More than ten years ago, the documentary Sharkwater hit the big screen and it was so powerful, it resulted in government policy changes to better protect sharks. Because of that, director Rob Stewart set out to make a sequel to continue to create change. Tragically, as he was working on the documentary, he drowned, but his work lives on thanks to his family and friends who worked to ensure his documentary came to life.
Sharkwater Extinction is basically a love letter to sharks.
One of the things Rob said when talking about sharks is: “You’re under water and you see the thing you were taught your whole life to fear, and it doesn’t want to hurt you, and it’s the most beautiful thing you’ve ever seen.”
To honour that sentiment, here are some fun, non-scary facts about these fascinating creatures.
Sharks don’t have bones
Sharks are known as “elasmobranch” fish, which means that they’re made of cartilaginous tissues rather than bones. Humans also have this lightweight tissue in our ears and the tip of our noses, but in sharks it helps them to be more buoyant in the water. But wait: how do you get those cool shark teeth necklaces in Florida without bones? The teeth have enamel in them making them strong, and as sharks age they deposit calcium into the skeletal cartilage that strengthens it, making it feel like bone even though it’s not.
Sharks love a good nap
Like a toddler after a sugar rush, sharks can go into trance-like state called tonic immobility if you flip them upside down in the water. This is how scientists are able to analyze them without injury. Although sharks don’t sleep because they need to keep the flow of water to their gills, some can rest while doing so. They call this “sleep swimming” since sharks shut down parts of their brains while still moving.
Sharks don’t have scales
Shark skin is made up of tiny structures called placoid scales that look like teeth. These dermal denticles are covered with enamel making them bumpy to the touch, almost like sandpaper. The scales are angled towards the tail to help the shark swim by reducing friction in the water. Shark skin is also the thickest in the animal kingdom: some have skin six-inches thick!
Female sharks can use sperm from different male sharks during the same pregnancy
This means that while the pups are delivered all at the same time, they may only be half-siblings! The gestation period of pregnant sharks ranges from five months to two years which is the longest pregnancy of any animal. And some species of sharks are carnivorous even in the womb; the first tiger shark pup to hatch often eats its siblings. Talk about a fierce sibling rivalry!
Sharks are actually legendary
Sharks have been around since the prehistoric times and have remained almost completely unchanged; they’re over 400-million years old, which is 200-million years before even dinosaurs roamed the earth. The first recorded shark attack was written by Herodoctus between 484-425 B.C. as he described hordes of “monsters” eating sailors of the Persian fleet who were shipwrecked. Over the decades there have been many myths surrounding sharks, making them legendary creatures. Until the nineteenth century, some citizens of the South Pacific islands considered sharks to be gods which they offered human sacrifices to. Even spookier: Solomon islanders thought that the ghosts of people who have passed on inhabited the bodies of sharks.
Sharks have a LOT of teeth
Sharks are every dentist’s dream; they have 40-45 teeth in up to seven rows and they lose teeth regularly. In fact, they can go through more than 30,000 teeth in their lifetime. And not all sharks have the same teeth either: some are curved, serrated, straight or triangular. You can tell which type of shark wined and dined their prey if you analyze the teeth marks.
Sharks really are silent
There’s a reason why Spielberg used the iconic “dun-dun” sound to a shark attack in Jaws: sharks don’t have any vocal chords! You’ll never hear a shark coming the way you might with a dolphin or a lion, but have no fear because shark attacks on humans are less common then getting stuck by lightning (1 in over 3 million!).
Sharks are brainiacs
Out of all the fish in the sea, sharks have the largest brains. Instead of using sound to communicate, they use body language. This includes zigzag swimming, hunched backs, head butts and head shaking. They also rely on electroreception to find prey and navigate their way through the ocean’s deep.
A shark’s greatest predator is you
Humans are the biggest killer of sharks: we kill 100-million per year. For every person killed by a shark, humans kill 25-million sharks. Sharks live a long life but they don’t have offspring until around 10-12 years of age and only produce a few pups at a time, meaning they’re at major risk of extinction. Industry fishing, habitat pollution and shark nets to protect swimmers at beaches are all a problem for sharks, but none as much as shark finning. Shark finning is a practice where fisherman catch sharks and cut off their fins to use in soups that are considered a delicacy, and the Blue Shark is the most endangered species in the world because of this. The live sharks are thrown back in the water without fins which leads to their swift death. Sharks are essential to the ecosystem as they’re an apex predator, meaning they have no natural predator above them. They keep fish stocks healthy, because without them the medium-sized prey would flourish and small fish would be at a major risk. So make some noise and support laws that stop practices like shark finning to protect these natural wonders!