Manatees are indeed protected and endangered species, and harming them can result in significant fines and penalties. In the state of Florida, where manatees are commonly found, the Florida Manatee Sanctuary Act provides for penalties of up to $500 and/or up to 60 days in jail for harassing, hunting, capturing, or killing a manatee.
If a person negligently harms a manatee, the penalties can be even more severe. The Marine Mammal Protection Act of 1972, which is a federal law, provides for fines of up to $100,000 and/or up to one year in jail for negligently harming a manatee. In addition to these penalties, a person may also be liable for civil damages resulting from the harm caused to the manatee.