百年来白令海海冰与生态环境变化的有机分子沉积记录及对气候和人类活动的响应

In the past centuries, the environmental settings of these marginal and high latitude seas has experienced the most extensive and quick changes, such as the sea ice retreat, rising temperature, the changed ecological structure and increased human influences. In this study, we choose the shelf areas of the Bering Sea as the target area, by employing the molecular biomarkers (IP25, n-alkanes, sterols, alkenones and persistent organic pollutants), coupling with the high resolution stratigraphy evolution, establish the high resolution records and flux of these indicators, examine the spatial and temporal variation of the sea ice and sea surface temperature (SST), construct the evolution of the phytoplankton community structure change, explain the relationship between the sea ice retreat, varied SST and changing phytoplankton community, extract the geochemical footprint of the human activity in the past century in the Bering Sea, and explore its environmental implications. By comparing the regional climate change records, this work will provide insight for the consequence of the molecular records for the changing climate and human interference. This work will also yield a scientific value on the marine environmental setting change in the high latitude and arctic regions.

百年来，高纬度边缘海及北极地区的海洋环境经历着快速和剧烈的变化，主要表现为海冰退化、水温升高、浮游植物生产力和群落结构变异和人类活动日益加剧等。本研究选择白令海陆架为目标区，应用有机分子标志物（IP25等类脂生标和持久性有机污染物等）为主要替代指标，结合高分辨年代地层序列，从分子水平建立目标指示物百年来高分辨率沉积记录，揭示百年来白令海海冰和表层水温的时空变异特征，重建百年来浮游植物生产力和群落结构的演变过程，阐明百年来海冰水温变化对浮游植物群落结构变化的制约及内在关系；提取百年来人类活动对白令海生态环境影响的地球化学指纹信息，探讨其生态环境效应；通过与区域气候变化参数的对比，揭示有机分子记录对百年来气候变化和人类活动的响应机制。研究成果将对阐明高纬度边缘海和北极海洋环境的演变有着重要的科学意义。

高纬度边缘海及北极地区的海洋环境经历着百年来最快速的变化，主要表现为海冰退化、水温升高、浮游植物生产力和群落结构变异和人类活动影响日益加剧等。本研究选择了白令海中西部和北部陆架/坡区的8根多管沉积短柱和1根重力柱状岩心，应用有机分子标志物（IP25、长链烷烃、甾醇类、持久性有机污染物等）为主要替代指标，结合高分辨年代地层序列，从分子水平建立目标指示物百年来高分辨率沉积记录，揭示百年来白令海海冰和表层水温的时空变异特征，重建百年来浮游植物生产力和群落结构的演变过程，阐明百年来海冰退化对浮游植物群落结构变化的制约及内在关系；提取百年来人类活动对白令海生态环境影响的地球化学指纹信息，探讨其生态环境效应；通过与区域气候变化参数的对比，揭示有机分子记录对百年来气候变化和人类活动的响应机制。基于陆坡地区重力长岩心，我们研究了白令海陆坡末次冰期以来至全新世期间海冰的扩张变化等气候变化背景及其对生产力和沉积物输入的影响，发现陆坡生产力冷期较低而暖期较高，海冰呈现阶段性变化，这对生产力和物质输运及碳酸盐保存都有影响。