Seagrasses are the only flowering plants found in marine environments, with about 60 species belonging to four families: Posidoniaceae, Zosteraceae, Hydrocharitaceae, and Cymodoceaceae. They evolved from terrestrial plants that returned to the ocean 70 to 100 million years ago.
The term “seagrass” refers to their long, narrow leaves, which spread like grass through rhizome extension, forming large meadows. Like other autotrophic plants, seagrasses photosynthesize in shallow, sheltered coastal waters, typically anchored in sand or mud. Many species undergo submarine pollination, utilizing a mixed biotic-abiotic strategy, where crustaceans and polychaete larvae help transfer pollen, which is produced in nutrient-rich clumps.
Seagrasses create dense meadows that are among the most productive ecosystems, acting as crucial carbon sinks and providing habitats and food for diverse marine life, comparable to coral reefs.
