The seagrass habitat provides different advantages to differing species of animals. For slow swimming animals, such as seahorses or filefish, seagrass provides a safe hiding place to avoid predators while other species, such as crabs, shrimp, small fish, and waterfowl, find it a safe place for laying eggs and sheltering their young. Until they are large enough and mature enough to take their chances in deeper waters juveniles of larger species, some of which are important parts of our food chain, find a safe haven in seagrass.
Not all animals can use seagrasses for food which is fortunate because seagrass extracts nutrients from the surrounding water which offers protection for fish from potentially fatal algae bloom. Animals that do include seagrass in their diet include: dugong, sea urchins, some fish, crabs, sea turtles, geese and swans.
Dugongs, manatees, and sea cows
Read more at the list of biomes of the world...