A 10-tonne fishing boat has been sunk by giant jellyfish off the coast of Japan.

The trawler capsized as its crew tried to haul on board a catch full of huge Nomura's jellyfish.

The net contained dozens of the 200kg creatures but the whopping haul proved too much for the boat.

The three-man crew of the Diasan Shinsho-maru were pitched into the sea off Chiba but were rescued by another trawler.

Waters around Japan have been inundated with the creatures this year; experts believe that weather and water conditions in the breeding grounds have been ideal in recent months and produced a bumper stock.

One of the largest jellyfish in the world, Nomura's jellyfish can grow up to 2 metres in diameter.

Another contributing factor to their prominence, according to marine specialists, could also be the decline in predators like turtle and certain kinds of fish.

The last time there was a glut of giant jellyfish in 2005, they damaged nets, rendered fish inedible with their toxic stings and even caused injuries to fishermen.