Explainer: eDNA
- emmarehn5
- Apr 1
- 2 min read
What is eDNA?
Environmental DNA (eDNA) is genetic material that organisms have left behind in the environment where they live – in water, soil, or air. Blood, skin, mucus, excrement, and other cells can all contribute to eDNA.
Any organism with DNA, from animals and bacteria to plants and fungi, can potentially leave behind traces in eDNA – but some organisms naturally shed more eDNA than others.
How do we measure it?
Water, soil, or air samples are collected in the field. In the lab, DNA is isolated from environmental samples and screened for presence of a particular species using species-specific genetic markers.
The extracted DNA can also be sequenced to target all organisms contained in the environmental samples; this technique is called eDNA metabarcoding. This technique allows scientists to detect multiple species at once by targeting a shared fragment of a gene.
Different approaches to sampling and detection may be necessary to suit the unique characteristics of target species or sampling environments, such as fast-flowing water, estuaries, and the ocean.
How are we using eDNA?
eDNA allows scientists to detect organisms without sighting them, which is valuable for many ecological applications. Our researchers are using eDNA for:
Early detection of invasive species.
Insights into the range of species living in an ecosystem.
Engaging with citizen scientists for biodiversity assessments.
Detecting endangered species.
Monitoring species that may be difficult to observe.
Sample collection for eDNA analysis is cost-effective and relatively simple. Citizen scientists can play a key role in collecting samples, allowing for analysis over large areas, and local communities can lead environmental monitoring efforts.
From finding endangered species to strengthening biosecurity, eDNA is a powerful tool to address a range of ecological challenges.
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