Manatees are the only marine mammals that eat only plants, which has earned them the title of "sea cow" but these cute and friendly animals are in trouble. Manatees like to hang out in warm rivers and springs in Florida during the cool winter months, which puts them in the same place as people with power boats. Manatees are being struck and killed by boats at an unprecedented rate, and losing their habitat to development. Jonathan journeys to Florida to investigate the situation, both underwater and above.