Animals

Eating Crispy Jellyfish Chips Might Help Curb a Thriving Aquatic Menace

Danish researchers have developed a method for quickly turning the stinging creatures into a crispy snack, making abundant jellyfish blooms a potential source of food.

How about a side of jellyfish with that sandwich?

Danish researchers have found a way to turn the floating, stinging bane of many beachgoers into a crispy snack in short order, using alcohol to reduce the gelatinous creatures to a desiccated, salty shell. The process may be a way to head off concerns about the so-called “jellification” of the oceans, as surges in jellyfish populations bump up against human activity.

Jellyfish have been a delicacy in Asia for centuries, with hundreds of thousands of tons harvested for consumption each year, but they’ve never found a place in the Western diet. What’s more, it takes more than a month to prepare them by soaking them in a mix of salt and alum — an aluminum-sulfur compound that is used as a preservative. An alternative process devised by Mie Thorborg Pedersen, a gastrophysicist at the University of Southern Denmark, produces something that resembles a potato chip within days.

“There are no fancy instruments. I just take the whole jellyfish, with tentacles and everything, put them in ethanol and leave them for two or three days,” she said. After a couple of days in the chilled solution, the jellyfish are taken out and left to dry. The alcohol extracts the water from the organism and evaporates, “and the next day I have these thin jellyfish crisps.”

Pedersen is the lead author of a study published recently in the International Journal of Gastronomy and Food Science. As a physicist, rather than a biologist or chemist, her interest in jellyfish was an outgrowth of earlier studies into how gels — mixtures of polymerized solids and a surrounding fluid — are affected by various solvents. Her supervisor suggested that jellyfish might be a good subject.

A dried jellyfish in the laboratory of University of Southern Denmark. | Anders Boe/SDU

Jellyfish have drawn scientists’ attention for other reasons as well: They’re becoming a nuisance, if not a hazard, in some parts of the world. Besides carrying stinging tentacles that deliver toxins ranging from merely irritating to literally heart-stopping, large clusters of jellies periodically jam power plant cooling-system intakes, overwhelm fishermen’s nets, and destabilize regional ecosystems by killing off large numbers of commercial fish species.

Pedersen and her colleagues applied their process to moon jellyfish, one of the most common species. They’re about 96 percent water, 3 percent salt, and 1 percent protein, mainly collagen. 

The resulting chip is a salty protein snack with a kind of papery texture, unlike the more seaweed-like feel of traditionally prepared jellyfish. The researchers also enlisted a Danish chef – Klavs Styrbaek, the owner of Styrbaek’s restaurant in Odense — to craft dishes with the chips.

Styrbaek said called Pedersen’s chips “brilliant,” saying they can be served on salads, marinated, or carefully fried to give them a slightly bitter taste.

“Another thing that’s good with jellyfish are combinations with cucumber, and also horseradish or turnips,” he said. “One of the best things we found was when you cook it with horseradish and oysters.”

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Moon jellies are “a problematic jellyfish the whole world over,” said Lisa-ann Gershwin, a research zoologist at the Australian science agency CSIRO and author of a 2013 book examining how the creatures can thrive even in harsh conditions. So she said finding a commercial use for the species was a great idea.

“I wonder however, about the impact of fishing out lots and lots and lots of jellyfish without addressing why the jellyfish are in abundance in the first place,” Gershwin said.

 “They’re not evil beings that are following their evil warlord and taking over the world,” she said. “They’re just responding to conditions that humans are giving them.”

The chef Klavs Styrbæk’s gastronomical suggestion for refreshment of ethanol prepared jellyfish: Crispy fried Aurelia aurita (after ethanol preparation) with nori seaweed, pickled yozu-turnip, fresh sansho pepper, and sesame powder. The diameter of the jellyfish crisp is around 5-10 centimeters. | Kristoff Styrbaek

Jellyfish blooms can emerge when their predators are reduced because of commercial fishing, or when low levels of dissolved oxygen chase off competition for food, allowing more jellyfish to thrive. They also appear to surge around undersea structures like oil rigs and wind turbines, which give their budding young more places to latch onto and grow.

But while spikes in jellyfish clusters, known as blooms, have wreaked havoc in some circumstances, fears that rising numbers of jellyfish are taking over the oceans “are probably a myth,” said Rob Condon, an oceanographer and marine scientist who studies the species.

“It’s more likely that we’re interacting more with them in their backyard rather than them being in our back yard,” he said.

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Condon started the Jellyfish Database Initiative, which compiles current and historical data on the creatures. Its data suggests jellyfish populations wax and wane in 20-plus year cycles, the last of which peaked more than a decade ago. He’s now the executive director of the Young Scientists Academy, a nonprofit that tries to foster interest in science among students, some of whom are helping update it now.

“Since about 2005 or 2006 we’re actually going through a declining phase in the cycle,” he said. “We’re about to hit another rising phase. So partially, those claims that jellies are increasing are correct — you’ve just got to get the right time period.” And with more people living and working on the coasts or offshore, “We’re going to experience these type of encounters more.”

While cyclical jellyfish blooms appear to be a global, natural phenomenon, Gershwin said populations can surge in some areas that have been “highly disturbed.”

“We’re taking out their competitors. We’re giving them warmer waters where they grow faster and reproduce faster. We’re giving them coastal construction that’s giving their polyp stages more room to live and grow their colonies,” she said. “We’re doing a whole lot of things that are giving them conditions they’ve never known in half a billion years. They’ve never had it so good.”

But consuming large numbers of jellyfish in response “just opens up eco-space for the next pest in line,” she said. “It doesn’t really solve the problem of why pests are getting into super-abundances.”

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Condon said Pedersen’s process sounds “kind of cool,” even though he’s not personally enthusiastic about the taste of jellyfish in general: “It’s okay. It’s something you should experience, I guess.”

But he said a process that fast-tracks the consumption of jellyfish should be subjected to further study to make sure they can be harvested sustainably. Jellyfish aren’t just pests. They’re the entire diet of leatherback turtles, they’re a major food source for some species, and their trailing tentacles are “almost a little microhabitat” for smaller marine life. Medical researchers have also used glowing jellyfish proteins to track genetic changes and fight diseases like AIDS.

And Pedersen said while her research may yield gastronomic benefits, she doesn’t see it as a magic bullet for fears of a jellified ocean.

“I don’t think we save the world by eating jellyfish crisps,” she said. “But I know there is a big discussion about the different kinds of jellyfish problems around the world, so it makes sense that we could eat some of them.”

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