DNA from the air could revolutionize the way we measure animal biodiversity
Two new studies published today in the journal Current biology show that environmental DNA (eDNA) collected from the air can be used to detect a wide range of animal species and offers a new, non-invasive approach to monitoring biodiversity.
The discoveries were made by two independent groups of researchers, one based in Denmark, the other based in the UK and Canada. The two research groups set out to test whether airborne eDNA could be used to detect terrestrial animal species. To do this, the research teams collected air samples from two European zoos, Hamerton Zoo Park, UK, and Copenhagen Zoo, Denmark.
The UK study was led by Assistant Professor Elizabeth Clare of York University, Canada, then Senior Lecturer at Queen Mary University in London, while the Danish study was led by Associate Professor Kristine Bohmann of The Globe Institute, University of Copenhagen.
Each team used a different method of filtering airborne eDNA, but both were successful in detecting the presence of many animal species within and beyond the boundaries of the two zoos.
Bohmann’s team collected air samples using three different air sampling devices; a commercial water-based vacuum cleaner and two blower fans with filters – the smaller of these was the size of a golf ball. They collected air samples from three locations: the okapi barn, the Rainforest House and outside between the outdoor enclosures.
Clare’s team used sensitive filters attached to vacuum pumps to collect more than 70 air samples from different locations in the zoo, both inside the animals’ sleeping areas and outside in the general environment of the zoo.
The results of both studies exceeded their expectations.
“When we analyzed the collected samples, we were able to identify the DNA of 25 different species of animals, such as tigers, lemurs and dingoes, of which 17 were known zoo species. We were even able to collect DNA from animals that were hundreds of feet away from where we were doing the test without a significant drop in concentration, and even outside sealed buildings. The animals were inside, but their DNA was leaking, ”says Clare.
“We were amazed to see the results,” says Bohmann. “In just 40 samples, we detected 49 species spanning mammals, birds, amphibians, reptiles and fish. In the Rainforest House, we even spotted the guppies in the pond, the two-toed sloth, and the boa. When sampling the air at a single outdoor site, we detected many animals with access to an outdoor enclosure in that part of the zoo, eg kea, ostrich and rhino.
Most of the species detected were kept in zoos, but remarkably both teams also detected species in the areas surrounding the zoo. The Eurasian hedgehog, endangered in the UK, has been detected outside Hamerton Zoo in the UK, while the water vole and red squirrel have been detected around Copenhagen Zoo . The two teams also noted the presence of food products for the zoo’s animals, such as chicken, cow, horse and fish. The wide range of species detected shows the potential that airborne eDNA could be used to detect and monitor terrestrial animal species in the wild. This would ultimately support global conservation efforts.
“The non-invasive nature of this approach makes it particularly valuable for observing vulnerable or threatened species as well as those found in hard-to-reach environments, such as caves and burrows. the region if we can recover traces of their DNA, literally out of thin air, ”says Clare. “Air sampling could revolutionize terrestrial biomonitoring and offer new opportunities to monitor the composition of animal communities as well as detect invasion of non-native species. “
Living organisms release DNA into their surrounding environment when they interact with them, and in recent years eDNA has become an important tool for the detection of species in a wide range of habitats. For example, eDNA analysis of water samples is commonly used to map species in aquatic environments. However, while air surrounds everything on earth, it is only now that airborne dNA has been explored for animal surveillance.
One of the main things when demonstrating a new type of eDNA sample is to make sure that the results are reliable, as eDNA assays are very sensitive and prone to contamination.
“Air is a difficult substrate to work with because air surrounds everything, which means that the risk of contamination is high. We wanted to make sure that the species we detected were from the zoo and not from the lab, for example. To make sure we didn’t have contaminating DNA floating around in the lab air, we sampled the lab air and also sequenced it, ”says Dr Christina Lynggaard, who is part of the team. Danish.
For these first studies, it is essential to be able to reproduce the work. The teams had no knowledge of each other’s work until the studies were completed, but were delighted by the parallel nature of the experiences. Clare and Bohmann agree that having two research teams independently demonstrating that airborne eDNA can be used to monitor a range of animal species greatly improves the strength of their work and clearly shows the potential of the technique.
“We didn’t think that aspiration of animal DNA into the air would work,” adds Bohmann, “It was a high-risk, high-reward science with the potential to push the boundaries of vertebrate biomonitoring. Clearly the sky is not the limit.
Using airborne eDNA sampling in natural environments will require additional research to unlock its full potential, but both research teams believe it could transform the way researchers study and monitor animal biodiversity.
The two research papers, Measuring biodiversity from DNA in the air, led by Clare, and airborne environmental DNA for monitoring the terrestrial vertebrate community, led by Lynggaard, were published today in the review Current biology.
Notes to Editors
- “Measuring biodiversity from DNA in the air” Elizabeth L. Clare, Chloe K. Economou, Frances J. Bennett, Caitlin E. Dyer, Katherine Adams, Benjamin McRobie, Rosie Drinkwater, Joanne E. Littlefair Current biology (2021). DOI: 10.1016 / j.cub.2021.11.064
- “Airborne Environmental DNA for Monitoring Terrestrial Vertebrate Communities” Christina Lynggaard, Mads Frost Bertelsen, Casper V. Jensen, Matthew S. Johnson, Tobias Guldberg Frøslev, Morten Tange Olsen and Kristine Bohmann Current biology (2021). DOI: 1016 / j.cub.2021.12.014
For more information or a copy of the article, contact:
Sandra McLean, York University Media Relations, 416-272-6317, [email protected]
Elizabeth Clare, Assistant Professor, York University, [email protected]
Sophie McLachlan, Faculty Communications Director (Science and Engineering), Queen Mary University of London, [email protected]
Mathias Traczyk, Communication Consultant, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark, +45 9356 5835, [email protected]