrossRefGoogle Scholar
  12. Hopkinson, Jr.,C. S. andE. M. Smith. 2004. Estuarine respiration: An overview of benthic, pelagic and whole system respiration, p. 122–146.In P. A. del Giorgio and P. J. LeB. Williams (eds.), Respiration in Aquatic Ecosystem. Oxford University Press, Oxford, U.K.Google Scholar
  13. Jorgensen, B. B. 1977. The sulfur cycle of a coastal marine sediment (Limfjorden, Denmark).Limnology and Oceanography 22:814–832.Google Scholar
  14. Kemp, W. M., E. M. Smith, M. Marvin-DiPasquale, andW. R. Boynton. 1997. Organic carbon balance and net ecosystem metabolism in Chesapeake Bay.Marine Ecology Progress Series 150:229–248.CrossRefGoogle Scholar
  15. Machás, R., R. Santos, andB. Peterson. 2003. Tracing the flow of orgnaic matter from primary producers to filter feeders in Ria Formosa lagoon, southern Portugal.Estuaries 26:846–856.CrossRefGoogle Scholar
  16. Martins, F., R. Neves, P. Leitão, andA. Silva. 2001. 3D modelling in the Sado estuary using a new generic vertical discretization approach.Oceanologica Acta 24:51–62.CrossRefGoogle Scholar
  17. Pai, S.-C., G.-C. Gong, andK.-K. Liu. 1993. Determination of dissolved oxygen in seawater by direct spectrophotometry of total iodine.Marine Chemistry 41:343–351.CrossRefGoogle Scholar
  18. Roland, F., N. F. Caraco, J. J. Cole, andP. del Giorgio. 1999. Rapid and precise determination of dissolved oxygen by spectrophotometry: Evaluation of interference from color and turbidity.Limnology and Oceanography 44:1148–1154.CrossRefGoogle Scholar
  19. Santos, A., H. Martins, H. Coelho, P. Leitão, andR. Neves. 2002. A circulation model for the European ocean margin.Applied Mathematical Modelling 26:563–582.CrossRefGoogle Scholar
  20. Silva, J., R. Santos, M. Calleja, and C. M. Duarte. in press. Submerged versus air-exposed intertidal macrophyte productivity: From physiological to community-level assessments.Journal of Experimental Marine Biology and Ecology.Google Scholar
  21. Smith, S. V. andJ. T. Hollibaugh. 1993. Coastal metabolism and the oceanic organic carbon balance.Reviews of Geophysics 31:75–89.CrossRefGoogle Scholar
  22. Smith, S. V. andJ. T. Hollibaugh. 1997. Annual cycle and interannual variability of net and gross ecosystem metabolism in a temperate climate embayment.Ecological Monographs 67: 509–533.CrossRefGoogle Scholar
  23. Strickland, J. D. H. andT. R. Parsons. 1968. A practical handbook of seawater analysis. Bulletin 167. Fisheries Research board of Canada, Ottawa, Canada.Google Scholar
  24. Valiela, I. 1995. Marine Ecological Processes, 2nd edition. Springer-Verlag, New York.Google Scholar
  25. Valiela, I., M. L. Cole, J. McClelland, J. Hauxwell, andJ. Cebrian. 2000. Role of salt marshes as part of coastal landscapes, p. 23–38.In P. Weinstein and D. Kreeger (eds.), Concepts and Controversies in Tidal Marsh Ecology. Kluwer Academic Publishers, Dordrecht, The Netherlands.Google Scholar

Copyright information

© Estuarine Research Federation 2004

Authors and Affiliations

  • Rui Santos
    • 1
  • João Silva
    • 1
  • Ana Alexandre
    • 1
  • Nuria Navarro
    • 2
  • Cristina Barrón
    • 2
  • Carlos M. Duarte
    • 2
  1. 1.Grupo de Ecologia das Plantas Marinhas, Centro de Ciências do MarUniversidade do Algarve, GambelasFaroPortugal
  2. 2.Grupo de Oceanografia Interdisciplinar, Instituto Mediterráneo de Estudios AvanzadosIMEDEA (CSIC-UiB)Esporles (Islas Baleares)Spain

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