Seagrasses are aquatic plants found all over our world’s oceans and estuaries on every continent except Antarctica. There are over 70 species identified by scientists. Some species are adapted to cold climates, while others prefer the warm waters of the tropics. They are the only flowering plants living in the seas.
Seagrasses attract many species of fish and shellfish, some of which are only found in seagrass meadows. Many fish species use seagrass meadows as nursery areas to grow and mature. Seagrass plants are important food sources for animal grazers including manatees, green sea turtles and aquatic birds. Seagrasses also filter water and produce oxygen. They control erosion by trapping soil and sand with their roots. In areas with intact seagrass beds, storms often do less damage to coral reefs and coastal lands because the seagrasses act as a buffer, absorbing energy from the waves.
A healthy watershed means healthy seagrass. Seagrasses need clean water and sunlight to thrive. Nitrogen and phosphorous from sewage treatment plants, streets and farms can pollute coastal waters and cause blooms of algae that deprive seagrasses of light and clean water. Dredging and shoreline development also damage seagrass habitat. The National Park Service is working with partners to improve water quality and flows to seagrass meadows.