Gigantic jellyfish from the Yellow Sea have drifted to the Sea of Japan, causing a nightmare for Japanese fishermen.
Scientists think that the Nomura's jellyfish, which can grow to 1.83 metres in diameter and weigh 204kg, originate from Chinese waters but have drifted to Japanese waters owing to ocean currents.
Monty Williams, a marine biologist at the Dauphin Island Sea Lab, USA, told CNN that the jellyfish stay in packs and wreak devastation when they become ensnared in fishing nets.
Mr Williams said that because these nets often stretch for hundreds of kilometers, the cumulative impact was particularly destructive to local economies.
After the jellyfish invasions of 2005 and 2007, Japan now has a warning system in place that will help fishermen save their expensive nets from the jellyfish.