Environmental DNA analysis is rapidly transforming biodiversity monitoring and bolstering conservation applications worldwide. This approach has been assisted by the development of metabarcoding PCR primers that are suited for detection of a wide range of taxa. However, little effort has gone into exploring the value of the non-target DNA sequences that are generated in every survey, but subsequently discarded. Here we demonstrate that fish-targeted markers widely employed in aquatic biomonitoring can also detect birds and mammals present in the surrounding habitats. We showcase this feature in three temperate estuaries over multiple seasons, where dozens of bird and mammal species offer valuable insights into spatial and temporal faunal variation. Our results indicate that existing metabarcode sequence data sets are suitable for mining and exploration of this "molecular by-catch", and that any future eDNA-based surveys can be designed to accommodate this enhanced property of this widely applicable tool.

中文翻译：

---

河口分子兼捕作为景观生物监测工具

环境脱氧核糖核酸分析正在迅速改变生物多样性监测并在全世界范围内促进保护应用。通过开发适用于检测各种分类单元的元条形码PCR引物，该方法得到了帮助。但是，几乎没有花力气去探索在每次调查中生成但随后被丢弃的非目标DNA序列的价值。在这里，我们证明了在水生生物监测中广泛采用的以鱼为目标的标记物还可以检测周围生境中存在的鸟类和哺乳动物。我们在多个季节的三个温带河口展示了此功能，其中数十种鸟类和哺乳动物物种为时空动物区系变化提供了宝贵的见识。