Dead dolphins washing up on the beaches of America's Gulf Coast aren't unusual. Since 2010, an estimated 700 dolphins have washed ashore on beaches spanning the Gulf of Mexico. Though sad, the deaths of these beautiful and intelligent creatures were the result of natural causes and occasional marine accidents. The circle of life doesn't play favorites with any of Earth's creatures.

But there have been at least six violent dolphin deaths that don't fit nature's relatively benign pattern. Dolphin carcasses have turned up from Alabama to Louisiana and Mississippi riddled with bullets or missing fins and lower jaws. One was punctured with multiple stab wounds from a screw driver, an unthinkable act of mutilation for a creature renowned for friendliness to humans.

Under the 1972 Marine Mammal Protection Act, killing a dolphin can result in a $100,000 fine and a year in prison. There's a $30,000 reward for information leading to the arrest of anyone involved in these recent dolphin killings. The National Oceanic and Atmospheric Administration is asking fishermen and those who see suspicious activity involving the killing or maiming of dolphins to report it immediately. A federal agent is working on the case full time. Tips are rolling in, but it won't be an easy case to close because the killings are taking place over a vast expanse of water.

There are theories that the killings may be the work of a frustrated fisherman or a group that considers the creatures a threat to their seafaring livelihoods. Whatever the rationale, it isn't enough to justify the murder of dolphins. With luck, the culprit or culprits will soon have to answer for it.