The River Conwy in north Wales has been surveyed by scientists to establish new genetic information that can be used to monitor freshwater rivers worldwide. The work, involving multiple institutions, and led by Bangor University, Cardiff University, University of Birmingham and the UK Centre for Ecology & Hydrology (CEH) is published in Nature Communications .

Human activities such as climate change and habitat modification are causing populations of freshwater species to decline around the globe. Conservationists and scientists therefore need to conduct baseline ecological surveys, in order to monitor and improve these environments, but traditional methods of conducting freshwater surveys rely on individual expertise and can be time-consuming.

Sampling the water and sediment for trace DNA can provide a far more in-depth understanding of the species connected to that environment. Environmental DNA, or eDNA, can not only reveal the presence of species too small to see with the human eye, it also detects larger animals and insects who have moved through that space, from salmon to dragonfly larvae, because of the tiny fragments of DNA they leave behind in the environment.