Surface Water Quality Indicators: Benthic macroinvertebrates in rivers (2021)

Water quality can be valued through the biological communities they host. These communities are disrupted by the human activity and pollution associated with this activity. The study of the flora and fauna found in an aquatic ecosystem, in front of the expected fauna and flora, allows to measure the situation of the ecosystem with respect to pollution. The biological indicators selected come from the study of the biological quality elements provided for in the assessment of ecological status in the Water Framework Directive 2000/60/EC (WFD), and the indices selected for each typology in the RDSE, since this information is regularly studied by means of standardised analyses that allow the collection of annual and quality data. In the case of continental surface waters rivers, the indicator will be configured from the data of phytobents and macroinvertebrates benthic, evaluated according to what is established in the RDSE for each typology. In the case of both taxonomic groups, the use of different indices is contemplated according to the type of river in which it is studied. Despite their different approaches, the expected indices assess the situation of the river with respect to a pressure, scoring each taxon found according to its ability to tolerate it. The greater the taxonomic diversity of the section to be studied and the greater number of pressure-intolerant taxa, the better the section will be in an environmental situation. To develop the situation graphs on benthic macroinvertebrates, it has been taken into account whether the indices applied to the analyses of benthic macroinvertebrates exceed the limit established in the RDSE between the good and moderate state for each type of river, or do not exceed it. In addition, the typologies without legal limit have been recorded as “No Valuation”.水体质量可通过其孕育的生物群落进行评估。此类生物群落会受到人类活动及相关污染的干扰与破坏。通过对比水生生态系统中实际检出的动植物群落与预期群落，可定量评估该生态系统受污染的状况。 本次选取的生物指标，源自《2000/60/EC水框架指令》(Water Framework Directive, WFD)中生态状况评估规定的生物质量要素，以及RDSE中针对各类水体类型设定的评价指数；此类信息可通过标准化分析手段定期采集，从而获取年度数据与高质量观测结果。 针对内陆地表河流，本指标将基于着生藻类(phytobents)与底栖大型无脊椎动物(benthic macroinvertebrates)的观测数据构建，并依据RDSE中针对各类水体类型的相关规定开展评估。 针对上述两类生物类群，本次研究将根据河流类型选用适配的评价指数。尽管各类指数的计算逻辑存在差异，但均围绕河流受干扰压力的状况开展评价：依据所检出分类单元的耐受能力对其进行评分。 研究河段的分类多样性越高，且对干扰不耐受的分类单元数量越多，则该河段的环境状况越好。 为构建底栖大型无脊椎动物的状况评估图表，本次研究将比对底栖大型无脊椎动物分析所用的指数是否超过RDSE中针对各类河流设定的"良好"与"中等"生态状态阈值。此外，无法定阈值的水体类型将被记录为"No Valuation"。