Estimating infection levels of Eelgrass (Zostera marina) by Labyrinthula zosterae in north-central California
By: Taylor Pantiga and Kai Atkinson
Department: Interdisciplinary Marine and Estuarine Sciences
Faculty Advisor: Dr. C. Sarah Cohen
Seagrasses are an important and challenged foundation species found around the globe, with their population health threatened by increased disease risk related to climate change. Seagrass wasting disease, caused by the net-slime mold Labyrinthula zosterae, is currently present at low levels in north-central California. Climate change may cause an increase in disease intensity for a native species of seagrass (Zostera marina, eelgrass) in north-central California due to increases in salinity and temperature. These environmental conditions are favorable for the mold, L. zosterae. Our goal is to determine the levels of disease intensity in six key eelgrass beds in San Francisco Bay (SFB) and Point Reyes National Seashore (PRNS) in comparison to current environmental stressors. To achieve this, we calculated the percent of lesion coverage on selected eelgrass blades collected from the six eelgrass beds. We expected to see a higher prevalence and intensity of seagrass wasting disease in beds in the urbanized SFB compared to the protected Drakes Estero and Tomales Bay in PRNS, due to a higher stress environment for the eelgrass in SFB. However, preliminary results showed a higher percentage of lesion coverage in Drakes Estero and Tomales Bay, two of the denser sampled locations. Understanding the current state of seagrass wasting disease in north-central California is valuable knowledge for managing eelgrass beds to limit the impacts of the disease.