Great crested newts (Triturus cristatus) are a common occurrence within the UK, however, populations are in decline throughout the UK and Europe therefore the species is protected under UK and European legislation. They need water bodies in which to breed and suitable surrounding land such as grassland, woodland, hedgerows or gardens in which to live.
Any development taking place needs to ensure the favourable conservation status of great crested newts is maintained within the local landscape. Any planning site needs to be fully assessed for its ecological impact – and now ecological consultants have another tool in their arsenal to be able to provide that service.
Typically, any development site containing ponds or within 500m of a pond needs to have surveys completed to see if great crested newts are present or likely absent. Traditional surveys to confirm presence or absence of great crested newts involved the deployment of modified plastic bottles in ponds to capture newts over four visits. The approach was time consuming and invasive.
Now eDNA (environmental DNA) is collected from the environment rather than from an individual organism. As a species spends time in a particular environment, they shed DNA through faeces, shed skin, carcasses and hair – which can be identified in a sample. This process is non-invasive, doesn’t damage the environment or stress any species, and is fast becoming the first step in identifying the presence of certain species in a given environment.
For great crested newts, eDNA surveys involve taking a small sample from the body of water, which is sent to a lab for testing. We know that great crested newt DNA breaks down in freshwater within 2-3 weeks, so the presence of eDNA shows that they have recently been in that body of water. The test itself has a 98% accurate result, simply showing whether newt DNA is present or absent.
If the eDNA test confirms absence of newt eDNA no further surveys or mitigation for great crested newts are needed. The test typically saves time, money and reduces the environmental impact of the survey.
If newt eDNA is confirmed further targeted surveys are needed if development proposals have the potential to impact upon a newt population, enabling design of appropriate mitigation, compensation and enhancement measures to maintain and enhance newt populations.
eDNA is revolutionising the way we identify and protect the biodiversity of our countryside.