Sharks might be scary, but the ocean needs them

By Casey Frye, CCNN Writer

Last I checked, sharks are vicious creatures who like to prey on cute animals like baby seals and dolphins. Why is it, then, that Dr. Michael Heithaus from Florida International University says fishermen should do everything they can to protect them?

The thing is, the shark population around the world is getting smaller every year. This allows more of their prey to survive and make their own populations larger. It may not seem like a bad thing – after all, that means more turtles and dolphins are swimming out in the Big Blue – but when you hear what could happen if all the sharks vanish, you might just change your mind!

reef shark
Grey reef shark.

Heithaus and his team went to Shark Bay, Western Australia for 15 years to study its ecosystem (the natural balance of plants, the environment, and animal life). Some of the members in this ecosystem include tiger sharks, turtles, fish, shellfish, and dolphins, but most importantly, the world’s largest seagrass bed. You see, this bed provides food for the many of the smaller animals in the bay, while removing a ton of carbon dioxide from the environment, so it’s good for us too.

Usually, many small fish rely on the the grass for food, but when big sharks are swimming around in the area, the sealife flee for their lives. As the number of sharks goes down, more fish can eat the plant more frequently. Sounds like a great deal for them right? Get rid of the sharks and feast all day! Actually, there are so many more of them grubbing on the seagrass that eventually it all gets eaten up and there’s no more food! It’s not just the fish that will die if that happens, the animals that eat the fish will die, and the animals that eat those animals will die too!

The university estimates around 100 million sharks are taken out of the ocean every year. The monsters don’t make babies too often and there are more sharks dying than there are being born. If the shark population dies, the rest of the sea life they affect could eventually die along with them.

So, while these large predators may not be nice and a bit scary-looking, they sure are important for the rest of the sea community.