Warming Oceans Contain Less Oxygen For Fish - Dead Zone Numbers May Rise Sharply - Scripps Scientist

[hatrack]

VICTORIA -- As the temperature of the world's oceans increases due to global warming, there may be more and more areas where oxygen in the water is either limited or absent, and that could have a deadly effect on huge numbers of marine species, a U.S. biological oceanographer warned a conference on the future of the world's oceans Thursday.

Lisa Levin, who works out of the Integrative Oceanography Division at the Scripps Institution of Oceanography in La Jolla, Calif., told an audience at the University of Victoria that most so-called "dead zones" are caused by excessive levels of nitrogen being dumped into the oceans. Nitrogen is a component of most commercial fertilizers, and rivers carry the residue of these fertilizers from farms to the ocean, she said.

When this happens, she explained, the number of nitrogen-consuming phytoplankton rises. This, in turn, prompts a concomitant rise in the number of microbes that feed on the phytoplankton -- microbes that collectively consume great quantities of oxygen. As a consequence, the number of man-made dead zones -- areas of the ocean where oxygen is either depleted or gone -- has grown to more than 150 in the last 50 years, some of them several thousand square kilometres in size.

But now, because of global warming, Levin said, it's possible that the number of such zones, where fish that need oxygen can't thrive, could rise even higher. "People are only beginning to study these second-order effects of global warming," she said. "But it's certainly an area that's worth watching."

EDIT

http://www.canada.com/vancouversun/news/story.html?id=3b46d225-f640-4ce5-af2a-f52a4e8d2b40

[phantom power]

1. no, wait, let me guess: faster than expected?

[Benhurst]

2. More, but hardly unexpected, bad news. Recommended. NT

[redqueen]

3. "People are only beginning to study these second-order effects of global warming"

Just wait for the third-, fourth-, and fifth-order effects...

[GliderGuider]

4. That conference in Vctoria sounds like it's a laff riot.

Scientist after scientist coming to the podium with a grim expression and a fist full of black-bordered Powerpoint slides.

"Hey, Dr. Finagle, Dr. Murphy - how bad are you guys going to say things are?"
"Well, Dr. Sod, I have irrefutable calculations that show the human race will be toast by Wednesday, July 17, 2079."
"Hell, that's nothing! I've got figures here that say the whole oceanic ecosystem is going to collapse by the middle of 2061."
"Ha, I've go you both beat! According to my numbers, the entire planetary ecosphere is going to dissolve into a thin layer of grey goo at 3:48 p.m. Saturday October 18, 2033!"
"Cool, you win. I'll buy lunch."

[NNadir]

5. Well, at least they're not talking about people who could be killed by

"dangerous nuclear waste."

We need to count our blessings.