夏、冬季青岛近岸海域渔业生物群落结构特征研究

Fishery communities in the coastal waters of Qingdao in summer and winter

中文关键词: 青岛近岸  群落结构  渔业生物  关键种  食物网拓扑结构

英文关键词: Coastal waters of Qingdao  Community structure  Fishery organisms  Keystone species  Food web topological structure

中文摘要:

      为掌握青岛近岸海域渔业资源结构变化特征，本研究基于青岛近岸海域2022年7―8月和11―12月渔业资源底拖网调查数据，研究了该海域渔业资源密度及群落结构动态特征。结果显示，夏季捕获渔业生物92种，冬季捕获86种，总更替率为42.5%。夏季优势种为戴氏赤虾(Metapenaeopsis dalei)、方氏云鳚(Enedrias fangi)和大泷六线鱼(Hexagrammos otakii)，冬季优势种为戴氏赤虾、枪乌贼(Loligo spp.)、鹰爪虾(Trachypenaeus curvirostris)、双斑蟳(Charybdis bimaculata)和尖海龙(Syngnathus acus)。夏季多样性指数(H′)和均匀度指数(J′)均高于冬季，而丰富度指数(D)低于冬季。青岛近岸海域渔业生物群落多样性处于正常水平，季节间水平结构和群落组成相对稳定。通过食物网拓扑结构分析发现，该海域渔业生物关键种为黄𩽾𩾌(Lophius litulon)和戴氏赤虾，食物网结构相对稳定。夏、冬两季青岛近岸海域渔业生物群落表现出较强的抗扰动能力。

英文摘要:

      The warm-temperate coastal waters of Qingdao, including Aoshan Bay, Jiaozhou Bay and Lingshan Bay, serve as crucial spawning and feeding grounds for diverse fishery organisms and as important fishing grounds. These areas have experienced significant ecological shifts due to escalated human activities, marine pollution, and increased fishing pressure, leading to changes in fishery resources towards miniaturization and domination by low economic value species. To understand the characteristics of the structural changes of the fishery resources in the coastal waters of Qingdao, the present study analyzed the composition, community structure, ecosystem stability, and biodiversity of fishery resources within the coastal waters of Qingdao, based on the data from the fishery surveys conducted in the summer (July-August) and winter (November-December) of 2022. The keystone species were identified using a food web topology, which is crucial for regulating marine ecosystems. A total of 92 and 86 fishery species were collected in the summer and winter with a notable replacement rate of 42.5% respectively. Specifically, Metapenaeopsis dalei is the predominant species in both seasons. The study also highlighted the seasonal dominance of Enedrias fangi and Hexagrammos otakii in summer and Loligo spp., Trachypenaeus curvirostris, Charybdis bimaculate and Syngnathus acus in winter. A discernible shift was observed in the structure of fishery resources, with the increasing dominance of invertebrates and a trend toward miniaturization and devaluation across fish, crustaceans, and cephalopods. In terms of biodiversity indices, the Shannon-Weaver (H') and Pielou evenness (J') indices were significantly higher in summer, whereas the Margalef richness index (D) was higher in winter, indicating normal ecosystem diversity and demonstrating stable seasonal horizontal structures and consistent community compositions. Notable ecological improvement was observed over the past decade, benefiting from the implementation of measures to restore fishery resources. The food web topology for the ecosystem, developed based on the feeding relationships of the local feeding relationships, incorporated 26–29 major species (S) and 116–165 feeding relationships, indicating substantial seasonal variations. The node density (Dd) in summer was greater (0.22>0.18), whereas other indices i.e., average path length (1.17<1.27), interspecific connectance (C) (0.17<0.20) and clustering coefficient (Cl) (0.18<0.25) were lower than those in winter. Based on a comprehensive analysis of the topological index ranking (D, Dout, Din, BC, CC, IC, TI1, TI3, TI5, K, Kb, Kt, F, and DF), Lophius litulon and Metapenaeopsis dalei were identified as key species, with the former being a primary predator and the latter an important prey species. Overall, the food web of the coastal waters of Qingdao exhibited relatively high connectivity and complexity, presenting strong stability and resilience against disturbances and thereby ensuring the provision of vital ecosystem services. Furthermore the role of keystone species must be fully considered in the subsequent conservation of fishery resources and adaptive management to achieve precise management. The findings of this study provide scientific data and knowledge for understanding the structure of the marine food web and biodiversity conservation in this area.