PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

Researchers quantify toxic ocean conditions during major extinction 93.9 million years ago

UC Riverside-led study points to an ancient oxygen-free and hydrogen sulfide-rich ocean that may foreshadow our future

2013-10-29
(Press-News.org) Contact information: Iqbal Pittalwala
iqbal@ucr.edu
951-827-6050
University of California - Riverside
Researchers quantify toxic ocean conditions during major extinction 93.9 million years ago UC Riverside-led study points to an ancient oxygen-free and hydrogen sulfide-rich ocean that may foreshadow our future RIVERSIDE, Calif. — Oxygen in the atmosphere and ocean rose dramatically about 600 million years ago, coinciding with the first proliferation of animal life. Since then, numerous short lived biotic events — typically marked by significant climatic perturbations — took place when oxygen concentrations in the ocean dipped episodically.

The most studied and extensive of these events occurred 93.9 million years ago. By looking at the chemistry of rocks deposited during that time period, specifically coupled carbon and sulfur isotope data, a research team led by University of California, Riverside biogeochemists reports that oxygen-free and hydrogen sulfide-rich waters extended across roughly five percent of the global ocean during this major climatic perturbation — far more than the modern ocean's 0.1 percent but much less than previous estimates for this event.

The research suggests that previous estimates of oxygen-free and hydrogen sulfide-rich conditions, or "euxinia," were too high. Nevertheless, the limited and localized euxinia were still sufficiently widespread to have dramatic effect on the entire ocean's chemistry and thus biological activity.

"These conditions must have impacted nutrient availability in the ocean and ultimately the spatial and temporal distribution of marine life," said team member Jeremy D. Owens, a former UC Riverside graduate student, who is now a postdoctoral scientist at the Woods Hole Oceanographic Institution. "Under low-oxygen environments, many biologically important metals and other nutrients are removed from seawater and deposited in the sediments on the seafloor, making them less available for life to flourish."

"What makes this discovery particularly noteworthy is that we mapped out a landscape of bioessential elements in the ocean that was far more perturbed than we expected, and the impacts on life were big," said Timothy W. Lyons, a professor of biogeochemistry at UCR, Owens's former advisor and the principal investigator on the research project.

Study results appear online this week in the Proceedings of the National Academy of Sciences.

Across the event 93.9 million years ago, a major biological extinction in the marine realm has already been documented. Also associated with this event are high levels of carbon dioxide in the atmosphere, which are linked to elevated ocean and atmospheric temperatures. Associated consequences include likely enhanced global rainfall and weathering of the continents, which further shifted the chemistry of the ocean.

"Our work shows that even though only a small portion of the ocean contained toxic and metal-scavenging hydrogen sulfide, it was sufficiently large so that changes to the ocean's chemistry and biology were likely profound," Owens said. "What this says is that only portions of the ocean need to contain sulfide to greatly impact biota."

For their analysis, the researchers collected seafloor mud samples, now rock, from multiple localities in England and Italy. They then performed chemical extraction on the samples to analyze the sulfur isotope compositions in order to estimate the chemistry of the global ocean.

According to the researchers, the importance of their study is elevated by the large amount of previous work on the same interval and thus the extensive availability of supporting data and samples. Yet despite all this past research, the team was able to make a fundamental discovery about the global conditions in the ancient ocean and their impacts on life.

"Today, we are facing rising carbon dioxide contents in the atmosphere through human activities, and the amount of oxygen in the ocean may drop correspondingly in the face of rising seawater temperatures," Lyons said. "Oxygen is less soluble in warmer water, and there are already suggestions of such decreases. In the face of these concerns, our findings from the warm, oxygen-poor ancient ocean may be a warning shot about yet another possible perturbation to marine ecology in the future."

INFORMATION:

A grant to Lyons from the National Science Foundation supported the study.

Owens and Lyons were joined in the study by UCR's Steven M. Bates; Benjamin C. Gill at Virginia Tech. and a former Ph.D. student with Lyons; Hugh C. Jenkyns at the University of Oxford, the United Kingdom; Silke Severmann at Rutgers University, NJ, and a former postdoctoral researcher with Lyons; Marcel M. M. Kuypers at the Max Planck Institute for Marine Biology, Germany; and Richard G. Woodfine at British Petroleum, the United Kingdom.

The University of California, Riverside (http://www.ucr.edu) is a doctoral research university, a living laboratory for groundbreaking exploration of issues critical to Inland Southern California, the state and communities around the world. Reflecting California's diverse culture, UCR's enrollment has exceeded 21,000 students. The campus will open a medical school in 2013 and has reached the heart of the Coachella Valley by way of the UCR Palm Desert Center. The campus has an annual statewide economic impact of more than $1 billion. A broadcast studio with fiber cable to the AT&T Hollywood hub is available for live or taped interviews. UCR also has ISDN for radio interviews. To learn more, call (951) UCR-NEWS.

END



ELSE PRESS RELEASES FROM THIS DATE:

Researchers detail possible resistance mechanisms of colorectal cancer to bevacizumab (Avastin)

2013-10-29
Researchers detail possible resistance mechanisms of colorectal cancer to bevacizumab (Avastin) A University of Colorado Cancer Center study published in the journal PLOS ONE shows that when colorectal cancer is targeted by the drug bevacizumab (Avastin), tumors ...

U of M researchers identify key proteins influencing major immune strategies

2013-10-29
U of M researchers identify key proteins influencing major immune strategies Findings could help define new vaccination applications MINNEAPOLIS/ST. PAUL (October 27, 2013) – New research from the Masonic Cancer Center, University of Minnesota, ...

UT Dallas study shows experts' attitudes influence what children believe

2013-10-29
UT Dallas study shows experts' attitudes influence what children believe Children are more apt to believe a nice, non-expert than a mean expert according to researchers at The University of Texas at Dallas. In the study published in Developmental Science, ...

Microbiome in gut, mouth, and skin of low birth weight infants differentiate weeks after birth

2013-10-29
Microbiome in gut, mouth, and skin of low birth weight infants differentiate weeks after birth Low birth weight infants are host to numerous microorganisms immediately after birth, and the microbiomes of their mouths and gut start out very similar but differentiate ...

GW researchers examine increased ER reimbursements after ACA insurance coverage expansions

2013-10-29
GW researchers examine increased ER reimbursements after ACA insurance coverage expansions WASHINGTON (Oct. 28, 2013) – Researchers at the George Washington University School of Medicine and Health Sciences (SMHS) found that outpatient emergency department encounters ...

HIV -- Geneticists map human resistance to AIDS

2013-10-29
HIV -- Geneticists map human resistance to AIDS Do our genes hold the key to future AIDS therapies? Using a supercomputer, scientists analyzed the genomes of thousands of strains of the HIV virus and have produced the first map of human AIDS ...

Obamacare could reverse long trend of uncompensated care in ERs

2013-10-29
Obamacare could reverse long trend of uncompensated care in ERs WASHINGTON — Emergency departments, which have suffered shortfalls in reimbursement for decades due to the high rate of uninsurance in the United States, may begin receiving "considerably ...

People seem more attractive in a group than they do apart

2013-10-29
People seem more attractive in a group than they do apart People tend to be rated as more attractive when they're part of a group than when they're alone, according to findings published in Psychological Science, a journal of the Association ...

Study finds new genetic error in some lung cancers

2013-10-28
Study finds new genetic error in some lung cancers May offer target for therapies in patients BOSTON – A fine-grained scan of DNA in lung cancer cells has revealed a gene fusion – a forced merger of two normally separate genes – that spurs the cells to ...

Timely, effective treatment of rheumatoid arthritis reduces disability 2 years out

2013-10-28
Timely, effective treatment of rheumatoid arthritis reduces disability 2 years out Discouraging patients from delaying treatment could reduce disability from RA, according to study Delaying treatment for rheumatoid arthritis could greatly increase the likelihood ...

LAST 30 PRESS RELEASES:

Brain stimulation can boost math learning in people with weaker neural connections

Inhibiting enzyme could halt cell death in Parkinson’s disease, study finds

Neurotechnology reverses biological disadvantage in maths learning

UNDER EMBARGO: Neurotechnology reverses biological disadvantage in maths learning

Scientists target ‘molecular machine’ in the war against antimicrobial resistance

Extending classical CNOP method for deep-learning atmospheric and oceanic forecasting

Aston University research: Parents should encourage structure and independence around food to support children’s healthy eating

Thunderstorms are a major driver of tree death in tropical forests

Danforth Plant Science Center adds two new faculty members

Robotic eyes mimic human vision for superfast response to extreme lighting

Racial inequities and access to COVID-19 treatment

Residential segregation and lung cancer risk in African American adults

Scientists wipe out aggressive brain cancer tumors by targeting cellular ‘motors’

Capturability distinction analysis of continuous and pulsed guidance laws

CHEST expands Bridging Specialties Initiative to include NTM disease and bronchiectasis on World Bronchiectasis Day

Exposure to air pollution may cause heart damage

SwRI, UTSA selected by NASA to test electrolyzer technology aboard parabolic flight

Prebiotics might be a factor in preventing or treating issues caused by low brain GABA

Youngest in class at higher risk of mental health problems

American Heart Association announces new volunteer leaders for 2025-26

Gut microbiota analysis can help catch gestational diabetes

FAU’s Paulina DeVito awarded prestigious NSF Graduate Research Fellowship

Champions for change – Paid time off initiative just made clinical trials participation easier

Fentanyl detection through packaging

Prof. Eran Meshorer elected to EMBO for pioneering work in epigenetics

New 3D glacier visualizations provide insights into a hotter Earth

Creativity across disciplines

Consequences of low Antarctic sea ice

Hear here: How loudness and acoustic cues help us judge where a speaker is facing

A unique method of rare-earth recycling can strengthen the raw material independence of Europe and America

[Press-News.org] Researchers quantify toxic ocean conditions during major extinction 93.9 million years ago
UC Riverside-led study points to an ancient oxygen-free and hydrogen sulfide-rich ocean that may foreshadow our future