Review: Host-pathogen dynamics of seagrass diseases under future global change

Human-induced global change is expected to amplify the disease risk for marine biota. However, the role of
disease in the rapid global decline of seagrass is largely unknown. Global change may enhance seagrass susceptibility
to disease through enhanced physiological stress, while simultaneously promoting pathogen development.
This review outlines the characteristics of disease-forming organisms and potential impacts of global
change on three groups of known seagrass pathogens: labyrinthulids, oomycetes and Phytomyxea. We propose
that hypersalinity, climate warming and eutrophication pose the greatest risk for increasing frequency of disease
outbreaks in seagrasses by increasing seagrass stress and lowering seagrass resilience. In some instances, global
change may also promote pathogen development. However, there is currently a paucity of information on these
seagrass pathosystems. We emphasise the need to expand current research to better understand the seagrasspathogen
relationships, serving to inform predicative modelling and management of seagrass disease under
future global change scenarios.