This huge species inhabits the seas between China and Japan (mainly the Yellow Sea and the East China Sea), and can grow almost as large as the Lion’s Mane, up to 2 m (6 ft 7 in) in diameter, and weigh over 220 kg (450 pounds).
In the last 4 years, the Nomura’s Jellyfish has repeatedly invaded the Japanese shores. In some places, this jellyfish density is reported to be “one hundred times higher” than normal. The present sudden proliferation had already been observed in 1958 and in 1995.
A number of factors are likely to contribute to that species proliferating and growing so large: the new Three Gorges Dam on the Yangtze river increased the amount of phosphorous and nitrogen in the waters off China and make them an ideal breeding ground for the Nomura’s Jellyfish; those waters have probably been further enriched in nutrients due to the increased farming activity; the development of Chinese ports and harbors has provided the Nomura larvae with new structures to attach themselves to; global warming has made the waters to heat up and to become more acidic, and thus ideal for these jellyfish (and others); by overfishing their waters, China also eliminated the predators that fed on the Nomura larvae.
The Nomura’s Jellyfish have become such a problem in Japan, that an official committee has been formed to combat them. They are caught in special nets and destroyed and researchers are trying to promote them as a food source: they are sold dried and salted, turned into cookies and a kind of tofu, and a collagen – a product beneficial for the skin- is being extracted from their skin.
MARE 171: Marine Biology 
These blooms are extremely concerning. Before this week when I saw footage of dense jelly blooms I thought they were beautiful but now I know better. I definitely agree with the authors suggestions that the sudden increase in nutrients from farming and pollution is to blame. This intense pollution is a relatively recent development along with the blooms and it follows the logic of, if there is enough food to sustain the populations expansion then it will expand. I read an article how a huge, destructive population of Mnemiopsis invaded the Caspian Sea in 1999, but it could be controlled by introduction of a predator species. Introducing a predator species would be the perfect means of control.
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Jellyfish are beautiful creatures, but I’d hate to live in a world where that’s all we have left in our oceans. Agricultural fertilizer runoff is a huge problem for our oceans for a multitude of reasons. I think in large part it is rooted in the disconnect between coastal communities and those inland. Coming from an agricultural area in the middle of a continent, most people don’t know how dependent we are on the oceans and how destructive our actions can be to waters that are hundreds of miles away.
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With the constant changes in environment, there are several different factors that make these creatures overabundant and causing them to rise in blooms. Some of the most likely reasons are due to the mass cullings without prior knowledge to their survival attempt by releasing their sperm and eggs. This causes millions of larvae to go down into the ocean. Mentioned in the article was also the overfishing of their natural predators. All these factors when put together are the complete reason for such large blooms and must be acted upon immediately. The author is correct in these reason why the species have been on the rise. But to decrease this species we need to figure out how to decrease their rate of reproduction from polyp stages and releasing their eggs in the medusa stage. If we can lower these tremendously we will have the opportunity to start an effective culling.
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Because of the way their life cycle works, jellyfish are highly adapted to thrive in environments that other organisms struggle in. All of the factors the author talked about could very well be contributing to the sudden explosion in the jellyfish population. Some of these factors are out of our control, but a lot of the things helping the jellyfish are directly caused by us. Rather than trying to kill off all the jellyfish, I think that we should shift our focus to reducing or completely eliminating the things we’re doing to promote population growth. Jellyfish are just an indicator that the ocean isn’t healthy. Even if we do manage to kill them all, something else will probably take their place. Instead I think we should stop over-fishing the organisms that eat or compete with jelly fish, and we should be more careful about what we’re putting in the ocean.
Plan B: If we can’t stop the jellyfish, lets join them and take over the world.
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1) What could be the cause of these blooms?
2) Do you agree with what the authors have suggested on the possible causes? Why, or Why Not?
3) What do you think can be done to control this species?
1. They are caused by humans over fishing and pouting the water.
2. Yes, because I think humans play a large part in what happens to our oceans and how they are effected.
3. I think we could fish a little less and disregard of our waste in a more proper way.
I think that instead of killing the jellyfish we should collect them and place them in huge tanks like the ones used for the larger mammals in other aquariums. We can free the whales and whale sharks in captivity to free up some of the larger tanks for the jellies. We can allow people to buy and name the jellies like they can stars, “jellies will stay at aquarium not go with buyer” and the money raised can go into saving more jellies and constructing more tanks.
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Although direct human interference has played a huge part in the overpopulation of these jellyfish, I think the root cause is how ocean chemistry is changing. Nutrient pollution is one of the main contributors but not the only one. Caused by the run off of fertilizers in the watersheds that lead to the Mississippi river, the nitrogen and phosphorus have had detrimental effects causing dead zones. Another example of how the chemistry of the ocean is changing is ocean acidification. This is caused by the uptake carbon dioxide and the over looming presence of it in the atmosphere which has already caused the degradation of coral reefs and has negatively impacted commercial important fishes. There is also offshore drilling which increases the risk of toxic exposure from oil contamination to wildlife and coastal communities. With all of these changes, I don’t find surprising that the jellyfish are reacting. I think it’s an indicator that serious conservation efforts must be taken before it’s too late.
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I agree with the authors in thinking that the main cause of these jelly blooms is due to eutrophication of water body’s. Certain chemicals in waste and runoff may make living conditions optimal and nutrients ample. The most downstream solution would be to simply keep harvesting and killing the jellyfish in order to control their population density. However an upstream alternative may be more logical, such as reducing and limiting the things we flush down toilets/put in the drain, the chemicals we farm with that runoff into streams and then oceans..etc. This way we are limiting the overpopulation of the jellyfish, and prohibiting other problems that are seen from human waste runoff in the ocean.
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1) What could be the cause of these blooms?
2) Do you agree with what the authors have suggested on the possible causes? Why, or Why Not?
3) What do you think can be done to control this species?
I think these blooms could indeed be caused by what the authors have speculated. But the most prominent of the bloom causes would probably be from the hacking and slashing of the Japanese fisherman on these jellyfish. As the article and videos from class showed, these jellyfish release millions of sperm. If you multiply that across the amount of jellyfish killed per day, the numbers could reach immense proportions. In my opinion, finding ways to further utilize the jellyfish for human good is one of the best options, as long as the jellyfish are harvested in a non-startling way. More research could also be done on their natural predators, and how we may be able to increase their population size as well.
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1) What could be the cause of these blooms?
2) Do you agree with what the authors have suggested on the possible causes? Why, or Why Not?
3) What do you think can be done to control this species?
I think that having less predators would be a key factor in these blooms. Without having something to balance out the jelly fish, their numbers can grow uncontrollably quickly. For example the Lionfish in the Atlantic, not having any natural predators in the area, its numbers are increasing drastically, and harming the ecosystem around them. I agree with all of the possible causes the author gives. As humans we have the special ability to think that the world revolves around us, and our decisions do not effect anyone, but as a budding scientist, i believe we all begin to recognize that we are all interconnected in the one place we call home. As far as controlling the species, possibly finding a virus could be a good answer. It sounds kind of morbid but since viruses are species specific, there wouldn’t have to be much concern about it infecting other species. One would hope that some of the jellyfish would be resistant to the virus though, as in to not completely wipe out a species.
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I would have to agree with the authors that suggested that the phosphorous, nitrogen and warmth levels in the waters were some of the causes of the jellyfish blooms because conditions like that are perfect for the Nomuras to thrive and repopulate. The way that the Japanese fisherman try to handle the overpopulation situation doesn’t seem very effective, considering that when the Nomuras feel threatened, they release millions of sperm so that they are able to create the next generation of jellyfish. Another main reason why the Nomuras are drastically multiplying would have to be the lack of predators that hunt and prey on them. One possible solution could be figuring out what type of predator feeds on them and work on multiplying the number of predators. Not so much that they too become a nuisance, but just enough to bring the population of the Nomuras back down to a less overwhelming number.
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I think a lot of the blooms have to do with the release of the egg and sperm when the animals are under attach. Especially since they take them up in large nets, It almost guarantees that there will be both sexes in the net and the egg and sperm will be released in the same site. I also agree that having less predators almost guarantees that they will continue to succeed in their successful offspring. More offspring will be produced due to the increased survival rate then be able to grow up and reproduce themselves in an on going cycle. As far as control goes, we need to first stop polluting the Earth both (land and sea) and stop over harvesting the oceans (and land). I think a good idea would be to bring in some of the jellies to an aquarium so people can see what they look like and research could be done with them. I do NOT think it’s a good idea to introduce a new species into a new population. If their natural predator is dying off– introducing more of them will not work because they will not survive just like the previous. We do not want to introduce a non-natural animal into this habitat because it would completely off set the balance and who knows what could happen.
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I agree with the author in their many explanations as to why these blooms are increasing so dramatically. Human influence has caused many things to change in the natural world. In the sea between China and Japan, human influence has increased the amount of nutrients in the water supportive to jellyfish life. That, along with people overfishing and there being less predators in the water, has made this ocean the ideal jellyfish environment. I think that there needs to be changes made to make that area sustainable once more. It could be a set of fishing or development laws that would help revitalize the fish population and balance that ecosystem.
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I agree as well, to why the author explains why these jellyfish blooms are increasing very rapidly. With what has been said in the article of human impact are some of the causes of the blooms is because people impact a whole lot of the world around us and knowing that people are making the problem quiet bigger, kind of relates to how people just make things worst than what they are trying to commend. So, I would agree with above and would like to see less of a human interaction on the marine environments, just so there would be enough of a balance to have a balance marine ecosystem in the oceans worldwide.
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The cause of the blooms is due to the lack of respect people have for the ocean, over fishing, and littering in the ocean. I do agree with the authors, humans have a major role when it comes to the ocean. Over fishing dumping unwanted trash and killing endangered species. Something we can do to control the species is educate and remind divers, fisherman and people near the beaches to make sure they clean up after themselves and only take what they need from the ocean.
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In my opinion, the human race is responsible for the proliferation of the Nomura’s Jellyfish. We not only contribute to the nutrient imbalance currently plaguing certain areas of the ocean, but climate change can also be traced back to our own actions. Unfortunately, the damage already done to the Earth cannot be erased, so we must think of other ways to combat the mentioned issues of jellyfish blooms and lethal algal blooms. First off, we need to find ways to properly dispose of fertilizers in our agricultural farms and improve on management of fertilizer runoff. Secondly, if we can find a beneficial way to combat the jellyfish problem such as the aforementioned consumption and utilization of the species, numbers would decrease drastically. This would create a sustainable supply of products for us humans, while simultaneously keeping Nomura’s Jellyfish populations under control.
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