, Volume 633, Issue 1, pp 137–149 | Cite as

Phytoplankton biomass response to nitrogen inputs: a method for WFD boundary setting applied to Danish coastal waters

  • Jacob CarstensenEmail author
  • Peter Henriksen


Reference conditions and boundary values between Water Framework Directive status classes were estimated for phytoplankton biomass from empirical relationships relating: (1) nitrogen inputs from land to total nitrogen (TN) concentrations and (2) TN concentrations to chlorophyll a (chl a) concentrations. Different periods during the last >100 years were used to characterise hypothesised ecological status, and a hind-casted time series was used to define boundary values for nitrogen inputs. Nitrogen levels in 35 coastal water bodies around Denmark were significantly related to inputs from land to various degrees (factor of 50) reflecting gradients from open coastal to freshwater-influenced estuaries. Significant differences in the relationship between chl a and TN across sites were found, suggesting that previous response models have been too simple and uncertain. Reference and boundary values for chl a, estimated with a relative uncertainty of 5–20%, varied substantially between sites, and the boundary value between good and moderate status was 6–81% higher than the reference condition with an average of 28%. Differences in bioavailability of nutrient sources and grazing pressure are important factors controlling site-specific phytoplankton biomass, and models for predicting phytoplankton responses to nutrient reductions must account for these. The boundary setting must be adaptive to incorporate improved quantitative knowledge and effects of shifting baselines.


Eutrophication Chlorophyll Total nitrogen Nutrient enrichment Ecosystem responses 



This study used data collected within the National Danish Aquatic Monitoring and Assessment Programme, and financial support was given by the Danish Environmental Protection Agency. Henning Karup and Jens Brøgger Jensen are acknowledged for constructive discussions of the approach and comments to the manuscript. This research is a contribution to the Thresholds Integrated Project, funded by Framework Program 6 of the European Commission (contract # 003933-2).


  1. Ærtebjerg, G., J. H. Andersen & O. S. Hansen, 2003. Nutrients and Eutrophication in Danish Marine Waters: A Challenge for Science and Management. National Environmental Research Institute, Roskilde, Denmark: 126 pp.Google Scholar
  2. Borum, J., 1996. Shallow waters and land/sea boundaries. In Jørgensen, B. B. & K. Richardson (eds), Eutrophication in Coastal Marine Ecosystems. Coastal and Marine Studies, Vol. 52. American Geophysical Union, Washington, DC: 179–203.Google Scholar
  3. Boström, C., S. P. Baden & D. Krause-Jensen, 2003. The seagrasses of Scandinavia and the Baltic Sea. In Green, E. P. & T. F. Short (eds), World atlas of Seagrasses. California University Press, Berkeley: 27–37.Google Scholar
  4. Carletti, A. & A.-S. Heiskanen, in press. Water Framework Directive Intercalibration Technical Report. Part 3: Coastal and Transitional Waters. European Commission Joint Research Centre, Institute for Environment and Sustainability.Google Scholar
  5. Carstensen, J., 2007. Statistical principles for ecological status classification of Water Framework Directive monitoring data. Marine Pollution Bulletin 55: 3–15.PubMedCrossRefGoogle Scholar
  6. Carstensen, J., D. J. Conley & B. Müller-Karulis, 2003. Spatial and temporal resolution of carbon fluxes in a shallow coastal ecosystem, the Kattegat. Marine Ecology Progress Series 252: 35–50.CrossRefGoogle Scholar
  7. Carstensen, J., D. J. Conley, J. H. Andersen & G. Ærtebjerg, 2006. Coastal eutrophication and trend reversal: a Danish case study. Limnology and Oceanography 51: 398–408.CrossRefGoogle Scholar
  8. Carstensen, J., P. Henriksen & A.-S. Heiskanen, 2007. Summer algal blooms in shallow estuaries: definition, mechanisms and link to eutrophication. Limnology and Oceanography 52: 370–384.CrossRefGoogle Scholar
  9. Conley, D. J. & A. Josefson, 2001. Hypoxia, nutrient management and restoration in Danish waters. In Rabalais, N. N. & R. E. Turner (eds), Coastal Hypoxia: Consequences for Living Resources and Ecosystems. Coastal and Estuarine Studies, Vol. 58. American Geophysical Union, Washington, DC: 425–434.Google Scholar
  10. Conley, D. J., H. Kass, F. Møhlenberg, B. Rasmussen & J. Windolf, 2000. Characteristics of Danish estuaries. Estuaries 23: 820–837.CrossRefGoogle Scholar
  11. Conley, D. J., J. Carstensen, G. Ærtebjerg, P. B. Christensen, T. Dalsgaard, J. L. S. Hansen & A. B. Josefson, 2007. Long-term changes and impacts of hypoxia in Danish coastal waters. Ecological Applications 17(5): S165–S184.CrossRefGoogle Scholar
  12. Directive, 2000. Directive 2000/60/EC of the European Parliament and of the Council of 23 October 2000 Establishing a Framework for Community Action in the Field of Water Policy. Official Journal of the European Communities L 327: 1–72.Google Scholar
  13. Duarte, C. M., D. J. Conley, J. Carstensen & M. Sánchez-Camacho, 2009. Return to Neverland: shifting baselines affect eutrophication restoration targets. Estuaries and Coasts 32: 29–36.CrossRefGoogle Scholar
  14. Fallesen, G., F. Andersen & B. Larsen, 2000. Life, death and revival of the hypertrophic Mariager Fjord, Denmark. Journal of Marine Systems 25: 313–321.CrossRefGoogle Scholar
  15. Guildford, S. J. & R. E. Hecky, 2000. Total nitrogen, total phosphorus, and nutrient limitation in lakes and oceans: is there a common relationship? Limnology and Oceanography 45: 1213–1223.Google Scholar
  16. Henriksen, P., 2009. Reference conditions for phytoplankton at Danish Water Framework Directive intercalibration sites. Hydrobiologia 629: 255–262.CrossRefGoogle Scholar
  17. Hoyer, M. V., T. K. Frazer, S. K. Notestein & D. E. Canfield Jr., 2002. Nutrient, chlorophyll, and water clarity relationships in Florida’s nearshore coastal waters with comparisons to freshwater lakes. Canadian Journal of Fishery and Aquatic Science 59: 1024–1031.CrossRefGoogle Scholar
  18. Josefson, A. B. & J. L. S. Hansen, 2004. Species richness of benthic macrofauna in Danish estuaries and coastal areas. Global Ecology and Biogeography 13: 273–288.CrossRefGoogle Scholar
  19. Kronvang, B., G. Ærtebjerg, R. Grant, P. Kristensen, M. Hovmand & J. Kirkegaard, 1993. Nationwide monitoring of nutrients and their ecological effects: state of the Danish Aquatic Environment. Ambio 22: 176–187.Google Scholar
  20. Møhlenberg, F., 1995. Regulating mechanisms of phytoplankton growth and biomass in a shallow estuary. Ophelia 42: 239–256.Google Scholar
  21. Mortimer, C. H., 1941. The exchange of dissolved substances between mud and water in lakes. Journal of Ecology 29: 280–329.CrossRefGoogle Scholar
  22. Nielsen, S. L., K. Sand-Jensen, J. Borum & O. Geertz-Hansen, 2002. Phytoplankton, nutrients, and transparency in Danish coastal waters. Estuaries 25: 916–929.CrossRefGoogle Scholar
  23. Petersen, J. K., J. W. Hansen, M. B. Laursen, P. Clausen, J. Carstensen & D. J. Conley, 2008. Regime shift in a coastal marine ecosystem. Ecological Applications 18: 497–510.PubMedCrossRefGoogle Scholar
  24. Phillips, G., O.-P. Pietiläinen, L. Carvalho, A. Solimini, A. Lyche-Solheim & A. C. Cardoso, 2008. Chlorophyll–nutrient relationships of different lake types using a large European dataset. Aquatic Ecology 42: 213–226.CrossRefGoogle Scholar
  25. Pritchard, D. W., 1967. What is an estuary: physical viewpoint. In Lauff, G. H. (ed.), Estuaries. American Association for the Advancement of Science, Publication No. 83, Washington, DC: 3–5.Google Scholar
  26. Rasmussen, B. & A. B. Josefson, 2002. Consistent estimates for the residence time of micro-tidal estuaries. Estuarine, Coastal and Shelf Science 54: 65–73.CrossRefGoogle Scholar
  27. Seitzinger, S. P., S. W. Sanders & R. Styles, 2002. Bioavailability of DON from natural and anthropogenic sources to estuarine plankton. Limnology and Oceanography 47: 353–366.CrossRefGoogle Scholar
  28. Smith, V. H., 2006. Responses of estuarine and coastal marine phytoplankton to nitrogen and phosphorus enrichment. Limnology and Oceanography 51: 377–384.CrossRefGoogle Scholar
  29. Smith, S. V. & J. T. Hollibaugh, 1989. Carbon-controlled nitrogen cycling in a marine ‘macrocosm’: an ecosystem-scale model for managing cultural eutrophication. Marine Ecology Progress Series 52: 103–109.CrossRefGoogle Scholar
  30. Spokes, L. & 29 others, 2006. MEAD: an interdisciplinary study of the marine effects of atmospheric deposition in the Kattegat. Environmental Pollution 140: 453–462.Google Scholar
  31. Vollenweider, R. A., 1968. Scientific Fundamentals of the Eutrophication of Lakes and Flowing Waters with Particular Reference to Nitrogen and Phosphorus as Factors of Eutrophication. Technical Report DA S/SCI/68.27.250, Organisation for Economic Cooperation and Development, Paris, France.Google Scholar

Copyright information

© Springer Science+Business Media B.V. 2009

Authors and Affiliations

  1. 1.Department of Marine EcologyNational Environmental Research InstituteRoskildeDenmark

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