Wasting disease of a marine foundation species links community interactions to disease dynamics

Infectious disease plays a key role in shaping marine communities, including in seagrass meadows, which form biodiverse coastal habitats. Eelgrass (Zostera marina) is the most widespread seagrass species and is susceptible to seagrass wasting disease, caused by the protist Labyrinthula zosterae. As a foundation species, eelgrass strongly influences ecosystem structure, function and services; recent work has begun to explore the links between critical community interactions and seagrass wasting disease. Here, we highlight recent advances about how the eelgrass community regulates and responds to seagrass wasting disease, from the microbiome to herbivores and filter feeders. We further show how efforts to model seagrass wasting disease progression can build on prior efforts to predict eelgrass growth and productivity and can inform our understanding of ecosystem health, resilience and vulnerability. As climate change alters environmental conditions, potentially favouring the wasting disease pathogen, efforts to integrate community interactions with disease ecology will be critical to forecast ecosystem dynamics and to develop effective coastal management strategies. We offer guidance on addressing major knowledge gaps in the study of eelgrass wasting disease in order to deepen both ecological theory and applied practices and identify how an integrated marine-disease-community ecology can inform a broader, cross-cutting understanding of disease.