Why Don't Fish Die When Lakes Freeze Over?

So I'm going to describe to you an extraordinary fact about water and why we're alive today. Okay? So watch, let's take a lake that has fish in it. Okay? Temperature drops outside and the lake slowly begins to get cooler because there's a time lag between the air temperature and the waters. That's why the first freeze, the lake is still there. It's got to be cold longer. All right? So what happens? The water gets cold on the surface. Okay? And it begins to, okay, the water gets cold on its surface and it begins to shrink. So that water falls, it shrinks. That makes it denser, it falls to the bottom. Fine. It does that down to about 4 degrees Celsius. As it goes from 4 degrees Celsius to 0 degrees Celsius, the freezing point, it begins to expand and become less dense than the water. So now, as the water wants to actually freeze, it stays on top. When it does freeze, you freeze the top surface of the lake. Well, how about the water below it? It's insulated from the dropping air temperature and the fish don't die. Imagine if ice were denser than water. What would happen? You'd freeze the top layer, it would sink. The bottom is frozen. Freeze the next layer, it sinks. The fish would be systematically forced to swim in shallower and shallower waters until they were all freeze dried on the top surface of the lake. And all fishes would be dead every winter in every lake. I think it's fish. I think it's fish. What? I think you're supposed to say fishes. Fishes is a double plural. You could do that? Yeah. You never heard fishes? All fish would be dead? Like all deer? Would you say all deers? Well, because generally it's one, if you had multiple kinds of deer. Oh, so if you had like, sick deer and white deers. But it's rare that they're all in the same place. You generally have one kind of deer on the plate. But the ocean has many kind of fish in the same place. Oh, that's interesting. So you would say fishes. Fishes is a double plural. It's different kinds of plural fish. Oh, double below my mind. You didn't know that? You knew it again. Oh no, no. I didn't know. I never thought about it that way. The many fishes in the, oh yeah. Yeah. So sorry. Fishes in the sea. Yeah, so multiple plurals of different kinds of fish. You can close it up to get where ocean water freezes, because that's where it gets probably really weird. Well, it's saltwater. Do you have the weird fishes up there? What are you pulling up, Jim? What is it? There's some weird anomaly that happened where there was too little oxygen in the water, and somehow the frozen fish got pushed out in a wall of ice. It was in South Dakota a couple years ago. Whoa. So there's too little oxygen because of... I don't know. I can't explain that. I don't know what happened there. It's somewhere else, but... If you look at the green in the water, most likely it's algae. So that happens with certain lakes that get polluted with certain types of algae. You can kill the lake by doing that. You can kill the lake. Well, you get it in the ocean until you get these zones. But I don't see how you get frozen fish, though. That's incredible. But you scroll... Stop. Go back up. Yeah. Scroll down so you could read it. Fish frozen in a wall of ice in South Dakota's Lake Andes National Wildlife Refuge. That's incredible, man. Is that a video, Jamie? I think it's just a picture, though. God, that's amazing. I don't know how they froze because they can just swim to where it's not frozen. So I'd have to do more homework on that one to see what caused that. Wow. So my point is, because of this property of water... How weird. That ice floats, it insulates the bottom layers of the lake, and fish can survive over the winter. That's how these blues work, too, right? Insulate so you can... inside you get a nice little spot. Yeah, sure. Yeah. Yeah. I mean, if you put a barrier between you and the changing elements outside, that's basically an insulating layer. Have you ever done ice fishing? No, I never... It's a good way of your life. I'm a New York City person. Well, they have them in New York City. People go ice fishing, I'm sure, in Central Park. Wait, do women go ice fishing to get away from their husbands? They do. Yeah, okay. It's a joke. It's like, why do people golf? You know, but ice fishing is particularly weird because you have to continually scoop out the ice and maybe even drill again. Right. So that works because frozen water is less dense than non-frozen water, and it's one of the rare ingredients for which that's so. And it's likely there would be no life on land or anywhere on Earth if that were the case. So water is a very special ingredient to life on Earth.