禁渔初期长江上游江津段鱼类群落结构研究及禁渔效果分析

Study on Fish Community Structure and Analysis of Fishing Ban Effect in the Early Stage of Fishing Ban in the Jiangjin Section of the Upper Yangtze River

关键词:  长江十年禁渔  江津段  鱼类  群落结构  效果评估

Key words:  10-year fishing ban on the Yangtze River  Jiangjin section  fish  community structure  effect evaluation

摘要:

为了解禁渔初期长江上游江津段鱼类群落结构状况，本研究分别于2023年5月、9月利用3层复合刺网和底置笼网开展主动捕捞，调查该水域鱼类资源状况和鱼类群落结构。结果显示：调查捕获鱼类80种，隶属于4目12科51属，其中珍稀特有鱼类16种，数量占比为16.44%，质量占比为41.22%。鱼类群落以底层、杂食性、中小型鱼类为主；厚颌鲂(Megalobrama pellegrini)、瓦氏黄颡鱼(Pelteobagrus vachelli)为优势种；Shannon-Wiener指数(H')、Margalef指数(D)、Simpson指数(X)和Pielou指数(J')分别为2.32-3.31、5.00-7.08、0.83-0.95、0.44-0.61；丰度/生物量比较曲线(ABC曲线)显示，江津段水域鱼类群落结构相对稳定，受干扰程度较低。综上所述，禁渔初期江津段鱼类群落结构稳定且维持较高的生物多样性水平，资源衰退趋势得到一定缓解。

Abstract:

To understand the status of fish community structure in the Jiangjin section of the upper Yangtze River during the early period of the fishing ban,active fishing was conducted using three-layer composite gillnets and bottom cage nets in May and September 2023 to investigate the fish resource status and fish community structure in this waters. The results showed that 80 fish species were captured in the survey,belonging to 4 orders,12 families,and 51 genera. Among them,there were 16 rare and endemic fish species,accounting for 16.44% of the total number and 41.22% of the total weight. The fish community is dominated by demersal,omnivorous,small and medium-sized fish.Megalobrama pellegrini and Pelteobagrus vachelli were the dominant species. Shannon-Wiener index,Margalef index,Simpson index and Pielou index were 2.32-3.31,5.00-7.08,0.83-0.95,0.44-0.61,respectively.The Abundance/Biomass Comparison curve (ABC curve) showed that the fish community structure in the Jiangjin section was relatively stable and less disturbed. In summary,the fish community structure in the Jiangjin section is stable and maintains a high level of biodiversity in the early stage of fishing ban,and the trend of resource decline has been alleviated to some extent.