Environmental effects of dredging on sediment nutrients, carbon and granulometry in a tropical estuary

  • S. NayarEmail author
  • D. J. Miller
  • A. Hunt
  • B. P. L. Goh
  • L. M. Chou


This monitoring study encompassed a period prior to dredging, during dredging and post dredging between July 1999 to June 2000 in Ponggol estuary located along the northeastern coast of Singapore. Mean concentrations of sediment nutrients in mg ⋅ Kg−1 (± standard error of means) prior to dredging, during dredging and post dredging were 9.75 ± 4.24, 8.18 ± 4.29 and 11.46 ± 4.74 for ammonium, 0.08 ± 0.05, 0.06 ± 0.02 and 0.09 ± 0.01 for nitrite, 0.04 ± 0.04, 0.11 ± 0.17 and 0.25 ± 0.30 for nitrate, 4.83 ± 3.48, 0.77 ± 0.48 and 8.33 ± 9.73 for phosphate respectively. Pre dredge, dredge and post dredge levels of total carbon (TC) were 18.5 ± 3.7, 20.2 ± 3.5 and 34.6 ± 12.0, of total organic carbon (TOC) were 10.5 ± 2.9, 19.5 ± 3.6 and 34.6 ± 12.0 and of total inorganic carbon (TIC) were 7.9 ± 1.0, 0.7 ± 0.4 and non detectable in the sediments, respectively. Both, sediment nutrients and carbon registered lower concentrations with onset of dredging, with the exception of nitrate and TOC. A shift in sedimentary carbon from inorganic carbon to organic carbon was also observed with the onset of the dredging activities when the organically enriched historically contaminated layer was exposed. Sediment granulometry showed that the sediments in the estuary were predominantly silt and clay prior to dredging, which changed to sand with onset of dredging. Silt load in the sediments was highest post-dredge. Sediment nutrients and sediment organic carbon were observed to associate with the finer fractions (silt and clay) of sediments. Finer fractions of sediments get resuspended during a dredging event and are dispersed spatially as the result of tides and water movements. Prior to this study, the potential for nutrient release and sediment granulometry due to dredging have been suggested, but there have been few studies of it, especially in the tropics. The baseline information gathered from this study could be used to work out effective management strategies to protect similar tropical ecosystems elsewhere, should there be no other alternative to dredging.


Dredging Nutrients Organic carbon Ponggol estuary Pollution Resuspension Inorganic carbon Sediment grain size Sediment surface area 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Amson, J.E. (1988). The Tampa Harbour project : A major monitoring success. Marine Pollutution Bulletin, 19, 637–646.Google Scholar
  2. Arfi, R., & Bouvy, M. (1995). Size, composition and distribution of particles related to wind-induced resuspension in a shallow tropical lagoon. Journal of Plankton Reserch, 17, 557–574.CrossRefGoogle Scholar
  3. Aston, S.R. (1980). Nutrients, dissolved gasses and general biogeochemistry in Estuaries. In: Olausson, E., & Cato, I. (eds.), Chemistry and biogeochemistry of estuaries, New York: John Wiley and Sons, pp. 231–262.Google Scholar
  4. Balls, P.W., Laslett, R.E., & Price, N.B. (1994). Nutrient and trace metal distributions over a complete semi-diurnal tidal cycle in the Forth Estuary, Scotland. Netherlands Journal of Sea Research, 33, 1–17.CrossRefGoogle Scholar
  5. Birch, G.F., & Taylor, S.E. (2000). The use of size-normalised procedures in the analysis of organic contaminants in estuarine sediments. Hydrobiologia, 431, 129–133.CrossRefGoogle Scholar
  6. Bubb, J.M., Rudd, T., & Lester, J.N. (1990). Distribution of heavy metals in the River Yare and its associated broads. III. Lead and ZInc. Science of the Total Environment, 102, 189–208.CrossRefGoogle Scholar
  7. Chan, E., Bursztynsky, T.A., Hantzsche, N., & Litwin, Y.J. (1982). The use of wetland for water pollution control. U.S.: Muncipal Environmental Research Laboratory, EPA-600/2-82-086.Google Scholar
  8. Cheung, Y.H., & Wong, M.H. (1993). Toxic effects of dredged sediments of Hong Kong coastal waters on clams. Environmental Technology, 14, 1047–1055.Google Scholar
  9. Chong, E.C., & Loo, M.G.K. (1990). A hydrobiological survey (1988) of Sungei Punggol. In Chou, L.M. (ed.), Coastal living resources of Singapore-Proceedings of a symposium on the assessment of living resources in the coastal areas of Singapore. Singapore: Department of Zoology, NUS, pp. 1–7.Google Scholar
  10. Chua, T.E. (1973). An ecological study of the Ponggol Estuary in Singapore. Hydrobiologia, 43, 505–533.CrossRefGoogle Scholar
  11. Coull, B.C., Greenwood, J.G., Fielder, D.R., & Coull, B.A. (1995). Subtropical Australian juvenile fish eat meiofauna : Experiments with winter whiting Sillago maculate and observations on other species. Marine Ecology Progress Series, 125, 13–19.Google Scholar
  12. Dunbabin, J.S., & Bowmer, K.H. (1992). Potential use of constructed wetland for treatment of industrial wastewaters containing metals. Science of the Total Environment, 111, 151–168.CrossRefGoogle Scholar
  13. Essink, K. (1999). Ecological effects of dumping of dredged sediments; options for management', Journal of Coastal Conservatrice, 5, 69–80.Google Scholar
  14. Fanning, K.A., Carder, K.L., & Betzer, P.R. (1982). Sediment resuspension by coastal waters: a potential mechanism for nutrient re-cycling on the ocean's margins. Deep-Sea Resrech, (Part A), 29, 953–965.CrossRefGoogle Scholar
  15. Ferreira, M.F., Chiu, W.S., Cheok, H.K., Cheang, C.F., & Sun, W. (1996). Accumulation of nutrients and heavy metals in surface sediments near Macao. Marine Pollution Bulletin, 32, 420–425.CrossRefGoogle Scholar
  16. Fisher, T.R., Carlson, P.R., & Barker, R.T. (1982). Sediment nutrient regeneration in three North Carolina estuaries. Estuarine, Coastal and Shelf Science, 14, 101–116.Google Scholar
  17. Forstner, U., Calmano, W., & Schoer, J. (1982). Metals in sediments from the Elbe, Weser and Ems Estuaries and from the German Bight : grain size effects and chemical forms. Thalassia Jugosi, 12, 30–38.Google Scholar
  18. Garstecki, T., Wickham, S.A., & Arndt, H. (2002). Effects of experimental sediment resuspension on a coastal planktonic microbial food web. Estuarine, Coastal and Shelf Science, 55, 751–762.CrossRefGoogle Scholar
  19. Goncalves, E.P.R., Boaventura, R.A.R., & Mouvet, C. (1992). Sediments and aquatic mosses as pollution indicators for heavy metals in the Ave River Basin. Science of the Total Environment, 114, 7–24.CrossRefGoogle Scholar
  20. Graf, G., & Rosenberg, R. (1997). Resuspension and biodeposition: a review. Journal of Marine Systems, 11, 269–278.CrossRefGoogle Scholar
  21. Gray, J.S., Aschan, M., Carr, M.R., Clarke, K.R., Herman, P.M. J., Huys, R., Smol, N., & Van Holsbeke, K. (1988). Analysis of community attributes of the benthic meiofauna of Frierfjord/Langesundfjord. Marine Ecology Progress Series, 46, 171–180.Google Scholar
  22. Goh, B.P.L., & Chou, L.M. (1997). Heavy metal levels in marine sediments of Singapore. Environmental Monitoring and Assessment, 44, 67–80.CrossRefGoogle Scholar
  23. Harbison, P. (1986). Mangrove muds–-A sink and a source for trace metals. Marine Pollution Bulletin, 17, 246–250.CrossRefGoogle Scholar
  24. Johnston, C. A. (1991). Sediment and nutrient retention by freshwater wetland: effects on surface water quality. Criteria Reviews of Environmental Contaminationrev, 21, 491–565.Google Scholar
  25. Kennish, M.J. (1986). Ecology of Estuaries. Florida, USA: CRC Press Inc.Google Scholar
  26. Kristensen, E. (1997). Carbon, sulfur and nitrogen biogeochemistry of tropical mangrove sediments. In Haq, B.U., Haq, S.M., Kullenberg, G., & Stel, J.H. (eds.), Coastal zone management imperative for maritime developing nations, Dordrecht: Kluwer Academic Publishers, pp. 393.Google Scholar
  27. Libes, S.M. (1992). An introduction to marine biogeochemistry. Singapore: John Wiley and Sons Inc.Google Scholar
  28. Lim, L.C., & Isao, S. (1984). A manual on chemical analysis of coastal water and bottom sediment. Singapore: Primary Production Department and Marine Fisheries Research Department, SEAFDC, pp. 42.Google Scholar
  29. Lohrer, A.M., & Wetz, J.J. (2003). Dredging–induced nutrient release from sediments to the water column in a southeastern saltmarsh tidal creek. Marine Pollution Bulletin, 46, 1156–1163.CrossRefGoogle Scholar
  30. Macfarlane, G.R., & Booth, D.J. (2001). Estuarine macrobenthic community structure in the Hawkesbury River, Australia: Relationships with sediment physicochemical and anthropogenic parameters. Environmental Monitoring and Assessment, 72, 51–78.CrossRefGoogle Scholar
  31. McHugh, J.L. (1976). Estuarine fisheries: Are they doomed? In: Wiley, M. (ed.), Estuarine Processes, Vol 1. New York: Academic Press, pp. 15–27.Google Scholar
  32. Morton, J.W. (1977). Ecological effects of dredging and dredge spoil disposal : A literature review. Technical papers of the US Fish and Wildlife Service, Technical paper 94, pp. 33.Google Scholar
  33. Nayar, S. (2003). Nutrient and biotic fluxes in relation to dispersal of pollutants in Ponggol river', PhD thesis, Faculty of Science. Singapore: National University of Singapore, pp. 424.Google Scholar
  34. Nayar, S., Goh, B.P.L., & Chou, L.M. (2004). The impact of petroleum hydrocarbons (diesel) on periphyton in an impacted tropical estuary based on in situ microcosms. Journal of Experimental Marine Biology and Ecology, 302, 213–232.CrossRefGoogle Scholar
  35. Nayar, S., Goh, B.P.L., & Chou, L.M. (2005). Environmental impacts of diesel fuel on bacteria and phytoplankton in a tropical estuary assessed using in situ mesocosms. Ecotoxicology, 14, 395–410.CrossRefGoogle Scholar
  36. Nixon, S.W. (1981). Remineralisation and nutrient cycling in coastal marine ecosystems. In Nielson, B.J., & Cronin, L.E. (eds.), Estuaries and Nutrients, Clifton, New Jersey: The Human Press, pp. 111–138.Google Scholar
  37. Nguyen, L.M., Cooke, J.G., & McBride, G.B. (1997). Phosphorus retention and release characteristics of sewage-impacted wetland sediments. Water Soil Air Pollution, 100, 163–179.CrossRefGoogle Scholar
  38. Parsons, T.R., Maita, Y., & Lalli, C.M. (1984). A manual of chemical and biological methods for seawater analysis. New York: Pergamon Press, p. 173.Google Scholar
  39. Pedersen, O.B., Christiansen, C., & Laursen, M.B. (1995). Wind-induced long-term increase and short-term fluctuations of shallow water suspended matter and nutrient concentrations. Ringkobing Fjord, Denmark', Ophelia 41, 273–287.Google Scholar
  40. Rivas, Z., Medina, H.L.D., Gutierrez, J., & Gutierrez, E. (2000). Nitrogen and phosphorus levels in sediments from tropical Catatumbo River (Venezuela). Water Soil Air Pollution, 117, 27–37.CrossRefGoogle Scholar
  41. Sakai, H., Kojima, Y., & Saito, K. (1986). Distribution of heavy metals in water and sieved sediment in the Toyohira River. Water Research, 20, 559–567.CrossRefGoogle Scholar
  42. Tengberg, A., Almroth, E., & Hall, P. (2003). Resuspension and its effects on organic carbon recycling and nutrient exchange in coastal sediments: in situ measurements using new experimental technology. Journal of Experimental Marine Biology and Ecology, 285–286, 119–142.Google Scholar
  43. Valiela, I. (1995). Marine Ecological Processes. 2nd ed. New York, USA: Springer Verlag.Google Scholar
  44. Wainright, S.C. (1987). Stimulation of heterotrophic microplankton production by resuspended marine sediments. Science, 238, 1710–1712.CrossRefGoogle Scholar
  45. Wainright, S.C. (1990). Sediment-to-water fluxes of particulate material and microbes by resuspension and their contribution to the planktonic food web. Marine Ecology Progress Series, 62, 271–281.Google Scholar
  46. Wilson, J.G., & Elkaim, B. (1992). Estuarine bioindicators –- a cause for caution. Acta Oecologica, 13, 345–358.Google Scholar
  47. Windom, H.L. (1976). Environmental aspects of dredging in the coastal zone. Critical Reviews of Environmental Control, 6, 91–109.CrossRefGoogle Scholar
  48. Wu, R.R. (1988). Marine pollution in Hong Kong: A review. Asian Marine Biology, 5, 1–23.Google Scholar
  49. Zimmerman, L.E., Jutte, P.C., & Van Dolah, R.F. (2003). An environmental assessment of the Charleston ocean dredged material disposal site and surrounding areas after partial completion of the Charleston Harbour deepening project. Marine Pollution Bulletin, 46, 1408–1419.CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, B.V. 2006

Authors and Affiliations

  • S. Nayar
    • 1
    Email author
  • D. J. Miller
    • 2
  • A. Hunt
    • 3
  • B. P. L. Goh
    • 4
  • L. M. Chou
    • 5
  1. 1.South Australian Research and Development Institute - Aquatic SciencesWest BeachAustralia
  2. 2.Department of Environment and HeritageCoast and Marine Conservation BranchKeswickAustralia
  3. 3.School of Biological SciencesUniversity of PlymouthPlymouthUK
  4. 4.Natural Sciences Academic Group, National Institute of EducationNanyang Technological UniversitySingaporeSingapore
  5. 5.Marine Biology Laboratory, Department of Biological SciencesNational University of SingaporeSingaporeSingapore

Personalised recommendations