长江口邻近海域环境演变的痕量元素示踪解析

The global changes and anthropogenic activities result in the frequent occurrence of coastal ecological disasters, which leading to marine ecological environment becoming increasingly unstable. However, how to trace these changes still not be researched systematically. Potential harmful trace elements (Se, Sb, Te, Sn, Ge, et al.) have the characteristics of low concentrations, large variances and sensitivity to ecological environmental changes, thus, the systemic analysis of their roles in tracing the marine ecological environmental changes is of important scientific significance. This project is aimed at the ecological environmental changes of the Changjiang Estuary and its adjacent areas under the anthropogenic impacts and focus on the study of trace element indication on ecological environmental changes. In the study, the spatio-temporal variation characteristics of trace elements and their speciation, coupled with the interannual variation of biomarkers (sterols) will be study to indicate the migration and transformation processes of trace elements and biomarkers, to assess the potential ecological risks of trace elements, to clarify the ecological environmental changes of the Changjiang Estuary and its adjacent areas in recent one hundred years and to build a sensitive tracing system to reflect the ecological environmental changes. An attempt is made to establish the scientific basis for sustainable development and utilization of marine resources and environment.

全球变化与人类活动导致近海生态灾害频发，使海洋生态环境变得愈来愈不稳定，但如何来示踪这些变化，至今还没有系统的研究。近海潜在污染物痕量元素（Se、Sb、Te、Sn、Ge等）具有浓度低、变化幅度大、对生态环境变化响应敏感等特点，系统解析其在示踪近海环境演变的作用具有重要的科学意义。本项目拟针对长江口邻近海域生态环境在人为作用下的演变这一重大科学问题，聚焦于生态环境变化的痕量元素示踪解析研究，通过鉴别其沉积物中痕量元素的赋存形态及时空变化特征，耦合生物标志物（甾醇等）的年际变化，诠释痕量元素与生物标志物迁移转化过程，判别痕量元素潜在生态风险，阐明长江口邻近海域近百年来其生态环境的变化特征，构建反映其变化的灵敏示踪体系，以期对持续开发利用海洋资源与环境奠定科学基础。

全球变化与人类活动导致近海生态灾害频发，使海洋生态环境变得愈来愈不稳定，但如何来示踪这些变化，至今还没有系统的研究。本项目聚焦于长江口邻近海域生态环境变化的痕量元素示踪解析这一科学问题，分别开展了痕量元素及其赋存形态和生物标志物的时空格局及迁移转化机制研究，运用风险评价准则和富集因子评价了痕量元素的潜在生态风险水平，运用二元混合模型和甾醇百分比判别了有机质的来源，重点构建了痕量元素-生物标志物的灵敏示踪体系，阐明了长江口邻近海域近百年来其生态环境的变化特征，特别是长江口邻近海域各历史阶段水体环境的污染水平对水体初级生产力的影响和响应关系。研究发现长江口邻近海域沉积物中痕量元素均存在轻度富集和低风险，且活性形态高值区出现在近岸和中北部区域，与长江输入、江苏沿岸流输入、大气输入和生物活动密切相关；长江输入是沉积物中痕量元素的主要来源，占元素总输入的80-95%；73-88%的痕量元素最终埋藏在沉积物中，主要分布在长江口和浙江近岸区域。长江口邻近海域沉积物有机质更多来自于海源输入，海源有机质和海源甾醇占总含量的平均百分比分别为65%和57%；长江输入是沉积物中陆源有机质和甾醇的主要来源，分别占总陆源输入的76.3%和76.8%；长江口和内陆架区域是有机碳和甾醇的主要累积区域，约有72%和65%的有机碳和甾醇沉积于此。人为污染输入指标和生产力变化指标均在1980年后呈显著增加趋势，表明生产力的增加与陆源人为活动输入的增多密切相关。 项目在研期间共发表SCI论文6篇。