Why and How Jellyfish are Taking Over the World’s Oceans

Tim Flannery provides an excellent review of Lisa-ann Gershwin’s new book Stung!: On Jellyfish Blooms and the Future of the Ocean in this New York Review of Books piece. It’s such a good, thorough review that I am disinclined to read the book.

From the Arctic to the equator and on to the Antarctic, jellyfish plagues (or blooms, as they’re technically known) are on the increase. Even sober scientists are now talking of the jellification of the oceans. And the term is more than a mere turn of phrase. Off southern Africa, jellyfish have become so abundant that they have formed a sort of curtain of death, “a stingy-slimy killing field,” as Gershwin puts it, that covers over 30,000 square miles. The curtain is formed of jelly extruded by the creatures, and it includes stinging cells. The region once supported a fabulously rich fishery yielding a million tons annually of fish, mainly anchovies. In 2006 the total fish biomass was estimated at just 3.9 million tons, while the jellyfish biomass was 13 million tons. So great is their density that jellyfish are now blocking vacuum pumps used by local diamond miners to suck up sediments from the sea floor.

This particular examples notes the collapse of the fishing economy in Bulgaria, Romania, and Georgia:

Would you believe, Gershwin asks, that “a mucosy little jellyfish, barely bigger than a chicken egg, with no brain, no backbone, and no eyes, could cripple three national economies and wipe out an entire ecosystem”? That’s just what happened when theMnemiopsis jellyfish (a kind of comb jelly) invaded the Black Sea. The creatures arrived from the east coast of the US in seawater ballast (seawater a ship takes into its hold once it has discharged its cargo to retain its stability), and by the 1980s they were taking over. Prior to their arrival, Bulgaria, Romania, and Georgia had robust fisheries, with anchovies and sturgeon being important resources. As the jellyfish increased, the anchovies and other valuable fish vanished, and along with them went the sturgeon, the long-beloved source of blini toppings.

By 2002 the total weight of Mnemiopsis in the Black Sea had grown so prodigiously that it was estimated to be ten times greater than the weight of all fish caught throughout the entire world in a year. The Black Sea had become effectively jellified. 

Some of the reasons for jellyfish growth are downright frightening;

One of the fastest breeders of all is Mnemiopsis. Biologists characterize it as a “self-fertilizing simultaneous hermaphrodite,” which means that it doesn’t need a partner to reproduce, nor does it need to switch from one sex to the other, but can be both sexes at once. It begins laying eggs when just thirteen days old, and is soon laying 10,000 per day. Even cutting these prolific breeders into pieces doesn’t slow them down. If quartered, the bits will regenerate and resume normal life as whole adults in two to three days.

Jellyfish are voracious feeders. Mnemiopsis is able to eat over ten times its own body weight in food, and to double in size, each day.

So what exactly is causing the jellyfish to thrive and take over the oceans? The reasons are numerous, and the review elucidates a few of them:

Our waste, such as plastic bags, and fishing methods like drift nets and long lines are busy destroying the few jellyfish predators, such as sea turtles. We are also creating the most splendid jellyfish nurseries. From piers to boat hulls, oil and gas platforms and industrial waste and other floating rubbish, we’re littering the oceans with the kind of artificial hard surfaces that jellyfish polyps love.

Then there is the amount of oxygen dissolved in seawater. Oxygen is created by plants using photosynthesis, and high oxygen levels allow fish and other complex creatures to compete successfully with jellyfish. But the oxygen in water can be depleted far more quickly that it can be replaced. Where humans add nutrients to seawater (such as fertilizer runoff from farms), areas with depleted oxygen, known as eutrophied zones, form. They can occur naturally, but are spreading quickly as the oceans become filled with excess phosphorus and nitrogen derived from a variety of agriculture and industrial human activities. In river estuaries, and in confined waters such as the Baltic, the Black Sea, and the Gulf of Mexico, eutrophied zones have spread to a frightening extent, and they appear to be permanent. Nothing that needs even moderate amounts of oxygen, including fish, shellfish, prawns, and crabs, can survive in them. But the jellyfish thrive.

Compelling read.

Surviving in Joshua Tree National Park

When promiment real estate broker Ed Rosenthal went missing for six days in Joshua Tree National Park one summer weekend, people assumed that he was a goner. But as he recounts in this amazing story in Los Angeles Magazine, he survived.

I finally admitted that I was really and truly lost. I was in a wasteland of ditches near where the park ends. I was too weak to move up the hill to see what was on the other side. No one would ever have found me or my bones. I couldn’t eat. The dates I tried to chew on just stuck to my tongue—I had to spit them out. It was frustrating, but you eventually get over not eating. Afterward I was told I was lucky I didn’t eat, that if you have food while you’re severely dehydrated, your body has to use up resources to help with digestion.

As evening approached I spotted some yuccas nearby. I started to cut away the sheathing at the base of one with my Swiss Army knife—you can suck on the tendrils for water. The stalk was too tough, though: I didn’t want to be away from the tree at night, so I gave up, went back to the tree, and struggled to make myself comfortable. But even under those branches I didn’t feel sheltered on that open hillside. It was freezing. The emergency blanket was falling apart. I tried to wrap pieces around me like a mummy—they just blew off into the night. So I spent my time slathering Mercurochrome and antiseptic from the medical kit onto my cuts. It reminded me of how I’d needed to apply Mercurochrome to my legs after a quadruple bypass ten years earlier: A calamitous real estate deal had triggered the heart attack that led to the surgery; the memory of it helped keep me calm that night. I was determined not to have another heart attack. 

Near the end of his piece, Rosenthal writes:

The moment they gave me water, I threw up all over the helicopter. They brought me to the hospital and started filling me up with fluids. I was in the ICU for two days. I experienced some heart damage, and my left ankle is shot. I don’t know what it is; they can’t do anything about it. But the rest of me is stronger. I’m hiking again. More with the Sierra Club. Now I experience plants as not being a separate species. They’re like cousins. It’s not like, There’s me and there’s plants. There’s us. I’m overwhelmed by how incredible they are.

I’ve hiked in Joshua Tree in October, and even in middle of autumn, the heat takes a lot out of you (even on a moderate three hour hike). Ed Rosenthal’s piece is a must-read story of survival.

The Man Who Sailed His House

In this month’s GQ, Michael Paterniti writes a remarkable story of a Japanese man named Hiromitsu who survived the March 11 earthquake and subsequent tsunami. Not only is the story incredible, but so is the narration (you here are this man, experiencing the catastrophe in the present):

At two forty-six, something rumbles from deep in the earth, a sickening sort of grinding, and then everything lurches wildly, whips back, lurches more wildly still. The cut boards stacked along the wall clatter down, and your first move is to flee the shed, to dive twenty feet free onto open ground and clutch it, as if riding the back of a whale. Time elongates. Three minutes becomes a lifetime.

When the jolting ends, stupefaction is followed by dismay—and then a bleary accounting. Already phones are useless. The boss, Mr. Mori, urges you to rush home to check on your wife and parents, but fearing a tsunami, fearing a drive down into the lowlands by the sea, and trusting the strength of your concrete house to protect your wife and parents, you at first refuse. There are ancient stone markers on this coast, etched warnings from the ancestors, aggrieved survivors of past tsunamis—1896, 1933—beseeching those who live by the water to build on the inland side of their hubris or suffer the consequences.

A description of the approaching tsunami:

You don’t look out to sea, not once; you stand staring at the mountain, Kunimi, in the distance. And now you can hear her downstairs, inside again, and now comes the creak of the bathroom door. Comes the sound of running water. Comes this vision of the mountain, placid, immovable—and then, to your right, to the north, within twenty feet, drifts the whole house of your neighbor. The house is moving past as if borne by ghosts. When you turn left, to the south and the garden, everything is as it’s always been, dry and in place. When you turn back the other way, you can see only this coursing field of ocean.

Just an incredible descriptive paragraph here:

This force is greater than the force of memory, or regret, or fear. It’s the force of an impersonal death, delivered by thousands of pounds of freezing water that slam you into a dark underworld, the one in which you now find yourself hooded, beaten, pinned deeper. The sensation is one of having been lowered into a spinning, womblike grave. If you could see anything in the grip of this monster, fifteen feet down, you’d see your neighbors tumbling by, as if part of the same circus. You’d see huge pieces of house—chimneys and doors, stairs and walls—crashing into each other, fusing, becoming part of one solid, deadly wave. You’d see shards of glass and splintered swords of wood. Or a car moving like a submarine. You’d see your thirty pigeons revolving in their cage. Or your wife within an arm’s reach, then vacuumed away like a small fish. You frantically flail. Is this up or down?

The experience of being out at sea, and deciding: should I drink? Should I eat? Can I?

At sunset, sky in scratches of purple light, a gnawing in your gut tells you it’s dinner, so you crack open the first can, drink, then, head tilted back, try to lick out the last drop. The roof is perhaps twelve feet by six, of corrugated metal nailed to wood beams, your raft at sea. Last night, you and Yuko slept beneath it, and now you perch atop it on the sea, above the goblin sharks and whatever else lurks below. 

Hiromitsu forces himself from going to sleep, and soon experiences hallucinations. Frightening:

You’re convinced you see a body coming near, and start screaming—Help me! But then it’s a tree trunk. In another you see a huge wave hurtling toward the roof and imagine turning into a tree to save yourself. But just as you think to stand and hang your arms like branches, you stop yourself for fear the roof will tip.

And what of the rescue?

Out of the oblivion, a clear voice responds, “We’re here,” and the boat drifts alongside your roof-home, and the voice asks, “Which side is safest?” And you say, “The side toward land, please,” as you strip the plastic container full of notes from your body and place it on the altar of your futon. Then one of the bundled figures steps out of the lifeboat onto the tippy roof and comes toward you with arms outstretched. The figure leads you across, five paces, and only when you lean forward into their boat and splay your body over its hard gunwale, like a glorious falling tree, do you know it’s real…

This is a story of survival, love, and loss. Hiromitsu lost his wife to the tsunami, but he carries her memory:

This is how you speak to her, through the scraps in the bag, but also aloud sometimes. Before eating, you might murmur, “Thank you,” as if she’s prepared the food on your plate. You might do the same on a beautiful day, as if she’s created it. And before bed each night, you tell her you love her. You say this to her presence or spirit, but you forgo mementos, little altars, or pictures on the wall. You can’t bear the idea of seeing her again, as you knew her in all those endless days before the wave.