字幕表 動画を再生する 英語字幕をプリント You unlock this world with a deep sea submersible. At 1000 meters you’re moving into a world of both shadows and wet substance, of things and stranger things, you've just crossed into… the bathypelagic zone. Hello there landlubbers, Julian here for DNews. Until July 10, 2016, the National Oceanic and Atmospheric Administration ship Okeanos will be over the deepest part of the Pacific ocean, the Marianas Trench, working 24 hours a day studying the ocean floor. And luckily for you, you can watch the live stream and have the chance to see creatures no person has ever seen before. They’ll be exploring areas of the ocean past the point where a little light gets through, called the mesopelagic or “twilight” zone, into a sea of constant darkness called the bathypelagic or “midnight” zone. Most of the volume of the world’s oceans is in the bathypelagic zone. Even deeper than that, from 4 km to 6 km down is the abyssopelagic zone, aka “The Abyss.” The Okeanos diving robots bottom out at 6 km in depth, where most of the seafloor is, but the marianas trench can cut as deep as 11 km. When you look at the life forms at these depths, the bathypelagic and abyssopelagic might as well be another planet. Giant isopods, viperfish, gulper eels, glowing jellyfish, almost everything looks like a nightmare or a fever dream. Even shrimp that cluster around hydrothermal vents are oddly pale and ghostly, why does everything look so weird down here? Well like all animals, their environment plays a huge role in their evolution, and the deep sea is about as extreme an environment you can find. The biggest factor is the pressure. For every kilometer you dive down, pressure becomes a hundred times greater than the air pressure we experience on the surface. That means at the ocean floor a body would have to withstand 600 times the pressure it would up here. To do that it helps to be flexible, with soft bodies or cartilage that bends without breaking. More watery bodies keep them from compressing, and it’s hypothesized that an elongated shape would help organisms cope with pressure too, which would explain the abundance of eel-shaped fish in the depths. Flat rays would really feel the pounds per square inch across their large area bodies. The pressure even affects deep sea life at a cellular level. Their cell membranes need more unsaturated fats to keep them liquid, otherwise their walls would become crushed and frozen solid and they wouldn’t function. Inside they have more organic molecules called piezolytes, which bind to water and keep their proteins from being distorted. Fish also need to find new ways to manage their buoyancy down there. Gas bladders that fish near the surface use would be crushed, so species develop workarounds. The blob fish’s flesh is gooey and low density. At depth the water crushes it into a workable shape, but unfortunately for the blobfish when we catch them and bring them to the surface they puff out and become the poster child for ugly animals. Other fish have fins so long they act as a tripod, allowing them to stand on the ocean floor. The long stilts sense vibrations and help them catch prey. That’s another problem in the deep: food scarcity. Since no light penetrates there is no plant life. Everything either survives off falling dead organic matter, chemicals coming out of occasional plumes, or the rare other living organisms they find. Unique hunting strategies are adopted, like anglerfish that lure in prey with bioluminescent light. They rely on ambush because it takes less energy, and have slow metabolisms to stretch out each meal. Anglers, viperfish and fangtooths have long teeth that trap prey like a cage. Other fish use lights to confuse predators, and some predators use lights to see, like lanternfish. Many animals have given up on sight entirely and may have non-functioning eyes or no eyes at all. While it’s hard to see and find food this deep, it’s even harder to find a mate. To overcome this, some fish are hermaphroditic, so no matter what mate they bump into they can reproduce. Anglerfish females release pheromones to attract tiny males. When a male comes along, it attaches himself to her, eventually fusing to her and providing sperm in exchange for sustenance. It’s not a hospitable environment, but even at these depths there is still life. Aside from the bizarre nightmare fish, there are also, sponges, sea stars, squid, and crabs. No word on pineapple houses though. Even though there are lots of fish in the sea, we’re still taking a pretty big bite out of them. To learn about one proposed solution to overfishing check out Trace’s video here. At the moment of international community has agreed to fish in seasons, with catch quotas and minimum size limits - with the hope this would allow time for the fish to mature, spawn and build the population back. News flash, it ain't working. More people have been to the moon than the bottom of the Marianas trench. So would you rather travel to the ocean floor or the surface of the moon? Let us know in the comments. Subscribe for more. And I will see you next time on DNews.