Creation, optimisation and validation of an airborne environmental DNA sampling asset for terrestrial biodiversity monitoring

Our project will deliver a step-change for terrestrial biodiversity monitoring by developing new sampling arrays and capabilities to monitor species with airborne environmental DNA (eDNA). Environmental DNA takes the form of small fragments of DNA-bearing particles shed from animals and plants as fur, skin cells, pollen, faeces, and exhaled in breath. Recently, our team has discovered that this material is present in air and can potentially reflect local biodiversity, representing a transfer of this technology from aquatic to terrestrial ecosystems. eDNA-based methods are important because they allow scientists to target a broad range of taxonomic groups at fine temporal scales, which is not usually achievable with other methods of biodiversity monitoring.

We will develop and optimise a sampling array composed of air samplers to measure change in biodiversity over time and to evaluate how animals use habitat to move around the landscape (functional connectivity). We propose to evaluate existing commercial options because many air samplers have already been developed for air quality and microbial monitoring applications, but the use of these instruments to capture airborne eDNA from animals and plants represents a novel use case which must be validated and optimised. We will test a variety of active (a power source is used to draw air through a filter onto which particles are captured) and passive (particles are deposited onto a surface and no power source is used) units using a combination of qPCR and metabarcoding techniques to evaluate the amount of eDNA, taxonomic richness and composition detected by the samplers. Sampling media and preservation techniques will be tested in combination with the different units to optimise their effectiveness.

We will use approaches from atmospheric science to understand the efficiency of the samplers at capturing eDNA particulates. We will compare the quantities of eDNA captured by samplers to predictions made by a forward dispersion model - an approach that uses wind strength and direction to model how particles move away from a source. We will optimise how samplers need to be positioned in the landscape in order to capture eDNA. Finally we will perform real-world testing of the optimised sampling arrays within two National Nature Reserves and compare our results to species records captured with conventional monitoring. We will use our array to evaluate whether animals are using areas as dispersal corridors between habitats.

We envisage that potential applications will include 1) detection of taxa at scales for national reporting and targets (e.g., Environment Act targets, Environmental Improvement Plan Outcome Indicator Framework and Global Biodiversity Framework targets) and 2) monitoring species at local scales (e.g. for species recovery programme, Biodiversity Net Gain, and to inform sustainable development). Potential end-users include wildlife NGOs, government, and commercial organisations providing a monitoring service using eDNA technology. Co-creation of our asset with end-users is embedded throughout our work programme. We are working with Natural England - who deliver a large part of the terrestrial components of the Natural Capital and Ecosystem Assessment Programme - as a co-investigator. We have embedded a survey of the needs of end-users into WP1 and a second survey in which end-users will evaluate our optimised sampling asset. The final work package is dedicated to dissemination and two-way engagement with end-users.