For years giant jellyfish have swarmed the Sea of Japan. But at up to seven feet in diameter and some weighing over 600 pounds, they have become a threat to the fishing industry.
Last month, the jellyfish sank a 10 ton fishing trawler when they got snagged in the boat's net.
This year there are more than ever and they are extending their drift to around the country.
"I had never seen anything this big before," said a local fisherman.
The jellyfish are poisoning the fishermen's catch.
"This is definitely an invasion," said Mitsunobu Iida. "Jellyfish are pests that kill our fish, the small delicacy ones. . . They are so big they crush our fish and that affects our market. We want to get rid of them."
For many, eating the massive jellyfish is not an option since larger fish tend to have less flavor.
Some say the jelly fish have drifted in from the waters of China and Korea. Others say over-fishing has wiped out their predators, allowing them to multiply and grow. Global warming has also been blamed. According to scientists, the temperature of the waters surrounding Japan is on the rise.
"The rising sea temperatures could be a factor behind this phenomenon as they foster the growth of these jellyfish," said Kiyoshi Kawasaki, Assistant Director at Japan's Fisheries Research Agency.
Some entrepreneurs, meanwhile, are trying to cash in. One Japanese company is selling giant jellyfish ice cream, and another plans a pickled plum dip with chunks of giant jellyfish.
But these intruders could affect consumers' bottom line.
"It will affect fish in the ocean," said Ki Jima Masa Kazu. "And if we can't get fish, we'll have to raise the price of fish, and that will be a problem for consumers."
Just one more reason to hope these beasts from deep, do not return next year.
The Associated Press contributed to this report.