Freshwater Habitats Trust played a pioneering role in testing the potential for eDNA monitoring to survey Great Crested Newts in ponds in 2013.  Now, we’re using this cutting-edge technique to monitor freshwater biodiversity in waterbodies across England and Wales.

What is environmental DNA (eDNA)?

Environmental DNA (eDNA for short) is DNA that’s released into the water by plants and animals in a host of ways: from their skin, faeces, mucous, hair, eggs and sperm, or when they die.

It is now possible to monitor the freshwater species that live in ponds, streams and other waterbodies simply by collecting a water sample, and analysing it for traces of DNA. Recent research has shown that the DNA of a range of aquatic organisms can be detected in water samples at very low concentrations using qPCR (quantitative Polymerase Chain Reaction) methods.

Man and woman sitting outside. Woman wearing blue surgical gloves, holding a water testing kit.

- National Trust staff help with the PondNet eDNA survey

How useful is eDNA monitoring?

eDNA monitoring can detect very small amounts of DNA. Our studies on eDNA monitoring for Great Crested Newt showed that a single water sample taken at any time during the newt breeding season is almost certain to detect the species when it is present. In fact, we saw eDNA monitoring deliver a 99.3% rate of detection. This was better than any combination of traditional survey methods for finding Great Crested Newts, including torch counting at night, bottle trapping or searching for eggs.

Our work has also shown that, with some training, volunteers can successfully carry out eDNA monitoring.

Hand holding a white box with the words 'Great Crested Newt eDNA testing kit' in orange. Grass in the background.