Environmental DNA or eDNA

Environmental DNA, also known as eDNA for short, is a recent method and survey technique which is sometimes used by our ecologists at Ellendale Environmental for protected species.

eDNA is DNA that is collected from a variety of environmental samples such as soil, water and droppings, rather than directly sampled from an individual organism. As animals interact with the environment, DNA is expelled and accumulates in their surroundings. Example sources of eDNA include, but are not limited to, faeces, shed skin, carcasses and hair.

Some of the protected species surveys undertaken by Ellendale Environmental ecologists can be assisted by undertaking eDNA analysis. Samples taken at a site can be analysed by high-throughput DNA sequencing methods in laboratories. The analysis of eDNA has great potential, not only for monitoring common species, but to genetically detect and identify other species present in a site that could influence conservation efforts,
particularly where presence / absence surveys are not always accurate or where animals frequently move between sites.

A benefit of using this technique is that it is less invasive for protected species and requires less time on site and could be a first step in providing information to inform planning. Recently, Ellendale Environmental ecologists have used this method to identify the likely presence / absence of Great Crested Newts in a pond (GCN). GCN are European Protected Species (EPS) and therefore a survey licence is required when surveying for them. Presence / absence surveys require a minimum of four repeat visits to a site, with a further two required if GCN are found. However, using eDNA, all that is required is a water sample to be collected from the pond, which is then sent to a laboratory for testing and the presence of GCN can be determined.

The technique can also be used for another group of protected species, namely bats. Bat droppings can be collected and sent to a laboratory where the species of bat can be confirmed. This method can be used as bats frequently move between roosts, some only using the roost for a single night during the year. Some species of bat are hard to identify using detectors, as their echolocation calls are quieter, have very directional calls or sometimes they use their eyes rather than echolocation! This makes it difficult for a bat
detector to pick up the bat. eDNA is less invasive than other advanced survey methods, such as physically catching bats or disturbing the bats while they are roosting.

If you think you may require assistance with eDNA sampling or would like to discuss protected species surveying, then please get in touch today and a member of our team will be very happy to assist you.

eDNA sampling ladel

eDNA sample of a water body for Great Crested Newts (GCN)