Are Sharks Consuming Cocaine in Florida Waters?

Cocaine sharks may sound like the subject of a silly low-budget movie, but they may be a reality in Florida’s coastal waters, as examined by a recent episode on Discovery Channel’s Shark Week.

The episode, "Cocaine Sharks," which aired July 26, looks into decades-old rumors of sharks coming into contact with cocaine tossed into the waters off Florida's coast.

Live Science explains that huge bundles of cocaine have been washing up on Florida’s beaches for decades after being smuggled from South and Central America. The bales are often dumped at sea to give to smugglers and to evade law enforcement.

According to Live Science, in June the U.S. Coast Guard seized more than 14,100 pounds of cocaine in the Caribbean Sea and Atlantic Ocean. The value of the June haul alone was approximately $186 million.

Marine biologist Tom "The Blowfish" Hird and University of Florida environmental scientist Tracy Fanara decided to conduct some experiments to find out if sharks off Florida’s coast were ingesting the dumped narcotics and, if so, how the drugs affected them.

"The deeper story here is the way that chemicals, pharmaceuticals, and illicit drugs are entering our waterways — entering our oceans — and what effect that they then could go on to have on these delicate ocean ecosystems," Hird told Live Science.

Hird and Fanara conducted their experiments in the Florida Keys, where anglers claim the sharks are consuming the drugs that are brought in by the current.

The episode shows the scientists diving with sharks to look for any unusual behaviors, which they notice in a couple of their subjects. One hammerhead comes straight at the team and appears to be swimming oddly. At a shipwreck 60 feet beneath the surface, Hird encounters a sandbar shark swimming in tight circles while fixated on something, despite there being nothing in sight.

Hird and Fanara design three experiments with packages similar in size and appearance to real cocaine bales to see how sharks may respond to bales of cocaine dropped in the water. In the first experiment, they set these fake cocaine bales next to dummy swans to see which the sharks go to. Surprisingly, the sharks head straight for the bales, taking bites from them. One shark even grabs a bale and swims off with it.

Next, they make a bait ball of highly concentrated fish powder, which would trigger a dopamine rush similar to that of cocaine. Video footage shows the sharks going wild.

"I think we have got a potential scenario of what it may look like if you gave sharks cocaine," Hird said in the film. "We gave them what I think is the next best thing. [It] set [their] brains aflame. It was crazy."

For the third experiment, the team drops fake cocaine bales from an airplane to simulate a real-life drug drop and watch as numbers of shark species, including tiger sharks, move in.

Hird explained that their experiments don’t necessarily prove that sharks in Florida are consuming cocaine. The sharks’ behaviors can be explained by a number of factors and the experiments would need to be repeated again and again to draw conclusions.

"We have no idea what [cocaine] could do to the shark," Hird told Live Science. "So we can't even say, ‘Well this is a baseline,’ and go from there.“

Hird said he hopes the show will result in more research and that he'd like to carry out more tests, including on tissue and blood samples, to see if the sharks’ bodies show evidence of cocaine.

He said they may discover that the problem is bigger than just cocaine. "The other thing we might find is actually this long flow, [this] drip of pharmaceuticals: caffeine, lidocaine, cocaine, amphetamine, antidepressants, birth control. This long, slow drift of them from cities into the [ocean] is… starting to hit these animals," Hird said.