1846 in science

Transcription

[SCARY MUSIC] Why are sharks so scary?! Bloodthirsty beasts just waiting out there in the waves to feast on human flesh. If only we could get rid of these guys our vacations would be so much safer, nothing to worry about while we're surfing and frolicking out there in the ocean. Except that's not the case. We don't have anything to fear from sharks in the ocean, no more than I have to fear in this swimming pool. Really, it's sharks who should be scared of us. [MUSIC] There's more than 400 species of sharks on Earth, and they’ve owned the ocean for 400 million years, since before the dinosaurs! Yet thanks to a combination of fear and neglect, we humans might just wipe them out in a few hundred… That bites. Why care about sharks? You might think a few less sharp teeth in the sea would make for a better world, but that’s not true. Let’s imagine, just for a minute, what would happen if we let that fear and neglect win, if we ignore what scientists and nature are telling us. What if there were no sharks? By and large, sharks are big fish. And one of Mother Nature’s simplest rules is: Big fish eat smaller fish, which eat even smaller fish. And some of those smallest fish eat… algae? If we kill that biggest fish, those sharks? Then instead of coral reefs we could have… this… yuck. Or take my friend Ray. Ray likes to eat scallops, and this shark likes to eat Ray and his friends. No shark, and it’s an all-you-can eat scallop ray buffet. That’s exactly what’s happened off the coast of North Carolina when sharks were overfished, and now there’s no more scallops there. That’s bad for Ray, and bad for us, because I happen to love scallops. Without sharks, the sick and injured fish that they usually eat could throw schools into chaos. And it’s not always about what sharks eat, sometimes their mere presence can change the way marine animals feed and behave. Most food webs are much more complicated than big fish eating little fish, which makes it hard to predict precisely what would happen in a shark-free ocean, but that doesn’t mean it’s a risk we should be willing to take. How ‘bout this: If you kill a shark, you pay for it. If you’re in Palau, that’ll cost you $2 million a piece. Research into the value of sharks to tourism show us that a living shark is worth way more than a dead one. Sharks keep ecosystems in balance, and that balance is the product of thousands, sometimes millions of years of evolution and adaptation. We don’t know how, or even IF, the oceans can respond to such sudden changes, because sharks are slow-growing species that don’t breed often, and that makes them extra-vulnerable. The ecosystems that sharks help manage cover two-thirds of our planet, they provide us with more than half the oxygen we breathe, and 3 billion people rely on them for food and their livelihood. Whatever might happen in a world without sharks, it’s not good for us. You’ve probably noticed that number getting bigger. That’s how many sharks were killed while you watched this video. Every year, humans kill more than 100 million sharks, 70% for their fins, which are made into soup, the rest by habitat destruction, or thrown away as bycatch from fishing. How many people do sharks kill? Not many. Come on in here, let’s have some #realtalk. Time after time in movies, and during certain week-long specials on cable TV, sharks are portrayed as these dangerous monsters, toothy terrors of the deep that are just out to get us. But if movies have taught us anything, it’s that the scariest monsters are the ones we don’t see, the ones that remain mysterious. All this week, a bunch of our favorite YouTube channels have teamed up to bring you awesome shark science, so go check ‘em out. Remember, the more you know, the less you’ll fear. Stay curious.