大型底栖动物群落结构和功能对季节性低氧胁迫的响应研究：以长江口和象山港为例

Hypoxia has been one of the most severe threats to global marine ecosystems, including inshore estuaries and bays. As one of the most important components of marine ecosystem, macrobenthos is highly susceptible to environmental disturbances such as hypoxia. The change of community structure, function and secondary production can easily result in detrimental effects on the health of marine ecosystem. However, ecological impact of hypoxia was still poorly studied, and the limited researches were restricted to the analyses of macrobenthic community composition and structure. Therefore, comprehensive and intensive research is badly needed. In view of the foregoing, this project will be performed in the Yangtze Estuary and Xiangshangang Bay which have been subjected to seasonal hypoxia. Combined with historical data, field investigation and manipulative experiments, the ecological effects of hypoxia stress will be studied in great detail. The relationship between hypoxia and macrobenthic community will be developed, and the response of macrobenthic function to hypoxic stress will be simulated and tested by a sigmoid function. The responding equation between hypoxia and macrobenthic secondary production will be educed and modeled by combined data of macrobenthic abundance, biomass, biological and environmental parameters. This research is expected to provide fundamental baseline and important scientific basis for further research on the role of macrobenthos in matter and energy flow, mechanism and principle of benthic community succession.

低氧是全世界河口和近海生态系统面临的最为严重的环境威胁之一。大型底栖动物作为海洋生态系统的重要组成部分，对水体中的低氧胁迫非常脆弱，由此导致的结构功能及生产力的改变可能会对整个水生生态系统产生深远的不良影响。尽管如此，国内对于低氧的生态响应影响研究仍相当有限，仅限于低氧影响下底栖群落组成和结构的简单分析，缺乏对低氧生态影响的全面深入的探讨。有鉴于此，本项目选择东海典型的受低氧影响的长江口和象山港作为研究海域，结合历史资料分析、海上生态调查和人为操控实验，综合分析低氧胁迫对大型底栖动物群落结构和功能的影响，阐明其变化和响应规律，建立并验证低氧胁迫下群落死亡率和群落次级生产力的响应关系模型。该研究有望在低氧生态危害的定量解析和预测上取得突破，并为今后研究底栖群落在物质转移和能量流动中的地位以及群落演变的机制原理提供重要的科学依据。

低氧是全世界河口和近海生态系统面临的最为严重的环境威胁之一。大型底栖动物作为海洋生态系统的重要组成部分，对水体中的低氧胁迫非常脆弱，由此导致的结构功能及生产力的改变可能会对整个水生生态系统产生深远的不良影响。尽管如此，国内对于低氧的生态响应影响研究仍相当有限，仅限于低氧影响下底栖群落组成和结构的简单分析，缺乏对低氧生态影响的全面深入的探讨。有鉴于此，本项目在过去四年间，以受低氧影响的长江口和象山港作为研究海域，根据收集到的2012~2020年的历史调查数据和野外现状调查，分析了最近十年长江口、象山港及邻近海域大型底栖生物群落组成和结构的时空变化规律，重点揭示了低氧影响下大型底栖生物物种组成、尤其是优势种的变化趋势；结合同期收集的海域溶解氧浓度、温度、盐度、深度、底质粒径、有机质含量、初级生产力以及水文化学条件等环境因素的变化资料，研究阐述了大型底栖生物变化与低氧等众多环境因素之间的相关关系和响应规律；依据大型底栖生物群落生物量信息以及同步的温度、相应的栖息环境和摄食功能群等信息，综合分析低氧对大型底栖动物功能群特征以及次级生产力的影响，建立了低氧影响下群落丰度变化和次级生产力的响应关系。通过本项目的顺利开展，形成了我国长江口及象山港大型底栖生物多样性的重要本底资料，并为今后研究底栖群落在物质转移和能量流动中的地位以及群落演变的机制原理提供重要的科学依据。