Posted on 12/01/2004 8:28:52 PM PST by neverdem
Scientists working off the west coast of Africa have identified sardines as an unexpected factor in global warming.
The fish are not acting like cattle or termites, whose gassy emissions (to put it politely) add heat-trapping methane to the atmosphere. Sardines improve the situation, the researchers say. Or they might, if they were not being fished out.
The scientists say that when sardines are plentiful they gobble up ocean phytoplankton, tiny plants that appear in vast numbers when ocean currents produce upwellings of deep water.
But when sardines are scarce, the phytoplankton survive uneaten, only to sink to the bottom, decompose and produce methane and hydrogen sulfide gas that rise to the surface in giant clouds.
Hydrogen sulfide smells like rotten eggs, can poison fish and strips oxygen from water as it moves to the surface, producing anoxic "dead zones."
That's bad enough, but methane is arguably worse, at least for world climate. Pound for pound methane traps 21 times as much heat as carbon dioxide, the most common greenhouse gas.
The researchers, Dr. Andrew Bakun from the University of Miami and Dr. Scarla J. Weeks of the University of Cape Town, devised their plankton-sardine-methane theory while working off Namibia, where once-abundant sardine populations have been devastated since the 1970's by heavy fishing. They described their findings in the current issue of the journal Ecology Letters.
Gaseous eruptions occurred in the area before the heavy fishing began, the researchers said, but they were smaller and less frequent.
They suggest that warming pressures make the nutrient upwellings more frequent and more intense, which, in the absence of sardines, means more and larger eruptions of methane, which in turn contribute to even more warming.
Though some researchers are skeptical about linking sardines to global warming, others think that Dr. Bakun and Dr. Weeks are onto something.
"This study demonstrates that overfishing of one species of fish, such as sardines, can profoundly alter an entire marine ecosystem," said Dr. Ellen Pikitch, who heads the Pew Institute for Ocean Science, which provides financial support for Dr. Bakun.
Other areas where sardines were once abundant, like waters off Northern California, may eventually see similar phenomena if sardines are not restored, Dr. Bakun said, although more research must be done to determine if that is likely.
Unfortunately, sardines are not as commercially important as some other species. "The problem with sardines," he said, "is that the federal government is not that interested in them."
King Oscar is deeply saddened.
So, sardines are going to be a protected species now? Oops, I just ate a bunch of them for supper! (Tomorrow night: Spotted Owl Kabobs...)
Save the sardines! Bash the skull in of an evil sardine eating baby seal!
We cause the number of cattle in the world to increase, and it's killing the environment!
We cause the number of fish in the world to decrease, and it's killing the environment!
We're just evil. We should all die. That would make the enviro-wackos happy.
FReepmail me if you want on or off my health and science ping list.
What about anchovies?
Bizarreeee!
On second thought, check that decision. Feed 'em to the hogs; put the hogs through the Saddam's shredders and airdrop the remains over Baghdad, Falujah, Mosul, and the rest of that rat infested country. Part two is to do the same over Mecca.
What BS!!!
Those tiny fish still have to poop.
Decomposing gas will still occur.
DUUH enviro's
Sorry Charlie
That's what I was thinking. And, what about the flatulence? Shouldn't we be calling for an international sardine flatulence tax on all sardine fishermen and consumers?
Slow news day?
Man, these people really know how to shoot themselves in the foot, as usual. Plankton, particularly the dinoflagellate Foraminifera, also provide the planet's largest carbon sink. Their skeletons are primarily calcium carbonate. They are the principal constituent of limestone.
Wasteful stewards? Nonsense!
Every time I lightly flour and snap fry a pan of fresh sardines, dusted with just a bit of paprika and drizzled with lemon juice upon reaching the table, I eat everything, including the heads.
I like sardines in tobasco. Hard to find those..
I think they've been shot in the head.
What about the remainder of their carcass? Could that generate the methane and hydrogen sulfide as they claim?
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