基于鱼类生物完整性的赤水河健康评估研究

Chishui River Health Assessment Based on Fish Biotic Integrity Index

赤水河是长江上游一级支流,生境类型复杂多样,在长江上游珍稀特有鱼类资源保护方面发挥着至关重要的作用.为了解赤水河健康状况,本研究于2020年5月和9月,在赤水河干流和重要一级支流31个点位开展鱼类调查,采用Shannon-Wiener指数、Simpson指数、Pielou指数评价鱼类多样性,构建了F-IBI(fish-based index of biotic integrity)指数评价赤水河健康状况.此次调查共采集6288尾,隶属于4目10科26属90种;鱼类Shannon-Wiener指数范围为0.21~2.87,平均值为1.48±0.46;Simpson指数范围为0.08~0.91,平均值为0.69±0.14;Pielou指数范围为0.13~0.97,平均值为0.76±0.13.上游至下游Shannon-Wiener指数和Simpson指数均呈现逐渐升高的变化规律.构建了包含物种总数、鲤形目个体数%、鮈亚科个体数%、鲌亚科个体数%等10个指标在内的F-IBI核心指标体系,采用比值法计算各点位F-IBI值,根据F-IBI值将流域健康状况划分为“健康”(F-IBI≥5.99)、“亚健康”(4.49≤F-IBI<5.99)、“一般”(2.99≤F-IBI<4.49)、“较差”(1.50≤F-IBI<2.99)和“极差”(F-IBI<1.50)5个等级.评价结果显示,所调查点位整体为健康状态,20个点位显示健康状态,5个点位显示亚健康状态,3个点位显示一般状态,3个点位显示较差状态.F-IBI值从上游到下游呈现逐渐上升趋势,且上、中、下游F-IBI值存在显著性差异(P<0.05).干流健康状况优于支流,较差健康点位位于桐梓河、五马河流域,一般健康点位位于习水河流域.研究显示,赤水河鱼类以鲤形目、鲤科为主要种群,构建的F-IBI评价体系可作为人类活动干扰的良好的预测因素,较好地反映赤水河水生生态系统健康状况,可作为赤水河水生生态系统健康评价和资源管理的工具.

The Chishui River is a first-level tributary of the upper reaches of the Yangtze River with complex and diverse habitat types,and plays an important role in the protection of rare and endemic fish resources in the upper reaches of the Yangtze River.In order to understand the health level of the Chishui River Basin,a fish survey was conducted at 31 sites on the main stream and primary tributaries of the Chishui River in May and September 2020.A total of 6288 fish species belonging to 4 orders,10 families,26 genera and 90 species were collected.The Shannon-Wiener index ranged from 0.21 to 2.87 with an average value of 1.48±0.46.The Simpson and Pielou index ranged from 0.08 to 0.91 with average values of 0.69±0.14 and 0.13-0.97 with an average value of 0.76±0.13,showing a gradual increase trend from the upstream to downstream.The F-IBI index was used to evaluate the health status of the Chishui River,the core index system included 10 indicators including the total number of species,the number of cypriniforms,the number of Gobioninae,the number of Culterinae,etc.The F-IBI value of each sampling point was calculated by the ratio method,and five health grades were classified into‘healthy(F-IBI≥5.99)’,‘subhealthy(4.49≤F-IBI<5.99)’,‘average(2.99≤F-IBI<4.49)’,‘poor(1.50≤F-IBI<2.99)’and‘extremely poor(F-IBI<1.50)’to evaluate the health status of each sampling point.In general,the surveyed sites were in a healthy state,among which 20 sites were in healthy state,5 sites were in a sub-healthy state,3 sites were in a general state,and 3 sites were in a poor state.The F-IBI values gradually increased from upstream to downstream,and there was a significant difference between the upper,middle and downstream(P<0.05).The main stream exhibited better health status than the tributaries,the poor health sites are located in the Tongzi River and the Wuma River,while the general health sites are located in the Xishui River Basin.Cypriniforms and Cyprinidae were the dominant fish fauna in the Chishui River,indicating that the F-IBI evaluation system was a good predictor of human disturbance and better reflected the health status of aquatic ecosystem in the Chishui River,which can be used as a tool for aquatic ecosystem health evaluation and resource management for the Chishui River.