Giant Jellyfish Attack Fishing Operations, But Have Plus Side Too

Have you ever seen a jellyfish while you were fishing or swimming? OK. Have you ever seen a jellyfish over six and a half feet across, and weighing up to 450 pounds? How about several thousand of them at once, drifting like a massive, toxic flotilla into your fishing net?

This is what Japanese fishing operations have been dealing with in recent months: legions of Nomura’s jellyfish (Nemopilema nomurai) have been floating out of their usual terrain in Korean and Chinese waters, possibly being pushed from the Yangtze delta by currents produced by unusually heavy rains in the region, and in to the nets of fishermen. Another hypothesis is that global climate change and heating ocean temperatures are creating optimal breeding conditions, thus leading to the jellyfish reproducing in unprecedented numbers. The jellyfish are very poisonous – in some rare cases even causing human fatalities – but more commonly are responsible for poisoning hauls of fish with their toxins while clogging nets.

There does seem to be a plus side, however: some fishing fleets have transformed the nuisance into cash by using the giant jellies as bait or fertilizer; some have even tried drying, shredding, and salting them into a novelty snack.

Even more optimistic are the findings of the Riken Discovery Research Institute, which has discovered that the Nomura’s jellyfish contain a large quantity of a compound called mucin, a glycoprotein that could have a number of medical applications for humans.