An international team of scientists has carried out the first national survey of biodiversity using a novel approach. Instead of recording species by sight, they harnessed the UK’s network of air quality monitors – which constantly measure toxic metal particles in the air – to capture and analyse tiny fragments of DNA.

Dr Joanne Littlefair from University College London, part of the research team, said: “Organisms lose bits of themselves all the time – dead skin cells, fragments of hair or feathers, saliva, even faeces and urine. Some of this will blow up into the air and become airborne ‘environmental’ DNA or eDNA.”

From these samples, researchers identified more than 1,100 species of plants and animals. These included familiar British wildlife such as trees, crops, earthworms, newts, robins and badgers, along with species of conservation concern like skylarks and hedgehogs. The study also revealed 65 species of butterflies and moths, among them the gatekeeper – currently ranked third in the Big Butterfly Count – and the purple hairstreak, a little-known butterfly that lives mainly in oak trees.

The survey detected invasive species including grey squirrels and muntjac deer, as well as newly arrived species and fungi considered agricultural pests. Crucially, the team also picked up the DNA of Hymenoscyphus fraxineus, the fungus responsible for ash dieback.

The UK national survey started from a chance spot on social media. Dr Andew Brown from the National Physical Laboratory said: “We saw a social media post about airborne eDNA projects at a zoo in Cambridgeshire and wondered whether if the air pollution filters in our labs contained hidden information about local biodiversity.”

Samples were collected from 15 monitoring stations across the UK, located in environments ranging from the kerbside of London’s busy Marylebone Road to rural Hampshire and a peat bog in Scotland.

Not all detections were from wild ecosystems – but these findings helped researchers understand how far environmental DNA (eDNA) can travel. At the kerb of London’s Marylebone Road, for instance, edible fish such as seabass and hake were traced back to seafood stalls about 1.1km away, while DNA from peacocks and parrots was linked to outdoor aviaries. From this, scientists estimated that each air monitoring site could detect biodiversity within a radius of roughly 19km.

Prof Elizabeth Clare from York University, Canada, part of the research team, said: “I think that this is only the beginning. Taking large national and continental measurements is now really possible. No other method can really scale to this geographic breadth.”

The results compared well with existing biodiversity records. Around one-third of the species identified were nocturnal – animals often missed by traditional surveys. Some species, however, went undetected, including blue tits and kestrels.

Even so, the study suggests that airborne eDNA could be a powerful new tool for monitoring biodiversity change, particularly in places not routinely surveyed. By repurposing air pollution monitoring stations – already in operation worldwide – scientists may be able to track shifts in wildlife on an unprecedented scale.

——————————————————————————

At Natural World Fund, we are passionate about restoring habitats in the UK to halt the decline in our wildlife.