Tiny microbes belching toxic gas helped cause—and prolong—the biggest mass extinction in Earth's history, a new study suggests.
Generally, scientists believe Siberian volcanos spitting greenhouse gases primarily drove the mass extinction event about 250 million years ago, at the end of the Permian period. The gases caused extreme warming, which in turn led 80% of all marine species, as well as many land species, to go extinct.
Until now, scientists could not explain exactly how the heat caused those deaths. A new UC Riverside-led study in Nature Geoscience shows that the heat accelerated microbes' metabolisms, creating deadly conditions.
"After oxygen in the ocean was used up to decompose organic material, microbes started to 'breathe' sulfate and produced hydrogen sulfide, a gas that smells like rotten eggs and is poisonous to animals," said UC Riverside Earth system modeler Dominik Hülse.
As ocean photosynthesizers—the microbes and plants that form the base of the food chain—rotted, other microbes quickly consumed the oxygen and left little of it for larger organisms. In the absence of oxygen, microbes consumed sulfate then expelled toxic, reeking hydrogen sulfide, or H2S, creating an even more extreme condition called euxinia. These conditions were sustained by the release of nutrients during decomposition, promoting the production of more organic material which helped to maintain this stinky, toxic cycle.
"Our research shows the entire ocean wasn't euxinic[*]. These conditions began in the deeper parts of the water column," Hülse said. "As temperatures increased, the euxinic zones got larger, more toxic, and moved up the water column into the shelf environment where most marine animals lived, poisoning them."
[*] Euxinic on Wikipedia.
Journal Reference:
Dominik Hülse, Kimberly V. Lau, Sebastiaan J. van de Velde, et al. End-Permian marine extinction due to temperature-driven nutrient recycling and euxinia, Nature Geoscience (DOI: 10.1038/s41561-021-00829-7)
(Score: 0) by Anonymous Coward on Wednesday December 22 2021, @10:36AM (3 children)
https://en.wikipedia.org/wiki/Dead_zone_(ecology) [wikipedia.org] -- looks like we are creating the right conditions, again. The question is how long until we start to get microbes that belch HS into the air?
(Score: 0) by Anonymous Coward on Wednesday December 22 2021, @11:22AM
>> The question is how long until we start to get microbes that belch HS into the air?
Stop worrying, an asteroid will wipe out life before then.
(Score: 2) by driverless on Wednesday December 22 2021, @12:13PM (1 child)
Silent but deadly.
(Score: 3, Informative) by Sourcery42 on Wednesday December 22 2021, @05:35PM
H2S is some insidious stuff. It has that gross, rotten eggs smell, but exposure to it rapidly deadens the sense of smell. People think they've moved out of it when in reality they can be standing in a cloud of it or moving into higher concentrations and they just can't detect it anymore.
(Score: 0) by Anonymous Coward on Wednesday December 22 2021, @11:44AM (5 children)
What about the asteroid?
Last week, it was an asteroid...
(Score: 1, Funny) by Anonymous Coward on Wednesday December 22 2021, @12:04PM (1 child)
i did not notice all life going extinct, always missing the next thing.
(Score: 2) by DannyB on Wednesday December 22 2021, @03:12PM
Zombies did not actually go entirely extinct. A few hid and went dormant. Waiting.
The server will be down for replacement of vacuum tubes, belts, worn parts and lubrication of gears and bearings.
(Score: 3, Informative) by maxwell demon on Wednesday December 22 2021, @12:41PM (1 child)
No, the asteroid that killed the dinosaurs was 65 million years ago. The mass extinction this article is talking about was 250 million years ago. Those are two different events.
The Tao of math: The numbers you can count are not the real numbers.
(Score: 0) by Anonymous Coward on Wednesday December 22 2021, @01:44PM
(Score: 1, Interesting) by Anonymous Coward on Wednesday December 22 2021, @02:16PM
An asteroid smells like a Nascar race—a bouquet of hot metal, diesel fumes and barbecue.
https://www.popsci.com/science/article/2011-01/fyi-what-does-space-smell/ [popsci.com]