Sea of Snot

 

Jellyfish swarms (like this one on Palau) are on the increase. Credit: Michael Dawson, UC, Merced

“Look around and see all the jellyfish,” the noted marine biologist Jimi Hendrix once declared. “You sayin’ flotation is groovy, baby.”

But it’s turning out to be too groovy and too floaty by at least half.

Massive jellyfish swarms are becoming a worldwide problem, according to a new study from The National Science Foundation with the strangely Snoop Dog title, Jellyfish Gone Wild: Environmental Change and Jellyfish Swarms.  Human activities are probably a factor, and it may be a bigger problem than occasionally getting stung at the beach.

Here’s what I write in my upcoming book Swimming With Piranhas at Feeding Time–My Life Doing Dumb Things with Animals (W.W. Norton, May 2009):

Jellyfish misbehavior may be at least partly our fault. No one knows for sure, but jellyfish blooms may occur in part because we overload a body of water with fertilizers and sewage. This leads to an increase in the planktonic plants and animals on which jellyfish feed and creates a low-oxygen environment in which fish die but jellies thrive. Jellies may also benefit when we knock out their major rivals through overfishing.
             But even now scientists have only the most rudimentary understanding of the relationship between jellies and other marine species, and our ignorance may have unfathomable consequences. In the Gulf of Maine, for example, copepods are the primary food for larval cod and other fish. But the cod have gone bust, and Marsh Youngbluth of Harbor Branch Oceanographic Institution in Florida worries that gelatinous creatures may be elbowing ahead of them at the copepod smorgasbord. “People think, ‘We’ll just stop fishing and the cod will come back,’” says Youngbluth. “Well, it doesn’t always work that way.” It can be a matter of who fills a niche first or more effectively.  Cod eat only what they can see. But jellyfish are nonvisual predators. They simply wait, everywhere, with dangling toxic tentacles like “a curtain of death” for the copepods. In the 1980s the Black Sea fishery was suffering from pollution and overfishing. Then some ship flushed its ballast water and accidentally introduced the comb jelly Mnemiopsis, which blossomed in its new home. The human catch of anchovies subsequently plunged from 600,000 down to 14,000 metric tons a year, and it has yet to recover.

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And here are some fascinatin’ facts from NSF:

Moon jelly loaded with prey. (Photo courtesy of NOAA)

 

 

 

 

 

 

Enviromental Change and Jellyfish Blooms

1. 1/3 of the total weight of all life in Monterey Bay is from gelatinous animals.

2. 3 minutes after a person is stung by a deadly box jellyfish, s/he may be dead.

3. 8 years after fast-reproducing comb jellies invaded in the Black Sea, they dominated it.

4. 20 to 40 people are killed annually from box jellyfish stings in the Philippines alone.

5. 100 foot-long tentacles may dangle from the Lion’s Mane Jelly.

6. 400 vast Dead Zones in world oceans are too polluted for almost all life except jellyfish.

7. 1,000+ fist-sized comb jellies filled each cubic meter of water in Black Sea jelly blooms.

8. 45,000 eggs may be released daily by a single jellyfish.

9. 500,000 people are stung by jellyfish in the Chesapeake Bay annually.

10. 500 million refrigerator-sized jellyfish float into the Sea of Japan daily during blooms.