Estuaries and Coasts

, Volume 30, Issue 1, pp 66–81 | Cite as

Variability of continental riverine freshwater and nutrient inputs into the North Sea for the years 1977–2000 and its consequences for the assessment of eutrophication

Article
Received:
Revised:
Accepted:

Abstract

We determined the monthly and annual riverine freshwater, nitrogen (N) and phosphorus (P) loading into the North Sea from Belgium, The Netherlands, and Germany for the years 1977–2000. An average of 133 km3 yr−1 of the 309 km3 yr−1 precipitation into the watershed is carried by the rivers into the sea. Total freshwater discharge fluctuates with a strong 6–7 yr periodicity, is strongly correlated with precipitation, and exhibits a slight long-term decrease. The temporal changes of regional patterns of precipitation lead to changing ratios of annual discharge of the western rivers compared to the eastern rivers, varying between 2.2 and 3.5. The long-term oscillations in discharge were more pronounced as discharge increased. The annual means of total and dissolved inorganic N and P loads were estimated to be 722 and 582 kt N yr−1 and 48 and 26 kt P yr−1, respectively. The monthly N loads were much more strongly correlated with discharge, compared to the monthly P loads. Total N and P as well as dissolved inorganic N also demonstrated a 6–7 yr periodicity. The annual N loads decreased by about 17 kt N yr−1 from 1977 to 2000. The total phosphorus and phosphate loads decreased from about 80 and 50 kt P yr−1 in the 1980s to 25 and 12 kt P yr−1, respectively, in the 1990s. The western rivers contributed the major part of the nutrient loads. The long-term oscillations in their nutrient loads were much more pronounced, compared to the eastern rivers. The area-specific loading rates estimated for all rivers are comparable to earlier estimates using shorter data records, smaller sample sizes, and a less complete watershed monitoring program. The monthly and annual average N:P ratios and their variability increased considerably for individual rivers during the study interval. These results confirm that the water quality of European continental rivers is strongly influenced by intense land use. They demonstrate the necessity for using long time series monitoring results to assess change and evaluate the effects of climate change on the North Sea coastal ecosystems, using ecosystem models on decadal time scales.

Keywords

Total Phosphorus Dissolve Inorganic Nitrogen North Atlantic Oscillation Index German Bight Freshwater Discharge 
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.
This is a preview of subscription content, log in to check access.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

Literature Cited

  1. Andersson, L. andB. Arheimer. 2003. Modelling of human and climatic impact on nitrogen load in a Swedish river 1885–1994.Hydrobiologia 497:63–77.CrossRefGoogle Scholar
  2. Anonymous. 1992. Guidance Document for the NSTF Modelling Workshop 6–8 May 1992. Rijkswaterstaat (RWS), Directoraat-Generaal. The Hague, The Netherlands.Google Scholar
  3. Anonymous. 1998. Gewässerüberwachungssystem Niedersach sen (GÜN)—Gütemeßnetz Fließgewässer: Meßstrategie und Meßnetzkonzeption. Niedersächsisches Umweltministerium und Niedersächsisches Landesamt für Ökologie. Hannover, Germany.Google Scholar
  4. Baretta, J. W., W. Ebenhöh, andP. Ruardij. 1995. The European Regional Seas Ecosystem Model (ERSEM), a complex marine ecosystem model.Netherlands Journal of Sea Research 33:233–246.CrossRefGoogle Scholar
  5. Baretta-Bekker J. G. andJ. W. Baretta. 1997. European Regional Seas, Ecosystem Model (ERSEM) II.Journal of Sea Research 38:169–436.CrossRefGoogle Scholar
  6. Behrendt, H. 2004. Past, present and future changes in catchment fluxes. EUROCATD4.1 and 4.2. EUROCAT Project WD 14. Brussels, Belgium.Google Scholar
  7. Behrendt, H., J. Van Gils, H. Schreiber, andM. Zessner. 2005. Point and diffuse nutrient emissions and loads in the transboundary Danube river basin.Large Rivers 16:221–247.Google Scholar
  8. Bennekom, A. J. v., W. W. C. Gieskes, andS. B. Tijssen. 1975. Eutrophication of Dutch coastal waters. Proceedings of the Royal Society of London, Series B.Biological Sciences 189:359–374.Google Scholar
  9. Bouwer L. M., J. E. Vermaat andJ. C. J. H. Aerts. 2006. Winter atmospheric circulation and river discharge in northwest Europe.Geophysical Research Letters 33:L06403, 10.1029/2005GL025548.CrossRefGoogle Scholar
  10. Bouwman, A. F., G. Van Drecht, J. M. Knoop, A. H. W. Beusen, andC. R. Meinardi 2005 Exploring changes in river nitrogen export to the world's ocean.Global Biochemical Cycles 19: GB1002, doi:10.1029/2004GB002314.CrossRefGoogle Scholar
  11. Brockmann, U., B. Heyden, M. Schütt, A. Starke, andD. Topcu. 2002. Assessment criteria for eutrophication areas-Emphasis German Bight.Umweltbundesamt Texte 48:1–109.Google Scholar
  12. Carlson, H. 1986. Quality status of the North Sea.Deutsche Hydrographische Zeitschrift, Ergänzungsheft Reihe B 16:1–424.Google Scholar
  13. Damm, P. E. 1997. Die saisonale Salzgehalts- und Frischwasserverteilung in der Nordsee und ihre Bilanzierung. Berichte aus dem Zentrum für Meeres- und Klimaforschung, Reihe B: Ozeanographie 28. Universität Hamburg, Hamburg, Germany.Google Scholar
  14. Dickson, R., J. Lazier, J. Meincke, P. Rhines, andJ. Swift. 1996. Long-term coordinated changes in the convective activity of the North Atlantic.Progress in Oceanography 38:241–295.CrossRefGoogle Scholar
  15. Dickson R. R., J. Meincke, S. A. Malmberg, andA. Lee. 1988. The “great salinity anomaly” in the northern North Atlantic 1968–1982.Progress in Oceanography 20:103–151.CrossRefGoogle Scholar
  16. European Environmental Agency (EEA). 2005. Source appointment of nitrogen and phosphorus inputs into the aquatic environment. European Environmental Agency, Copenhagen, Denmark.Google Scholar
  17. Emeis, K., C. Christiansen, K. Edelvang, S. Jähmlich, J. Kozuch, M. Laima, T. Leipe, A. Lóffler, L. C. Lund-Hansen, A. Miltner, K. Pazdro, J. Pempkowiak, G. B. Shimmield, T. Shimmield, J. Smith, M. Voss, andG. Witt. 2002. Material transport from the nearshore to the basinal environment in the southern Baltic Sea II: Synthesis of data on origin and properties of material.Journal of Marine Systems 35:151–168.CrossRefGoogle Scholar
  18. Fock, H. O. 2003. Changes in the seasonal cycles of inorganic nutrients in the coastal zone of the southeastern North Sea from 1960 to 1997: Effects of eutrophication and, sensitivity to meteoclimatic factors.Marine Pollution Bulletin 46:1434–1449.CrossRefGoogle Scholar
  19. Galloway, J. N., R. W. Howarth, A. F. Michaels, S. W. Nixon, J. M. Prospero, andF. J. Dentener. 1996. Nitrogen and phosphorus budgets of the North Atlantic Ocean and its watershed.Biogeochemistry 35:3–25.CrossRefGoogle Scholar
  20. Gazeau, F., S. V. Smith, B. Gentili, M. Frankignoulle andJ.-P. Gattuso. 2004. The European coastal zone: Characterization and first assessment of ecosystem metabolism.Estuaries, Coastal and Shelf Science 60:673–694.CrossRefGoogle Scholar
  21. Greatbatch, R. J. 2000. The North Atlantic OscillationStochastic Environmental and Risk Assessment 14:213–242.CrossRefGoogle Scholar
  22. Grimvall, A., P. Stalnacke, andA. Tonderski. 2000. Time scales of nutrient losses from land to sea—A European perspective.Ecological Engineering 14:363–371.CrossRefGoogle Scholar
  23. Heath, M. R., A. C. Edwards, J. Pätsch, andW. R. Turrell. 2002. Modelling the behaviour of nutrient in the coastal waters of Scotland. Report of the Fisheries Research Services 10. Fisheries Research Services, Aberdeen, Scotland.Google Scholar
  24. Hickel, W. 1998. Temporal variability of micro- and nanoplankton in the German Bight in relation to hydrographic structure and nutrient changes.ICES Journal of Marine Science 55:600–609.CrossRefGoogle Scholar
  25. Hickel, W., J. Berg, andK. Treutner. 1992. Variability in the biomass in the German Bight near Helgoland, 1980–1990.ICES Marine Science Symposia 195:249–259.Google Scholar
  26. Hickel, W., P. Mangelsdorf, andJ. Berg. 1993. The human impact in the, German Bight: Eutrophication during three decades (1962–1991).Helgoländer Meeresuntersuchungen 47:243–263.CrossRefGoogle Scholar
  27. Howarth, R. W., G. Billen, D. Swaney, A. Townsend, N. Jaworski, K. Lajtha, J. A. Downing, R. Elmgrem, N. Caraco, T. Jordan, F. Berendse, J. Freney, V. Kudeyarov, P. Murdoch, andZ. Zhu. 1996. Regional nitrogen budgets and riverine N and P fluxes for the drainages to the North Atlantic Ocean: Natural and human influences.Biogeochemistry 35:75–139.CrossRefGoogle Scholar
  28. Hurrell, J. W. 1995. Decadal trends in the North Atlantic Oscillation: Regional temperatures and precipitation.Science New Series 269:676–679.Google Scholar
  29. Hurrell, J. W. andH. Van Loon. 1997. Decadal variations in climate associated with the North Atlantic Oscillation.Climatic Change 36:301–326.CrossRefGoogle Scholar
  30. Ibrekk, H. O., J. Molvaer, andB. Faafeng. 1991. Nutrient loading to Norwegian coastal waters and its contribution to the pollution of the North Sea.Water Science and Technology 24: 239–249.Google Scholar
  31. Jickells, T. D. 1998. Nutrient biogeochemistry of the coastal zone.Science 281:217–222.CrossRefGoogle Scholar
  32. Kempe, S. 1995. Coastal seas: A net source or sink of atmospheric carbon dioxide? LOICZ/R&C/95-1, LOICZ. Texel, The Netherlands.Google Scholar
  33. Lenhart, H.-J. andJ. Pätsch. 2001. Daily nutrient loads of the European continental rivers for the years 1977–1998. Berichte aus dem Zentrum für Meeres- und Klimaforschung. Reihe B: Ozeanographic 40. Institut für Meereskunde, Hamburg, Germany.Google Scholar
  34. Lenhart, H.-J., J. Pätsch, andG. Radach. 1996. Daily nutrient loads for the European continental rivers for the years 1977–1993. Berichte aus dem Zentrum für Meeres- und Klimaforschung; Reihe B: Ozeanographie 22. Institut für Meereskunde, Hamburg, Germany.Google Scholar
  35. Lenhart, H.-J., G. Radach, andP. Ruardij. 1997. The effects of river input on the ecosystem dynamics in the continental coastal zone of the North Sea using ERSEM.Journal of Sea Research 38:249–274.CrossRefGoogle Scholar
  36. Littlewood I. G., C. D. Watts, andJ. M. Custance. 1998. Systematic application of United Kingdom river flow and quality databases for estimating annual river mass loads (1975–1994).The Science of the Total Environment 210:21–40.CrossRefGoogle Scholar
  37. Lozan, J. L. andH. Kausch. 1996 Warnsignale aus den Flüssen. Verlag Paul Parey. Berlin, Germany.Google Scholar
  38. McIsaac, G. F., M. B. David, G. Z. Gertner, andD. A. Goolsby. 2002. Nitrate flux in the Mississippi River,Nature 414:166–167.CrossRefGoogle Scholar
  39. Moll, A. andG. Radach. 2003. Review of three-dimensional ecological modelling related to the North Sea shelf system-Part 1: Models and their results.Progress in Oceanography 57:175–217.CrossRefGoogle Scholar
  40. Nelissen P. H. M. andJ. Steffels., 1988. Eutrophication in the North Sea. NIOZ Rapport. 4. Netherlands Institute of Sea Research, Texel, The Netherlands.Google Scholar
  41. Nixon, S. W., J. W. Ammerman, L. P. Atkinson, V. M. Berounsky, G. Billen, W. C. Boicourt, W. R. Boynton, T. M. Church, D. M., Ditoro, R. Elmgren, J. H. Garber, A. E. Giblin, R. A. Jahnke, N. J. P. Owens, M. E. Q. Pilson, andS. P. Seitzinger. 1996. The fate of nitrogen and phosphorus at the land-sea margin of the North Atlantic Ocean.Biogeochemistry 35:141–180.CrossRefGoogle Scholar
  42. North Sea Task Force. 1993 North Sea Quality Status Report 1993. Oslo and Paris Commission (OSPAR). Olsen and Olsen, Fredensborg, Denmark.Google Scholar
  43. Oslo and Paris Commission (OSPAR). 2000. Quality Status Report 2000—Region II Greater North Sea. Oslo and Paris Commission, London, U.K..Google Scholar
  44. Oslo and Paris Commission (OSPAR). 2001. EUC 00/3/3, Annex 2, Appendix 3, Tables B, update June 2001. EUC 00/3/3. Oslo and Paris Commission, London, U.K.Google Scholar
  45. Oslo and Paris Commission (OSPAR). 2002. Proposal from ETG 2001 for draft common assessment criteria, their assessment levels and area classification within the Comprehensive Procedure of the Common Procedure. EUC 01/2/2. Oslo and Paris Commission, London, U.K.Google Scholar
  46. Oslo and Paris Commission (OSPAR). 2003. OSPAR integrated report 2003, on the eutrophication status of the OSPAR maritime areas based upon the first application, of the Comprehensive Procedure. Oslo and Paris Commission, London, U.K.Google Scholar
  47. Oslo and Paris Commission (OSPAR),M. Villars, I. de Vries, M. Bokhorst, J. Ferreira, S. Gellers-Barkman, B. Kelly-Gerreyn, C. Lancelot, A. Menesguen, A. Moll, J. Pätsch, G. Radach, M. Skogen, H. Soiland, E. Svendsen, and H. J. Vested. 1998. Report of the ASMO modelling workshop on eutrophication Issues, 5–8 November 1996, The Hague, The Netherlands. Oslo and Paris Commission, The Hague, The Netherlands.Google Scholar
  48. Pätsch, J. andH.-J. Lenhart. 2004. Daily loads of nutrients, total alkalinity, dissolved inorganic carbon and dissolved organic carbon of the European continental rivers for the years 1977–2002. Berichte aus dem Zentrum für Meeres- und Klimaforschung; Reihe B: Ozeanographie 48. Institut für Meereskunde, Hamburg, Germany.Google Scholar
  49. Pätsch, J. andG. Radach. 1997. Long-term simulation of the eutrophication of the North Sea: Temporal development of nutrients, chlorophyll and primary, production in comparison to observations.Journal of Sea Research 38:275–310.CrossRefGoogle Scholar
  50. Postma, H. 1978. The nutrient contents of North Sea water: Changes in recent years, particularly in the Southern Bight.Rapport et Proces-verbaux des Reunions de Conseil Permanent International Pour l'Exploration de la Mer 172:350–357.Google Scholar
  51. Proctor, R., J. T. Holt, I. Allen, andJ. Blackford. 2003. Nutrient fluxes and budgets for the northwest European shelf from a three-dimensional model.The Science of the Total Environment 314–316:769–785.CrossRefGoogle Scholar
  52. Radach, G. 1992. Ecosystem functioning in the German Bight under continental nutrient inputs by rivers.Estuaries 15:477–496.CrossRefGoogle Scholar
  53. Radach, G. 1998. Quantification of long-term changes in the German Bight using an ecological development index.ICES Journal of Marine Science, 55:587–599.CrossRefGoogle Scholar
  54. Radach, G., J. Berg, andE. Hagmeier. 1990. Long-term changes of the annual cycles of meteorological, hydrographic, nutrient and phytoplankton time series at Helgoland and at LV ELBE 1 in the German Bight.Continental Shelf Research 10:305–328.CrossRefGoogle Scholar
  55. Radach, G. andH.-J. Lenhart. 1995. Nutrient dynamics in the North Sea: Fluxes and budgets in the water column derived from ERSEM.Netherlands Journal of Sea Research 33:301–335.CrossRefGoogle Scholar
  56. Radach, G. andA. Moll. 2006 Review of three-dimensional ecological modelling related to the North Sea shelf system—Part 2: Model validation and data needs.Oceanography and Marine Biology. An Annual Review 44:1–60.Google Scholar
  57. Rhyther, J. H. andW. M. Dunstan. 1971. Nitrogen, phosphorous, and eutrophication in the coastal marine environment.Science 171:1008–1013.CrossRefGoogle Scholar
  58. Rosenberg, R. 1985. Eutrophication—the future marine coastal nuisance?Marine Pollution Bulletin 16:227–231.CrossRefGoogle Scholar
  59. Seitzinger, S. P. andA. E. Giblin. 1996 Estimating denitrification in North Atlantic continental shelf sediments.Biochemistry 35: 235–260.Google Scholar
  60. Shorthouse, C. A. andN. W. Arnell. 1999. The effects of climatic variability on spatial characteristics of European river flows.Physics and Chemistry of the Earth B 24:7–13.Google Scholar
  61. Stalnacke, P., A. Grimvall, C. Libiseller, M. Laznik, andI. Kokorite. 2003. Trends in nutrient concentrations in Latvian rivers and the response to the dramatic change in agriculture.Journal of Hydrology 283:184–205.CrossRefGoogle Scholar
  62. Sündermann, J., G. Becker, P. Damm, D van den Eynde, A. Frohse, R. Laane, W. van Leussen, T. Pohlmann, W. van Raaphorst, G. Radach, H. Schultz, andM. Visser. 1996. Decadal variability on the northwest European Shelf.Deutsche Hydrographische Zeitschrift 48:365–400.CrossRefGoogle Scholar
  63. Thomas, H., Y. Bozec, H. de Baar, K. Elkalay, M. Frankignoulle, W. Kühn, H. Lenhart, A. Moll, J. Pätsch, G. Radach, L.-S. Schiettecatte, andA. Borges. 2006. Carbon and nutrient budgets of the North Sea. In L. Atkinson, K. K. Liu, R. Quinones, and L. Talaue-McManus (eds.), Carbon and Nutrient Fluxes in Global Continental Margins. Springer, New York, In press.Google Scholar
  64. Van Beusekom, J. E. E., P. Bot, J. Göbel, M. Hanslik, H.-J. Lenhart, J. Pätsch, L. Peperzak, T. Petenati, and,K. Reise. 2005. Eutrophication.Wadden, Sea Ecosystem 19:141–154.Google Scholar
  65. Van Beusekom, J. E. E., U. H. Brockmann, K. H. Hesse, W. Hickel, K. Poremba, andU. Tillmann. 1999. The importance of sediments in the transformation and turnover of nutrients and organic matter in the Wadden Sea and German Bight.Deutsche Hydrographische Zeitschrift 51:245–266.CrossRefGoogle Scholar
  66. Van Beusekom, J. E. E. andS. Diel-Christiansen. 1994. A synthesis of phyto- and zooplankton dynamics in the North Sea environment. International Report June 1994. World Wide Fund For Nature (WWF). Hamburg, Germany.Google Scholar
  67. Visser, M., S. Batten, G. Becker, P. Bot, F. Colijn, P. Damm, D. Danielssen, D. van den Eynde, L. Foyn, A. Frohse, G. Groeneveld, R. Laane, W. van Raaphorst, G. Radach, H. Schultz, andJ. Sündermann. 1996 Time series analysis of monthly mean data of temperature, salinity, nutrients, suspended matter, phyto- and zooplankton at eight locations on the Northwest European shelf.Deutsche Hydrographische Zeitschrift 48:299–323.CrossRefGoogle Scholar
  68. Voß, M. andU. Struck. 1997. Stable nitrogen and carbon isotopes as indicators of eutrophication in the Oder River (Baltic Sea).Marine Chemistry 59:35–59.CrossRefGoogle Scholar
  69. Wulff, F., L. Rahm, andP. Larsson (eds.) 2001. A Systems Analysis of the Baltic Sea. Ecological Studies 148. Springer, Berlin, Germany.Google Scholar

Copyright information

© Estuarine Research Federation 2007

Authors and Affiliations

  1. 1.NorderstedtGermany
  2. 2.Institut für MeereskundeHamburgGermany

Personalised recommendations