Why did dolphins get Flipper while sharks got Jaws? These majestic, diverse animals bring balance to the ocean ecosystem – and they’re in grave danger ( source : The Guardian)
But if all you knew about sharks you learned from Hollywood, you’d think they were aquatic horrors. Sharks have a film genre all their own: there are movies about ghost sharks and zombie sharks, sharks that squirt acid, killer sharks that swim through sand or snow, and a staggering six instalments of the Sharknado film franchise.
In reality, sharks are overfished in their millions. They aren’t adapted to being prey, rather than predator: sharks grow slowly, spending ages as teenagers before reaching maturity; they lay few eggs and give birth to few pups, not enough to replenish dwindling populations. Those that stay alive can spend decades, even centuries, absorbing man-made pollutants and plastics. Individual sharks have seen their world become hotter and more acidic in their lifetime: Greenland sharks swimming around today were born when the Arctic Ocean was several degrees cooler. The upshot of all this is bleakly predictable. At last count, a quarter of all sharks and their flattened cousins, the rays, were found to be threatened with extinction.
Sharks matter not just because they can be useful for humans, however, but entire ocean ecosystems. “Lots of shark species have been shown to be keystone predators,” says Graham. “They maintain balance in ecosystems and keep things in order, removing weaker, sicker prey and stopping any single species from exploding in numbers and taking over.” One study comparing remote islands in the Central Pacific showed that when sharks are fished out, coral reefs can become dominated by small fish and overrun by algae. “We don’t understand until we lose the species how important it was,” says Graham.
Sharks maintain balance in ecosystems and keep things in orderJasmin Graham, shark biologist
We need to talk about sharks. Though no sharks have yet gone the way of the dodo, plenty of species are lined up for imminent extinction. And the loss of sharks is not just about species blinking out, but a diminishment from their former abundance. Just like the erasing of native fauna from the continents – of bears and wolves, tigers and lions, koalas and kakapos – so the oceans are now losing their sharks. The only difference is that their dying out mostly goes unnoticed.
The Awareness Day – https://www.sharktrust.org/blog/shark-awareness-day
