Shark Stewards Guest Blog
By Levi Varela, 14 years old
Sharks are incredibly important to the ocean ecosystem. Being one of the apex predators in the ocean, if they go, the entire food chain will collapse. Even if only great white sharks were to become extinct, it would be a disaster. The great white’s diet consists mainly of fish and marine mammals, including seals, sea lions, and pinnipeds. Great whites eat about .5 to 3 percent of their total body weight per day; the average weight for a full-grown white shark is around 2,750 pounds, so an adult white shark would eat from 13.75 to 82.5 pounds per day; the mean of that is 48.125 pounds. If a great white would eat 48.125 pounds of food per day consistently, it would eat 17,565.625 pounds per year! There are currently around 3,500 great white sharks left in the ocean, and their numbers continue to deplete. Altogether, that would be 61,479,687.5 pounds of fish and marine mammals per year! If great whites were extinct, that would be around 127,750 marine mammals and fish still in the ocean to reproduce and over-populate the ocean, and when one (or in this case a few) species of animal gets too populated, it seriously messes up the food chain.
People think of sharks as if they are on the hunt for humans, and that we’re on their list of prey, but this is not true. Julia Russell from the Houston Museum of Natural Science has something to say about it:
When people hear the word “shark,” they typically picture mindless killing machines, but they couldn’t be further from the truth. Sharks have highly adapted hunting strategies that have been honed over millions of years to make them one of the most efficient predators on the planet. (para. 1)
Sharks have had their hunting techniques developed over an incredibly long period of time, so why is it that almost all shark attacks do not end in deaths? It’s because, once they get a taste, they realize that you aren’t on their list of prey. For example, great white sharks have a favorite form of hunting they especially like to use on marine mammals. In this strategy, the shark spots its prey and dives deeper out of sight, then the great white will start swimming upward like a torpedo and reach speeds of up to thirty miles per hour! The shark will ram its prey head-on, sending the shark and its prey flying out of the water. The shark can put up to fifteen feet between it and the water. Great whites rarely, if ever, use this hunting technique on humans when they attack people. This is the great white’s favorite strategy for hunting its prey, so why wouldn’t it use it on humans, too? They don’t use it on humans because sharks do not intend to hunt humans—we just aren’t on their list of prey.
Next time you hear the word “shark,” don’t think of it as a mindless killing machine. Think of it as an animal that could harm you but chooses not to—and as an animal that is vital to the stability of the ocean’s ecosystem.
Russell, Julia. “Saltwater SWAT team: Top 5 fascinating shark hunting techniques | BEYONDbones.” Beyond Bones, Houston Museum of Natural Science, 19 May 2015, https://blog.hmns.org/2015/05/saltwater-swat-team-top-5-fascinating-shark-hunting-techniques/. Accessed 14 February 2023.