Where is a Manatee on the Marine food Web?

My inquiry question is "Where is a manatee on the marine food web?". So far I have found that manatees and dudongs are among the only mammals to eat mostly plants. I say mostly because sometimes when manatees are eating sea grass, they sometimes accidentally slurp up snails that are living in the sea grass. This gives the manatees extra protein. Sometimes manatees are mistaken for mermaids! -Chapin