摘 要 ：根据2007-2008年在南海北部（107°00′-120°00′ E、17°00′-23°30′N）进行的海洋生态综合调查数据，应用Ecopath with Ecosim软件构建了南海北部生态系统的生态通道模型，并通过模型分析了南海北部海洋生态系统的食物网结构、能量流动和系统的总体特征，并简要总结过度捕捞生态系统的基本特征。结果表明，南海北部海洋生态系统以捕食食物链为主要能流通道，初级生产者是系统能量的主要来源。各功能群的营养级范围为1-3.99，哺乳动物占据了最高的营养层，平均渔获物营养级为2.93。利用生态网络分析，系统的能量流动主要有6级，来自初级生产者的能流效率为12.6%，来自碎屑的转换效率为10.4%，平均能量转换效率为11.5%。系统连接指数（Connectance Index, CI）和系统杂食指数（System Omnivory Index, SOI）分别为0.290和0.239；Finn’s循环指数（Finn’s cycling index, FCI）和系统平均路径长度（Finn’s mean path length, MPL）分别为4.380和2.476；总初级生产力/总呼吸为2.596，综合研究表明当前南海北部海洋生态系统处于不成熟阶段。
Abstract:In this paper we developed a mass-balance model (Ecopath) using Ecopath with Ecosim software for the northern South China Sea (NSCS, 107°00′-120°00′ E、17°00′-23°30′N). Input data were mainly from the information collected in marine ecology surveys during 2007-2008. Using the Ecopath model, we evaluated the trophic structure, energy flow and system attribute，and briefly summarizes the characteristic of the over-fishing ecosystem also. The balanced model suggests that the system was dominated by the grazing food chain; with primary producers serving as a principal source of energy in the system. Fractional trophic levels ranged from 1.0 to 3.99, with marine mammals occupying the highest trophic level. The mean trophic level of fishery catch in the NSCS ecosystem for the 2007-2008 was 2.93. Using network analysis, the system network was mapped into a linear food chain and six discrete trophic levels were found with a mean transfer efficiency of 11.5%, 10.4% from detritus and 12.6% from primary producer within the ecosystem. In this study the Connectance index (CI) and system omnivory index (SOI) were 0.290 and 0.239, respectively. A Finn cycling index (FCI) of 4.380 and mean path length (MPL) of 2.476 were obtained also. Furthermore, the ratio of total primary production/total respiration (TPP/TR) was 2.596 in the system. We can conclude that, therefore, the system is still immature and instable through analysis and discussion. This paper also briefly summarizes the characteristic of the over-fishing ecosystem.