What Would The Oceans Be Like If Sharks Didn't Exist?

Although mostly known for their many rows of teeth and ruthless predatory behavior due to varied Hollywood on-screen depictions, sharks are actually more than what we usually give them credit for. In fact, they represent a very impressive success story when it come to evolution, since they have been swimming the world’s oceans longer than trees have been present on Earth. Today, there are around 500 known species (and more likely to be discovered), and many of these have adapted enough to be able to live on lakes and rivers as well.

And while a mention of the word “shark” would immediately bring to mind the aggressive Great White Shark (thanks to numerous movies), their look and sizes are just as varied as the next sea-dwelling creature. There’s the hammerhead shark, there's the tiger shark, there’s the massive whale shark, palm-sized pocket shark and even friendly ones called Lemon sharks.

As such, their existence on our oceans is important for biodiversity and the food chain, and their disappearance would create devastating changes. But what if sharks actually did disappear?

Per  Jenny Bortoluzzi, a doctoral candidate in the Department of Zoology at Trinity College Dublin in Ireland, all sharks have evolved to be predators, meaning that their existence is important to their habitat’s health. For example, sharks usually keep the fish population healthy by hunting and feeding on weak ones while some stop overfeeding on vegetation in shallow waters by scaring off sea turtles.

Their presence alone is vital to ecosystems, since they help to keep the population at a healthy size. And so, losing them would cause fish populations to grow out of control, which would then lead to food scarcity on the fishes’ part. This would then cause algae to move into the reef, stopping corals from photosynthesizing and killing them.

They also serve as food for marine predators, since they are often eaten by other animals after dying. Their poo is also nitrogen-rich, which serves as nourishment for various sea organisms.

With all this in tow, losing them would definitely impact the oceans more than we know, and with their numbers dwindling down due to human activities, it’s hard to not imagine a future where all these aren’t possible.

sharks A new game by Tripwire Interactive lets you play as a shark tasked with taking revenge on a human that killed its mother. Guillaume Baviere, CC BY-SA 2.0.