Oft-Overlooked Jellyfisheries Are Too Big to Ignore

Jellyfish fisheries are booming, but we still don’t know if they’re a good idea.

Published December 8, 2016

Georgia fisherman Wynn Gale lifts a massive teardrop-shaped net over his boat, where it bobs and bounces when it hits the deck. That’s because it’s not filled with the rigid bodies of shrimp or fish, but thousands of gelatinous jellyfish, straining the netting like so many water balloons. Gale opens the bottom of the net, and tonnes of cannonball jellyfish—named for their bulbous bells—slip onto the deck until the boat is shin deep in the slimy creatures.

Gale catches shrimp in the fall and spring. But in the winter, when cannonball jellyfish form thick blooms from Florida to South Carolina, he fishes for jellies, an activity he calls jellyballing. And Gale loves jellyballing. It’s a “hard, fast fishery,” he says. And the money is good. His best year was 2014, when he caught nearly 1,000 tonnes. After expenses, he cleared US $20,000. Not bad for a few months’ work.

You probably haven’t seen jellyballs on the menu at your local seafood joint, but jellyfishing is big business. Much bigger, in fact, than official records suggest.

Jellyfish are fished worldwide from India to Russia to Bahrain, with the bulk of the catch coming from China and Thailand*. Lucas Brotz, a scientist at the University of British Columbia, recently published the first global assessment of the jellyfishing industry. “Every single aspect of jellyfish fisheries that I investigated has previously been underestimated: the number of countries, the number of species, and the magnitude of the catch itself,” he says.

More recently, American fishers like Gale have jumped into the market. Most Americans don’t have a taste for jellyfish, so the bulk of Gale’s catch is shipped to Asia where jellyfish are often eaten in salads and are considered a health food.

Besides Georgia, where jellyballs are now the third-largest fishery by weight, fishermen in Florida’s Gulf of Mexico bring in as much as 1,100 tonnes a year. In Mexico’s Gulf of California, the jellyballing fleet has more than 400 boats and employs several thousand people to process and transport the roughly 30,000 tonnes of annual catch.

Cannonball jellies are often eaten as a salad. Photo by rakratchada torsap/Alamy Stock Photo

For the most part, the jellyfish harvest has raised few concerns—after all, jellyfish appear in crowded blooms, and seem to be faring well along many of today’s overfished, polluted, overdeveloped, and acidified coasts. And there’s evidence that the large meshed nets used for jellyfishing cut down on by-catch compared to other fisheries. So maybe fishing them isn’t a bad idea?

Not so fast, says Brotz. The global jellyfish catch is nearly a million tonnes, easily twice official estimates and on par with the global catch of lobster. But lobster fishing is regulated and has been for a long time. In the United States for instance, conservation measures such as lobster size limits have been in place since the 1870s.

In contrast, the jellyfish industry is happening with limited oversight. In many places, size restrictions, catch quotas, and poaching are largely unchecked. Currently, jellyfish catch in the United States is limited only by the capacity of jellyfish processors and demand from Asian markets.

Jellyfish science that could inform regulators has lagged behind studies of more commercial animals, such as crabs and fish. But the existing science does suggest that jellyfish play a more integral role in ecosystems than had been assumed, both as significant predators of zooplankton, and as prey for dozens of fish species and all sea turtles (including the critically endangered leatherback turtle).

Juana López-Martínez has studied the cannonball jellyfish fishery in Mexico and says the environmental consequences of jellyfishing “may be considerable, but we don’t know for sure.”

Muddying the waters is the fact that most jellyfish have life cycles that are not fully understood. Cannonball jellyfish cycle through various life stages. Larvae attach to a firm surface and grow into anemone-like polyps. Then, multiple free-swimming medusa bud off each polyp, eventually growing into adults. But no one knows exactly where cannonball jellyfish polyps live, or what causes the populations to “bloom,” filling the waters with massive swarms of jellies at certain times of year. These ecological strategies may serve as a hedge against overfishing, but the data is slim.

Both Brotz and López-Martínez point to past examples of fisheries collapse and see the burgeoning jellyfisheries as an opportunity to do better. But that will take a more comprehensive understanding of jellyfish ecology, fishing methods, and economics.

All the uncertainty means that figuring out whether jellyfisheries can be managed sustainably is—like the creatures themselves—very slippery.

*Correction: This article erroneosly said Taiwan, not Thailand.