Of the threats assessed, industrial and agricultural run-off, coastal infrastructure development, and dredging were determined to have the greatests impacts on seagrasses globally. No seaweed species is known to be poisonous. Crustaceans like crabs, crayfish and lobsters eat seaweed, as do plankton and humans. Many ecologically and economically important species are dependent on seagrass beds during juvenile phases. Because seaweed "eats" by converting sunlight into energy, it must live high enough in the ocean to receive sun rays. (2012) identified many of the major threats to seagrass communities. The canopy of seagrass protects smaller marine animals, including the young of such species as drums, sea bass, snappers and grunts, from larger predators. Johnson’s seagrass has paired leaves originating from a single rhizome node. Adults of many species hunt in seagrass beds, including snappers, groupers, and sharks. For example, you may dine on a lobster that ate a mingle that ingested seaweed. Sea grass is a producer. Other animals derive nutrition from eating algae and small animals that live upon seagrass leaves. An animal that eats plants is called herbivore. Light is required for the plants to make food through photosynthesis. This seagrass was added to the list of threatened species under the Endangered Species Act on September 14, 1998. In the marine food chain, animals eat seaweed, predators eat those animals and people eat the predators. Like other grasses, to which they are not closely related, seagrasses are monocots, the smaller and simpler group of flowering plants. An animal that eats both meat and plants is an omnivore. There are roughly 1,500 species of green seaweed, 6,500 species of red seaweed and 1,800 species of brown seaweed in the world today. Of the 60 species of seagrass … Some animals, such as manatees, urchins, conches and sea turtles, eat seagrass blades. For example, an adult dugong eats about 64 to 88 pounds (28 to 40 kg) of seagrass a day, while an adult green sea turtle can eat about 4.5 pounds (2 kg) per day. Manatees eat seagrass. Many of these large grazers are endangered, in large part because of habitat destruction and hunting, but once they were very common. The seagrass Thalassia testudinum is commonly known as "turtle grass" because in some areas like the Caribbean, green sea turtles eat it almost exclusively. Like land plants, seagrass produce oxygen. Seagrass is a fairly recent evolutionary innovation, having evolved from saltwater-tolerant land plants, especially mangroves, which are believed to be its immediate ancestor. An animal that eats animals exclusively is called a carnivore. If you have a look at a food web it will show you what eats sea grass and the exact definition of a producer. By combining the knowledge of several seagrass experts, Grech et al. Habitat: Seagrass beds are important habitat for adult organisms, vital in the life cycles of some species, and active hunting grounds for other species. The depth at which seagrass are found is limited by water clarity, which determines the amount of light reaching the plant. Sponges contain spicules (glass-like spines) and toxins which the hawksbills immune to, making less competition for this food source. Measuring 0.04-0.12 inches (1-3 mm) wide and 4-8 inches (10-20 cm) in length, the blades are light green with a brown midrib and veins.