岷江上游鱼类完整性指标现状调查评价

鱼类完整性指标F-IBI是以鱼类为研究对象,开展河流健康状况评价的指标。本文在广泛收集岷江上游鱼类调查资料的基础上,结合Fausch等修订的12个指标体系,提出了适用于岷江上游的,包括鱼类组成、耐受性、营养结构、丰富度指标、鱼类数量与健康状况等五个方面的12项指标。以河流水电开发前为背景,拟定了F-IBI指标期望值和赋值标准,利用2011年的鱼类调查结果对岷江上游鱼类完整性指标进行评价。评价结果表明岷江上游鱼类生物完整性属差和一般的状态,说明岷江上游鱼类种类减少,种类组成与期望值比较趋向单一化,外来种类增加,未见顶级肉食者,年龄级缺失,数量、生长和体质等指标下降,鱼类资源量下降,渔获物个体小型化,可见水电工程的建设后鱼类资源退化,建议开展过鱼设施研究及设计,同时开展下泄生态流量及生态调度研究。

Fish integrity biotic indexes of the upper Min river reaches and their assessment

Fish integrity biotic indexes (F-IBIs) are indicators of river health status evaluation oriented to fishes as research object. This study has developed a system of 12 F-IBIs for the upper Min River (Sichuan) reaches, based on the Fausch-modified indexes and the fish survey data extensively collected over these reaches, covering five aspects of the fishes, i.e. their composition, tolerance, nutrition structure, richness index, species number, and health. Expectation and evaluation standard of these F-IBIs were specified for the existing river status of hydropower development, and the F-IBIs were evaluated using the survey in 2011. The results show that in the upper Min river, fish biological integrity is changing from average to poor state, indicating a decrease in fish species. Species composition and expectations tend towards single, with exotic species increasing and no top carnivorous. Several indexes are dropping, including age class, quantity, growth, and physical fitness; fish resources are declining, and fish-catching individuals are smaller. All these indicate deterioration in fish resources caused by the construction of hydropower projects in these reaches, and thus we suggest further studies on fish pass facilities and their design and on ecological flow and ecological regulation.