应用鱼类完整性指数F-IBI评价巢湖流域的主要河流健康

保护河流健康是河流生态管理的重要目标,鱼类对维护河流生态系统健康的作用重要且不可替代。依据2013年10月巢湖53个河流采样点的鱼类调查数据,采用假设参照值法构建鱼类生物完整性指数(F-IBI)的参照系统,进而评价河流健康状况。基于29个候选生物参数,通过参数与环境因子间的相关性分析、参数间的冗余分析及其分布范围分析,确定F-IBI由鱼类总物种数、鲤科鱼类物种数百分比、中下层鱼类物种数百分比、肉食性鱼类数量百分比、产粘性卵鱼类数量百分比和耐受性鱼类数量百分比等6个参数构成。利用比值法统一各参数量纲,F-IBI值即为各构成参数比值的累加,进而评价河流水生态健康的等级,其中亚健康的采样点占16.98%,健康状况一般的采样点占50.94%,健康状况较差的采样点占32.08%。此外,影响巢湖主要河流F-IBI的重要水环境变量是叶绿素a。对重点污染区域,修复水生态系统和制定科学合理的策略,是恢复巢湖流域生态健康的重要手段。

The Health Assessment of the Main Rivers in the Chaohu Basin Using Fish-Index of Biotic Integrity

Protecting the health of rivers is the crucial goal for the ecological arrangement, and fishes play a vital role in preserving the health of river ecosystems. Based on the fish data collected from 53 sampling river segments in the Chaohu basin during October, 2013, we assessed the health of sampled rivers using hypothetical reference method in this study. We formed the F-IBI by the procedures about correlation analysis between metrics and environment factors, the redundancy analysis and distribution analysis among candidate metrics for 29 metrics. Furthermore, total number of fish species, Cyprinid species richness percentage, middle and lower layer species richness percentage, carnivorous species percentage, viscid-egg species percentage, tolerance species percentage were screened out to form a F-IBI for the Chaohu basin. F-IBI value was the sum of values of variously component metrics in this system by ratio scoring method made indexes into a uniform score. In terms of the river health in the Chaohu basin, about 16.98% cases were sub-health, about 50.94% cases were fair and about 32.08% cases were poor for 53 sampling river segments. Furthermore, the chlorophyll a was suggested as the major factor influenced F-IBI values. Meanwhile, restoring river ecosystem and making scientific and reasonable management strategies were important means for heavily polluted regions in the Chaohu basin.