Hydrobiologia

, Volume 492, Issue 1–3, pp 119–127 | Cite as

Inorganic nutrient and oxygen fluxes across the sediment–water interface in the inshore macrophyte areas of a shallow estuary (Lake Illawarra, Australia)

  • Wenchuan Qu
  • R. J. Morrison
  • R. J. West
Article

Abstract

Rates of inorganic nutrient and oxygen fluxes, and gross community primary productivity were investigated using incubated cores in July, August and September 2001, in a seagrass meadow of Lake Illawarra, a barrier estuary in New South Wales, Australia. The results indicated that rates of gross primary productivity were high, varying from C = 0.62 to 1.89 g m−2 d−1; low P/R ratios of 0.28–0.48 define the system as heterotrophic and indicate that more carbon is respired than is produced. In order to determine the effect of macroalgae on O2 and nutrient fluxes, measurements were also conducted on cores from which the macroalgae had been removed. The results showed that the O2 fluxes during light incubations were significantly lower in the cores without macroalgae (P<0.01), indicating that macroalgae could be a significant contributor to the primary production in the lake. In general, nutrient fluxes showed a typical diurnal variation with an efflux from sediments in the dark and a reduced efflux (or uptake) in the light. Dissolved inorganic nitrogen (NO2+ NO3+NH4+) net fluxes were directed from the sediments towards the water column and dominated by the NH4+ fluxes (>80%). NO2+ NO3 and o-P fluxes were always very low during the sampling period. The increasing tendency of net nutrient effluxes, especially NH4+ from July to September, is consistent with the increase of the water temperature and seagrass biomasses. However, in September, significantly lower light, dark and net NH4+ effluxes were found in the cores with macroalgae (SA-sediments) compared with the cores without macroalgae (S-sediments). These results support the hypothesis that actively-growing dense macroalgal mats (i.e., algal blooms in September) may act as a filter reducing the flux of nutrients to the water column.

benthic fluxes primary production Lake Illawarra sediments nutrients seagrass 

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References

  1. Berelson, W. M., D. Heggie, A. Longmore, T. Kilgore, G. Nicholson & G. Skyring, 1998. Benthic Nutrient Recycling in Port Phillip Bay, Australia. Estuar. coast. shelf Sci. 46: 917-934.Google Scholar
  2. Bartoli, M., M. Cattadori, G. Giodani & P. Viaroli, 1996. Benthic oxygen respiration, ammonium and phosphorus regeneration in surficial sediments of the Sacca di Gorro (northern Italy) and two French coastal lagoons: a comparative study. Hydrobiologia. 329: 143-159.Google Scholar
  3. Cabrita, M. T. & V. Brotas, 2000. Seasonal variation in denitrification and dissolved nitrogen fluxes in intertidal sediments of the Tagus estuary, Portugal. Mar. Ecol. Prog. Ser. 202: 51-65.Google Scholar
  4. Christensen, P. B., L. P. Nielsen, J. Sorensen & N. P. Revsbech, 1990. Denitrification in nitrate-rich streams: Diurnal and seasonal variation related to benthic oxygen metabolism. Limnol. Oceanogr. 35: 640-651.Google Scholar
  5. Davey, S., 1994. Nutrient Flux Rates in Sediments in Lake Illawarra. Australian Water Technologies, Sydney Water Board, Sydney: 23 pp.Google Scholar
  6. Duarte, C. M., 1995. Submerged aquatic vegetation in relation to different nutrient regimes. Ophelia 41: 87-112.Google Scholar
  7. Ellis, J., S. Kanamori & P. G. Laird, 1977. Water pollution studies on Lake Illawarra I. Salinity variations and estimation of residence time. Aust. J. mar. Freshwat. Res. 28: 479-484.Google Scholar
  8. Eyre, B. D. & A. J. Ferguson, 2002. Comparison of carbon production and decomposition, benthic nutrient fluxes and denitrification in seagrass, phytoplankton, benthic microalgal and macroalgal dominated warm temperate Australian lagoons. Mar. Ecol. Prog. Ser. (in press).Google Scholar
  9. Ford, P.W. & I. T. Webster, 1997. Analysis of Nitrogen Fluxes from Lake Illawarra Sediments. Interim Report. CSIRO Division of Land and Water, Canberra: 17 pp.Google Scholar
  10. Harris, M. M., 1977. Ecological study on Illawarra Lake with special reference to Zostera Capricorni Ascherson. School of Botany, University of NSW. M. Sc. Thesis.Google Scholar
  11. Hemminga M. A., B. P. Koutstaal, J. van Soelen & G. A. Merks, 1994. The nitrogen supply to intertidal eelgrass (Zostera marina). Mar. Biol. 118: 223-227.Google Scholar
  12. Kamer K., K. A. Boyle & P. Fong, 2001. Macroalgal blooms dynamics in a highly eutrophic southern California estuary. Estuaries 24: 623-635.Google Scholar
  13. King, R. J., 1988. The seagrass of Lake Illawarra, New SouthWales. Wetlands (Australia) 8: 21-26.Google Scholar
  14. Kirkman, H., 1997. Seagrass of Australia. State of the Environment Technical Paper Series (Estuaries and the Sea). Environment Australia. Central Queensland University Publishing Unit. Queensland.Google Scholar
  15. Krause-Jensen, D., K. McGlathery, S. Rysgaard & P. B. Christensen, 1996. Production within dense mats of the filamentous macroalga Chaetomorpha linum in relation to light and nutrient availability. Mar. Ecol. Prog. Ser. 134: 207-216.Google Scholar
  16. Kuster, N., 2000. An Assessment of Carbon: Nitrogen Content and Stable Isotope Ratios of Seagrasses, Macroalgae and Sediment in Lake Illawarra NSW. University of Wollongong. MEnv. Sc. Thesis: 78 pp.Google Scholar
  17. LIA, 1995. Lake Illawarra Works Program Environmental Appraisal (Impact on Lake Nutrient Dynamics). Lake Illawarra Authority, Wollongong: 122 pp.Google Scholar
  18. Miller, C. L., 1998. Examination of Nutrient Budgets for the Lake Illawarra System: Utilizing LOICZ Modelling Techniques. University of Wollongong. MEnv. Sc. Thesis: 57 pp.Google Scholar
  19. Raffaelli D. G., J. A. Raven & L. J. Poole, 1998. Ecological impact of green macroalgal blooms. In Ansell A. D., R. N. Gibson & M. Barnes (eds), Oceanography and Marine Biology: an Annual Review. UCL Press.Google Scholar
  20. Revsbech, N. P., 1989. An oxygen microsensor with a guard cathode. Limnol. Oceanogr. 34: 474-478.Google Scholar
  21. Rizzo, W. M., B. E. Rerry, R. L. Wetzel, S. K. Dailey, D. J. Lackey & R. R. Christian, 1996. A metabolism-based trophic index for comparing the ecological values of shallow-water sediment habitats. Estuaries 19: 247-256.Google Scholar
  22. Rysgaard, S., N. Risgaard-Petersen & N. P. Sloth, 1996. Nitrification, denitrification, and nitrate ammonification in sediments of two coastal lagoons in Southern France. Hydrobiologia 329: 133 -141.Google Scholar
  23. Schramm, W., E. Gualberto & C. Orosco, 1984. Release of dissolved organic matter from marine tropical reef plants: temperature and desiccation effects. Bot. Mar. 27: 71-77.Google Scholar
  24. Sherman, B., P. W. Ford, I. T. Webster, R. J. Morrison & R. J. West, 2000. Lake Illawarra Data Compilation and Assessment. Report prepared for the Lake Illawarra Authority, CSIRO Division of Land & Water, Canberra: 41 pp.Google Scholar
  25. Smith S. V., S. Ibarra-Obndo, P. R. Boudreau & V. F. Camacho-Ibar, 1997. Comparison of carbon, nitrogen and phosphorous fluxes in Mexican coastal lagoons. LOICZ Reports & Studies 10. URL: www.kellia.nioz.nl/loicz.Google Scholar
  26. Webster, I. T., P. W. Ford & B. Hodgson, 2002. Microphytobenthos contribution to nutrient-phytoplankton dynamics in a shallow coastal lagoon. Estuaries 25: 540-551.Google Scholar
  27. Welsh, D. T., M. Bartoli, D. Nizzoli, G. Castaldelli, S. A. Riou & P. Viaroli, 2000. Denitrification, nitrogen fixation, community primary production in an intertidal Zostera noltii meadow. Mar. Ecol. Prog. Ser. 208: 65-77.Google Scholar
  28. Yassini, I., 1985. Nutrient Pools of Lake Illawarra: Investigation and Management Strategy. Lake Illawarra Management Committee, Wollongong: 26 pp.Google Scholar
  29. Yassini, I. & A. Clarke, 1986. Aspects of Urban Stormwater Pollution of Lake Illawarra. Wollongong. Lake Illawarra Management Committee, Wollongong: 40 pp.Google Scholar

Copyright information

© Kluwer Academic Publishers 2003

Authors and Affiliations

  • Wenchuan Qu
    • 1
    • 2
  • R. J. Morrison
    • 1
  • R. J. West
    • 1
  1. 1.Oceans and Coastal Research Centre, Environmental ScienceUniversity of WollongongAustralia
  2. 2.Lake Sediment and Environment Research LaboratoryNanjing Institute of Geography and Limnology, Chinese Academy of SciencesNanjingChina

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