It happened again last week, this time on the southeastern coast of Sweden: A bloom of moon jellyfish was sucked into the cooling-water intake pipes of a nuclear reactor. The jellies clogged the system, forcing engineers to shut down the boiling-water reactor—the largest such plant in the world.
While they have yet to shut down a stock exchange (as a squirrel managed to do in 1987), jellyfish are in many ways akin to the chief terrestrial disruptors of human activity. Just as squirrels regularly chew through power lines and blow transformers, jellyfish-caused power-plant shutdowns are increasingly common. The watery, ethereal sea creatures also manage to wreak seemingly unlikely havoc by clogging fishing nets, infesting the bilge water of ships, and causing tourist beaches to close with their stinging presence.
Concern over the rising, havoc-wreaking population has some asking if eating more jellyfish could help keep the growing horde in check.
At the Swedish plant, engineers cleared out the pipes and were preparing to restart the reactor when spokesman Andres Osterberg spoke to the New York Times on October 1. He said pressure in the filtration system likely killed the jellies, not the superheated water near the reactor’s core. “There will be no dinner of boiled jellyfish,” Osterberg told the paper.
While boiling—especially in reactor water—isn’t the preferred method of preparation, jellyfish are edible, and throughout Asia the crunchy texture and bland flavor are just the kinds of things diners get super excited about. More than 900 million pounds of jellies are purposefully netted for human consumption on an annual basis. Gelatinous zooplankton, the scientific catchall term for jellyfish, have been drifting in the ocean for some 400 million years—they’re the oldest multi-organ animal—and humans appear to have first figured out they made for a good meal around 1700 years ago, in China.
Despite millennia of relatively peaceful jellyfish-human cohabitation—though box jellyfish have killed their fair share of humans throughout the ages—there's a growing sense that the jellyfish threat has moved beyond concern over individual stings and into something bigger.
“If I offered evidence that jellyfish are displacing penguins in Antarctica—not someday, but now, today—what would you think?” biologist Lisa-Ann Gershwin writes in her new book, Stung! On Jellyfish Blooms and the Future of the Ocean, “If I suggested that jellyfish could crash the world’s fisheries, outcompete the tuna and swordfish, and starve the whales to extinction, would you believe me?”
While jellies appear to be growing their ranks, humans are working to develop anti-jellyfish weapons. Well, at least the Koreans are. Scientists at the Korean Advanced Institute of Science and Technology have designed a robot capable of dispatching any infringing swarm with an array of fan blades. The Jellyfish Elimination Robotic Swarm is capable of pureeing 900 kilograms of jellyfish per hour (there's video).
Both Gershwin and researchers at the Food and Agriculture Organization of the United Nations endorsed the “if you can’t beat them, eat them” approach in the past year. And in Georgia, where shrimping boats have been spending part of the year trawling for Cannonball jellyfish under a pilot program since 1998, they had their first official season for a full-fledged commercial fishery in 2013.
The catch, the third largest in the state behind shrimp and crabs, is exported to Asia.
In the FAO report, which focuses mainly on increased blooms in the Mediterranean and Black Sea, the authors suggest that “the development of conservation and packaging practices to sell them where they are appreciated might be a wise strategy.” Since they’re nearly three-quarters water, jellyfish require processing unlike other seafood: they’re covered with salt and alum, which helps suck out the liquid, and then allowed to dry. In light of their unique nature, the FOA also recommends “adapting the fishing fleets and the commercial network behind them to take advantage of sudden abundances of this product-to-be.”
The “sudden abundances” appear to be subject to debate, however.
“The recent jellyfish pulse might thus be a snapshot within a long series of natural cycles,” Laura Poppick writes for the Monterey Bay Aquarium Research Institute. A recent study of jellyfish sightings from 1874 to 2011 conducted by MBARI suggests that the blooms follow a cyclical pattern, one that peaks every 20 years. Throughout the 137 years examined by the marine biologists, only the past 40 years show a rise in jellyfish population—a “weak statistically significant rise.” They’re even declining in some areas, like off of the coast of India, “where increasing culinary interest in the floaters threatens the sea turtles that feed on them,” writes Poppick.
The Research Institute’s sister organization, the Monterey Bay Seafood Watch, doesn’t issue a rating for the Cannonball fishery in Georgia or the other Southern states where jellyballs, as locals call them, are caught.
“Usually we treat brand new untapped fisheries with extreme caution due to a lack of data,” Seafood Watch’s Erin Hudson writes in an email. “It’s hard to apply sustainable fishing pressure if you don’t have a full understanding of the target species population size, bycatch species and gear type interactions with the surrounding habitat.” Which is to say, you can't fairly judge the impact a fishery will have on the fish (or jellyfish), other species that may be affected, and the envoirnment they live in without looking at statistics over a period of time.
As in India, sea turtles depend on jellies off the coast of Georgia too, and the state’s Department of Natural Resources does require jellyfish trawlers to be equipped with a “federally approved” Turtle Excluder Device that’s modified to keep large leatherback sea turtles out of their nets.
Hudson does allow that an offense-minded jelly fishery would operate somewhat differently than one that’s desperately trying to keep stocks of cod or salmon from crashing. “We recognize however that some fisheries such as the invasive lionfish may have different goals than traditional fisheries (eradication instead of sustainability),” she writes, “and so we are currently working on adding additional criteria that would evaluate invasive species and other non-traditional fisheries. This may allow us to evaluate some of the invasive jelly species in the future.”
Jim Paige, a biologist at the Georgia DNR, makes it clear that they aren't taking a Jellyfish Elimination Robotic Swarm approach to managing the fishery. The state has 30-year dataset of jellyball populations to check the stock against. “We use that to look at the jellyball population itself to see if things are looking ok or if they aren’t looking ok,” and can adjust regulations accordingly, says Paige.
If Seafood Watch looked at Paige's data and gave the fishery a good raiting, would sustainable cred turn Georgia’s jellyballs into the new local darling of Atlanta’s dining scene? They are long on protein and collegen, which help lure the kale-and-quinoa crowd. But at the end of the day, it’s the bland flavor and texture that, outside of Asia, are the biggest hurdle to get past. Thornell King, who catches jellyballs in Georgia, told Voice of America last year, “Actually they taste a little like the gristle of a chicken bone.” Which, even in this nose-to-tail era of dining, might be a tough sell.