基于延绳钓观察员数据的热带太平洋中东部食物网拓扑结构分析

热带太平洋是金枪鱼类、旗鱼类等渔业的主要作业海域，但目前针对此海域食物网的研究仍十分缺乏。本文根据2017年6月-11月中国金枪鱼科学观察员在热带太平洋中东部海域（13°09''N -34°27''S, 100°03''-176°17''W）采集的鱼类样品，结合胃含物及其他分析方法以35个物种间的摄食关系为基础对此海域的食物网结构进行了分析。拓扑学指标（节点强度，D；中心性指数，BC和CC；拓扑重要性指数，TI¹和TI³；关键性指数，K、K_t和K_b）和Key-Player算法（KPP-1和KPP-2）用来筛选关键种，并结合体长数据建立了基于关键种的简化食物网。肯德尔相关性分析和聚类分析结果表明，不同拓扑学指标筛选出的关键种是一致的。大多数关键种与太平洋其他海域的研究结果是相同的，如剑鱼（Xiphias gladius）、长鳍金枪鱼（Thunnus alalunga）、小吻四鳍旗鱼（Tetrapturus angustirostris）头足类和鲭属。移除5个关键种后，食物网将被离散为许多互不连接的部分（F=0.632，F^D=0.795，R^D=0.957），表明这些物种在维持食物网结构和稳定性中的必要性。物种体长是本研究构建简化食物网时的决定性因素。研究结果有助于提高对热带太平洋食物网结构的认识，同时为进一步的生态系统动力学研究提供科学依据。

Topology-based analysis of pelagic food web structure in the central and eastern tropical Pacific Ocean based on longline observer data

The tropical Pacific Ocean supports many productive commercial fisheries. However, few studies of ecosystem structure in the tropical Pacific Ocean have been carried out. In this study, we analyzed the food web structure in the central and eastern tropical Pacific Ocean based on trophic relationships of 35 pelagic species collected by Chinese tuna longline observers from June to November in 2017. Topology indices (node degree, D; centrality indices, BC and CC; topological importance indices, TI¹, TI³; keystone indices, K, K_t and K_b) and Key-Player algorithms (KPP-1, KPP-2) were used to select key species and construct a simplified food web combined with body size data. The Kendall rank correlation and hierarchical clustering analysis indicated that different topology indices resulted in consistent rankings of key species. Most key species were the same as those selected in other studies in the Pacific Ocean, such as Shortbill spearfish (Tetrapturus angustirostris), Swordfish (Xiphias gladius), Albacore tuna (Thunnus alalunga), cephalopods and scomber. The food web would be separated into many unconnected parts (F=0.632, F^D=0.795, R^D=0.957) after the removal of the five key species, indicating the key roles of these species in the food web structure and stability. Body size was considered an influential indicator in constructing the simplified food web. This study can improve our understanding of the food web structure in the tropical Pacific Ocean and provide scientific basis for further ecosystem dynamics studies.