Oxygen-depleted toxic oceans had key role in mass extinction over 200 million years ago

April 1, 2015, University of Southampton
Life of the Triassic met a choking end in a runaway greenhouse climate, heating the seas into warm stagnation. The greenhouse was caused by CO2 released by massive outpourings of basalt from fissure eruptions associated with the opening of the Atlantic Ocean. The resulting boom in marine microbes consumed oxygen and released poisonous hydrogen sulfide into water and air, creating "dead zones" above and below, worldwide. Hydrogen sulfide posioning is detected by molecular fossils (biomarkers), depicted in lenses. Credit: Victor Leshyk

Changes in the biochemical balance of the ocean were a crucial factor in the end-Triassic mass extinction, during which half of all plant, animal and marine life on Earth perished, according to new research involving the University of Southampton.

The study, published in the upcoming edition of Geology, reveals that a condition called 'marine photic zone euxinia' took place in the Panathalassic Ocean- the larger of the two oceans surrounding the supercontinent of Pangaea.

Photic zone euxinia occurs when the sun-lit surface waters of the ocean become devoid of oxygen and are poisoned by hydrogen sulphide - a by-product of microorganisms that live without oxygen that is extremely toxic to most other lifeforms.

The international team of researchers studied fossilised organic molecules extracted from sedimentary rocks that originally accumulated on the bottom of the north-eastern Panthalassic Ocean, but are now exposed on the Queen Charlotte Islands, off the coast of British Columbia, Canada.

The team found molecules derived from photosynthesising brown-pigmented green sulphur bacteria - microorganisms that only exist under severely anoxic conditions - proving severe oxygen depletion and poisoning of the upper ocean at the end of Triassic, 201 million years ago.

The researchers also documented marked changes in the nitrogen composition of organic matter, indicating that disruptions in marine nutrient cycles coincided with the development of .

Previous studies have reported evidence of photic zone euxinia from terrestrial and shallow, near-shore environments during the latest Triassic, but the new research is the first to provide such evidence from an open ocean setting, indicating these changes may have occurred on a global scale.

The University of Southampton's Professor Jessica Whiteside, who co-authored the study, explains: "As tectonic plates shifted to break up Pangaea, huge volcanic rifts would have spewed carbon dioxide into the atmosphere, leading to rising temperatures from the greenhouse effect. The rapid rises in CO2 would have triggered changes in circulation, acidification and deoxygenation."

"These changes have the potential to disrupt and alter food chains essential for the survival of marine ecosystems. Our data now provides direct evidence that anoxic, and ultimately euxinic, conditions severely affected food chains."

"The same CO2 rise that led to the oxygen depleted oceans also led to a mass extinction on land, and ultimately to the ecological take-over by dinosaurs, although the mechanisms are still under study."

Although the Earth was very different during the Triassic Period compared to today, the rate of carbon dioxide release from volcanic rifts are similar to those that we are experiencing now through the burning of fossil fuels.

Professor Whiteside comments: "The release of CO2 was probably at least as rapid as that caused by the burning of fossil fuels today, although the initial concentrations were much higher in the Triassic. The consequences of rapidly rising CO2 in ancient times inform us of the possible consequences of our own crisis."

Explore further: Carbon release from ocean helped end the Ice Age

More information: "Episodic photic zone euxinia in the northeastern Panthalassic Ocean during the end-Triassic extinction." Geology April 2015 DOI: 10.1130/G36371.1

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gkam
2.1 / 5 (11) Apr 01, 2015
Are there any Deniers left?
gkam
1.8 / 5 (10) Apr 01, 2015
Time to buy shares of the Soylent Corp.
TheGhostofOtto1923
2.8 / 5 (12) Apr 01, 2015
Time to buy shares of the Soylent Corp.
George I notice you are already posting this morning at a rate of about 5 min per post. And how many posts was it yesterday? 50? 60? And how many of these are of the manic ADD-generated empty single line variety?

How you post can be a lot more indicative of the state of your mental health than what you post. But even reading their content gives us some idea of the sorry state you must be in.
http://www.helpgu...rder.htm
gkam
2.5 / 5 (11) Apr 01, 2015
Unable to debate the issues, this kid otto has to make personal attacks. With no experience or education, it is all he has.

What do you think of Oxygen-depleted oceans? Do you know what anaerobic process smell like?
gkam
2.1 / 5 (10) Apr 01, 2015
"How you post can be a lot more indicative of the state of your mental health than what you post"
----------------------------------------------

Really, Doctor otto? What if I scream filthy words and '"LIAR" in all caps?

Is that what you mean as poor mental health?
antigoracle
3.3 / 5 (9) Apr 01, 2015
Time to buy shares of the Soylent Corp.

Someone really filled up their bowl of stupid this morning.
RWT
2 / 5 (8) Apr 01, 2015
It was a good article, until the cultist invoked intervention from their CO2 diety. CO2 has little to do with global ocean circulation or even overall ocean chemistry for that matter. There seems to be a major disconnect between carbonate sedimentologists (or any real scientist studying marine sciences) and anyone involved in climastrology. They need to learn basic oceanography and geochemistry. I look at the data and see evidence of catastrophic overturning of the ocean probably caused by an extraterrestrial impact of major tectonic event, but the climastrologists see everything through CO2 colored lenses. These changes supposedly caused by CO2 are not supported by science whatsoever.

http://www.biogeo...2010.pdf
gkam
2.6 / 5 (12) Apr 01, 2015
RWT, I read your article. It discusses the effect of CO2 on forms of carbonates and such, mostly regarding Mg/Ca ratios in the seas. But the atmosphere is not the only factor to consider, and nobody is saying CO2 causes everything.
wade_jeffords
3 / 5 (2) Apr 01, 2015
Things have definitely gotten better since then.
crownvic5l
1.9 / 5 (9) Apr 01, 2015
What?? It wasn't mans fault? Imagine that? So so global warming IS a natural occurrence WOW! I thought for sure they would find some way to blame us I mean we are at fault now right? Hey maybe NOT!
RWT
1.5 / 5 (11) Apr 01, 2015
gkam, It's the last 5 paragraphs of the article that I really take exception with where Whiteside invokes intervention from the CO2 diety and implied it was all about CO2. This Dr. Whiteside has a B.A and M.A, no surprise she doesn't even have a true science degree. pCO2 has had little influence on the paleochemistry of the world's oceans and the real control is ion exchange within flood basalts at mid ocean ridges. It can be argued that the modern times are different, but this research focused entirely on the End Triassic extinction.
nevermark
5 / 5 (9) Apr 01, 2015
RTW, many great researchers published good papers as undergrads. Your self-serving lack of personal respect for someone you don't know is irrelevant to the content of the paper.

Denigrating scientists with phrases like "Cultist" and "CO2 diety" is another obvious attempt to use personal disrespect as some kind of non-point.

The end of the Triassic was marked by huge amounts of volcanic activity that increased C02 to the point that warmer temperatures and higher ocean acidification killed off a substantial number of species. Ocean chemistry is driven by numerous inputs, C02 is undeniably one of them.

Why are you posting three completely unrelated and unsupported arguments against this article? What is your target audience? What is the point you really want to make?
gkam
2.7 / 5 (7) Apr 01, 2015
RWT, I am unable to debate that point.

I thank those who are.

Thanks.
barakn
4.6 / 5 (11) Apr 01, 2015
gkam, It's the last 5 paragraphs of the article that I really take exception with where Whiteside invokes intervention from the CO2 diety and implied it was all about CO2. This Dr. Whiteside has a B.A and M.A, no surprise she doesn't even have a true science degree. -RWT
It's ok to lie about people you disagree with? Whiteside earned a PhD (with distinction) in Earth & Environmental Sciences in 2006 at Columbia University.
Bongstar420
1 / 5 (4) Apr 01, 2015
They must have been Ocean volcanoes...Land volcanoes cause ice ages ;)

http://www.livesc...ons.html

crownvic
What?? It wasn't mans fault? Imagine that? So so global warming IS a natural occurrence WOW! I thought for sure they would find some way to blame us I mean we are at fault now right? Hey maybe NOT!


Crownvic - if you are challenging the understanding that the current warming trend we are experiencing is caused by human insertion of C02 into the atmosphere - would you please give us your explanation of the driver/s of the current warming?

Vietvet
4.2 / 5 (5) Apr 01, 2015
@Putdown the bong

They must have been Ocean volcanoes...Land volcanoes cause ice ages ;)

http://www.livesc...uptions.

I suggest finding a remedial reading class in your area.
Vietvet
4.4 / 5 (7) Apr 02, 2015
@Putdown the bong

They must have been Ocean volcanoes...Land volcanoes cause ice ages ;)

http://www.livesc...uptions.

You totally misunderstood your link. It didn't claim "land" volcanoes caused ice ages. It did point to ice ages influencing volcanic activity.
JoeBlue
2 / 5 (4) Apr 02, 2015
So let me get this right, around 200 million years ago, when there was a massive volcano output after a meteor strike in what is now France there was a mass die off...

Great, we knew this already. Glad tax dollars were spent for this report....
bobc896
not rated yet Apr 02, 2015
Perhaps there is a greater need for the newly developed CPCSMS than previously thought. See related info

On slide share.net /RobertMCoe/cpcsms3-46112583
viko_mx
1 / 5 (6) Apr 02, 2015
I wonder to the conviction of those brave explorers who discover what it was before hundreds of millions of years back in time when they do not know from what date are started isotopic clocks suing for these events and how during this hypothetical period physical and chemical processes are influenced these clocks. Such stories are pure science fiction invented by a bored journalists or volunteers on fee. Where are serious scientific standards in modern science?
jsdarkdestruction
5 / 5 (7) Apr 03, 2015
Viko. What are serious scientific standards to you? What evidence would be sufficient for you to change your mind about evolution and the dating of ages? Why do you think what you do? What evidence other than the bible do you have that dating is flawed?
Mike_Massen
2.3 / 5 (3) Apr 11, 2015
viko_mx claimed
Such stories are pure science fiction invented by a bored journalists or volunteers on fee. Where are serious scientific standards in modern science?
Why don't u give us an example please ?

While at it, please let us know how your Moses was schooled to be able to recognise the difference between a real god and a devil who was a cheat ?

ie. HOW was Moses trained & by who, so he could recognise guile ?

Answer please viko_mx ?

Add to that example of real "serious Science" please ?

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