Editor's note: Happy Shark Week! All week long we'll be re-capping some highlights from Shark Week programming, starting with today, and "Great White Invasion."
Great white sharks appear to be more common than ever nowadays, according to “Great White Invasion,” which aired last night as a part of Shark Week's first night of programming. The episode tracked these huge predators as they encroach on popular beaches from Australia to South Africa to southern California.
Why they are coming closer to shore is not completely understood, but scientists point to the availability of fish as well as the opportunity for sharks to sunbathe and enjoy higher oxygen levels in shallower waters as possible explanations. And even though the number of annual shark attacks worldwide has risen in recent years, it is still extremely low compared to the number of beachgoers.
So are great whites really “invading” our coastlines? Not quite. In fact, according to the Census for Marine Life, scientists estimate that there are only about 3,500 great white sharks left in the entire world. Of these, an estimated 219 live off the central California coast, so in reality, sharks aren’t exactly swarming in our oceans just yet.
And even though it is fantastic that great whites are protected in U.S. waters, as this episode showed, great whites in California routinely travel into warmer, Mexican waters in the winter months, where they are targeted by gillnet fishermen.
This practice is not unique to Mexico, either. Shark fisheries exist around the world, and approximately 100 million sharks are killed every year. Many sharks are killed solely for their fins, which are used to make shark fin soup.
This episode also illuminated the health problems that pollution causes for great white sharks, particularly for babies off the California coast. Scientists found levels of mercury, a highly toxic chemical, in young great whites that were higher than ever documented before in any marine animal. Shark netting, used to keep sharks out of swimming areas in Australia and South Africa, has been shown to entangle not only sharks, but countless other species of fish, marine mammals, and sea turtles.
Clearly, humans pose a much greater risk to great whites than vice versa. Do your part by taking action to help protect sharks from being fished to extinction.