There is a way to lull a shark to sleep… to put them in a deep trance for a few minutes, just enough so you can pet it or let others gently touch it and feel its sandpaper-like skin. It is called tonic immobility: a state in which the shark is placed in a natural state of paralysis. It is an instinctive reaction when stimulated a certain way. It does not harm them. Science still doesn’t know the purpose of this reaction, but it is a truly fascinating thing.
Calming a shark and putting it to sleep is something I have done a hundred times, but I never get tired of it. I love sharks, and when I hold them in their trance-like state, there is a great fascination that I feel for these incredible creatures.
It all starts with choosing the right shark to handle. A great subject is the Caribbean reef shark. When diving underwater, you have to be completely calm and find a shark that is relaxed and does not seem aggressive. One that is swimming lazily and slowly. It may seem more intimidating, but the bigger ones are usually the more stable and willing. Additionally, females are almost always the easiest to entice.
When I spot one, I extend a hand to feed it, usually with a herring. Although it may seem like free food, not all sharks can be lured to it. Others who do not want the attention would simply swim away. The shark should be willing to take the food before you are able to pet it. When it comes close enough, I start petting it under the snout. That’s where the magic happens.
Under the shark’s snout are freckle-like dots called ampullae of Lorenzini. It is so sensitive, that if you twitch just a single muscle, they would be able to sense it. Because it is overly sensitive, it is also easily stimulated. So when you gently touch and massage it, they feel an overwhelming sense of stimulation that limits their mobility. Their bodies fall into a completely relaxed state. You can touch and move them around without much struggle. How long does this trancelike state last? About a few minutes. I have once handled a shark for 30 minutes in this state. If I want them to snap out of the trance, I simply stop stimulating and let go. Then they go back to their business like nothing happened. It is truly an amazing phenomenon.
I usually do this in front of an audience, not to draw attention to myself but to show them how fascinating sharks are. Tonic immobility is just one of the interesting facts about them and there are so much more people ought to know.
To lull a shark to sleep requires a great amount of diving experience and extensive knowledge about their behavior. I don’t encourage inexperienced divers to do this when they encounter a shark. What I do encourage is for everyone to get to know these amazing creatures. I hope more people will love them and save them, in the same way that my fellow divers and I do.