Three minutes to talk about popular science
Some huge, brainless creatures have quietly swam to Japan's waters in recent years, posing a threat not only to Japan's fishing industry, but also to nuclear power plants.
Echizen jellyfish outbreaks are nothing new in Japan, but every time they appear on a large scale, they can be called a disaster.
Giant jellyfish are quietly overflowing.
Jellyfish are known for their unique morphology and lifestyle. They are usually transparent or translucent, with an umbrella-like body and long tentacles. Some jellyfish have tentacles that contain toxins, and they can be said to be ruthless characters in the ocean that no one likes to provoke.
But when there are too many jellyfish, they become a problem in human society.
In August 2005, Japanese fishermen fishing in the Sea of Japan began to find that the sea area where they daily netting was occupied by a giant jellyfish. These uninvited objects are so large that they can easily break through fishing nets, and even crush other catches to pieces.
In Japan, the Echizen jellyfish (also known as the Nomura jellyfish) is one of the main jellyfish species that causes problems. These jellyfish are exaggerated, often more than 1 meter in diameter, and some individuals can reach 2 to 3 meters.
When fishermen in Japan catch fish, they often find that giant Echizen jellyfish are caught in the nets that should have been caught, and not only do they experience the "air force" of the fishing boats at sea.
On top of that, catching even a few Echizen jellyfish can cause their venom to contaminate and oppress other catches, an experience that annoys fishermen in Japan.
In addition to its impact on fisheries, Echizen jellyfish also pose a threat to Japan's nuclear power plants. Jellyfish can accumulate in the seawater cooling system of a nuclear power plant, causing a blockage of the water intake. In 2006, it even led to power outages at nuclear power plants, affecting the operation of electricity** and other infrastructure.
Of course, Japan, a country that "relies on fishing for food", will not sit idly by, and the joint efforts of the scientific community and the catering industry have eased the current situation slightly.
Researchers have not only developed a set of jellyfish early warning systems, but also track the distribution of jellyfish in real time through satellite monitoring and data from ocean observatories, so that fishermen can avoid bycatching Echizen jellyfish as much as possible.
Japanese chefs, on the other hand, sharpened their knives and learned Xi Chinese to make useless Echizen jellyfish into delicacies, such as jellyfish salad and jellyfish sushi, which were also well received and reduced the negative impact of Echizen jellyfish on Japan's fishing industry to a certain extent, so that the sea invaders turned into Japanese cuisine.
Jellyfish soup, jellyfish yogurt, jellyfish raw "fish" slices.
However, despite this, the problem of the Echizen jellyfish has not been completely solved. It seems that there is still a long way to go to deal with the problem of Echizen jellyfish!
Why did Echizen jellyfish break out.
In fact, over the past few decades, the problem of Echizen jellyfish flooding has become more and more serious, and the main reason is due to the overfishing behavior of our humans. When fishing activities reduce the number of natural predators of jellyfish, jellyfish are able to reproduce rapidly.
And for example, some other animals affected by humans, such as sea turtles, are a big predator of jellyfish, and their numbers are decreasing, which leads to a surge in jellyfish. The Echizen jellyfish, which reproduces very quickly, is a prime example.
The rise in sea temperature caused by global warming has also created favorable conditions for the growth of jellyfish. Jellyfish are able to mature more quickly in warmer waters, and global warming has made such conditions more common.
Freshwater flow is also a factor that should not be overlooked. Fresh water from rivers into the sea brings in a lot of nutrients that also promote the growth of jellyfish food. At the same time, the inflow of fresh water also alters the salinity of seawater, and certain jellyfish species are better able to survive in low-salinity environments.
In fact, marine ecosystems are a complex network, and changes in the number of any one species can cause a chain reaction. When marine ecosystems are out of balance, species like jellyfish have the opportunity to reproduce in large numbers.
Echizen jellyfish are not mysterious.
The Echizen jellyfish is a giant jellyfish in the family Aechizoae. This jellyfish is very large, with a limit weight of up to 200kg, and is one of the largest jellyfish in the world and one of the largest cnidarians in the world.
Its name comes from the ancient Reiki country name "Echizen Province" in Hokkaido, Japan. They are mainly found in the Yellow Sea, the East China Sea, the Sea of Japan, and other places, and various marine problems have also appeared in the Sea of Japan since the 1960s, and the number is increasing year by year.
Although the venom of the Echizen jellyfish can cause you to suffer a little bit of flesh at most, in some cases the injured person has been fatal due to stinging. Therefore, Japanese fishermen are fully armed when dealing with Echizen jellyfish.
The body structure of the Echizen jellyfish is fairly simple, consisting mainly of two parts: an umbrella-like top and tentacles hanging from the top. Their umbrella-like part is translucent, with wavy edges and a raised part in the middle called the umbrella top.
Underneath the top of the umbrella is the nutrient body of the jellyfish, or the "mouth", through which they ingest their food. Echizen jellyfish's tentacles are very long and filled with stinging cells capable of releasing toxins that help them catch prey and defend themselves.
The same monk's hat jellyfish has a similar structure.
The life cycle of Echizen jellyfish consists of several stages. They start as eggs, develop into larvae after fertilization, and then attach to the seafloor or other fixed objects, forming multiple jellyfish.
The multi-mouthed jellyfish will continue to **, eventually forming a mature Echizen jellyfish. This process can take anywhere from a few months to a year.
In the food chain, Echizen jellyfish feed mainly on plankton, such as small crustaceans and fish eggs. Their presence has an important impact on the marine ecosystem.
Echizen jellyfish are very reproductive, especially in warm, trophic-rich environmental conditions, which allows them to reproduce in large numbers in certain years, resulting in jellyfish outbreaks. In addition, the Echizen jellyfish treatment method more than ten years ago was very simple and crude, and after being caught, it would be "killed" and thrown into the sea.
However, it turned out that more and more jellyfish were killed, and even in the season when jellyfish should not have exploded, there were swarms of jellyfish.
After research, it was found that the Echizen jellyfish automatically excreted germ cells when killed, and when multiple jellyfish were killed at the same time, the fishing boat became an extremely efficient "marriage agency", which sowed the offspring of the Echizen jellyfish wherever it went, which also caused the phenomenon of species outbreaks to a certain extent.
Epilogue. Overall, the Echizen jellyfish are a very common and mysterious species, and although they can cause problems in some cases, it cannot be denied that the Echizen jellyfish are also an important part of marine biodiversity.
Only a better understanding of the problem of jellyfish outbreaks can be more effective in curbing the problem of jellyfish outbreaks, and it can also help Echizen jellyfish to return to normal population size in nature.
Other than that, "cold jellyfish" just helps everyone understand. Although the Echizen jellyfish and the jellyfish we often eat are all of the order of the Root Mouth Jellyfish, the jellyfish belong to the Root Mouth Jellyfish family, while the Echizen Jellyfish belongs to the crown jellyfish family, which is a completely different species