The movie Jaws was the worst movie ever produced when it came to scaring the public about shark attacks and spreading misinformation about the apex predators.
For more than 50 years now I have been diving with big sharks and trying to educate the public about their true behavior and recently new scientific information has come forward that has helped me with my mission to protect the world’s sharks.
If the public knew that sharks do not eat people, then my job would be much easier and now new research has shown why sharks don’t eat people. On average, only 15 people per year worldwide get killed by sharks and none of those people actually get eaten by the shark that accidentally killed them.
Large sharks are designed to feed on marine animals, not land animals and there is a reason why. Due to gravity land animals need to have more bones than marine animals to support their weight.
A whale the same size as an elephant has fewer bones and the bones are less dense because the seawater supports their weight not their bone structure. Tiger sharks and great white shark teeth are designed to bite through skin and fat, not large bones.
The large sharks have several rows of teeth and when they feed on their normal prey they lose several teeth, but new ones replace the lost teeth quickly. Large sharks are warm blooded and they live in a cold ocean so they need lots of fat in their diet to produce heat to stay warm.
Land animals like us humans have a lot of thick dense bones and very little fat compared to a seal, whale or tuna. If a Tiger shark or great white was to eat a human it would break off a lot of teeth and get very little food value in return.
Just like we don’t want to eat the branch off of a tree as we would break our teeth and get very little food in return. All animals have to feed on food types that they can spend less energy on and get a maximum amount of food. Sharks are the same. Humans just don’t supply enough food value for the effort it would take for a shark to eat us.
What we know now is how the sharks can tell a human in the water vs a marine mammal like a seal or baby whale. Sharks have highly developed sensors on their sides that can detect wave movement underwater.
When a seal swims near a large shark it makes an underwater wave pattern that the shark can detect. When a human swims near a large shark, we also produce a wave pattern but ours is different then the seals. A bony land animal makes a different wave pattern then a nice fat marine mammal does and the sharks can tell the difference between the two.
Sharks accidentally bite people from time to time, usually when they are chasing their normal prey. This is not so unusual, as us humans sometimes bite into a woody stem when we are eating a piece of fruit we just picked off of a tree. When we bite the stem we spit it out, just like when a shark bites a human they spit it out.
Even humans that are bleeding in the water do not attract sharks. We have proven this over and over. In the old books and movies about the sailors in the 1800s, who fell overboard in the middle of a battle were not eaten by the sharks as so often assumed. That is just pure drama to sell books and movies.
Sharks clean our ocean of dead and dying marine animals and this keeps our marine environment clean and healthy, but us humans kill millions of sharks just because we are afraid of them, so maybe we can stop this irrational behavior and stop spreading the myth that sharks eat people.
One of the best shark stories I have seen is a guy in South Africa that loved great white sharks and spent time protecting them until he passed away. In his will, he wanted to be laid to rest in the sea so he could be eaten by a great white.
He got his last request and was weighted down and sunk to the sea floor right in the great white’s known habitat and they shot video of the event. The great whites left the area and the poor guy got eaten by crabs, and it was all captured with video.
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Terry Lilley is a marine biologist living in Hanalei Kaua‘i and co-founder of Reef Guardians Hawai‘i, a nonprofit on a mission to provide education and resources to protect the coral reef. To donate to Reef Guardians Hawaii go to www.reefguardianshawaii.org.
