Lui is awsome!
Manatees are a gentle giant and most the time they don't need to protect themselves Manatees have no natural predators only humans they can't stop a boat from hitting them so your answer is they don't protect themselves other than moving away from danger.
Manatees have no defences, save the thick blubber that covers their body.
NO
they don't need to because they have no natural enemies
They don't do anything really all they do is research
manatees have a third eyelid ,which is clear, to protect it from water getting into it.
They protect themselves by squirting ink.
Citizens protect themselves with police departments. Nations protect themselves with a military.
they use their sting tail to protect themselves
how do lionfish protect themselves
They have flippers to steer themselves and huge flat, spoon shaped tail fins to propel themselves. Their snouts are prehensile, like an elephant's trunk, allowing them to get at plants that grow at the bottom of the sea. Manatees are large enough that predators like sharks and alligators don't bother them. Manatees are also able to live in both fresh and salt water.
Manatees are on the endangered species list. In the 1970s, the government gave protection to this animal under the Federal Marine Mammal Protection Act. The population of Florida manatees is about 5000.