Marine angiospermas are a unique group of flowering plants that have adapted to live completely submerged in the sea for 40 million years. They form dense, productive grasslands and provide a wide range of ecosystem functions and services such as nutrient regeneration, improved water quality, coastal protection, breeding habitats (including economically relevant species) and CO2 burial. But as beneficial as they are to our environment, marine phanerogams are also among the world’s most threatened ecosystems as a result of human pressure, with an annual global decline rate of 7% and nearly 14% of all species at risk of extinction.