Authorities are trying to determine who is responsible for this.
At least six bottlenose dolphins with gun shot wounds have washed ashore along the U.S. Gulf Coast in the past several months.
Some with missing body parts have also washed up.
Because the killings have spanned several states, authorities doubt a single person is responsible.
(SOUNDBITE) (English) MOBY SOLANGI, DIRECTOR, INSTITUTE FOR MARINE MAMMAL STUDIES, SAYING: (SOUNDBITE COVERED BY B-ROLL OF DOLPHIN)
"They're protected by the Marine Mammal Protection Act. There are law enforcement agents looking. They have forensic evidence now, with the bullets we have recovered. And so, sooner or later, the perpetrators will be found."
Dolphins are covered by the Marine Mammal Protection Act, a 1972 law that makes killing them punishable by up to $20,000 in fines for each violation and a year in prison.