More than 6 ft 7 inches wide, over 450 lbs…while it may sound more like a sumo wrestler description we’re actually talking about the Giant Jellyfish or Nomura’s Jellyfish (Echizen kurage in Japanese) found lurking in the Yellow Sea and East China Sea. No stranger to Japanese waters, these massive creatures have been known to invade Japan’s coastline in swarms bought in by ocean currents and potentially cause severe losses to Japan’s Billion Yen fishing industry.

Giant jellyfish are one of about 200 species of coastal jellyfish or large jellyfish that exist around the world.  Nomura’s stand out because of their enormous size. Quite a spectacle for divers, the pink jelly like mass with seemingly countless tentacles is in fact poisonous like all jellyfish. An Echizen’s sting can be fatal, causing a build-up of fluid in the lungs. Victims take up to a day to die and there have been 8 reported deaths from this particular type of jellyfish.

*Photo credit: YOMIURI SHIMBUN/AFP/Getty Images

The news of such an invasion of Nomura’s jellyfish may bring a smile to a divers face and is often much awaited by scientists to study,  local fishermen however, are not impressed.  In 2005, the Japanese fishing industry reported an estimated 300 to 500 million monster jellyfish to have passed through the Tsushima Strait into the Sea of Japan. The jellyfish destroy fishermen’s nets, getting trapped in them, tearing holes and ruining catches. Their size often compared to that of sumo wrestlers, it only takes about 5 or 10 of them to destroy a commercial fishing net. In addition to damaging nets, the giant jellyfish are said to be responsible for killing other fish in the catch with their venom, capsizing trawlers and stinging fishermen much to the nightmare of fishermen.

Similar invasions have previously been reported in 2002, 2005, 2008 and now 2009 becoming an increasing regular nuisance. Some theories surrounding the skyrocketing numbers of the giant jellyfish include, overfishing in Chinese waters decreasing the populations of the jellyfishes natural predators, development of ports and harbours along the Chinese coast providing more structures for the Nomura larvae to attach themselves to and thirdly, global warming which causes the heating up of the seawater and encourages jellyfish breeding. No definite cause has been identified but studies are being undertaken to find out, while precautions to decrease the damage they cause are in full force.