Seagrass Wasting Disease and the Causative Agent, Labyrinthula zosterae: Detection, Quantification, and Potential Mitigation
Loading...
Links to Files
Permanent Link
Author/Creator
Author/Creator ORCID
Date
2023-01-01
Type of Work
Department
Marine-Estuarine Environmental Sciences
Program
Marine-Estuarine Environmental Sciences
Citation of Original Publication
Rights
This item may be protected under Title 17 of the U.S. Copyright Law. It is made available by UMBC for non-commercial research and education. For permission to publish or reproduce, please see http://aok.lib.umbc.edu/specoll/repro.php or contact Special Collections at speccoll(at)umbc.edu
Distribution Rights granted to UMBC by the author.
Access limited to the UMBC community. Item may possibly be obtained via Interlibrary Loan thorugh a local library, pending author/copyright holder's permission.
Distribution Rights granted to UMBC by the author.
Access limited to the UMBC community. Item may possibly be obtained via Interlibrary Loan thorugh a local library, pending author/copyright holder's permission.
Abstract
Eelgrass (Zostera marina) is an ecologically important seagrass providing numerous ecosystem services to coastal habitats globally. Z. marina is currently experiencing universal decline due to multiple factors, including degrading environmental conditions and disease. One disease commonly found in Z. marina beds is seagrass wasting disease (SWD) caused by the opportunistic pathogen Labyrinthula zosterae. SWD has previously caused mass die-offs of seagrass beds. Seagrass beds are well-surveyed in the Chesapeake Bay but SWD presence and prevalence remains unknown in the region. In this present study, seagrass beds were sampled in the Chesapeake Bay for SWD presence, lesion severity, and infection intensity. SWD and L. zosterae were present at four sites with one site having significantly higher disease severity and infection intensity. An undertested disease mitigation strategy is the use of farmed and naturally occurring oysters in wild populations, near eelgrass beds. The Pacific oyster, Crassostrea gigas, has been previously found to reduce and transmit SWD in Z. marina during laboratory trials. However, the density threshold of C. gigas needed to significantly reduce SWD is still unknown. Previous lab experiments also used higher doses of L. zosterae compared to recently determined environmentally relevant levels. Thus, understanding the impact of oyster densities on SWD at previously tested pathogen concentrations and more environmentally realistic concentrations is essential for a better understanding of the dynamics between disease, host, and a nonhost receptor. A mesocosm experiment was conducted with Z. marina co-cultured with two densities of oysters and exposed to two concentrations of pathogen, measuring their effect on blade growth, lesion severity, and infection intensity. High oyster density impeded growth while Z. marina growth benefited from low oyster densities. High pathogen concentrations increased SWD severity and L. zosterae infection intensity. High oyster densities significantly reduced the likelihood of L. zosterae infection presence. Results from this experiment confirmed that bivalves can reduce SWD under environmentally realistic pathogen concentrations and paves the way for integrated disease management. Further field testing is required to validate in-situ oyster filtration as a viable method for SWD mitigation.