At Greenlight, our Ecology and Protected Species Surveys consist of visiting sites and identifying habitats and species present in the environment.
While this approach works well for development planning applications and legislation, it can be enhanced with additional methods, to further strengthen our findings, and allow us to build a more detailed picture of species presence and population sizes.
In the blog, we’ll cover everything you need to know about an eDNA, how it supports ecological work, and how eDNA surveys are carried out.
Understanding Environmental DNA
Environmental DNA (eDNA) refers to DNA that is released from an organism and left behind in its habitat. Instead of taking a DNA sample directly from the species to learn about them, this science means we can take small particles of DNA from their habitat instead for the same purpose.
Some of the most common sources of eDNA include faeces, shed skin, hair, mucus and carcasses, and these can be found in soil, water or snow. It is generally used to detect Great Created Newts and Bat species identification, along with aquatic mammals.
How eDNA Supports Ecology Surveys
Ecology surveys are used in order to protect our wildlife from developmental changes and to keep an eye on fluctuating populations. However, certain species can be harder to detect using traditional visual observation methods, particularly those that are rare, present in low densities, or recovering from environmental pressures.
Environmental DNA oMers an approach that can support and enhance these surveys, providing additional insight to help build a more comprehensive understanding of species presence directly from the field.
How Environmental DNA (eDNA) Helps
To start with, eDNA is much more cost-effective method of surveying biodiversity. Although visual observation is still key to the methodology, by taking samples and identifying opportunities for eDNA while surveying, there is a greater chance of finding results.
Secondly, environmental DNA sampling is a non-invasive technique to monitor species across the country. This means there is little risk of disturbance to both their habitat and to the species itself, and all testing occurs off-site so there is no further invasion taking place.
Finally, eDNA gives us the ability to broaden the ecology analysis spectrum to include more protected species. eDNA methods can be used to detect aquatic mammals, fish species, invertebrates and non-native species, with ongoing advancements improving their sensitivity and reliability.
How to Conduct eDNA Surveys
The next step is to explore how this approach is applied in practice. It’s important to understand the methodology behind collecting and analysing these samples.
eDNA Survey Protocol
eDNA surveys can only be conducted during certain timeframes, which are between 15 April and 30 June, to ensure accurate detection. It involves taking 20 water samples by an ecologist using eDNA test kits, which include a mixing bag, a sterilised pipette, a sampler, preserving fluid tubes and a pair of gloves.
Once the sample is taken, it is sent to a laboratory where it is analysed using DNA sequencing methods for a fast and eMicient method of monitoring and measuring biodiversity. The results are usually returned within two weeks.
eDNA vs Field Surveying
Field surveying in ecology is a detailed, on-site assessment conducted by professionals to identify, map and evaluate habitats within a specific area, whereas eDNA is the method for detecting genetic materials to determine species presence.
Some of the main advantages of eDNA surveys over field surveying include the following:
- Time-Savings: A single visit during the correct eDNA survey season can verify the presence of a protected species such as the great crested newt. Similarly, conducting one eDNA survey can also confirm the absence of a species, whereas four visits would be needed under a conventional survey to come to a negative conclusion. A field survey is more time-consuming and will involve methods such as egg searching, bottle trapping and torching.
- Greater Accuracy: The eDNA approach is generally more accurate and errorfree compared to conventional methods, therefore, providing better results.
- Disturbance-Free: With eDNA surveying, there is no need to disturb species in their natural habitats to determine their presence.
- Less Risk of Spreading Disease: eDNA samples are taken using sterile equipment, and there is no need to enter the water in order to take a sample.
This reduces the chance of introducing alien or invasive species and the spread of diseases.
eDNA surveys are a useful method of ascertaining the species present in a particular area without needing to collect or capture the wildlife itself. They are a great partner to traditional surveying and can be used alongside other visual observation methods to create a more accurate picture.
At Greenlight, we are able to conduct a variety of surveys to suit your project requirements. Take a look around our website today or get in touch with us directly to find out more about what we can do for you.
