Data from: A systematic approach to evaluate the influence of environmental conditions on eDNA detection success in aquatic ecosystems

The use of environmental DNA (eDNA) to determine the presence and distribution of aquatic organisms has become an important tool to monitor and investigate freshwater communities. The successful application of this method in the field, however, is dependent on the effectiveness of positive DNA verification, which is influenced by site-specific environmental parameters. Factors affecting lower eDNA concentrations in aquatic ecosystems include flow conditions, and the presence of substances that possess DNA-binding properties or inhibitory effects. In this study we investigated the influence of different environmental parameters on the detection success of eDNA using the invasive goby Neogobius melanostomus. In a standardized laboratory setup, different conditions of flow, sediment-properties, and fish density were compared, as well as different potential natural inhibitors such as algae, humic substances, and suspended sediment particles. The presence of sediment was mainly responsible for lower eDNA detection in the water samples, regardless of flow-through or standing water conditions and a delayed release of eDNA was detected in the presence of sediment. Humic substances had the highest inhibitory effect on eDNA detection followed by algae and siliceous sediment particles. The results of our study highlight that a successful application of eDNA methods in field surveys strongly depends on site-specific conditions, such as water flow conditions, sediment composition, and suspended particles. All these factors should be carefully considered when sampling, analyzing, and interpreting eDNA detection results.利用环境DNA（eDNA）确定水生生物的存在与分布，已成为监测与研究淡水群落的重要手段。然而，该方法的野外成功应用依赖于阳性DNA验证的有效性，而这一有效性又受特定位点环境参数的影响。水生生态系统中导致eDNA浓度降低的因素包括水流条件，以及具有DNA结合特性或抑制效应的物质。本研究以入侵性黑口新虾虎鱼（Neogobius melanostomus）为对象，探究了不同环境参数对eDNA检测成功率的影响。在标准化实验室设置中，我们对比了不同水流条件、沉积物特性与鱼类密度，以及藻类、腐殖质、悬浮沉积物颗粒等多种潜在天然抑制剂的影响。无论处于流水还是静水环境，沉积物的存在均是导致水样中eDNA检出率降低的主要因素，且在沉积物存在时可检测到eDNA释放延迟。腐殖质对eDNA检测的抑制效应最强，其次为藻类与硅质沉积物颗粒。本研究结果表明，eDNA方法在野外调查中的成功应用，高度依赖于特定位点的环境条件，如水流状况、沉积物组成与悬浮颗粒。在采样、分析及解读eDNA检测结果时，需充分考量上述所有因素。