MOBILE, Alabama -- Someone has been shooting Gulf Coast dolphins, cutting off their body parts and mutilating them, according to officials who are asking folks in Alabama, Mississippi and Louisiana to be on the look out for such cruelty.

Within the last two weeks, four dead dolphins have been recovered in Alabama, Mississippi and Louisiana waters.

A female dolphin, recovered in Mobile Bay near Fairhope, had its tail cut off. That was apparently by a straight knife cut, indicating that a human did it, said Moby Solangi, executive director of the Institute for Marine Mammal Studies in Gulfport, Miss., which has performed non-human autopsies, known as necropsies, on the dolphins.

One dolphin off Ship Island in Mississippi had its lower jaw cut off.

One near Ocean Springs, Miss., had a bullet in it, as did another recovered off Elmer’s Island, Louisiana.

“It looks like there is someone, a person, who is perpetrating the dolphins” Solangi said. “It’s not only cruel; it’s illegal.”

Harassing, harming, killing or feeding wild dolphins is prohibited under the Marine Mammal Protection Act of 1972. Those found guilty of breaking the law can be fined up to $100,000 and be sentenced to up to a year in jail per violation, according to the National Oceanic and Atmospheric Administration, NOAA.

“It’s repugnant. It’s cruel. It’s illegal. It’s senseless,” Solangi said. “These dolphins are already under stress from the oil spill, Hurricane Katrina, and the dead zones. A number of dolphins have died in recent years. There’s no reason for this.”

NOAA's Office of Law Enforcement is investigating these incidents. Anyone with information is asked to call that office at: 1-800-853-1964. Tips can be left anonymously, said NOAA spokeswoman Allison Garrett.

"We have no information as to what has happened to these dolphins," Garrett said.

It is not clear if these incidents are related to a bottlenose dolphin that was found dead in June with a screwdriver stuck in its head near the Alabama-Florida border.

Garrett said officials are trying to get the word out that humans should not feed or try to get close to dolphins, as this may encourage them to approach other humans and possibly put themselves into dangerous situations.

"Enjoy watching them from a distance," she said.

Dolphins are generally docile animals, Solangi said. They care for their young. They travel in groups because they are social. And they are known to be friendly to humans, approaching boats and interacting with them.

“I don’t know if some people think this is funny or a sport,” Solangi said, adding that it’s almost as if someone is gathering various body parts as “trophies.”

It doesn't appear as if the meat has been taken for food.

Solangi urges anyone who knows about these incidents or who sees something suspicious to call any type of law enforcement to report it. You can also call IMMS at: 1-888-SOS DOLPHIN.

Updated at 6:48 p.m. to include comments from NOAA's Allison Garrett.