The Influence of Pathogen Diversity and Temperature on Eelgrass Wasting Disease Outcomes
By: Angela Ayala and Rebecca Lucia Maher
Abstract
Eelgrass meadows are highly biodiverse marine ecosystems found worldwide; however, warming temperatures threaten their vital roles in carbon storage, coastal protection, and as fish nurseries. Eelgrass hosts a complex microbial community on its surface that reacts jointly to environmental changes; therefore, changes in microbial life caused by abnormal heat waves serve as an indicator of meadow health. Eelgrass is vulnerable to invasion by Labryinthula zosterae, a pathogenic protist that is the causative agent of eelgrass wasting disease (EWD). Deeper understanding of opportunistic conditions for L. zosterae to cause EWD is becoming increasingly important as eelgrass meadows rapidly decline. At Friday Harbor Labs, WA, we tracked the eelgrass (Zostera marina) microbiome and disease severity to evaluate how differing pathogen strains and elevated temperatures influence disease outcomes. Eelgrass leaf segments were placed into 11°C or 19°C aquarium tanks and inoculated with two L. zosterae strains: a historic lab strain, MVA V1 and a newly isolated strain. Microbiome sampling occurred before, during, and after inoculation to assess 16S rRNA sequencing. After measuring final percent lesion severity, we observed that MVA V1 is more pathogenic than the new strain at 11°C and led to complete tissue death at 19°C. Additionally, warmer temperatures significantly exacerbated lesion severity for both strains. These findings provide insight into eelgrass meadow disappearance by demonstrating how warmer temperatures exacerbate disease severity and tissue wilting.
Language: English
Published on: Mar 20, 2025
Published by: University of North Georgia
In partnership with: Paradigm Publishing Services
Keywords:
© 2025 Angela Ayala, Rebecca Lucia Maher, published by University of North Georgia
This work is licensed under the Creative Commons Attribution 4.0 License.