Yang, Bo, Timothy L. Hawthorne, Lillian Aoki, Deanna S. Beatty, Tyler Copeland, Lia K. Domke, Ginny L. Eckert, Carla P. Gomes, Olivia J. Graham, C. Drew Harvell, Kevin A. Hovel, Margot Hessing-Lewis, Leah Harper, Ryan S. Mueller, Brendan Rappazzo, Luba Reshitnyk, John J. Stachowicz, Fiona Tomas, and J. Emmett Duffy. 2023. “Low-Altitude UAV Imaging Accurately Quantifies Eelgrass Wasting Disease From Alaska to California.” Geophysical Research Letters 50(4):e2022GL101985. doi: 10.1029/2022GL101985.
Declines in eelgrass, an important and widespread coastal habitat, are associated with wasting
disease in recent outbreaks on the Pacific coast of North America. This study presents a novel method for mapping and predicting wasting disease using Unoccupied Aerial Vehicle (UAV) with low-altitude autonomous imaging of visible bands. We conducted UAV mapping and sampling in intertidal eelgrass beds across multiple sites in Alaska, British Columbia, and California. We designed and implemented a UAV low-altitude mapping protocol to detect disease prevalence and validated against in situ results. Our analysis revealed that green leaf area index derived from UAV imagery was a strong and significant (inverse) predictor of spatial distribution and severity of wasting disease measured on the ground, especially for regions with extensive disease infection. This study highlights a novel, efficient, and portable method to investigate seagrass disease at landscape scales across geographic regions and conditions.