Study backs use of eDNA to assess biodiversity

DNA concept

Analysis of DNA traces in the environment is an effective way to assess the health of ecosystems, a new study in Scotland has found.

Environmental DNA, or eDNA, is genetic material present in the environment, such as in water, soil, or air. eDNA can be traced from shed cells, bodily fluids, or biological secretions deposited by animals, plants, fungi, and bacteria.

Recent research, directed and supported by organisations including the Scottish Environment Protection Agency (SEPA), NatureScot, and the Scottish Government’s Marine Directorate, and delivered by NatureMetrics, has shown how studying traces of this genetic material can help inform efforts to tackle the ecological crisis, on land and sea.

The collaborative project was aimed to test the effectiveness of environmental DNA analysis as a practical tool for biological monitoring programmes and biodiversity reporting purposes across a wide variety of habitats in Scotland.

The main report showed eDNA analysis can be used to detect, identify, and map the distribution of many different species, including important threatened and invasive species, simultaneously – without directly observing or collecting them.

Dr Pauline Lang, Lead Project Partner and Research Contract Manager for SEPA, said: “Using eDNA methods can help us increase monitoring coverage and get a more holistic picture of nature – to better understand the diversity of life across Scotland and target changes needed to help protect and improve our environment.”

“While conventional habitat monitoring requires a wide variety of survey techniques, expertise, and resources, eDNA-based monitoring employs relatively simple field sampling methods that can be applied to different habitats.”

Monitoring biodiversity across different habitats 

The study was conducted across Scotland, with eDNA samples taken from sites including Loch Lomond and Trossachs National Park and Cairngorms National Park.

During one sampling survey conducted as part of the project, researchers detected nearly 9,000 different species present in 358 eDNA samples collected from four habitat types in Scotland: marine lochs, freshwater lochs, woodlands, and peatlands.

They were able to identify differences in biological communities associated with distinct habitat conditions, and therefore classify sites based on their condition by eDNA testing alone.

The classification for freshwater lochs using fish and invertebrate eDNA showed encouraging results, as did sampling fungal eDNA to assess woodland soil condition.

The report recommends studying eDNA in more undisturbed habitats to measure environmental quality, determining the minimum number of samples to be collected for different monitoring objectives, and establishing standard guidelines for producing, storing, and using eDNA data.

Dr Iveta Matejusova, Environmental Genomics Group Leader for The Scottish Government’s Marine Directorate and Project Partner, said: “eDNA offers a valuable insight into the biodiversity of aquatic and terrestrial habitats. This study provides further demonstration of its potential applications, for example to assess the health of seabed habitats.

“We are pleased to see the progress made on determining the minimum number of samples to be collected for different monitoring objectives and we are excited to start building on and incorporating these findings into our monitoring and reporting frameworks.”

Prof Colin Bean, NatureScot’s Senior Policy and Advice Manager for Fish and Fisheries and Project Partner, commented: “This research clearly demonstrates the advantages of using eDNA to screen ecological health and monitor biodiversity.

“It should provide valuable insights on how to use this technology to assess Scotland’s habitats in future years – in turn, helping us tackle the nature-climate crises.”



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