南捧河轩莱水电站坝址段水生生物资源调查与评价

Survey and Evaluation of the Hydrobiology in the Dam Area of Xuanlai Hydropower Station on Nanpeng River

南捧河轩莱水电站坝址段水体属于寡污贫营养型,水生生物种类和数量较少,生物量较低。5个采样点共采集浮游植物6门29属38种,以硅藻、绿藻和蓝藻为主;硅藻为优势种,生物量最大。采集浮游动物3门21属25种,区域分布极不均匀,原生动物种类最多,桡足类生物量最大。采集底栖动物13种,以水生昆虫为主,其次为软体动物,但生物量均较低。采集水生维管束植物14种,多为岸边湿生植物。总体上,干流中的水生生物种类和生物量明显高于支流。评价区域内共调查到21种鱼类,90%以上为土著种类,是低纬度高原山区喜激流底栖性鱼类和特殊生境鱼类的代表;以鲤科鱼类为主,但属于多个区系类群,多样性较丰富。根据调查结果,本文预测评价了电站运行后水生生物和鱼类种群的演替趋势,并提出维持河流生态系统的生态需水量是水生生物和鱼类资源保护与修复的基本措施。

The water was oligotrophy without pollution in the region of the dam of Xuanlai hydropower station, where the amount of aquatic organisms and biomass were at a low level. Altogether, there were 38 species of phytoplankton from 5 locations, belonging to 6 phyla, 29 genera. The main phyla were Bacillariophyta, Chlorophyta, and Euglenophyta, and the dominant phylum was Bacillariophyta with the highest biomass. There were 25 species of zooplankton in total, belonging to 3 phyla, 21 genera, with the dominant phylum of Protozoa, and the highest biomass was Copepoda; while, their distribu- tions were non-uniform. Thirteen species of Zoobenthos were surveyed in 5 locations. The dominant species were aquatic insects and mollusks with the low levels of biomass. There were 14 species of a- quatic vascular plant, and most of them were hygrophyte living in the river bank. In summary, the stem stream contained more species and biomass of the hydrobiology than the branch stream. Twenty- one species of fish were surveyed through artificial capture and consulting literatures, and more than 90% of them were native species, which were the representative of the demersal fish and fish of pos- sessing the special habitat in the low latitude and pXateau mountain area. Although the Cyprinidae was the dominant species, all of the surveyed fishes were grouped into several faunas and species, sugges- ting an abundant diversity of these fishes. Based on these results, the change tendency of the composition and succession for the hydrobiology and fish after the hydropower station operation were also predicted and evaluated. We consider that fish is maintaining the ecological water the principle way to protect and remediate the hydrobiology and requirement for river ecosystem.