基于大型底栖动物生物完整性的洱海健康评价

Health Assessment on Lake Erhai Using Benthic Index of Biotic Integrity

为了解洱海水生态系统健康状况,该研究于2021年3月、6月、9月和12月对洱海11个断面共27个采样点开展为期1年的底栖动物群落结构调查,并在此基础上构建洱海底栖动物生物完整性评价指数(B-IBI)体系。结果表明,共获得底栖动物56属种,隶属4门6纲28科54属。经过分布范围、判别能力及相关性分析等筛选,得出由总分类单元数、摇蚊类个体数百分比和BMWP指数3个核心参数组成的洱海B-IBI评价指标体系。采用比值法统一量纲,将洱海健康状况按评分分为5个等级:>2.61为健康,2.10~2.61为亚健康,1.82~2.10为一般,1.42~1.82为差,<1.42为极差。结果表明,2021年洱海整体健康状况评价结果为一般。其中,有5个点处于健康状态,占18.5%;6个点处于亚健康状态,占22.2%;5个点处于一般状态,占18.5%;9个点处于差状态,占比33.3%;2个点处于极差状态,占比7.4%。

To understand the health status of aquatic ecosystem in Lake Erhai,the community structure of benthic animals was investigated based on 27 samples from 11 typical monitoring sections in March,June,September and December 2021,and the benthic index of biotic integrity(B-IBI)assessment system was also established.The results showed that Lake Erhai contains 56 genera and species of benthic animals,which refers to 4 phyla,6 classes,28 families and 54 genera.The assess⁃ment system of B-IBI for Lake Erhai consists mainly of the total number of classification units,proportion of chironomid indi⁃viduals,and BMWP index,which obtained by range test,discriminatory power and Pearson correlation screen.The health sta⁃tus of aquatic ecosystem in Lake Erhai can divide into five grades according to ratio scoring method,i.e.,>2.61,2.10~2.61,1.82~2.10,1.42~1.82 and<1.42,representing health,sub-health,fair,poor and very poor health status,respectively.Based on above method and standard,the health of aquatic ecosystem for Lake Erhai in 2021 is fair status.Specifically,five,six,five,nine and two sampling sites were in health,sub-health,fair,poor and very poor health status,accounting for 18.5%,22.2%,18.5%,33.3%and 7.4%of the total sites,respectively.