南海珊瑚礁:从全球变化到油气勘探——第三届地球系统科学大会专题评述

Studies on the Coral Reefs of the South China Sea: From Global Change to Oil-Gas Exploration

第三届地球系统科学大会设置了关于南海珊瑚礁的专题,系统讨论了南海珊瑚礁从响应、记录全球变化到岛礁工程建设和油气勘探等的研究进展。受全球气候变暖和人类活动加剧等因素的双重影响,南海珊瑚礁在过去50多年来退化幅度高达80%,不少区域现代活珊瑚的覆盖度<20%。珊瑚骨骼的地球化学指标清楚地揭示,自工业革命以来南海海水的污染程度增加、CO2驱动的海水p H值降低(变酸)等,这些环境问题对南海珊瑚礁构成了进一步的威胁。而日益增加的珊瑚礁区工程活动将不可避免地对珊瑚礁带来更大的环境压力,因此建议充分研究珊瑚礁区的工程地质特征,充分考虑珊瑚礁生态的脆弱性特点,进行岛礁工程的合理规划和布局,倡导"绿色工程"的理念。广布于南海的生物礁,其主要成礁时期为中新世以来,多种礁型储层及其良好的生储盖组合,决定了南海生物礁油气藏具有广阔的勘探前景,同时也具有多时间、空间尺度的环境记录功能。

Studies on the coral reefs of the South China Sea （SCS） was the theme of the 6th Session of the 3rd Conference on Earth System Science （CESS） in Shanghai, 2014. This session discussed the most recent study de- velopments on the SCS coral reefs, including coral reefs＇ responses to global changes, coral reefs＇ records on past climatic variations, and the activities about constructions and oil-gas explorations in the coral reefs areas of the SCS. Disturbed by intensive anthropogenic activities and global climate warming, coral reefs in the SCS have de- clined dramatically, reflecting the up to 80% decrease of living coral cover and many areas having less than 20% of living coral cover. Geochemical data of SCS coral skeletons clearly show that since the Industry Revolution, the pol- lution situation of the SCS have dramatically increased and the seawater pH values have been continuously lowering, i.e. oceanic acidification. All these environmental phenomenon are further stressing the healthy development of the coral reef ecosystem in the SCS. Meanwhile, the poor coral reef ecosystems in the SCS are facing more anthropo- genic disturbances such as coastal developments and engineering constructions. Obviously, the SCS coral reefs will be faced with more environmental challenges in the coming future. We therefore suggest that the policy makers should realize the extreme importance and the fragile of the coral reef ecosystems, and scientifically and with great cautions design construction project when in coral reef areas. We initiated the concept of ＂green engineering＂ for future developments in coral reef areas. Coral reefs are widely spreading in the whole SCS, and most of them devel- oped since Miocene. Variations in coral reef structures provide good future oil-gas exploration. Because the SCS coral reefs have a long-developing history and a wide spatial distribution, they provide great potential in recording past environmental changes.