应用鱼类生物完整性指数评价北运河河流健康

评估北运河水系生态状况，为判别北运河水系水生态恢复成效提供参考。2020 年5月、8月调查了北运河13个采样点的鱼类及生境状况，采集到鱼类20种，分属3目9科18属。采用F-IBI评价北运河健康状况。选择人类活动干扰较轻的点作为参照点，从物种种类组成与丰富度、营养结构、耐受性和敏感性、繁殖共位群以及鱼类数量等5个方面构建F-IBI候选指标体系，然后依据分布范围检验、敏感性分析和相关性检验，筛选出F-IBI 核心指标体系，包括鱼类物种数、Shannon-Wiener 多样性指数、鲤科物种数百分比、漂流性卵鱼类个体数百分比、沉性卵鱼类个体数百分比、黏性卵鱼类个体数百分比、外来物种数量所占比例。采用比值法计算各采样点F-IBI值，并将其划分为“优”“良”“中”“一般”和“差”5个健康评价等级，评价各采样点健康状况。评价结果表明：北运河健康状况整体为中等偏上，其中7.69%的采样点健康状况为“优”，23.08% 的采样点健康状况为“良”，53.85%的采样点健康状况为“中”，15.38%的采样点健康状况为“一般”。北运河水生态治理取得一定成效。

Health Assessment of North Canal River Based on the Fish-Index of Biotic Integrity

The North Canal River serves the important functions of urban flood control and water drainage for Beijing. In recent years, the aquatic ecosystem of the North Canal River has recovered well following a series of ecological restoration projects carried out by the Beijing Municipal government. In this study, we evaluated the ecological health status of the North Canal River using the established fish-index of biotic integrity (F-IBI) to provide a reference for assessing the ecological restoration projects. In May and August of 2020, fishery resource and habitat condition investigations were conducted at 13 sampling sites along the North Canal River. A total of 20 fish species were collected during the investigation, belonging to 18 genera, 9 families and 3 orders. Sampling sites with low human disturbance were used as the baseline and the F-IBI evaluation system was established based on investigation results. The index system included 32 indices from 5 aspects of species composition and richness, nutritional structure, tolerance and sensitivity, reproductive colocation and fish quantity. After the distribution range test, sensitivity analysis and correlation test, 7 parameters were identified as core indicators: total number of fish species, Shannon-Wiener diversity index, percentage of cyprinid species, percentage of individuals for species with pelagic eggs, percentage of individuals for species with demersal eggs, percentage of individuals for species with viscid-egg, and percentage of alien species. The score of each core index of the F-IBI evaluation system was calculated and the ratio method was then used to calculate the F-IBI value of each sampling site. The F-IBI values were divided into five grades of river health: excellent, good, moderate, fair and poor. The health status of the sampling stations along the North Canal River was generally above moderate. The percentage of stations in excellent condition was 7.69%, while 23.08% of the stations ranked as good, 53.85% ranked as moderate, and 15.38% ranked as fair. We conclude that management of aquatic ecology in North Canal River has been very effective.