Welsh rivers provide evidence for more effective river monitoring - Bangor University
Baseline established for riverine eDNA transport
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.
eDNA analyses are already being used in lakes and the sea. To be used effectively in rivers, one question needed resolving - how far downstream does eDNA travel before it is no longer detected?
By intensely sampling the River Conwy and comparing resulting data with other comparator rivers in Wales (Tywi), England (Gwash), Switzerland (Glatt) and the USA (Skaneateles), the team from Bangor University, Cardiff University, University of Birmingham and UKCEH have answered the question.
The work has revealed that eDNA does not survive much beyond a kilometre downstream. This means that ecologists can be sure that the species detected within an eDNA sample are representative of where the water sample was taken, and not of habitats many kilometers upstream.
Posted On: 19/06/2024
More on: