Fishing Boat Sunk by Giant Jellyfish

Thousands of jellyfish washed ashore onto Florida's beaches in 2007. Credit: Erion Cuko, Jacksonville, Fl.

Moon jellyfish have invaded many ocean habitats, likely transported and introduced by ships. Credit: NOAA

A Japanese trawler capsized when its 3-man crew apparently tried to haul up a net that was too heavy — loaded with giant Nomura's jellyfish.

"Each of the jellyfish can weigh up to 200 kg [440 pounds] and waters around Japan have been inundated with the creatures this year," according to The Telegraph. The men were tossed overboard in calm seas and rescued by another boat.

Jellyfish have indeed invaded many parts of the world in recent decades. Swarms are not uncommon.

"Jellies have likely swum and swarmed in our seas for over 600 million years," says "jellyologist" Monty Graham of the Dauphin Island Sea Lab in Alabama. "When conditions are right, jelly swarms can form quickly. They appear to do this for sexual reproduction."

Nomura's jellyfish can grow to 6 feet in diameter and travel in packs. Past spikes in Nomura population are thought to have occurred in 1958 and 1995.

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