Abstract:

Haihe River Basin with dense population and numerous large and medium-sized cities, is an important industrial base and economic developed region in the northern China. In order to evaluate the health conditions of reservoirs in the Haihe Basin, benthic macro-invertebrate assemblages were sampled from 14 reservoirs in April and June of 2018, and benthic index of biotic integrity (B-IBI) was calculated. During the study, a total of 56 benthic macro-invertebrates taxa were identified, including 1 taxa of Platyhelminthes, 7 of Annelida, 8 of Mollusca and 40 of Arthropoda. Of all the collected taxa, 21.4% were susceptible and 37.5% were tolerant; Radix swinhoei, Cricotopus sp. and Chironomus sp. were the top three frequently occurring taxa. Aquatic ecosystem healthy assessment was conducated using Benthic Index of Biotic Integrity (B-IBI). Meanwhile, the total number of taxa, percent EPT taxa, Botic Index and number of filterer taxa were screened out to form a B-IBI index system. Ratio scoring method for B-IBI index was used to get a uniformed score. Using the 25^th percentile of reference sites as a criteria to evaluate the aquatic ecosystem health, the results showed that it was healthy when B-IBI>2.96, sub-health when B-IBI=2.22?2.96, fair when B-IBI=1.48?2.22, poor when B-IBI=0.74?1.48, and very poor when B-IBI<0.74. Assessment results using B-IBI showed that of all the reservoirs, 1/3 were in a healthy status, and 2/3 were in a sub-health, general or poor condition. The evaluation of the ecological status of typical reservoirs in the Haihe River Basin based on the Index of Biotic Integrity compensates for the shortcomings of using only a single biological evaluation index. The evaluation results from this study provide data reference and technical support for further understanding the water ecological status and protection and restoration of reservoirs in the Haihe River Basin.

Key words: Haihe Basin, reservoir, benthic macro-invertebrates, ecological health assessment

摘要：

为了解海河流域典型供水型水库的水生态健康状况，于2021年4－6月对流域14座典型水库的大型底栖动物进行了调查，构建并应用大型底栖动物完整性指数（Benthic Index of Biotic Integrity，B-IBI）对水库的水生态健康状况进行评价。调查共采集到大型底栖动物56个分类单元，包括节肢动物门40种，其中昆虫纲35种，占据明显优势；此外，软体动物门8种，环节动物门7种，扁形动物门1种。从大型底栖动物的耐污值（Tolerance Value，TV）看，TV≤3的敏感类群12种，占21.4%；TV≥7的耐污类群所21种，占37.5%。调查中出现频率最高的3个物种分别为椭圆萝卜螺（Radix swinhoei，出现频率为78.6%）、环足摇蚊属一种（Cricotopus sp.，64.3%）和摇蚊属一种（Chironomus sp.，64.3%），3个种均为耐污值较高的种类。选择分类单元数、主要类群的相对丰度、耐污能力和功能摄食群等四大类合计25个指标作为构建大型底栖动物完整性指数的候选指标，经分布范围检验、判别能力分析和Pearson相关性分析，最终确定总分类单元数、EPT类群数量百分比、Hilsenhoff生物指数和滤食者数量等4个指数为构成海河流域典型水库大型底栖动物完整性指数评价的核心指数。结果显示，海河流域的14座典型水源型水库中，约1/3水库的水生态状况为健康状态，2/3为亚健康、一般和差的状态，且整体呈现山区水库水生态状况优于平原水库。基于大型底栖动物完整性指数对海河流域的典型水库的水生态状况进行评价，弥补了仅使用单一生物评价指数的不足。该研究所形成的评价结果对进一步掌握海河流域水库的水生态状况及其保护修复提供数据参考和技术支撑。

关键词: 海河流域, 水库, 大型底栖动物, 水生态健康评价