Ever since video footage of ‘intoxicated’ adolescent dolphins chewing together on poisonous pufferfish was released in 2014, there has been longstanding belief that that this was evidence of recreational drug use. But were we reading too much into it?
Whilst you may think of recreational drug use as a very human concept, it turns out that it is actually fairly common in the animal kingdom. Horses are known to eat hallucinogenic weeds, elephants can get drunk on overripe fruit and big horn sheep seem to love chewing narcotic lichen. Our own love of alcohol is even believed to have evolved from an attraction to sugary ethanol-containing fruits, as displayed in modern day monkeys. So the idea of adolescent dolphins getting high by chewing on poisonous pufferfish doesn’t seem that far-fetched. We have even seen this behaviour on multiple occasions and the footage is pretty convincing. However we might be mistaking youthful exuberance and play with a remarkable resilience to one of nature’s most toxic substances.
Most people know pufferfish for the ballooning defensive behaviour they employ to scare off potential predators. However something less well known about them is that they also contain one of the most deadly poisons in the animal kingdom, tetradotoxin. It is a neurotoxin that is over 1000 times stronger than cyanide, with no known antidote. It works by blocking nerve signals throughout the body associated with muscle control which leads to blindness, paralysis and eventually suffocation, all of which can happen in a matter of minutes. Pufferfish are not the only marine creature known to contain tetradotoxin, the tiny yet deadly blue-ringed octopus also uses the neurotoxin as a defence as well as to hunt. Whilst in medicine, despite its lethal properties, it has also been tested as a potential pain relief medication for cancer patients.
Playing with puffers
The first real evidence of dolphins chewing on pufferfish in a social and potentially recreational setting came in 2014 with the BBC TV series ‘Spy in the Pod’. In one episode hidden cameras inside remotely controlled robotic animals, including turtles and even a pufferfish, captured footage of a group of adolescent dolphins biting down on and passing around a real life puffer. The playful behaviour lasted for around 20 minutes with the befuddled pufferfish eventually escaping to safety. Afterwards the pod is left immobilised by the surface in what appears to be a sort of trance like behaviour. It is not the only documented case, in 2017 researchers from Mandurah Dolphin Rescue Project snapped pics of a wild dolphin nicknamed Huubster chewing and throwing around a pufferfish in the same way. You can check out this bizarre behaviour for yourself in the video below.
A recreational buzz?
As you can imagine the footage of the teenage dolphins chewing together on a toxic fish took the internet by storm when it was released in 2014. As a result many people now firmly believe that what we have witnessed is the first evidence of recreational drug use in marine mammals. The show’s creator John Downer added fuel to the flames by stating he believed they were seeking out the high on purpose. He also firmly believes what you can see in the video is dolphins tripping out at their own reflection. In a lot of ways it makes sense considering what we know about dolphins. They are fiercely intelligent and social creatures and this sort of behaviour is something that on the face of it seems totally believable.
Just harmless play?
On the other hand some researchers are having a hard time buying into the idea these dolphins are seeking out the pufferfish to get high. First of all this playing behaviour is seen a lot throughout dolphins. Multiple species are known to throw around objects in this way which can include rocks, shells, jellyfish and even crabs. Pufferfish could very well just be the right size and shape to be substituted into this scenario if nothing else can be found.
Secondly neuroscientists strongly question whether the tetradotoxin is even capable of creating a ‘high’ at all. From what we know about the chemical it shuts down nerve cells leading to loss of muscular control and in no way crosses the blood-brain divide to create hallucinations or alter brain chemistry. It is therefore much more likely that what we are seen is a short term form of paralysis or immobilisation. This may still be something the dolphins seek out for unknown reasons, but it could equally just be an unfortunate result of playing with the wrong thing.
Doing drugs or a side effect?
Although the idea of dolphins getting high on pufferfish is entertaining and the evidence is at face value rather compelling, it is hard for researchers to confirm that this is really the case. From what we know about the toxin it seems unlikely and without any research being done on the subject it cannot be backed up, but at the same time it is also impossible to disprove the argument either. Regardless of whether this behaviour is teens experimenting with narcotics or just the by-product of inquisitive playfulness, it just goes to show how complex and charismatic these marine mammals really are.