To the great relief and puzzlement of fishermen and researchers, the Sea of Japan this year has seen a drastic decline in the huge, toxic jellyfish that have damaged the nation's seafood haul in recent years.
Known either as Nomura's jellyfish or Echizen "kurage" (jellyfish), the bottom creatures can reach 1 to 2 meters in diameter and weigh 100 to 200 kg.
Thousands can attach themselves to a single fixed fishing net, poisoning the fish inside and often breaking the net itself.