Juli Berwald, in her new book, "Spineless," shows how nature's creatures — in this case, jellyfish — can provide information about and give life to our messed-up ecosystems, our persecuted environment, our overdeveloped landscapes and the human condition.

Her main premise is that jellyfish are misunderstood. For years they've been maligned by scientists and civilians alike: in research because they are not as "durable" as the rest of the sea life that researchers scoop up from the ocean floor, and thus understudied. And they are loathed by swimmers and divers for their aspic-like exterior or painful sting, not to mention their slow sloshing in the witless waves of my youth. But as Berwald shows, the fragility of a jellyfish underlies its power. It can help clean up oil spills and feed undernourished people, and has the capabilities of rebirth and regeneration — in one word, immortality. In other words, they are as complex as the oceans they swim in.

Like the thin shells of Rachel Carson's bird eggs in "Silent Spring" that were a harbinger of environmental extinction, jellyfish are a messenger sent from the seas. But what is the message?

One of Berwald's investigative lines is to ascertain if the jellyfish population is increasing or decreasing despite acidifying seas. In fact, it is this metaphor the book revolves around: the jellyfish as a symbol for resilience and annihilation, nature's winners and losers. And like the semisolid state of its body, jellyfish reflect the fate of our planet: suspended between survival and oblivion at the hands of those who choose to ignore it.

While the metaphors and analogies can be conspicuous ("Maybe the time of the jellyfish's origin was an era before hunting, before aggression, before violence") and the memoir thread doesn't emerge clearly, the book doesn't suffer too much for it. The author's obsession (with jellies) becomes the readers' own. If by the end you still don't love jellyfish, you will at least respect them and look at them with new understanding, of their footprint even though they have no feet.

Maybe the jellyfish should be our new symbol. In America, the bald eagle, whose population was on the brink of extinction because of DDT, represents power and independence.

The jellyfish, conversely, illustrates what humans are liable for: an inadequate response to the destruction of our planet and its varying and diverse ecosystems. In other words, spinelessness.

Yes, the jellyfish should be the new world mascot to herald our own human failings.

Kerri Arsenault serves on the National Book Critics Circle Board and as book editor for Jewels of the North Atlantic and Arctic. She also writes a column for Lithub.

Spineless
By: Juli Berwald.
Publisher: Riverhead, 336 pages, $27.