Local Transport of Vertebrate Airborne eDNA Is Captured by Wind‐Directed Catchment Area Models

ABSTRACT

Airborne environmental DNA (eDNA) offers a scalable tool for biodiversity monitoring, yet our limited understanding of airborne eDNA transport makes it challenging to define sample origin. We address this by investigating local spatial dynamics of eDNA dispersal using passive samplers and wind data. Over 3 weeks, we deployed passive samplers at Rotterdam Zoo (the Netherlands) and collected airborne eDNA at 5 locations for multiple durations over 96 h, where all samplers were started simultaneously. Vertebrate diversity was sequenced at 12S and 16S and resident zoo species identified ( N  = 24). Wind‐directed catchment areas were estimated using two models (Circular Sector model, using simple wind‐directed data from a nearby weather station, and Footprint model using gridded meteorological data). Catchment areas were defined by wind characteristics, with size and orientation determined by speed and directional variability. Results showed 100% species detections fell within predicted catchment areas up to 100 m (not all species in zoo detected). At longer ranges up to 655 m, 62% of the total detected species fell within the wind‐directed catchment areas. Species detections outside of the catchment areas suggest additional mechanisms may influence longer range transport of airborne eDNA. Longer sampling durations significantly increased the probability of species detections inside catchment areas and both models performed comparably well. Together, our results suggest simple wind characteristic models accurately identify vertebrate airborne eDNA catchments at local scales, increasing confidence that species signals originate at < 200 m downwind from sampler placement. Our work thus helps to enable more spatially explicit biomonitoring inferences.