Oil spill recorded by skeletal delta C-13 of Porites corals in Weizhou Island, Beibu Gulf, Northern South China Sea
Oil spill recorded by skeletal delta C-13 of Porites corals in Weizhou Island, Beibu Gulf, Northern South China Sea
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南海北部湾涠洲岛滨珊瑚骨骼三角洲C-13记录的溢油事件
DOI：
10.1016/j.ecss.2018.04.031
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发表时间：
2018
期刊：
影响因子：
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通讯作者：
Chu Minghang
中科院分区：
文献类型：
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作者：
Xu Shendong;Yu Kefu;Wang Yinghui;Liu Tao;Jiang Wei;Wang Shaopeng;Chu Minghang
石油是一种天然产物，是生物体产生的，是一种13 C贫化的天然产物。珊瑚骨骼δ 13 C是环境和气候变化的重要记录。然而，目前关于溢油对珊瑚骨骼δ 13 C影响的研究较少。这一研究对于从珊瑚骨骼δ 13 C中获取环境和气候信息具有重要意义。2015年10月在涠洲岛边缘礁采集了2个连续生长的Poritescarals（W1和W3），年龄分别为22和31年（1994-2015和1985-2015），分析了珊瑚骨骼的δ 13 C和δ 18 O。此外，在2018年1月28日的溢油事件中收集了海水，并用于δ 13 CDIC（DIC的δ 13 C值）分析。目的是探讨溢油对δ 13 CDIC和珊瑚δ 13 C的潜在影响。溢油时的δ 13 CDIC值显著低于正常海水（Δδ 13 C =-2.38‰）。自2008年以来，两个珊瑚群的珊瑚δ 13 C值均显示出较低的值（2008年前后W1和W3的δ 13 C平均值分别由-2.04 ± 0.48‰变化到-3.33 ± 0.55‰ ‰和-1.77 ± 0.49‰变化到-2.88 ± 0.54‰），特别是2008年、2009年、2011年的几次突然负移，溢油发生的2012年和2014年（δ 13 C变化幅度分别为W1：−3.08‰、− 1.82 ‰、−1.82 ‰、−1.53‰、−1.37‰; W3：−3.27‰、−1.8‰、−1.91‰、−1.21‰、−1.13‰）。我们的研究结果清楚地表明，当溢油发生时，微生物对石油的降解应导致海水溶解无机碳（DIC）的13 C/12 C比值降低，而DIC是珊瑚钙化的最终碳源。
Oil, is one kind of natural product of biological origin which is depleted in13C. Coral skeletal δ13C is an important archive of environmental and climatic change. However, few studies have been conducted on the effect of oil spill on the coral skeletal δ13C at present. This kind of research is useful for us to obtain environmental and climatic information from coral skeletal δ13C. In this study, two continuously growingPoritescorals (W1 and W3), aged 22 and 31 years (1994–2015 and 1985–2015), respectively, were collected from the fringing reef of Weizhou Island in October 2015, coral skeletal δ13C and δ18O were analyzed. Besides, seawater was collected during an oil spill in 28 January 2018, and was used for δ13CDIC (δ13C values of DIC) analysis. The purpose is to explore the potential impact of oil spills on δ13CDIC and coral δ13C. δ13CDICvalue during oil spill was significantly lower than that of normal seawater (Δδ13C≈-2.38‰). Coral δ13C of both two coral colonies showed lower values since 2008 (average value of δ13C before and after 2008 change from −2.04 ± 0.48‰ to −3.33 ± 0.55‰ ‰ and −1.77 ± 0.49‰ to −2.88 ± 0.54‰ of W1 and W3 respectively), especially, several abrupt negative shifts in 2008, 2009, 2011, 2012 and 2014 when oil spills occurred (extent of δ13C variation were W1:−3.08‰, −1.82‰, −1.82‰, −1.53‰, −1.37‰; W3:−3.27‰, −1.8‰, −1.91‰, −1.21‰, −1.13‰ respectively). Our results clearly show that degradation of oil by microorganisms when oil spill occurs should render a decrease in the13C/12C ratio of the seawater dissolved inorganic carbon (DIC) which is the ultimate carbon source of coral calcification.