湟水河上游大型底栖动物多样性及水体理化因子调查分析

Diversity of Benthic Macroinvertebrates and Water Physical and Chemical Indexes in Upstream of Huangshui River

为研究青藏高原农牧交错地带水生生物与环境指标的关系,于2015年5月(枯水季)和8月(丰水季),调查分析了湟水河上游47个样点水体的理化指标和大型无脊椎底栖动物。水体物理指标现场采用多参数水质检测仪和FP311杆式流速仪检测;采集水样带回实验室测定化学指标,总氮和总磷采用过硫酸钾氧化紫外分光光度法测定;NH4+-N含量采用纳氏试剂光度法测定。底栖动物采用索伯网和D形网采集。结果显示:支流各项理化指标数据均优于干流,尤其以浊度、细砂淤泥比例、NH4+-N、TN和TP最为显著。底栖动物共鉴定出28科57属59种,其中昆虫纲7目54种,占所有底栖动物种类的91.5%,个体数4444头,占所有底栖动物数量的76.4%,甲壳纲、软体动物类、寡毛类等底栖动物个体数占底栖动物总量的23.6%。湟水河上游支流底栖动物平均分类单元数(6.76)基本与干流相当(8.04),对水质敏感的EPT平均分类单元数支流(3.36)也与干流相当(2.48),但干流底栖动物耐污染种类比例明显高于支流,而支流敏感种类比例明显高于干流。从底栖动物群落结构和水体理化指标来看,湟水河上游支流总体优于干流,其差异源于干流受污染较重。

To study the relationship between aquatic organisms and environmental indexes in the interlaced areas of agriculture and animal husbandry in Qinghai, diversity of benthic macroinvertebrates and physical andchemical indexes were investigated at 47 sampling sites in the upstream of Huangshui River in April（dryseason） and August（rainy season） of 2015. In the sampling sites, water physical indexes of Huangshui Riverwere determined by multiparameter water quality tester and FP311 bar-type flow meter. And water chemicalindexes were tested in the laboratory. The contents of total nitrogen and total phosphorus were determined byultraviolet spectrophotometry of potassium persulfate oxidation, the content of NH4＋- N was determined byNessler＇s reagent spectrophotometry, and benthic macroinvertebrates were collected by Sauber＇s net andD-shaped net. The results showed that the physical and chemical indexes in the branch stream of HuangshuiRiver were better than that in the trunk stream, especially the turbidity, proportion of fine sand, contents ofNH4＋- N, TN and TP. There were totally 59 species of the macro- invertebrates in 57 genera, 28 families.Among them, 4444 individuals of 54 species belonged to 7 orders of Insecta, accounting for 91.5% of allspecies and 76.4% of the total individuals. Individuals in Crustacean, Mollusca and Oligochaeta occupied23.6% of the total individuals. The average number of total taxa of benthic macroinvertebrates in the branchstream of Huangshui River was 6.76, which was not far from that in the trunk stream（8.04）; the averagenumber of total taxa of EPT in the branch stream of Huangshui River was 3.36, which had no obviousdifference compared with that of the trunk stream（2.48）. However, the species number of the pollution-tolerantmacroinvertebrates in the trunk stream was larger than that in the branch stream, and the species number of thepollution- sensitive macroinvertebrates in the branch stream was larger than that in the trunk stream. Theresults indicated that water quality in the branch stream of was better than that of the trunk stream, and the difference was caused by the heavier pollution in the trunk stream.