Environmental DNA (eDNA) testing is a relatively new survey technique that can help determine the presence or absence of great crested newts (GCN) in water bodies. Great crested newt DNA is released into aquatic environments through shed skin cells, urine, faeces and saliva. It can remain in water for several weeks and can therefore be collected and tested.
The technique can be used only in the newt breeding season, from late April to the end of June. Samples are taken from each separate water body with potential to support GCN. The samples are then quickly sent to an approved laboratory for analysis. Sampling can be undertaken in a single visit to the site, therefore saving on survey effort.
Dependent on the laboratory used, results from the tests can be expected within a few weeks.
This method is a technique approved by Natural England to confirm the likely presence (or absence) of GCN. It can be particularly useful when there are a large number of ponds that need to be sampled, or where there is a long lead in time to a project, as it only requires one visit to the site, whereas conventional survey methods (such as bottle trapping and egg searches) require numerous visits which can be costly and time-consuming.
If, however, GCN are found by the eDNA test to be present in the ponds, then further conventional surveys will still be required to determine the population size present. This information is necessary to inform a robust mitigation strategy for planning purposes and/or to support an a EPS licence submission to Natural England (and it’s counterparts elsewhere in the UK).
In the majority of instances this technique has been found to yield relatively quick and reliable data, making it an attractive alternative to traditional survey methods. As with the emergence of any new survey technique it is, nonetheless, an evolving science and therefore may not be appropriate in all circumstances.
Our ecology team is qualified and experienced in eDNA testing and are all GCN licence holders. To find out more about the technique, or to discuss any other ecology survey methods or requirements, please contact our Principal Ecologist, Caroline Chipperfield, via firstname.lastname@example.org