Seagrasses are the only flowering plants that live in the sea. They can be found inhabiting shallow and brackish waters around the world, typically along gently sloping, protected coastlines. They are so-called seagrass, because of their morphological resemblance (long, narrow green leaves) to terrestrial grass. Seagrasses are often confused with seaweeds, while they actually belong to different phyla. Compared to coral reefs and mangroves, seagrasses receive little attention and perhaps they are the most under-appreciated marine habitat. Although often underestimated, they are one of the most productive and multifunctional ecosystems in the world. Seagrasses are home to incredibly diverse community of animals, from tiny invertebrates to large fish, mollusks, crabs, turtles, marine mammals and birds. Seagrasses provide many important services to people as well, from fisheries production to climate change mitigation. Despite their importance, seagrasses are continuously degrading due to anthropogenic stressors, e.g. pollution, destructive fishing, and sedimentation. To help conserve this important ecosystem, we need to increase public awareness and get more people involved in seagrass monitoring and conservation.