Subscribe to our free daily newsletters
. Earth Science News .




Subscribe to our free daily newsletters



WATER WORLD
Ancient ocean deoxygenation provides an urgent warning
by Staff Writers
Tallahassee FL (SPX) Aug 17, 2017


Jeremy Owens is an assistant professor of geology in the Department of Earth, Ocean and Atmospheric Sciences. Image courtesy Stephen Bilenky.

A 94-million-year-old climate change event that severely imperiled marine organisms may provide some unnerving insights into long-term trends in our modern oceans, according to a Florida State University researcher.

In a study published in the journal Science Advances, Assistant Professor of Geology Jeremy Owens traces a 50,000-year period of ocean deoxygenation preceding an ancient climate event that dramatically disturbed global ocean chemistry and led to the extinction of many marine organisms. He also draws parallels to similar rates of oxygen depletion observed in our contemporary oceans.

"We found that before this major shift in the climate, there was a stretch of oxygen depletion of about 50,000 years," Owens said. "The rate of deoxygenation during that time is somewhat equivalent to the rate at which many scientists suggest we're losing oxygen from our oceans today."

Alongside scientists from Arizona State University and the Woods Hole Oceanographic Institution, Owens used a newly devised Thallium isotope analysis to examine organic-rich sediment from the Demerara Rise, an underwater plateau off the coasts of Suriname and French Guyana.

In these samples, Owens and his collaborators discovered evidence of rapid oxygen loss tens of thousands of years prior to the globally recognized climate event.

The best indicator for a significant climate disturbance like the one Owens and his colleagues investigated is the burial of large amounts of organic carbon. Owens said that the 50,000-year interval of deoxygenation preceding the climate event may help explain the relationship between buried organic carbon and major climatic shifts.

"The easiest way to bury organic carbon is for there to be a lack of oxygen because decreased oxygen slows down microbial respiration, and thus more primary producers sink down to the seafloor," Owens said. "This oxygen depletion prior to the event makes a lot of sense as it sets the stage for widespread organic carbon burial - carbon that we now use for some of our fossil fuels."

In the study, Owens found that the onset of the deoxygenation period corresponded with a marked rise in volcanic activity. As volcanism increased, carbon dioxide was pumped into a warming atmosphere and the oceans were suffused with an excess of nutrients, leading to a process of dense aquatic plant growth and rapid oxygen depletion called eutrophication.

The cascade of events that seems to have precipitated the 50,000-year deoxygenation period - carbon dioxide emissions, a warming atmosphere and eutrophication - is a familiar one to those studying modern fossil fuel combustion and climate change.

"The volcanism linked to deoxygenation in the past represents the same kind of process as we see today - we're just dealing with different sources," Owens said. "If the climate event in our study is analogous to modern events, we have to consider what that might mean for our oceans."

While it's unknown exactly how quickly the world's oceans are deoxygenating, scientists estimate that they lose a small percentage every decade. On the scale of a human lifetime, this pace seems negligible. But on a geologic scale, this is happening quickly and could have major effects on the global ecosystem.

"It's not a problem way off in the distance, and it's not just carbon dioxide we should be worried about," Owens said. "These processes are also having an impact on oxygen levels, and that's a major issue for many organisms."

WATER WORLD
Marine noise pollution stresses fish out
Washington (UPI) Aug 11, 2017
New research suggests fish are becoming stressed and confused as a result of growing underwater noise pollution. Scientists at Newcastle University measured the stress levels of European sea bass while replicating the types of piling and drilling sounds heard during underwater construction projects. They found the fish were made anxious and uncomfortable by the noise pollution. W ... read more

Related Links
Florida State University
Water News - Science, Technology and Politics


Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.

SpaceDaily Contributor
$5 Billed Once


credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly


paypal only

Comment using your Disqus, Facebook, Google or Twitter login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

WATER WORLD
Urban flooding on the rise, as countryside dries up

Hunter fells elephant that killed 15 in India

Shoot-to-kill: India hunts serial killer elephant

Libya navy bars foreign ships from migrant 'search and rescue' zone

WATER WORLD
Researchers 3-D print first truly microfluidic 'lab on a chip' devices

2-faced 2-D material is a first at Rice

Fewer defects from a 2-D approach

Tiny terahertz laser could be used for imaging, chemical detection

WATER WORLD
New technique offers clues to measure the deoxygenation of the ocean

Guam leader backs 'punch in the nose' for Pyongyang

Chinese fishers held in Ecuador over endangered sharks

Guam residents pray for peace as North Korea deadline looms

WATER WORLD
Not all glaciers in Antarctica have been affected by climate change

Extreme melt season leads to decade-long ecosystem changes in Antarctic polar desert

Researchers crack the 'Karakoram anomaly'

Alaska's North Slope snow-free season is lengthening

WATER WORLD
Oceans possess vast, untapped potential for sustainable aquaculture

Efforts to reduce pollution from agriculture paying off slowly

'Inefficient' sailing fleet keeps oyster fishery alive

Can offshore fish farming feed a hungry world?

WATER WORLD
Floods kill hundreds across India, Nepal, Bangladesh, Iran and Africa

Hurricane Gert churns up dangerous swells on US east coast

China combs through quake region for victims

Tourism a major casualty of China quake

WATER WORLD
Dalai Lama cancels Botswana trip with 'exhaustion'

UN says Nigeria relations 'intact' after unauthorised raid

Nigerian forces in 'unauthorised search' of UN camp

Kenyan opposition demands Odinga be 'declared president'

WATER WORLD
New 13-million-year-old infant skull sheds light on ape ancestry

Arrival of modern humans in Southeast Asia questioned

Ancient infant skull yields insights into human-ape lineage

New look at archaic DNA rewrites human evolution story




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News






The content herein, unless otherwise known to be public domain, are Copyright 1995-2017 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement