Study highlights successes of Virginia’s oyster restoration efforts

Virginia Institute of Marine Science

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Spreading oyster shells on top of existing reefs provides new habitat on which juvenile oysters attach and helps maintain the reef’s structure after commercial harvests. Photo by Alexandria Marquardt.

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Credit: Alexandria Marquardt

Virginia has made significant investments in the restoration of oyster reefs in the Chesapeake Bay, and now a study led by William & Mary’s Batten School & VIMS suggests those management practices are literally paying off in the Rappahannock River. The study, recently published in the Journal of Environmental Management, was led by Batten School of Coastal & Marine Sciences Ph.D. student Alexandria Marquardt, who presented the results to the Virginia Marine Resources Commission’s (VMRC) Shellfish Management Advisory Committee on February 19. 

In addition to supporting local economies, oysters filter the surrounding water removing algae and excess nutrients while clumping together to form large reefs that serve as habitat for many fish and marine animals. Though once abundant, oyster populations in the Chesapeake Bay collapsed in the mid-1980s due to a combination of overfishing and disease. While Virginia Institute of Marine Science has endeavored to increase wild oysters’ resistance to virulent pathogens, the VMRC regulates the fishery in Virginia and oversees efforts to restore oyster reefs. 

“Oyster restoration typically focuses on shell replenishment, in which oyster shells are spread over existing reefs on which juvenile oysters attach and grow. This was an exciting project, because it was the first to evaluate the benefits of replenishment activities both biologically and for the fishery,” said Marquardt, who collaborated on the study with faculty and scientists at the Batten School & VIMS and the VMRC. “Oyster reefs located in public fishing grounds are largely not studied, but we saw significant benefits from even modest replenishment. When combined with rotational harvests, the underlying reef structure was maintained and commercial harvests increased.”

The study showed that the density of juvenile oysters known as spat increased immediately following shell replenishment while the density of market-sized oysters peaked three years after, reinforcing the VMRC’s current 3-year rotational harvest protocol. Spat density, though highly variable, was highest in years coinciding with higher brown shell volumes, a measurement of reef health that refers to the amount of oysters and shell above the bottom sediment layer. Marine protected areas were shown to have higher market oyster densities and offer protection from commercial fishing for larger oysters, which may provide a valuable spawning function for the fishery.

VMRC began their shell replenishment program in 2000 and implemented rotational harvests in 2007. These practices have resulted in steady increases in brown shell volume throughout the Rappahannock River and increased the likelihood of watermen meeting daily harvest limits. Overall, the study showed that oyster harvests steadily increased with the improvement of the oyster reefs, with market oyster densities increasing substantially since 2018. 

Since the 2007-2008 harvest season, more than 500,000 bushels of oysters valued at more than $24 million were harvested from the Rappahannock River. The VMRC has invested more than $14 million toward replenishment in the river since 2000.

“It’s rewarding to see that science-based management of this fishery is providing benefits for both the environment and local economies,” said Marquardt. “I’m thankful for the opportunity to work with the VMRC and contribute to a sustainable oyster industry in Virginia.”

View a summary of the study.

The results of the study showed that oyster management practices in the Rappahannock River provide significant biological and commercial benefits.

Credit

Alexandria Marquardt

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Journal

Journal of Environmental Management

DOI

10.1016/j.jenvman.2025.124179 

Subject of Research

Animals

 

Optimism can encourage healthy habits

Syracuse University

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Syracuse University Researcher Jeewon Oh

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Credit: Syracuse University

Do you see the glass as half empty or half full? If you rewind to the start of the COVID-19 pandemic, chances are you experienced some level of pessimism. And who could blame you? With social isolation, health concerns and economic uncertainty, fear and anxiety became a daily reality for many.

A team of researchers from Syracuse University and Michigan State University recently explored the personal characteristics that help people handle prolonged stressors, such as the pandemic. Led by Jeewon Oh, assistant professor of psychology in Syracuse University’s College of Arts and Sciences, the group delved into optimism and pessimism and how those mindsets influence well-being.

The group utilized data from the Health and Retirement Study, a large-scale panel study that gathers a nationally representative sample of Americans aged 50 and older (Sonnega et al., 2014). In 2016, participants responded to questions assessing their levels of optimism, such as “In uncertain times, I usually expect the best,” and pessimism, such as “I hardly ever expect things to go my way.” During the COVID-19 pandemic (between March and May 2020), respondents answered questions on health-related behaviors that either increased or reduced the risk of COVID transmission, including masking frequency, travel habits and the likelihood of staying home.

The team used this data to explore how people’s mindsets affected their psychological and physical well-being during challenging times. Among their findings, they found that greater optimism promotes resilience and well-being when faced with stressors like the pandemic, while lower pessimism is linked to safer health behaviors. Their findings appeared in the Journal of Research in Personality.

In the following Q&A, Professor Jeewon Oh shares some key insights from their research.

What was the motivation for this study?

Jeewon Oh (JO): The pandemic introduced many changes, and we wanted to know more about personality traits that can help people cope with enduring and uncontrollable stressors like the pandemic. We examined optimism, because it motivates action. Since optimists view stressful situations positively, they are more likely to directly address the issue or try to adapt when things are uncontrollable.

What were the benefits for those who were more optimistic? How did optimism/pessimism correlate with well-being during the pandemic?

(JO): Both optimism and pessimism had independent associations with psychological well-being. So, people who are more optimistic and less pessimistic worried less, were less stressed and lonely and were more resilient. This was partly because these people engaged in more physical activity and perceived more social support and less strain from their relationships.

Interestingly, when it came to COVID/health-relevant behaviors, pessimism played a significant role, but optimism didn’t. In other words, individuals with a less pessimistic mindset (but not a more optimistic mindset), who have weaker negative expectations tended to engage in less risky behaviors, such as traveling, and more activities at home ranging from watching TV and gardening to meditating.

How does optimism or pessimism influence the way people approach challenges and setbacks?

(JO): In general, regular optimism/pessimism isn't about thinking they wouldn't get sick, or they will be more likely to get sick (compared to others), but about knowing the reality and still thinking that things will eventually work out. This positive mindset helps people to problem-solve and cope. Afterall, if you think things would never work out, why would you even try?

Is there a way to boost one’s optimism during times when they may be more anxious, like during the pandemic?

(JO): It can be easier to think about doing what optimists do rather than trying to think differently (or change your optimism). So, people with lower pessimism mentioned changing their behaviors to adapt to the situation, meeting with people on Zoom more frequently and exercising at home (vs. going to the gym and meeting up with people in person). It was these changes in behaviors like exercising more that partly helped people's well-being.

What does this study reveal about health and psychological well-being in the post-pandemic world? What factors can we consider for maintaining and improving mental health?

(JO): There has been evidence before the pandemic that optimistic people fare well in many situations. Even though more research is needed to understand why, our study found that optimists fared better even during new difficulties. Therefore, developing optimism and learning how to flexibly cope can help maintain and improve mental health in diverse situations.

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Journal

Journal of Research in Personality

 

Solving the case of the missing platinum

DOE/SLAC National Accelerator Laboratory

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A top-view visualization of a platinum surface during cathode corrosion. Platinum and hydrogen atoms are represented in black and white, respectively. Blue and purple triangles indicate where hydrogen atoms have been bound to platinum atoms.

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Credit: Selwyn Hanselman/Leiden University

For nearly two decades, scientists have tried to understand how negatively polarized platinum electrodes corrode, a costly mystery that plagues water electrolyzers, a promising energy technology for making hydrogen, as well as electrochemical sensors using platinum electrodes.

Now, a close collaboration between researchers at the Department of Energy’s SLAC National Accelerator Laboratory and the Leiden University has finally identified the culprit, potentially paving the way for cheaper hydrogen energy production and more reliable electrochemical sensors. The results were published in Nature Materials.

Electrolyzers and many other electrochemical devices often rely on negatively polarized platinum electrodes submerged in an electrolyte – essentially saltwater. That’s an expensive but durable and generally stable option, “but being quite stable doesn't mean it doesn't degrade," says Dimosthenis Sokaras, a senior scientist at Stanford Synchrotron Radiation Lightsource (SSRL) and the SLAC team’s principal investigator.

For most metals, being negatively polarized protects against corrosion. But platinum electrodes can rapidly break down under these conditions, a strange quirk that has puzzled scientists.

"If you take a piece of platinum and you apply a very negative potential, you can dissolve your platinum in a matter of minutes," says Marc Koper, a professor of catalysis and surface chemistry at Leiden University, and the Leiden team's principal investigator.

Two prominent theories had attempted to explain this process. Some scientists thought that sodium ions from the electrolyte solution were to blame. These ions, the thinking went, pushed their way into the platinum’s atomic lattice and formed platinides – platinum atoms lugging around positively-charged sodium ions – that peel away. Others suggested a similar process but pointed the finger at sodium and hydrogen ions – that is, protons – working together to produce platinum hydrides instead.

The research team knew they would need to somehow observe platinum as it was corroding in an electrolyte while making lots of hydrogen. To do so, the team turned to SSRL where researchers have developed high-energy-resolution X-ray spectroscopy techniques that could penetrate the electrolyte and filter out other effects, allowing the researchers to focus in on subtle changes in the platinum electrode in operando, or during operation.

"High-energy-resolution X-ray absorption spectroscopy, for us, was the only technique we could come up with that could sort of deal with the experimental conditions," said SLAC scientist Thom Hersbach.

In addition, the team developed a special “flow cell,” Sokaras said, that could clear hydrogen bubbles that form during the electrode’s operation and interfere with the X-ray experiment.

Using those capabilities together, the team made the first ever observations of platinum actively corroding, recording X-ray spectra from the negatively polarized electrode's surface.

Prior to running the experiment, the researchers had a hunch that hydrides were to blame for the corrosion, but it took several years of analyzing the data before they could prove this hypothesis.

"It just took loads and loads of different iterations of trying to figure out 'how do we accurately capture what's going on?'" Hersbach said.

Using computational models of platinum hydrides and platinides, the researchers simulated the spectra they would expect to see from each structure under the SSRL X-ray beam. Comparing the numerous simulated spectra with the results of their experiment confirmed that only platinum hydride could have produced their results. “By advancing the frontiers of X-ray science, SSRL has developed operando methods that, combined with modern supercomputing, now allow us to tackle decades-old scientific questions,” Sokaras said.

Now, the team's findings can be used to develop solutions for platinum corrosion in electrolyzers and many other electrochemical devices. The project, Koper says, "shows how important in science it is to put a lot of expertise together."

SSRL is a DOE Office of Science user facility.

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Journal

Nature Materials

DOI

10.1038/s41563-024-02080-y 

Method of Research

Experimental study

Subject of Research

Not applicable

Article Title

Platinum hydride formation during cathodic corrosion in aqueous solutions

 

Study reveals Arabia's rainfall was five times more extreme 400 years ago

As the Middle East rapidly urbanizes, wide variability of Late Holocene rains should be considered in flash flood preparedness and future hydroclimate trajectories

University of Miami Rosenstiel School of Marine, Atmospheric, and Earth Science

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Brine pools are one of the most extreme environments on Earth, yet despite their high salinity, exotic chemistry, and complete lack of oxygen, these pools are teeming with life and offer a unique record of Earth's rainfall patterns. 

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Credit: OceanXplorer

A new study reconstructing extreme rainfall in Arabia has uncovered that rainfall in the region was five times more extreme just 400 years ago, highlighting the need for preparedness amid growing urbanization.

The findings from the University of Miami Rosenstiel School of Marine, Atmospheric, and Earth Science-led study suggest that the last 2,000 years were much wetter, with the region’s climate once resembling a vegetated savannah roaming with lions, leopards, and wolves, unlike its present-day hyper-arid desert. The study was published Feb. 21 in the journal Science Advances.

“As major development projects like NEOM in Saudi Arabia continue to reshape the landscape, these findings underscore the critical need for enhanced climate resilience and disaster preparedness to address the growing threat of extreme weather events in the region,” said the study’s lead author Sam Purkis, a professor and chair of the Department of Marine Geosciences at the University of Miami Rosenstiel School.

Using a remotely operated vehicle (ROV) at over a mile depth deployed from the research vessel OceanXplorer, the research team extracted sediment cores from a deep-sea brine pool in the Gulf of Aqaba, an extension of the northern Red Sea. The brine's chemistry preserves undisturbed sediment layers, providing a unique and highly accurate record of Late Holocene rainfall trends. 

They found that the last 2,000 years in Arabia were much wetter, with the region once a vegetated savannah and about 200 years ago, rainfall was double the current amount.

“This is a key record to fill in the history of Middle Eastern climate. What it tells us is that the climate, both the average and the extremes, can change dramatically in this region, and the assumption of long-term climate stability in future development is not a good one.” said Amy Clement, a professor in the Department of Atmospheric Sciences at the University of Miami Rosenstiel School.

The Middle East is considered a climate hotspot, with increasing flash floods from torrential winter rains, interspersed by harsh droughts, in Arabia causing widespread chaos and humanitarian disasters. The variability of Late Holocene rainfall highlights the need for better flash flood and drought preparedness and understanding future hydroclimate trends as the Middle East rapidly urbanizes. The catastrophic flooding across the Arabian Peninsula in the winter of 2024 underscores the urgency of studying the frequency and triggers of such extreme weather events.

“Utilizing the technology on OceanXplorer in combination with multidisciplinary experts in ocean and climate science we can further our understanding of the linkages between ocean systems and long-term weather and climate trends, to help at-risk areas be ready for the future.” said Mattie Rodrigue, science program director at OceanX. 

The study, titled “A 1,600-Year Record of Extreme Rainfall in Northern Arabia,” was published in the journal Science Advances. The study was supported by NEOM Agreement (No: SRA-ENV-2023-001 / AWD-008854) and National Science Foundation Climate and Large-Scale Dynamics Grant (# 2241752).

 

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Journal

Science Advances

DOI

10.1126/sciadv.adq3173 

Method of Research

Observational study

Subject of Research

Not applicable

Article Title

A 1,600-Year Record of Extreme Rainfall in Northern Arabia

Article Publication Date

21-Feb-2025

 

Scented wax melts may not be as safe for indoor air as initially thought, study finds

American Chemical Society

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Researchers monitored the nanoparticles produced from scented wax melts using lab equipment set up inside a model home.

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Credit: Purdue University/Kelsey Lefever

As traditional candles burn, they can contribute to indoor air pollution by emitting volatile compounds and smoke, which may pose inhalation risks. Scented wax melts are often marketed as safer alternatives to candles because they’re flame- and smoke-free. But in a study in ACS’ Environmental Science & Technology Letters, researchers describe how aroma compounds released from the melted wax can react with ozone in indoor air to form potentially toxic particles.

Previous research has shown that scented wax melts emit more airborne scent compounds than traditional candles. The direct heating of the wax maximizes its surface area, thereby releasing more fragrance – such as volatile organic compounds (VOCs) made of hydrocarbons – into the air. Researchers know that these chemicals can react with other compounds in the air to form nanometer-wide particles, which have been linked to negative health effects when inhaled. However, the potential for nanoparticle formation during wax-melt use was unknown. So, Nusrat Jung, Brandon Boor and colleagues set out to investigate this process using wax melts in a full-scale house model that mimicked a typical residential house.

The researchers conducted experiments on 15 commercially available wax melts, both unscented and scented (e.g., lemon, papaya, tangerine and peppermint), in the model house. They first established a baseline of indoor air pollutants and then switched on the wax warmer for about 2 hours. During and after this period, the researchers continuously sampled the air a few yards (meters) away from the wax melts and found airborne nanoparticles, between 1 and 100 nanometers wide, at levels that were comparable to previously reported levels for traditional, combustion-based candles. These particles could pose an inhalation risk because they are small enough to pass through respiratory tissues and enter the bloodstream, say the researchers.

Additionally, using literature data, the team calculated that a person could inhale similar amounts of nanoparticles from wax melts as from traditional candles and gas stoves. Previous studies have found exposure to high levels of nanoparticles in indoor air can be linked to health risks like decreased cognitive function and increased prevalence of childhood asthma.

In the experiments, the main VOCs emitted from the wax melts were terpenes, such as monoterpenes and monoterpenoids. The researchers identified that the airborne terpenes reacted with ozone and formed sticky compounds, which aggregated into nanoscale particles. However, after warming an unscented wax melt, the team observed no terpene emissions or nanoparticle formation, which suggests that these aroma compounds contribute to nanoparticle formation.

The researchers say this study challenges the perception that scented wax melts are a safer alternative to combustion-based candles; however, they emphasize that more toxicology research is needed on the risks of breathing in nanoparticles formed from wax melts.

A deeper analysis by the researchers of how airborne nanoparticles form indoors from volatile scent compounds was published in 2024 in ACS ES&T Air.

The authors acknowledge funding from the National Science Foundation; Purdue University; and the American Society of Heating, Refrigerating, and Air Conditioning Engineers.

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The American Chemical Society (ACS) is a nonprofit organization chartered by the U.S. Congress. ACS’ mission is to advance the broader chemistry enterprise and its practitioners for the benefit of Earth and all its people. The Society is a global leader in promoting excellence in science education and providing access to chemistry-related information and research through its multiple research solutions, peer-reviewed journals, scientific conferences, e-books and weekly news periodical Chemical & Engineering News. ACS journals are among the most cited, most trusted and most read within the scientific literature; however, ACS itself does not conduct chemical research. As a leader in scientific information solutions, its CAS division partners with global innovators to accelerate breakthroughs by curating, connecting and analyzing the world’s scientific knowledge. ACS’ main offices are in Washington, D.C., and Columbus, Ohio.

Registered journalists can subscribe to the ACS journalist news portal on EurekAlert! to access embargoed and public science press releases. For media inquiries, contact newsroom@acs.org.

Note: ACS does not conduct research but publishes and publicizes peer-reviewed scientific studies.

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Journal

Environmental Science & Technology Letters

DOI

10.1021/acs.estlett.4c00986 

Article Title

“Flame-Free Candles Are Not Pollution-Free: Scented Wax Melts as a Significant Source of Atmospheric Nanoparticles”