Cuesta College, with support from the Estuary Program, embarked on a research effort to study Labyrinthula spp., which is the slime mold that can lead to wasting disease. At other estuaries around the country, wasting disease has been responsible for widespread eelgrass declines. Cuesta professors Laurie McConnico and Silvio Favoreto wanted to better understand the prevalence of this disease and how it impacts eelgrass.
The Estuary Program awarded funding to the two professors to purchase reagents and equipment and to pay the course registration fees for students volunteering in the lab. The project involved the Cuesta faculty and students collecting eelgrass blades with and without signs of necrosis (dark areas on the blades) throughout Morro Bay and using this material for the isolation of strains of Labyrinthula spp., resulting in 18 isolates cryopreserved in liquid nitrogen. During the summer of 2018, they collected eelgrass from four sites (Coleman Park, Windy Cove, Mid Bay, and Back Bay) and in summer 2019 they collected from three sites (Coleman Park, Windy Cove, and Back Bay). The blades were used to quantify necrotic tissue and an Excess Green Index was created, to represent the health of the eelgrass based on its color. All samples were collected and initially processed by students participating in a summer environmental microbiology course. Preliminary data analysis indicates Labyrinthula spp. is found at all sample locations within the estuary, and in both green and necrotic eelgrass tissue.
The researchers’ efforts will include sampling in 2020.