oceans are massive bodies of salt water that cover the majority of Earth's surface and ocean bios have some special terminology. We should go over now. The littoral zone of oceans is a little different. You see the waterline where oceans meet. The land is not fixed. Oceans have a tide, so the water level will actually flow from the high tide point to the low tide point. And this area, this literal zone is called the intertidal zone. And here we're looking at it, you know, as a beachhead. But sometimes thes intertidal zones will actually be rocky and can have verticality to them. And they can also have depressions that water gets trapped in That we call tide pools and type pools could be incredibly rich and diverse ecosystems. Now, the area that extends out from the littoral zone or the intertidal zone, is called the Neurotic zone, and this is basically just shallow ocean that covers the continental shelf. Now the Continental shelf is the extension of land that comes off of contents, rather continents that goes under water. So, uh, you know, imagine, uh, if you were to pull the continent out of the ocean, a little bit. You know, this would just look like a continuation of the landmass. Now at the edge of the Continental Shelf, you'll have a sharp drop off, and there is where you get the open ocean. Scary stuff. The open ocean where the zone of open ocean is called the Oceanic pally GIC zone. And it's just what's beyond the continental shelf. Now. The benthic zone in oceans is going to be markedly different from the benthic zone of a lake, for example, because oceans air so much deeper and more vast now, the marine benthic zonas it's called or sea floor, if you prefer, is basically in darkness. Always now, coastal areas will receive light. If you know they're the benthic zone is shallow enough. However, the majority of the marine benthic zone is going to be in total darkness Now. Coral reefs are you know, it's hard to over sell them. They're just incredible ecosystems. And, you know, they're such a rich bio in terms of species and in terms of you know, the sort of services they provide to the areas around them. And here's a map. You can see the location of coral reefs all over the world. They're going to be built by coral, which are these little animals that secrete these structures made of calcium carbonate. That's probably what you picture when you think of coral and those calcium carbonate structures are, you know, you probably look at them and think of them as rock or something. It's actually not rock, but you know, you can see these structures here in this this massive coral. Now the reason I bring up calcium carbonate is because coral reefs are super threatened by ocean acidification. Calcium carbonate will readily react with acids because carbonate is a base. So even a small increase in acidity can result in great damage to coral reefs. And you can see it from satellite photos. You know, looking at the Great Barrier Reef, see just how much of that has been eroded. Now, the last bio I want to talk about are these deep sea hydrothermal vents. These air fissures in the earth that release geo thermally heated water really, really hot water. And there are two reasons I want to bring these up. One is because they're potentially the source of life on Earth. Here you can see what's called the Lost City. Thes are a special group of hydrothermal vents that form these carbon stacks. And it is It has been proposed that life may have started inthe e little nano tubes in thes carbon stacks. I'm not gonna get too much into the details, but, you know, it's cool stuff. It's a very interesting theory, whether or not you believe it. Now, this is the other reason I wanted to bring up thes hydrothermal vents because they have some really interesting ecosystems, uh, or rather say communities of organisms that have developed there, you see, pretty much everywhere we've been talking about. Up to this point, uh, has been a community that's more or less supported on photosynthetic organisms. But these communities are not supported by photo autotrophs, but by chemo autotrophs they're supported by bacteria and archaea that can uhh, you know, essentially fixed carbon from the uhh you know, from performing various chemical reactions with the inorganic, uh, compounds available or sorry, not inorganic compounds. Theknot compounds available to them from these hydrothermal vents. Basically, they're just very cool ecosystems because they're so different from like everything else we see. You know, it's, uh, they're super unique in that there's like a very rich, diverse community built on top entirely on top of chemo autotrophs, you know, we're so deep down there's no photosynthesis is happening here. So very cool stuff. Now that's all I have for this lesson. I'll see you guys next time.
