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UK’s hidden biodiversity could be revealed by technology that samples the air for DNA
Every moment of every day, living organisms are constantly shedding their DNA into the air around them.
By using new technology to capture, filter and analyse these fragments, researchers hope to find out more about the UK’s wildlife.
Much of the world’s biodiversity is hidden from us – but what if we could find it at the touch of a button?
Though it may sound far-fetched, a new project might be able to do just that. Researchers from the Natural History Museum and the Earlham Institute have developed pioneering technology that can suck in and identify environmental DNA (eDNA) floating in the air.
Following initial tests, the team are now ready to try out their system on a larger scale. The devices will be set up in eight sites across Norfolk covering a range of habitats to see what species they can find.
Over the next year, the tests will then be repeated every three months to see whether the changing seasons have an impact on the wildlife being detected.
“We’re blessed to be based in a county with such an exceptionally diverse range of habitats and species,” says Dr Richard Leggett, who has been leading the development of the project’s technology. “This gives us a unique opportunity to use the air to explore biodiversity across different environments and seasons - all without leaving Norfolk.”
Dr Matt Clark is a genetics expert at the Natural History Museum, and part of the project team.
“When we previously worked together to trial similar technology in the old urban gardens surrounding the Natural History Museum, we were blown away by how the air-biome changed hugely across the seasons as indeed the ecosystem does,” Matt adds.
“The Earlham Institute's project is building further on the technology, allowing us to unlock rich data about the biodiversity of Norfolk's unique habitats and a key agricultural region feeding the UK. It will show how impactful the study of airborne eDNA can be.”
Advances in DNA sequencing technology have made it possible to sequence vast amounts of genetic material cheaply and quickly. Image © Elpisterra / Shutterstock.
DNA sequencing – a rapidly developing field
While the structure of DNA was first revealed in the 1950s, it would be many years before the first genome of an organism was sequenced. This eventually took place in 1976, when researchers pieced together the DNA of a small microbe known as bacteriophage MS2.
While scientific developments helped to speed up the process, DNA sequencing remained a long and expensive process. For example, it took 13 years and billions of pounds for the Human Genome Project to work out 92% of our species’ genetic code.
Today, however, an entire human genome can be sequenced in as little as five hours at the cost of a few hundred pounds. This has all been made possible by the development of next-generation sequencing, which allows millions of DNA fragments to be read simultaneously.
It’s also made the use of DNA sequencing a reality for biologists out in the field. Scientists can now sequence and identify the eDNA fragments in soils, ice and water to find out what’s been living nearby.
Detecting airborne eDNA has proven more difficult. Species shed relatively little DNA into air compared to water or ice, and it’s much harder to prove where it has come from.
However, the technology has been developing rapidly. In 2022, two research groups revealed that they could identify the presence of zoo animals from hundreds of metres away by testing the air for eDNA. The challenge is now to prove the technology’s worth out in the field.
This is what the team hope to demonstrate in Norfolk.
“We’ve got a fair idea of some of the species we might expect to find and, at this time of year, there’s likely to be a lot of pollen in the air,” explains Richard. “But we may pick up things we can’t identify, or that have never been recorded in the region before.”
“I’m not suggesting we’ll find a Loch Ness monster on the [Norfolk] Broads but this is probably the best available approach for finding traces of species we’d normally struggle to spot by eye.”
Advances in DNA sequencing technology have made it possible to sequence vast amounts of genetic material cheaply and quickly. Image © Igor Klyakhin / Shutterstock.
What could airborne eDNA reveal?
This new technology uses pumps to suck thousands of litres of air through a filter. Any biological material floating in the air is then trapped and its DNA sequenced.
The resulting mixture of eDNA fragments are then analysed by a piece of software called MARTi. This compares them to a library of DNA sequences from known organisms.
Over the year, the scientists hope to build up an overview of life living along Norfolk’s coastline, urban areas and green spaces. They’re particularly interested any crop diseases detected.
Currently, the only signs that these economically damaging infections are present in crops is when the plants develop visible symptoms, at which point it is often too late to save them.
But if the technology can successfully detect microbes in the air before they have infected the plants, then it might one day become an important farming tool.
Dr Darren Heavens, a member of the research team, says, “The approach we’ve developed can be used by farmers to alert them to the appearance of pathogens, allowing them to take immediate action to minimise crop losses.”
“It potentially provides an unbiased, ‘always on’ monitoring system to continuously read the DNA and RNA sequences of microbes collected from the air. And, because we’re looking at the genome, we can even identify resistance genes or new strains emerging.”
If any DNA can’t be identified, then its sequence will be stored for future research. While the team don’t have any immediate plans to study any unknown fragments, they might be reinvestigated in the future as the number of known genomes expands.
