Explanation:

About Herbivores Marine Animal

! Marine herbivores are found within four groups of species in the animal kingdom -- invertebrates, fish, reptiles and mammals -- and include zooplankton, mollusks, the green sea turtle, the marine iguana and some fish species. Manatees and dugongs are the only herbivores among marine mammals

Sea Cows, Manatees and Dugongs are herbivores marine mammals. They make their living grazing on sea grasses, marine algae in coastal temperate and tropical waters of North America, Asia and Africa.

! Statement 2 and 3 are incorrect: Seals and sea lions come under the order of carnivore.