基于底栖动物的东江上游生态健康状况评价

大型底栖动物是评价水生态健康状况最常用的生物类群。为系统评价东江流域上游生态健康水平,以底栖动物为指示生物,2013年11月对东江上游的重要支流—鱼潭江、浰江、车田水、小庙水、彭寨水、沙洲水、罗浮水和黄麻布水进行采样调查,通过计算底栖动物的Shannon-Wiener多样性指数(H′)、Pielou均匀度指数(J)、Margalef丰富度指数(D)和BMWP(Biological Monitoring Working Party)指数,评估了8条支流的生态健康状况。结果显示,东江流域上游共采集到底栖动物109属种,隶属5门、9纲、55科,其中水生昆虫为主要类群,占总物种数的72.4%,EPT类群采集到18属种。研究区域的生物多样性指数较高,物种组成丰富,就不同水体而言,浰江的种类最丰富,小庙水种类数最少,各个支流均以水生昆虫类群占优势。底栖动物平均密度为2362个/m²,平均生物量为39.1 g/m²。河蚬(Corbicula fluminea)为第一优势种,出现率90%,第二和第三优势种分别为涡虫纲一种(Turbellaria sp.)和四节蜉属一种(Baetis sp.)。BMWP指数作为应用广泛的生物评价指数,对河流生态健康的指示作用最强,可达到快速准确的效果。研究表明,东江上游8条支流的生态健康状况总体较好,其中5条河流为极清洁。

Ecological Health Assessment of the Upper Dongjiang River Based on Macrozoobenthos

Macrozoobenthos are the most commonly used organisms for assessing aquatic ecological health. Based on macrozoobenthos, the ecological health of 8 tributaries in the upper reaches of the Dongjiang River Basin was assessed. A total of 109 genera and species were collected, belonging to 5 phyla, 9 classes and 55 families. Aquatic insects were the main group, accounting for 72.4% of the total species. EPT group was collected to 18 species. In terms of different water bodies, Lijiang River has the richest species, followed by Yutanjiang River, Pengzhaishui River and Huangmabushui River. The proportion of aquatic insects is higher, while other water bodies have the lowest species richness. The average density and biomass of benthic animals were 2362 ind./m2 and 39.1 g/m2, respectively. Corbicula fluminea is the first dominant species; almost every sampling station has been collected. It not only occupies the absolute dominance of biomass, but also occupies the dominance of density in some rivers. Next are Baetis sp. and Polypedilum sp. The biodiversity index of the study area is high and species composition is abundant. Especially the number of aquatic insects is large and the number of species is large. BMWP index is used to evaluate the ecological health status. The health status of 8 tributaries in the upper reaches of the Dongjiang River Basin is generally excellent, four rivers are extremely clean and four rivers are clean.