NYT - Scientists Seeking Benchmark For Carbon-Stressed Ocean Look To Permian Extinction

[hatrack]

EDIT

Now, painstaking analyses of fossils from the period point to a different way to think about the problem. And at the same time, they are providing startling new clues to the behavior of modern marine life and its future. In two recent papers, scientists from Stanford and the University of California, Santa Cruz, adopted a cellular approach to what they called the “killing mechanism”: not what might have happened to the entire planet, but what happened within the cells of the animals to finish them off. Their study of nearly 50,000 marine invertebrate fossils in 8,900 collections from the Permian period has allowed them to peer into the inner workings of the ancient creatures, giving them the ability to describe precisely how some died while others lived.

“Before, scientists were all over the map,” said one of the authors, Matthew E. Clapham, an earth scientist at Santa Cruz. “We thought maybe lots of things were going on.”

Dr. Clapham and his co-author, Jonathan L. Payne, a Stanford geochemist, concluded that animals with skeletons or shells made of calcium carbonate, or limestone, were more likely to die than those with skeletons of other substances. And animals that had few ways of protecting their internal chemistry were more apt to disappear.

Being widely dispersed across the planet was little protection against extinction, and neither was being numerous. The deaths happened throughout the ocean. Nor was there any correlation between extinction and how a creature moved or what it ate. Instead, the authors concluded, the animals died from a lack of dissolved oxygen in the water, an excess of carbon dioxide, a reduced ability to make shells from calcium carbonate, altered ocean acidity and higher water temperatures. They also concluded that all these stresses happened rapidly and that each one amplified the effects of the others.

EDIT

http://www.nytimes.com/2012/05/01/science/new-studies-of-permian-extinction-shed-light-on-the-great-dying.html?_r=1

[longship]

1. The largest extinction in the history of the planet

Remarkably, it hit hardest for sea lifeforms. This made the K/T extinction (the one that wiped out the dinosaurs) look like a minor ripple.

Interesting article.

[Nihil]

2. I think we're covering all the bases ...

> the animals died from a lack of dissolved oxygen in the water,

Check (ref. spreading dead zones)

> an excess of carbon dioxide,

Check (ref. Mauna Loa et al)

> a reduced ability to make shells from calcium carbonate,

Check (ref. reports on spreading shell weakness)

> altered ocean acidity

Check (ref. above reports on spreading shell weakness)

> and higher water temperatures.

Check (ref. about half of the interesting items in E&E these days)


> They also concluded that all these stresses happened rapidly and that
> each one amplified the effects of the others.

"Faster than expected"?

Check (OK XemaSab?)


Oh joy ...

[GliderGuider]

3. What you said.

nt