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Advances in the aquatic sciences
RESEARCH ARTICLE

The relationship between sediment and water quality, and riverine sediment loads in the wave-dominated estuaries of south-west Western Australia

L. C. Radke A F , I. P. Prosser B , M. Robb C , B. Brooke A , D. Fredericks A , G. B. Douglas D and J. Skemstad E
+ Author Affiliations
- Author Affiliations

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

B CSIRO Land and Water, GPO Box 1666, Canberra, ACT 2601, Australia.

C Waters and Rivers Commission, PO Box 6740, East Perth, Western Australia.

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

E CSIRO Land and Water, PMB 2, Glen Osmond, SA 5064, Australia.

F Corresponding author. Email: Lynda.Radke@ga.gov.au

Marine and Freshwater Research 55(6) 581-596 https://doi.org/10.1071/MF04044
Submitted: 10 March 2004  Accepted: 20 May 2004   Published: 14 September 2004

Abstract

We examine surface sediment and water column total nutrient and chlorophyll a concentrations for 12 estuaries with average water depths <4 m, and calculated sediment loads ranging from 0.2 to 10.8 kg m−2 year−1. Sediment total nitrogen, phosphorus and organic carbon concentrations vary inversely with sediment loads due to: (i) the influx of more mineral-rich sediment into the estuaries; and (ii) increasing sediment sulfidation. Sediment total organic carbon (TOC) : total sulfur (TS) and TS : Fe(II) ratios correlated to sediment loads because enhanced sedimentation increases burial, hence the importance of sulfate reduction in organic matter degradation. Curvilinear relationships were found between a weathering index and organic matter δ13C in sediment, and sediment load. The rising phase of the curve (increasing weathering, lighter isotopic values) at low to intermediate loads relates to soil erosion, whereas regolith or bedrock erosion probably explains the declining phase of the curve (decreasing weathering, heavier isotopic values) at higher sediment loads. The pattern of change for water column total nutrients (nitrogen and phosphorus) with sediment loads is similar to that of the weathering index. Most water quality problems occur in association with soil erosion, and at sediment loads that are intermediate for the estuaries studied. Limited evidence is presented that flushing can moderate the impact of sediment loads upon the estuaries.

Extra keywords: Australian National Land and Water Resources Audit, chlorophyll a, gully erosion, harmful algal blooms, pyrite, riverbank erosion.


Acknowledgments

We are grateful to Ian Webster, Ralf Haese, Graham Skyring, Phillip Ford and David Heggie for reading earlier drafts of this paper and for providing important critical feedback. The comments provided improved the overall quality of the manuscript. Thanks also to Colin Tindall, Ian Atkinson, Geoff Bastyan, Ben Boardman and Linda Kalnejais for helping with the field-work, Cam Mitchell for assistance with geographic information systems (GIS), David Champion for providing the average chemical composition of Yilgarn granites; Veronika Galinec, Chris Fitzgerald and Brian Pashley for drafting the figures; and Alan Hinde, Tan Kok Piang and Lesley Wyborn for advice regarding methods. X-ray fluorescence and X-ray diffractometer analyses were conducted at Geoscience Australia by John Pyke, and Algis Juoldvalkis respectively. The 210Pb dating used to determine sedimentation rates was done by Henk Heijnis and Jenny Harrison (Green Trends, ANSTO).


References

Abernethy, B. , and Rutherfurd, I. D. (2000). The effect of riparian tree roots on the mass-stability of riverbanks. Earth Surface Processes and Landforms 25, 921–937.
Crossref | GoogleScholarGoogle Scholar | Kalnejais L. , McMahon K. , and Robb M. (1999). Swan-Canning Estuary, Western Australia. In ‘Australasian Estuarine Systems: Carbon, Nitrogen and Phosphorus Fluxes’. LOICZ Reports and Studies No. 12. (Eds S. V. Smith and C. J. Crossland.) pp. 74–90. (LOICZ IPO: Texel, The Netherlands.)

Lovely, D. R. (1991). Dissimilatroy Fe(III) and Mn(IV) Reduction. Microbiological Reviews 55, 259–287.
PubMed | Shapiro L. , and Brannock W. W. (1962). ‘Rapid Analysis of Silicate, Carbonate and Phosphate Rocks. USGS Bulletin 1144-A.’ (United States Geological Survey: Reston, VA, USA)

Singh, B. , and Gilkes, R. J. (1991). Phosphorus sorption in relation to soil properties for the major soil types of south-western Australia. Australian Journal of Soil Research 29, 603–618.
Sloss C. (2001). ‘Holocene Stratigraphic Evolution and Recent Sedimentological Trends, Lake Illawarra, NSW.’ BSc Honours Thesis (University of Wollongong: Wollongong, Australia.)

Thornton, J. A., McComb, A. J. and  Ryding, S.-O. (1995). The role of sediments. In ‘Eutrophic Shallow Estuaries and Lagoons’. (Ed A. J. McComb.)  pp. 205–223. (CRC Press: Boca Raton, Florida, USA.)

Wallbrink, P. J. , Olley, J. M. , Murray, A. S. , and Olive, L. J. (1998). Determining sediment sources and transit times of suspended sediment in the Murrumbidgee River, NSW, Australia using fallout 137Cs and 210Pb. Water Resources Research 34, 879–887.
Crossref | GoogleScholarGoogle Scholar |

Wasson, R. J. , Olive, L. J. , and Rosewell, C. J. (1996). Rates of erosion and sediment transport in Australia. International Association of Hydrological Sciences Publication 236, 139–148.


Webster, I. T. , and Harris, G. P. (2004). Anthropogenic impacts on the ecosystems of coastal lagoons - modelling fundamental biogeochemical processes and management implications. Marine and Freshwater Research 55, 67–78.
Crossref | GoogleScholarGoogle Scholar |