A man was shown in a video diving into a body of water with two manatees in it. Police are treating it as another case of people harassing sea cows.
The act of harassing sea cows is illegal due to their endangered status.
This recent video seems to have been shot a year ago in Brevard County, near Florida's eastern coast.
In it, someone is heard laughing before the diver says "I'm gonna do it, I'm gonna do it," and then jumps into the water onto the manatees.
"Go get one!" a man responds.
There is a third person also in the video, seen emptying a hose into the water in an attempt to get the creatures closer to the dock.
The U.S. Fish and Wildlife Service is opening a joint investigation with Florida Fish and Wildlife Conservation Commission.
There have been other cases of people harassing manatees. In February, a 21-year-old man was arrested in Florida for holding a manatee calf.
The man, Ryan Waterman, said he did not know it was illegal to disturb a manatee. The crime can result in six months in jail or a $500 fine and is considered a misdemeanor.
A biologist said it is dangerous for baby manatees to be disturbed as they easily suffer from stress. Taking one out of the water can also harm its health.
In addition to Waterman, there was another case of a manatee disruption last fall. That one included 53-year-old Ana Gutierrez turning herself in for riding a manatee like a bodyboard.
She also claimed to not know it was illegal to touch the creature.