水中の驚き by デイビッド・ガロ

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David Gallo: Underwater astonishments

小さいことは気にすんなッ、主題と主張をつかもう！

【話題】海の中は驚きでいっぱい

【時間】 5分27秒
【要約】
デビッド・ガロさんが海中の驚くべき生物たちを見せてくれます。

彼は地質学者なのですが、地球という星に興味をもつうちに、海という未知の世界に魅了されました。海のうち、人間が調査がしているのは、実に３％の過ぎないと彼は言います。海の中には、山や谷、湖や川がある!? そして、残りの97％はどうなっているのかサッパリわかっていない。

また、海の中は地上のジャングルと同じように多様な生物に満ちている、と彼は言います。

この未知の世界へビデオカメラを潜らせ、さまざまな海底の生物たちの様子を見せてくれます。ホタルのように生物発光する生物は、その光で、敵を威嚇したり、エサの動物をおびきよせたりします。

イカやタコといった頭足類は、周りの環境に合わせて、すばやく体の色を変え、カメレオンのように景色に溶け込んで身を隠すことが出来ます。また、イカのオスは、メスに対しては穏やかな色を、オスに対しては攻撃的な色を、場合によっては身体を部分的に分けて色を変えることもできます。

まるでコンピュータ・グラフィックスのようですが、これが自然の生物がもっている能力なのです。

【語彙】

bioluminescence ：生物発光

geologist ：地質学者

prey ：獲物

pulsating ：脈を打つ

diversity ：多様性

density ：密度

Cephalopods ：頭足類

calamari ：イカ

phenomenon ：現象

cuttlefish ：コウイカ

droopy ：垂れ下がった

algae ：海藻

spook ：怯えさせる

bluff ：はったりをかます

【transcripts】

We're going to go on a dive to the deep sea, and anyone that's had that lovely opportunity knows that for about two and half hours on the way down, it's a perfectly positively pitch-black world. And we used to see the most mysterious animals out the window that you couldn't describe: these blinking lights -- a world of bioluminescence, like fireflies. Dr. Edith Widder -- she's now at the Ocean Research and Conservation Association -- was able to come up with a camera that could capture some of these incredible animals, and that's what you're seeing here on the screen.

That's all bioluminescence. So, like I said: just like fireflies. There's a flying turkey under a tree. (Laughter) I'm a geologist by training. But I love that. And you see, some of the bioluminescence they use to avoid being eaten, some they use to attract prey, but all of it, from an artistic point of view, is positively amazing. And a lot of what goes on inside ... there's a fish with glowing eyes, pulsating eyes. Some of the colors are designed to hypnotize, these lovely patterns. And then this last one, one of my favorites, this pinwheel design. Just absolutely amazing, every single dive.

That's the unknown world, and today we've only explored about 3 percent of what's out there in the ocean. Already we've found the world's highest mountains, the world's deepest valleys, underwater lakes, underwater waterfalls -- a lot of that we shared with you from the stage. And in a place where we thought no life at all, we find more life, we think, and diversity and density than the tropical rainforest, which tells us that we don't know much about this planet at all. There's still 97 percent, and either that 97 percent is empty or just full of surprises.

But I want to jump up to shallow water now and look at some creatures that are positively amazing. Cephalopods -- head-foots. As a kid I knew them as calamari, mostly. (Laughter) This is an octopus -- this is the work of Dr. Roger Hanlon at the Marine Biological Lab -- and it's just fascinating how cephalopods can, with their incredible eyes, sense their surroundings, look at light, look at patterns. Here's an octopus moving across the reef, finds a spot to settle down, curls up and then disappears into the background. Tough thing to do.

In the next bit, we're going to see a couple squid. These are squid. Now males, when they fight, if they're really aggressive, they turn white. And these two males are fighting, they do it by bouncing their butts together, which is an interesting concept. Now, here's a male on the left and a female on the right, and the male has managed to split his coloration so the female only always sees the kinder gentler squid in him. And the male ... (Laughter) We're going to see it again. Let's take a look at it again. Watch the coloration: white on the right, brown on the left. He takes a step back -- so he's keeping off the other males by splitting his body -- and comes up on the other side ... Bingo! Now I'm told that's not just a squid phenomenon with males, but I don't know. (Laughter)

Cuttlefish. I love cuttlefish. This is a Giant Australian Cuttlefish. And there he is, his droopy little eyes up here. But they can do pretty amazing things, too. Here we're going to see one backing into a crevice, and watch his tentacles -- he just pulls them in, makes them look just like algae. Disappears right into the background. Positively amazing. Here's two males fighting. Once again, they're smart enough, these cephalopods; they know not to hurt each other. But look at the patterns that they can do with their skin. That's an amazing thing.

Here's an octopus. Sometimes they don't want to be seen when they move because predators can see them. Here, this guy actually can make himself look like a rock, and, looking at his environment, can actually slide across the bottom, using the waves and the shadows so he can't be seen. His motion blends right into the background -- the moving rock trick. So, we're learning lots new from the shallow water. Still exploring the deep, but learning lots from the shallow water. There's a good reason why: the shallow water's full of predators -- here's a barracuda -- and if you're an octopus or a cephalopod, you need to really understand how to use your surroundings to hide.

In the next scene, you're going to see a nice coral bottom. And you see that an octopus would stand out very easily there if you couldn't use your camouflage, use your skin to change color and texture. Here's some algae in the foreground ... and an octopus. Ain't that amazing? Now, Roger spooked him so he took off in a cloud of ink, and when he lands the octopus says, "Oh, I've been seen. The best thing to do is to get as big as I can get." That big brown makes his eyespot very big. So, he's bluffing. Let's do it backwards -- I thought he was joking when he first showed it to me. I thought it was all graphics -- so here it is in reverse. Watch the skin color; watch the skin texture. Just an amazing animal, it can change color and texture to match the surroundings. Watch him blend right into this algae. One, two, three. (Applause) And now he's gone, and so am I. Thank you very much.

デイビッド・ガロ 「海は驚きでいっぱい」

デイビッド・ガロ「海は驚きでいっぱい」