Register      Login
Marine and Freshwater Research Marine and Freshwater Research Society
Advances in the aquatic sciences
Shopping Cart: ( empty )
You are here: Home > Journals > MF > MF05046
RESEARCH ARTICLE
Contents Vol 57(8)

Seasonal changes in major ions, nutrients and chlorophyll a at two sites in the Swan River estuary, Western Australia

D. P. Hamilton A B E , G. B. Douglas C , J. A. Adeney C and L. C. Radke D
+ Author Affiliations
- Author Affiliations

A Centre for Biodiversity and Ecology Research, University of Waikato, Private Bag 3105, Hamilton 3240, New Zealand.

B Previous address: Centre for Water Research, The University of Western Australia, Crawley, WA 6009, Australia.

C CSIRO Land and Water, Centre for Environment and Life Sciences, Private Bag Floreat, WA 6014, Australia.

D Geoscience Australia, GPO Box 378, Canberra, ACT 2601, Australia.

E Corresponding author. Email: d.hamilton@waikato.ac.nz

Marine and Freshwater Research 57(8) 803-815 https://doi.org/10.1071/MF05046
Submitted: 6 March 2006  Accepted: 10 October 2006   Published: 28 November 2006

Abstract

Seasonal variations in major ions, nutrients and chlorophyll a were examined at two sites in the upper reaches of the Swan River estuary, Western Australia. Intra-annual variations between the variables were strongly influenced by seasonal riverine discharge, though major ions behaved highly conservatively across a wide range of salinity. Reduced discharge following winter produced strong density stratification that coincided with upstream salt wedge propagation and produced distinct physico-chemical identities of surface and bottom waters. Anoxia of bottom waters associated with the salt wedge region induced increased concentrations of ammonium and phosphate, especially at the deeper of the two sites. Locally variable groundwater flow may have also been important in transporting sediment porewater nutrients into the water column. The seasonality of riverine discharge produced large intra-annual variations in temperature (13–29°C) and salinity (3–30). Transient increases in turbidity occurred when the salt wedge coincided with the position of sampling locations. The subsequent flocculation process likely contributed to further oxygen consumption and nutrient regeneration from the bottom sediments, while simultaneously depositing nutrient-rich flocs with low molar N:P ratios (3–8) to the sediment surface. Nutrient ratios and absolute nutrient concentrations suggest that nitrogen is the nutrient most likely to limit phytoplankton growth over most of the year.

Extra keywords: anoxia, major ions, nutrients, salt wedge, sediments.


Acknowledgments

The authors acknowledge the assistance of Y. Oliver, J. Hosking and B. van Herk (water quality analysis), S. Gunashanhar (water sampling) and the Water and Rivers Commission and the Swan River Trust (algal identification and field assistance). We thank G. Jones for a review of an earlier version of this manuscript. This study was funded by the CSIRO Blue-Green Algal Program.


References

Ackroyd, D. R. , Millward, G. E. , and Morris, A. W. (1987). Periodicity in the trace metal content of estuarine sediments. Oceanologica Acta 10, 161–168.
APHA (1985). Standard methods for the examination of water and wastewater. American Public Health Association, Washington, D.C.

Astill, H. , and Lavery, P. (2001). The dynamics of unattached benthic macroalgal accumulations in the Swan-Canning Estuary. Hydrological Processes 15, 2387–2399.
| Crossref | GoogleScholarGoogle Scholar | Douglas G. B., Hamilton D. P., Gerritse R. G., and Adeney J. A. (1996). An investigation of water quality at two sites in the Swan River estuary 1993/4. CSIRO Division of Water Resources Report 96–2.

Douglas G. B., Hamilton D. P., Gerritse R. G., Adeney J. A., and Coad D. N. (1997). Sediment geochemistry, nutrient fluxes and water quality in the Swan River Estuary, Western Australia. In ‘Managing Algal Blooms, Outcomes from CSIRO’s multi-divisional blue-green algal program.’ (Ed. J. R. Davis.) pp. 15–30. (CSIRO Land and Water.)

Ebina, J. , Tsutsui, T. , and Shirae, T. (1983). Simultaneous determination of total nitrogen and total phosphorus in water using peroxodisulfate oxidation. Water Research 17, 1721–1726.
| Crossref | GoogleScholarGoogle Scholar | Hamilton D. P., Thompson P. A., Kurup R., and Horner-Rosser J. (1999). Dynamics of dinoflagellate blooms in the Swan River Estuary. In ‘Wetlands for the Future, INTECOL’S Vth International Wetlands Conference’. (Eds A. J. McComb and J. A. Davis.) pp. 273–286. (Gleneagles Publishing: Adelaide.)

Hamilton D. P., Chan T. U., Robson B. J., and Hodges B. R. (2000). The effects of freshwater flows and salinity on phytoplankton biomass and composition in an urban estuary, The Swan River, Western Australia. In ‘Proceedings, 3rd International Hydrology and Water Resources Symposium (Hydro 2000)’ (Volume 1). pp. 114–119.

Hamilton, D. P. , Chan, T. , Robb, M. S. , Pattiaratchi, C. B. , and Herzfeld, M. (2001). The hydrology of the upper Swan River with focus on an artificial destratification trial. Hydrological Processes 15, 2465–2480.
| Crossref | GoogleScholarGoogle Scholar | Henderson A., Humphries R. B., and Hosja W. (1983). Time series plots of Swan-Canning estuarine system, physico-chemical data 1944–1980. Applied Systems Working Group Paper WP/25. Centre for Resource and Environmental Studies. Australian National University, Canberra.

Herczeg, A. L. , and Lyons, W. B. (1991). A chemical model for the evolution of Australian sodium chloride lake brines. Palaeogeography, Palaeoclimatology, Palaeoecology 84, 43–53.
| Crossref | GoogleScholarGoogle Scholar | Jack P. (1987). Nutrient monitoring in the Swan River Estuary. In ‘Curtin University Environmental Studies Group Report No. 1’. (Ed. J. John.) pp. 45–64. (Curtin University, Western Australia.)

Johannes, R. , Pearce, A. , Weibe, C. , Crossland, C. , Rimmer, D. , Smith, D. , and Manning, C. (1994). Nutrient characteristics of well mixed coastal waters off Perth, Western Australia. Estuarine, Coastal and Shelf Science 39, 273–285.
| Crossref | GoogleScholarGoogle Scholar | John J. (1994). Eutrophication of the Swan River Estuary, Western Australia and the management strategy. In ‘Global Wetlands: Old World and New’. (Ed. W. J. Mitsch.) pp. 749–757. (Elsevier Science, B.V.)

Kerner, M. , and Gramm, H. (1995). Changes in oxygen consumption at the sediment-water interface formed by settling seston from the Elbe Estuary. Limnology and Oceanography 40, 544–555.
Keywood M. (1995). Origins and sources of atmospheric precipitation from Australia: chlorine-36 and major element chemistry. Ph.D Thesis, Australian National University, Canberra.

Kuo, A. Y. , and Nielson, B. J. (1987). Hypoxia and salinity in Virginia estuaries. Estuaries 10, 277–283.
| Crossref | GoogleScholarGoogle Scholar | McComb A. J., and Lukatelich R. J. (1986). Nutrients and plant biomass in Australian estuaries, with particular reference to south-western Australia. In ‘Limnology in Australia’. (Eds P. De Deckker and W. D. Williams.) pp. 433–456. (CSIRO/Dr W. Junk, Melbourne.)

Monbet, Y. (1992). Control of phytoplankton biomass in estuaries: a comparative analysis of microtidal and macrotidal estuaries. Estuaries 15, 563–571.
| Crossref | GoogleScholarGoogle Scholar | Redfield A. C., Ketchum B. H., and Richards F. A. (1963). The influence of organisms on the composition of seawater. In ‘The Sea, Vol. 2’. (Ed. M. N. Hill.) pp. 26–79. (Wiley Interscience: New York.)

Riegman R., Noordeloos A. A. M., and Cadee G. (1992), Phaeocystis blooms and eutrophication of the continental coastal zones of the North Sea. Marine Biology 112, 479–484.

Riggert T. L. (1978). The Swan River estuary development, management and preservation. The Swan River Conservation Board, Western Australia.

Robson, B. J. , and Hamilton, D. P. (2003). Summer flow event induces a cyanobacterial bloom in a seasonal Western Australian estuary. Marine and Freshwater Research 54, 139–151.
| Crossref | GoogleScholarGoogle Scholar | Ryther J. H., and Officer C. B. (1981). Impact of nutrient enrichment of water uses. In ‘Estuaries and Nutrients’. (Eds B. J. Neilson and L.E. Cronin.) pp. 247–261. (The Humana Press.)

Sellner, K. G. , Sellner, S. G. , Lacouture, R. V. , and Magnien, R. E. (2001). Excessive nutrients select for dinoflagellates in the stratified Patapsco River estuary: Margalef reigns. Marine Ecology Progress Series 220, 93–102.


Smetacek, V. , von Bodungen, B. , von Brockel, K. , and Zeitschel, B. (1976). The plankton tower II. Release of nutrients from sediments due to changes in the density of bottom water. Marine Biology 34, 373–378.
| Crossref | GoogleScholarGoogle Scholar |

Smith, S. M. , and Hitchcock, G. L. (1994). Nutrient enrichments and phytoplankton growth in the surface waters of the Louisiana Bight. Estuaries 17, 740–753.
| Crossref | GoogleScholarGoogle Scholar |

Stephens, R. , and Imberger, J. (1996). Dynamics of the Swan River Estuary; the seasonal variability. Marine and Freshwater Research 47, 517–529.
| Crossref | GoogleScholarGoogle Scholar |

Sweerts, J.-P. R. A. , Rudd, J. W. M. , and Kelly, C. A. (1986). Metabolic activities in flocculent surface sediments and underlying sandy littoral sediments. Limnology and Oceanography 31, 330–338.


Thompson, P. A. (1998). Spatial and temporal patterns of factors influencing phytoplankton in a salt wedge estuary, the Swan River, Western Australia. Estuaries 21, 801–817.
| Crossref | GoogleScholarGoogle Scholar |

Thompson, P. , and Hosja, W. (1996). The temporal dynamics of nutrient limitation in phytoplankton blooms from the Swan River Estuary, Western Australia. Marine and Freshwater Research 47, 659–667.
| Crossref | GoogleScholarGoogle Scholar |