Introduction Coastal ecosystems, such as coral reefs, mangroves and seagrasses, are among the most diverse and ecologically productive systems on Earth (Cooley et al., 2022) and provide societal benefits forecasted to be worth $3 trillion to the ocean economy by 2030 (OECD, 2016). Seagrass extent has declined by an estimated 29% globally since 1879 (Waycott et al., 2009) driven by eutrophication, coastal development and physical disturbance (Dunic et al., 2021; Short et al., 2011).