辽宁省主要河流底栖动物群落结构及水质评价研究

Study on Benthic Macroinvertebrates Community Structure and Water Quality Evaluation in Main Rivers of Liaoning Province

利用2021年辽宁省主要河流47个点位的底栖动物监测数据分析其群落结构的空间分布、群落结构与环境因子的关系、不同评价指数以及它们与环境因子的相关关系,为辽宁省水生态监测与评价方法的优化提供参考。结果表明,(1)辽宁省主要河流共检出底栖动物4门8纲22目57科98属120种,以水生昆虫为主,其种类数和生物密度均占据优势地位。上游点位以水生昆虫和甲壳动物为优势类群,33%的上游点位以蜉蝣目、襀翅目和毛翅目(EPT)为优势类群;中游点位以甲壳动物为优势类群,软体动物和环节动物明显增多;下游点位以甲壳动物和环节动物为优势类群,水生昆虫和软体动物的相对密度明显减少;从上游到下游整体呈现水生昆虫相对密度不断减少、环节动物相对密度不断增多、软体动物相对密度先增多后减少、甲壳动物基本稳定的趋势。(2)RDA分析结果表明,氟化物、化学需氧量、生化需氧量和总磷与底栖动物群落数显著负相关,溶解氧和锌与底栖动物群落数显著正相关。溶解氧与总分类单元数相关性最高(F=2.37,P=0.02),锌与环节动物相关性最高(F=3.30,P=0.01)。(3)构建了涵盖总分类单元数、EPT分类单元数、耐污种分类单元数和香农-维纳多样性指数的底栖动物完整性指数并建立了评价标准。Pearson相关性分析结果表明,底栖动物多样性指数和底栖动物分值指数的评价结果与底栖动物完整性指数的评价结果高度相关(r=0.86,P=0.00;r=0.84,P=0.00),二者计算方法较底栖动物完整性指数简单易行,可以作为辽宁省主要河流水质生物评价的重要指标。

Based on the monitoring data of benthic macroinvertebrates at 47 points of major rivers in Liaoning Province in 2021,the spatial distribution of community structure,the relationship between community structure and environmental factors,and the correlation between different evaluation indexes and environmental factors were analyzed,providing references for the optimization of monitoring and evaluation methods concerning water ecology in Liaoning Province.The results show that(1)a total of 4 phyla,8 classes,22 orders,57 families,98 genera,and 120 species of benthic macroinvertebrates have been detected in the main rivers of Liaoning Province.Aquatic insects were the dominant group,and their species number and biological density were dominant.Aquatic insects and crustaceans were dominant groups at the upstream sites;Ephemeroptera,Plecoptera,and Trichoptera(EPT)were dominant groups in 33%of the upstream sites;Crustaceans were the dominant group in midstream,mollusks and annelids increased significantly;Crustaceans and annelids were dominant groups at the downstream sites,while the relative densities of aquatic insects and mollusks decreased significantly.From the upstream to the downstream,the relative density of aquatic insects decreased continuously;the relative density of annelids increased continuously;the relative density of mollusks increased first and then decreased,and the relative density of crustaceans was basically stable.(2)The RDA analysis results indicate that Fluoride,Chemical oxygen demand(COD),Biochemical oxygen demand(BOD5)and total phosphorus(TP)were significantly and negatively correlated with the benthic macroinvertebrates community numbers,while dissolved oxygen(DO)and zinc were significantly and positively correlated with the benthic macroinvertebrates community numbers.DO had the highest correlation with the total number of taxons(F=2.37,P=0.02),and zinc has the highest correlation with annelids(F=3.30,P=0.01).(3)The benthic macroinvertebrates index of biological integrity(B-IBI)including the total number of taxons,the number of EPT taxons,the number of pollution tolerant species taxons and the Shannon-Wiener Diversity Index(SDI)was constructed and the evaluation criteria was established.Based on the Pearson correlation analysis,the evaluation results of the SDI and the Chinese benthic macroinvertebrate score index(CMSI)were highly correlated with B-IBI(r=0.86,P=0.00;r=0.84,P=0.00).The calculation methods for both were simpler and more feasible than that for B-IBI,and can be used as important indicators for the biological evaluation of water quality in major rivers in Liaoning Province.