Coral record of increased sediment flux to the inner Great Barrier Reef since European settlement
Coral record of increased sediment flux to the inner Great Barrier Reef since European settlement
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DOI：
10.1038/nature01361
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发表时间：
2003-02-13
期刊：
影响因子：
64.8
通讯作者：
Barnes, D
中科院分区：
文献类型：
--
作者：
McCulloch, M;Fallon, S;Barnes, D
欧洲定居对澳大利亚大堡礁水质的影响是一个长期存在且有争议的问题（1-6）。自欧洲人定居以来，这一地区河流集水区的侵蚀和沉积物输送大幅增加（6-10），但这些变化的幅度仍不确定（1-10）。在这里，我们报告的Ba/Ca比分析长寿滨珊瑚从哈瓦纳礁-大堡礁内的一个网站，是由洪水羽流的伯德金河的影响，建立一个记录的沉积物通量从1750年到1998年。我们发现，在早期的记录，河流洪水的悬浮沉积物到达内礁区只是偶尔，而在大约1870年后，欧洲定居点的开始，一个5 - 10倍的增加，沉积物的交付记录与最高通量发生在干旱破坏洪水。我们的结论是，自欧洲定居以来，清理和过度放养等土地利用做法导致半干旱河流集水区严重退化，导致进入大堡礁内的沉积物大幅增加。
The effect of European settlement on water quality in the Great Barrier Reef of Australia is a long-standing and controversial issue(1-6). Erosion and sediment transport in river catchments in this region have increased substantially since European settlement(6-10), but the magnitude of these changes remains uncertain(1-10). 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.