Massive swarms of jellyfish are a growing threat to swimmers, the fishing industry, and even the nuclear power industry, a new report argues, and it’s high time for scientists to begin researching the causes of the population boom and how to reverse the trend. The new report from the National Science Foundation may tend towards sensationalism (the report is titled “Jellyfish Gone Wild!!“), but the problem is very real. The report says more than 1,000 fist-sized comb jellies can be found in a cubic yard (meter) of Black Sea water during a bloom. They eat the eggs of fish and compete with them for food, wiping out the livelihoods of fishermen, according to the report [Reuters]. A big swarm of jellies can also burst a fishing net or poison and crush a load of captured fish, the report says, and their bodies can clog boat engines.
“When jellyfish populations run wild,” the NSF jellyboffins warn, “they may jam thousands of square miles with their pulsing, gelatinous bodies.” It seems that no less than half a billion “refrigerator sized” slimy horrors weighing 450 pounds each invade the Sea of Japan daily, while Australian waters are plagued with “deadly, peanut-sized” Jellybabies of Death [The Register]. Popular tourist beaches from Spain to Alabama have been closed in recent years when swarms of stinging jellies threatened to harm bathers. As for their impact on nuclear power: The report claims that swarms of jellies sometimes clog the water intake pipes of power plants, and notes that in 1999 just such an incident forced a power plant in the Philippines to shut down, which “plunged 40 million people into darkness and started rumors of a coup d’etat.”
Jellyfish (which are not really fish, as they’re invertebrates) have been called the cockroaches of the sea for their ability to thrive under all sorts of conditions, and the report says their numbers are now booming because they’re able to adapt to a variety of man-made environmental changes. They’re … definitely linked to ocean pollution. There are now oxygen-starved dead zones in the oceans so polluted that jellyfish are the only creatures able to survive. Also, their major natural enemy are sea turtles but all seven sea-turtle species are now indecline and threatened. And warming seas make it easier for the various soft-bodied critters to spread and thrive [ZDNet].
The report comes at the same time as the European Union is reviewing the fish quotas set for commercial fishing operations, a process that has been heavily criticized by scientists and environmentalists who say that high quotas are putting many fish species at risk of extinction. Scientists have said that unless the system is completely overhauled fish stocks will continue to deplete to the point of extinction by 2048, leaving consumers little option but to eat jellyfish or the small bony species left behind at the bottom of the ocean…. “If we do not change our ways we will have less and less to catch… so jelly fish could end up on the menu as opposed to cod in our fish and chips” [Telegraph], said marine conservationist Callum Roberts.
Related Content:
DISCOVER: Do Jellyfish Rule the World? accompanied by a photo gallery
DISCOVER: Return of the Blob, on trying to drum up an appetite for jellyfish
Image: Michael Dawson, University of California, Merced




December 16th, 2008 at 9:17 am
Of course, this has nothing to do with global climate change, and the actions of mankind? Right? :P
December 16th, 2008 at 12:44 pm
Maybe it’s the over fishing that us humans are doing. So now the Jelly fish don’t have
any natural predators…
December 16th, 2008 at 2:26 pm
…or competitors because they are also eliminated by overfishing.
December 16th, 2008 at 10:59 pm
We could trawl for jellyfish. They are considered a delicacy in a number of Asian countries (e.g., Japan and China) when properly prepared. They are basically stripped of their tentacles and dessicated. They are said to have a good “crunchy” flavor. We should encourage a market for them worldwide. They could be prepared so as not to resemble jellyfish, just flat round pancake like seafood that can be deep fried or prepared in other ways. To improve marketing, we could even bestow a euphemistic name on them, such as
“seacakes”, etc. Jellyfish are high in minerals and good for you nutritionally, too.
We should try and remove as many of them as possible, since their natural predators are almost gone, conditions are good for their growth, and they are devouring a large portion of the young of remaining fish and other marine species. In essence we need to become their new predators in order to save the oceans.
December 17th, 2008 at 3:17 pm
Nuke ‘em.
December 17th, 2008 at 7:59 pm
and they frie up well with sweet chilly and butter or oil ,sliced crummed in a hot pan,, :)
December 17th, 2008 at 8:20 pm
I knew it all along – that the problem was not overfishing, it’s the
Jellyfish – very bad Jellyfish …
January 6th, 2009 at 12:31 pm
mmmmm, Jellyfish sushi!
Write a letter to your favorite restaurant and maybe we’ll start seeing it on the menu!
January 22nd, 2009 at 1:34 pm
mmm….peanut butter and jellyfish sandwich
February 3rd, 2009 at 1:25 am
Before we decide to start yet another bioenineering project that eventually causes more harm than good maybe we should be asking ourselves why jellyfish are “taking over”. You know after a forest fire all the normal species of plant and animal life do not just magically re-appear. First certain specific species begin to “take over” like fireweed. But these genesis species help to pave the way for the reintroduction of the others by bringing the ground PH etc back to normal. Maybe jellyfish are trying to bring things back to normal. Now is it in response to Climate Change or PCBs or overfishing, who knows. But a kneejerk “Lets kill ‘em all!” attitude could be exactly what we shoudn’t do. In other words, can we please Think before we act?
February 3rd, 2009 at 2:00 am
Make them into shoes that our teenage daughters will beg us for.
February 3rd, 2009 at 2:30 am
Can they be turned into liquid fuel? That would be pretty sweet.
February 3rd, 2009 at 3:40 am
We had some blooms here in Durban years ago, but since the Turtle populations have started to recover its been great! DOWN WITH TURTLE FISHING, CITES must ban all Turtle catches.
Cheero and thanks for the amazingly appropriate article
February 3rd, 2009 at 7:43 am
All of the cute little balloons blown out to sea, discarded plastic bags, and plastic handles for six packs all wind up in the ocean. They look like jellyfish to turtles, the natural predators of jellyfish.
We are stupidly eating turtle eggs, (seems cheaper than Viagra) and our plastic litter is killing the turtles so that jellyfish are taking over. “Let them eat jellyfish,” say our overlords. And the fetid, cancerous, polluted world we leave to posterrity? Gouge out your eyes so you won’t see the disaster we created.
February 3rd, 2009 at 7:52 am
Tell Spongebob.
February 4th, 2009 at 1:18 pm
It’s very simple the increased food for jellyfish from fertilizer runoff into the oceans example – Austrailia runoff that increases the Giant jellies and starfish that destroy the Coral reefs and the decline of the Seaturtles from the poaching of their eggs,nets,plastic ingestion,trawling,pollution,ECT…How to fight this?Ck out http://www.catchconservationfund.com and the other sites w/it.
December 4th, 2009 at 11:53 am
the jellyfish are adorable!!!! let em live!
December 4th, 2009 at 11:53 am
the jellyfish are adorable!!!! let em live!