Overfishing has reduced populations of large, predatory fish, allowing jellyfish populations to bloom. In some formerly biologically diverse areas of ocean, jellyfish biomass now exceeds that of fish. This shift is likely to continue: Climate change and pollution are changing the ocean chemistry, creating conditions favorable to jellyfish.
What's more, jellyfish eat fish eggs, so once they become dominant in a marine ecosystem, they tend to be there for good. "Jellyfish will be the seafood of the future not because that's what we want to eat, but because that's the only option," says Jennifer Jacquet, a doctoral student at the University of British Columbia's Fisheries Centre.
The Japanese have learned to make the flavorless, nutritionally sparse creatures more palatable; consumers can find jellyfish ice cream, jellyfish biscuits, rum-soaked jellyfish, and even wasabi-flavored jellyfish sold in vending machines.