美国国家公共电台 NPR In 'Spineless,' How Jellyfish Have Survived Throughout Time（在线收听）

ARI SHAPIRO, HOST:

News reports about jellyfish often have an ominous flavor.

(SOUNDBITE OF DOCUMENTARY, "RISE OF THE JELLYFISH")

UNIDENTIFIED MAN: Jellyfish are invading all over the world. The Baltic, the Black Sea, Australia, the Bering Sea, the waters of South Africa have all been under attack.

SHAPIRO: That's from "Rise Of The Jellyfish," a documentary about massive swarms called blooms. Scientists disagree on whether these blooms are natural or exacerbated by climate change and pollution. That's one of the questions that pulled the author Juli Berwald back to the ocean. Berwald was landlocked in Austin, Texas, writing high school textbooks. She hadn't used her biology Ph.D. in years. Then she became hypnotized by these creatures that are fragile enough to fall apart between your fingers, yet powerful enough to kill a person in four minutes. Her new book is part memoir, part science. It's called "Spineless: The Science Of Jellyfish And The Art Of Growing A Backbone." When I spoke with her, I asked, why jellyfish?

JULI BERWALD: Jellyfish are - well, they're an incredible muse because they sort of live in this space between angelic and demonic...

SHAPIRO: Ooh (ph), yeah.

BERWALD: ...Because, you know, you can't deny how gorgeous they are. And when they swim there's something very - that connects to you on sort of a very primal level. But there's also this demonic side in that they have this horrible sting. And they're - I mean, they're actually lethal, some of them. But the real reason was because jellyfish - well, there was a lot of debate about whether their numbers were increasing globally and what that increase in abundance could tell us about how we're treating our oceans.

SHAPIRO: And the answer's not very simple.

BERWALD: No, the answer is not very simple. And part of the reason the answer isn't simple is because we've systematically understudied jellyfish for most of the 20th century. Once we started looking at the oceans using motors and nets, the things that were too fragile to come up in those motors and nets stopped being counted. So our view of the ocean became one that was biased towards things that were durable. That said, there are certainly places in the world like those places mentioned in the documentary where jellyfish abundances are increasing. And in those places, jellyfish are definitely telling us that our care for the ocean is not what it should be.

SHAPIRO: You write that some of the greatest fisheries in the world have just collapsed, and now it's all jellyfish.

BERWALD: Yeah. Yeah. Off of Namibia and South Africa it used to be one of the world's richest fisheries, you know, producing, like, a million tons of fish a year. And now it's estimated that the biomass there is two to three times more jellyfish than fish. And that ecosystem's unlikely to flip back to be fish-dominated.

SHAPIRO: So as you said, demonic and also angelic.

BERWALD: Absolutely.

SHAPIRO: You also write about these incredible structures that cause stings or propulsion or navigation. Is there one, like, jelly fish fun fact that you've been dropping at dinner parties that you learned as you were writing this book?

BERWALD: Yeah, that stinging cell - it's the fastest motion in the animal kingdom that we know of.

SHAPIRO: Wait. Really?

BERWALD: Yeah.

SHAPIRO: I'm sure that was somewhere in the book, which I did read cover to cover, but that didn't stick out to me - the fastest motion in the animal kingdom.

BERWALD: Oh, my - yeah. So, you know, if you just drop, like, a pencil onto the table it falls with an acceleration of one G. And then, like, a Ferrari accelerates with an acceleration of, like, three G's. But the stinging cell of a jellyfish explodes with an acceleration of 5 million G's.

SHAPIRO: How can an animal as simple as a jellyfish have something so sophisticated as part of its biology?

BERWALD: It's astonishing. I agree. That stinging cell is kind of a marvel of nature that is extremely underappreciated. But also, I mean, if you think about it, jellyfish have been swimming in our oceans for over half a billion years. And part of what allowed them to remain jellyfish that whole time is this stinging cell. It's really the key to their survival.

SHAPIRO: There was another jellyfish moment in this book that I liked where you were asking a biologist, like, why is it see-through? Why doesn't it actually have some features? And the biologist was like, it's really hard to see-through, and it's a huge advantage to be see-through. So...

BERWALD: Yeah. I mean, that's - that was another thing. I popped myself on the forehead when he said that to me. I mean, in the ocean there's nothing - there's nothing to hide behind or hide in. It's just water. So if you look like water you're at an advantage.

SHAPIRO: Which means you have to hide everything that's inside of you, all of the guts...

BERWALD: Yes.

SHAPIRO: ...The brains, the everything.

BERWALD: The more cellular you are, the harder it is to stay clear. So the jellyfish do it by having this watery inside which allows them to sort of hide as a big creature using as few cells as possible. It's kind of brilliant.

(LAUGHTER)

SHAPIRO: So the process of writing this book led you away from your old life as a high school textbook writer back to your roots as a marine biologist. Do you think you're there to stay?

BERWALD: I really hope so. I think I've found that I'm definitely happiest when I have the ocean to think about. And I also feel like the ocean's been neglected by us to some extent. We're damaging it in many ways that we don't think about very often. And so if I could continue to write about the ocean and what's going on with it, I would be really happy.

SHAPIRO: Julie Berwald's new book is called "Spineless: The Science Of Jellyfish And The Art Of Growing A Backbone." It's been great talking to you. Thanks a lot.

BERWALD: Thank you so much, Ari. It's been really fun.

(SOUNDBITE OF ELSE'S "PACIFIC 704")