Nomura's Jellyfish also known as the Echizen kurage by the Japanese, is a large Japanese Jellyfish whose width is slightly larger than a height of a fully grown man. It can grow up to 2 meters and weigh about 450lb (220 kg) which is as heavy as a male lion. It is the biggest jellyfish in the world.
The mating and migration habits of this animal are not clearly understood and a series of studies have been encouraged by the Japanese government to research it.
The sting of this giant jellyfish is rather painful but not toxic enough to cause serious harm to humans. But there have been reports that the sting has caused build-up of fluid inside the lungs. Although the reported number of human injuries is low, a few unlucky swimmers have been killed by this giant.
Nomura's Jellyfish are unwelcome visitors who are normally found in the ocean of China and Korea. The numbers have grown in hundreds in some parts of Japan as well, with the population centralized in the Yellow Sea and the East China Sea.
Their population is on the rise in the fishing waters and is a serious problem to the fishermen because a large number of the Nomura's Jellyfish gets caught in their nets. The cause for greater concern is that they poison their catch with their toxic stingers or crush them to death. And often break the nets due to their weight. It's a serious crisis which has started to affect their livelihood. There are even reports where they destroy the local fisheries with their taste for fish eggs and larvae. In some areas the density is reported to be hundred times more than normal.
There are many theories that is said to be the cause of this explosion. One is global warming where the seas have been warmed and are better suited for their breeding. And scientists blame the over-fishing of the natural predators of the Jellyfish and the pollution along the coast. The high levels of nutrients in the water are also linked to this sudden jellyfish bloom.
When the Nomura's Jellyfish is under attack or killed they release billions of sperm or eggs, they connect with the water and attach to rocks or coral formations. These eggs detach from their home when the conditions are favorable and grow into more jellyfish millions at a time. This makes the problem of combating the Nomura Jellyfish even more difficult. And the baby Nomura's Jellyfish grow from the size of a grain of rice to the size of a washing machine in less than six months.
Japan has led the government to form a committee solve this problem. The issue was so serious in 2005/2006 that the fisheries officials from South Korea, Japan, and China met to discuss strategies for dealing with the invasion at a jellyfish summit.
The coastal communities in Japan are trying to promote jellyfish as a novelty food which is sold dried and salted. It is reported that collagen extracted from Jellyfish is beneficial to the skin, and Anglers have found out that they also make good crab food and fertilizer.