Macher Till-Hendrik, Beermann Arne J, Arle Jens, Foerster Julia, Greyer Matthias, Mora Demetrio, Koschorreck Jan, Rolauffs Peter, Rother Anne, Schüler Susanne, Zimmermann Jonas, Hering Daniel, Leese Florian
University of Duisburg-Essen, Aquatic Ecosystem Research, Universitaetsstr. 5, 45141, Essen, Germany; University of Trier, Biogeography, Universitaetsring 15, 54296, Trier, Germany.
University of Duisburg-Essen, Aquatic Ecosystem Research, Universitaetsstr. 5, 45141, Essen, Germany; University of Duisburg-Essen, Centre for Water and Environmental Research (ZWU), Universitaetsstr. 3, 45141, Essen, Germany.
Water Res. 2025 Mar 15;272:122987. doi: 10.1016/j.watres.2024.122987. Epub 2024 Dec 15.
The ecological state of aquatic ecosystems is systematically monitored using various bioindicators in many countries worldwide. In the European Union, freshwater biomonitoring is the central component of the EU Water Framework Directive (WFD, 2000/60/EC) and currently based on morpho-taxonomic methods. DNA metabarcoding is a novel approach to assess the ecological state fast and efficiently based on organismal DNA signatures and thereby support and upscale biomonitoring. However, compliance of metabarcoding with existing morpho-taxonomic methods must be ensured prior to official implementation. Thus, this study, co-designed by research institutions and environmental agencies, explored necessary key parameters and performed method intercalibration for the implementation of metabarcoding into WFD assessments of running waters. We focussed on benthic invertebrates as the most commonly used bioindicators. We analysed 170 invertebrate samples collected as part of the German federal state WFD routine stream biomonitoring, first via microscopic determination and then using metabarcoding. Our goals were to quantify overlap in i) taxonomic composition and ii) ecological status derived with both methods. For this purpose, we established data harmonisation measures to integrate invertebrate metabarcoding data into the official national WFD classification modules considering abundance and presence/absence data. Our results revealed a high (ca. 70 %) overlap of bioindicator taxa found with both methods. Metabarcoding identified significantly more small invertebrate taxa and detected similar proportions of the important bioindicator 'EPT' taxa (mayflies, stoneflies, caddisflies). Despite deviations in some detected bioindicator taxa, the derived ecological status classes were highly correlated between methods, particularly after intercalibration (R = 0.74, Spearman rho = 0.86). Regardless of whether we used abundance or presence/absence data, the resulting stream type classifications showed strong agreement. Thus, our study not only demonstrates the consistency of the methods for the stream types analysed but is also the first to operationalise a path to integration of metabarcoding data into the WFD assessment modules based on formal intercalibration guidelines.
世界上许多国家都在使用各种生物指标对水生生态系统的生态状况进行系统监测。在欧盟，淡水生物监测是欧盟水框架指令（WFD，2000/60/EC）的核心组成部分，目前基于形态分类学方法。DNA宏条形码技术是一种基于生物体DNA特征快速高效评估生态状况的新方法，从而支持并提升生物监测水平。然而，在正式实施之前，必须确保宏条形码技术与现有的形态分类学方法相符。因此，这项由研究机构和环境机构共同设计的研究，探索了必要的关键参数，并对将宏条形码技术应用于WFD流水评估进行了方法间校准。我们将重点放在底栖无脊椎动物上，它们是最常用的生物指标。我们分析了作为德国联邦州WFD常规河流生物监测一部分收集的170个无脊椎动物样本，首先通过显微镜鉴定，然后使用宏条形码技术。我们的目标是量化两种方法在以下两方面的重叠情况：i）分类组成；ii）得出的生态状况。为此，我们建立了数据协调措施，将无脊椎动物宏条形码数据纳入官方国家WFD分类模块，同时考虑丰度和存在/缺失数据。我们的结果显示，两种方法发现的生物指标类群有很高（约70%）的重叠。宏条形码技术识别出的小型无脊椎动物类群明显更多，并检测到重要生物指标“EPT”类群（蜉蝣、石蝇、毛翅目昆虫）的比例相似。尽管在一些检测到的生物指标类群上存在偏差，但两种方法得出的生态状况类别高度相关，特别是在校准之后（R = 0.74，斯皮尔曼等级相关系数 = 0.86）。无论我们使用丰度数据还是存在/缺失数据，得出的河流类型分类都显示出很强的一致性。因此，我们的研究不仅证明了所分析河流类型方法的一致性，也是首个根据正式校准指南将宏条形码数据整合到WFD评估模块中的可操作路径。
