A set of violent dolphin deaths along the northern Gulf Coast has sparked an investigation among federal officials. Investigators are trying to figure out who is behind the gruesome deaths of dozens of dolphins.

Bullet wounds, missing lower jaws and hacked off fins are among the injuries that were inflicted upon dolphins that are washing up dead along the northern Gulf Coast. The latest is a dolphin with a missing lower jaw that washed up in Mississippi.

The National Oceanic and Atmospheric Administration is asking the public to keep a lookout for injured and dead dolphins and any suspicious behavior between the animals and people.

"It's very sad to think that anyone could do that to any animal," said Erin Fougeres, a marine mammal scientist for NOAA's southeast office in St. Petersburg, Fla., according to the Associated Press. "There have been some obviously intentional cases."

So far, five dolphins were found shot dead. Two were shot in Louisiana, one inf 2011 and one this year. Three were found shot in Mississippi this year, including once last week.

However the deaths get even more gruesome. A dolphin was found with a screwdriver stuck in its head this past summer. Another in the state was found with its tail cut off, but it survived. Others were found with missing fins and other wounds.

"I think it is outrageous,"  Moby Solangi, the executive director of Institute for Marine Mammal Studies in Gulfport, Miss. told AP. "These animals are very docile, very friendly and they're very curious. They come close to the boats, so if you're out there, you'll see them riding the bows. And their curiosity and friendship brings them so close that they become targets and that's the unfortunate thing."

Harming a dolphin is a very serious crime as they are protected by the 1972 Marine Mammal Protection Act. Those who violate the act may receive a fine up to $10,000 and face a year in prison.

The Animal Legal Defense Fund  is offering a $5,000 reward for information leading to the arrest of those who are harming the dolphins.

The violent deaths are just one of many problems facing the dolphins in the area in recent years. Shortly before the BP oil spill in 2010, dolphins started to strand themselves and the death rate was higher due to a cold winter season. The oil spill added insult to injury as the death rate grew even higher after it occurred. 

At least 700 dolphins have been found dead since Feb. 2010.The cases of missing jaws and fins may not have killed the animals. Experts say that the dolphins could have died of natural causes and their fins or jaws were cut off by someone who found a dead dolphin that washed up.

"We have to do a necropsy on the animal and collect tissue samples to try to determine whether or not the injury was pre-or post-mortem" Fougeres told AP.

If there is a dolphin murderer out there, there may be more than one."The cases are fairly spread apart," she said. "I don't think there is one dolphin murderer out there."

If you see a dead or injured dolphin or have any information about people harassing one of the creatures,  call the NOAA Enforcement hotline at 800-853-1964.