Coral record of increased sediment flux to the inner Great Barrier Reef since European settlement

Fig. 2. The coral Ba/Ca record of Burdekin River suspended sediment.
The coral Ba/Ca record of suspended sediment into the GBR by the Burdekin river over approximately the past 250 years.
Coral record of increased sediment flux to the inner Great Barrier Reef since European settlement
Nature
Vol. 421, 727 - 730 (13 February 2003)
doi:10.1038/nature01361


Malcolm McCulloch1, Stewart Fallon1,3, Timothy Wyndham1, Erica Hendy1, Janice Lough2,and David Barnes2.

1 Research School of Earth Sciences, Australian National University, Canberra 0200, Australia
2 Australian Institute of Marine Science, Townsville, Queensland 4810, Australia
3 Present address: Lawrence Livermore National Laboratory, California, USA.

ABSTRACT:
The effect of European settlement on water quality in the Great Barrier Reef of Australia is a long-standing and controversial issue. Erosion and sediment transport in river catchments in this region have increased substantially since European settlement, but the magnitude of these changes remains uncertain. Here we report analyses of Ba/Ca ratios in long-lived Porites coral from Havannah Reef- a site on the inner Great Barrier Reef that is influenced by flood plumes from the Burdekin river- to establish a record of sediment fluxes from about 1750 to 1998. We find that, in the early part of the record, suspended sediment from river floods reached the inner reef area only occasionally, whereas after about 1870-following the beginning of European settlement- a five- to tenfold increase in the delivery of sediments is recorded with the highest fluxes occurring during the drought-breaking floods. We conclude that, since European settlement, land-use practices such as clearing and overstocking have led to major degradation of the semi-arid river catchments, resulting in substantially increased sediment loads entering the inner Great Barrier Reef.

DATA:
Download the data from this study:
Burdekin River flow and coral Ba/Ca data

To read or view the full study, please visit the Nature website.
It was published in Nature Vol. 421, 727 - 730 (13 February 2003) doi:10.1038/nature01361

This research is supported by a grant from the ARC.


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4 April 2003