Environmental DNA (eDNA) metabarcoding is a sensitive and widely used approach for species detection and biodiversity assessment. The most common eDNA collection method in aquatic systems is actively filtering water through a membrane, which is time consuming and requires specialized equipment. Ecological studies investigating species abundance or distribution often require more samples than can be practically collected with current filtration methods. Here we demonstrate how eDNA can be passively collected in both tropical and temperate marine systems by directly submerging filter membranes (positively charged nylon and non-charged cellulose ester) in the water column. Using a universal fish metabarcoding assay, we show that passive eDNA collection can detect fish as effectively as active eDNA filtration methods in temperate systems and can also provide similar estimates of total fish biodiversity. Furthermore, passive eDNA collection enables greater levels of biological sampling, which increases the range of ecological questions that eDNA metabarcoding can address.

环境 DNA (eDNA) 元条形码是一种敏感且广泛使用的物种检测和生物多样性评估方法。水生系统中最常见的 eDNA 收集方法是通过膜主动过滤水，这既耗时又需要专门的设备。调查物种丰度或分布的生态研究通常需要比使用当前过滤方法实际收集的样本更多的样本。在这里，我们展示了如何通过将过滤膜（带正电的尼龙和不带电的纤维素酯）直接浸入水柱中，在热带和温带海洋系统中被动收集 eDNA。使用通用鱼类元条形码分析，我们表明，在温带系统中，被动 eDNA 收集可以像主动 eDNA 过滤方法一样有效地检测鱼类，并且还可以提供类似的鱼类总生物多样性估计。此外，被动 eDNA 收集可以实现更高水平的生物采样，这增加了 eDNA 元条形码可以解决的生态问题的范围。