Coastal macrophytes throughout temperate and polar regions worldwide support rich biodiversity, fuel productive coastal food webs, and modify the local physical environment through their roles as primary producers and foundation species. These important ecosystems are increasingly at threat from human activities that act on local (e.g. pollution and fishing) and global (e.g. climate change) scales. As a result of synergies between various stressors, macrophytes such as kelps and seagrasses are disappearing in many areas of the world. My research works to understand how human disturbances impact the diversity, productivity, and resilience of kelp and seagrass ecosystems, as well as the services (e.g. carbon flux and storage, commercial fisheries) they provide to humans.