Bloomin' jellyfish! Overfishing, climate change and ocean dead zones may be downers for humans and other critters, but they turn out to be a boon for jellyfish schools, reports the recent "Jellyfish Joyride" paper in Trends in Ecology and Evolution.

A surge in jellyfish populations may eventually lead to what study authors call "a less desirable gelatinous state," which could have "lasting ecological, economic and social consequences."

Swimming safely in aquariums, jellyfish might look like rare, delicate creatures, but many species are quite hardy—not to mention, harmful. Aside from bothering beachgoers, they've been known to wreck fishing nets and actually kill swimmers. The heftier jellies, such as the Nomura (Nemopilema nomurai) can reach diameters of 6.5 feet (2 meters) and weigh as much as 440 pounds (200 kilograms).

About 470,000 tons (425,000 metric tons) of jellyfish are already harvested for fine dining in Southeast Asia every year. Are we looking at a future of jellyfish burgers and popcorn polyps?

Not all scientists are convinced that a gelatinous takeover is on the horizon. "There is some debate about this issue," says Jack Costello, a professor of biology at Providence College, who wasn't involved in the study. Some species of jellyfish aren't tolerant to new and changing ocean conditions and actually seem to be in decline, he notes.

But there's one thing jellyologists agree on: we still have a lot to learn about these mysterious creatures. 

Have a look. Slide show: Bloomin' Jellyfish!

7 Comments

1. 1. hotblack 02:30 PM 6/16/09

   "but many species are quite hardynot to mention, harmful. Aside from bothering beachgoers, they've been known to wreck fishing nets and actually kill swimmers."
   
   Harmful for whom, is the key. What's harmful for us may not be harmful for the greater ocean. I'd be interesting to see the long-term effects of the process at work here. Perhaps this signifies a (even slight) "taking back" of the ocean, the jellyfish being the bulldozers, to clear and ultimately give way to other life forms...
   
   The nature of life is battle, & no species rules forever.

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2. 2. This User 08:34 PM 6/16/09

   I recently watched a program on National Geographic regarding this subject. The problem is the jelly fish are killing off all areas where groups of fish once populated, thus causing some small countries to not have the ability to harvest their main staple of food. In turn, the farmers are killing off the jelly fish. When that happens, the jelly fish release their fertility (sperm/eggs) and is getting fertilized in the water, creating more. The show of course gave a very gloomy outlook, but since that show, I've seen more and more articles regarding the issue.

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3. 3. Shoreliner11 in reply to hotblack 01:43 PM 6/17/09

   The bottom line is we just don't know. From the sheer diversity of life in the oceans, its safe to say, some species will benefit from climate change, some will not. With that said, for the majority of organisms currently studied with regards to climate change, they will not benefit from increased temp and decreased pH (ocean acidification). Jellyfish stand to potentially fill some of these empty niches because some are hardy (just as the article mentioned) and they also can withstand low pH and low dissolved oxygen which could kill (the DO part) fishes.
   
   Hotblack,
   We see this as harmful because the more diversity in a foodweb, the greater the resilience (in other words it withstands stresses better and is less prone to collapse). If you create a monoculture of the oceans, this drastically reduces the systems resilience. The jellyfish will just fill open niches and utilize resources which have become underutilized due to those previous fish and invert. species dieing out. I would also classify the loss of many species to gain a lot of one, being "harmful."

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4. 4. rwilliston 03:16 PM 6/25/09

   It would be more economical to start paying the fishermen more for each jellyfish caught than they get for the fish. Then they'd stop cutting them up and dumping them, increasing their numbers and decimating the fish population. Bring them ashore and dispose of them safely and the problem will be mitigated somewhat.

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5. 5. nimpkish 05:51 PM 10/8/09

   This past summer, our local tidal lake(Nitinat) had thousands and thousands of jellyfish in it. very unusual from what I am told. Is it the warmer waters?

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6. 6. irjsiq 12:59 AM 7/16/10

   Testing sign in name/password for comment on Jelly Fish explosion

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7. 7. irjsiq 01:13 AM 7/16/10

   Led to this site/article while seeking info 'Clean Oceans Project'
   Led to 'Bearded Gobi feasting? and/or co mingling among Jellyfish for protection from Predators . . .
   Related information '470,000 Tons harvested annually' for Fine Dining in Southeast Asia! 'Jellyfish Burgers' mentioned as a Joke? or are they being served in Fine Dining zones?
   
   Search 'Clean Oceans Project' relates to: "When life gives Lemons . . . .
   "When Oceans agglomerate 'Plastic' . . . Make 'Plasticade' and form 'New Land' by recycling the Plastic 'In Situ'!
   more written in 'gemail account': <jrjsjq@gmail.com>
   send email to that address if interested in hearing more about 'Plasticade' concept.
   Roy Stewart,
   Phoenix AZ
   <jrjsjq@gmail.com>

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