基于底栖动物完整性指数的长江口-杭州湾潮间带水生态状况评价

Assessment of the Yangtze River Estuary and Hangzhou Bay Intertidal Zone Based on Benthic Index of Biotic Integrity(B-IBI)

利用生物完整性指数评价流域水生态状况,所得结果对水环境管理决策有重要指导意义。以2006年崇明东滩底栖动物监测数据为参照状态数据,利用长江口1991—2019年和杭州湾2004—2019年潮间带底栖动物监测数据构建底栖动物完整性指数(B-IBI),最终从56个候选指标中确定了6个核心指标:Marglef指数、软体动物相对多度、甲壳动物+多毛纲相对多度、ASPT、科级生物指数和捕食者相对多度。B-IBI评价结果显示:优秀等级样本有44个,良好等级72个,中等等级31个,较差等级7个,很差等级4个;杭州湾北岸水生态状况显著优于长江口南岸(P<0.05)。经验证,B-IBI与水质综合污染指数呈极显著相关(P<0.01),能够有效指示研究区域的水生态状况。

Assessing watershed aqua-ecological status with index of biotic integrity provides important information for water environment management and decision.Using the reference sites set at Chongming Dongtan in 2006,the benthic index of biotic integrity(B-IBI)was developed on the historical data of macrobenthos from 1991 to 2019 in the Yangtze River Estuary intertidal zone and from 2004 to 2019 in Hangzhou Bay intertidal zone.Among the 56 candidate biotic metrics,totally 6 core metrics were confirmed to calculate the score of B-IBI,which included Margalef richness index,relative abundance of Mollusca,relative abundance of crustacea and polychaete,average score per taxon(ASPT),family biotic index(FBI)and relative percentage of predators.The B-IBI assessing results indicated that 44 samples were excellent,72 samples were good,31 samples were fair,7 samples were poor and 4 samples were very poor.The aqua-ecological status of the northern Hangzhou Bay was significantly better than that of the southern Yangtze River Estuary(P<0.05).It has been proved that B-IBI had extremely significant correlation with the water comprehensive pollution index(P<0.01),which can effectively indicate the regional aqua-ecological status.