Measuring and Reporting on Seagrass as an Essential Ocean Variable for Science and Management

To effectively manage and protect ocean life and the people who depend on it, we need coordinated, comparable observations of ocean biodiversity. Seagrass cover and composition is an essential ocean variable (EOV) of the Global Ocean Observing System because seagrasses are the foundation of coastal ecosystems worldwide, and support diverse marine life and ecosystem services. We present guidelines for collecting and reporting seagrass data that fulfill specifications for the EOV, including three priority measurements to maximize compatibility among data sets: seagrass cover, species composition, and areal extent, with priority environmental variables for interpreting changes in status and condition. To promote interoperability, we present a standard format for seagrass EOV data and metadata. These guidelines will enable better monitoring and assessment of seagrass ecosystems, facilitate syntheses, inform the Kunming–Montreal Global Biodiversity Framework headline indicator “Extent of natural ecosystems,” and support evidence-based conservation and sustainable development.