New measurements from Northern Sweden show less methane emissions than feared

GREENHOUSE GASES

Peer-Reviewed Publication

UNIVERSITY OF COPENHAGEN - FACULTY OF SCIENCE

 

IMAGE: ON THE LEFT IS A POND VEGETATION CONTROLLED BY HIGH WATER LEVELS AND ON THE RIGHT A DRIER TUNDRA VEGETATION, WHICH IS BECOMING MORE PREVALENT IN AREAS WHERE THE WATER LEVEL IS LOW AND THE SOIL DRIES OUT IN SUMMER. IN AREAS WHERE PERMAFROST DISAPPEARS, NEW STUDIES SHOW THAT THE RELEASE OF METHANE CAN BE REDUCED BY A FACTOR OF 10 DUE TO CHANGES IN HYDROLOGY, PLANT COMMUNITY AND THE COMPOSITION OF MICROORGANISMS IN THE SOIL (PHOTO: BO ELBERLING) view more 

CREDIT: PHOTO: BO ELBERLING, UNIVERSITY OF COPENHAGEN.

It is widely understood that thawing permafrost can lead to significant amounts of methane being released. However, new research shows that in some areas, this release of methane could be a tenth of the amount predicted from a thaw. The research was conducted in Sweden by an international group that includes researchers from the University of Copenhagen. A crucial, yet an open question is how much precipitation the future will bring.

A typical landscape in northern Sweden. On the left is a pond vegetation controlled by high water levels and on the right a drier tundra vegetation, which is becoming more prevalent in areas where the water level is low and the soil dries out in summer. In areas where permafrost disappears, new studies show that the release of methane can be reduced by a factor of 10 due to changes in hydrology, plant community and the composition of microorganisms in the soil (photo: Bo Elberling)

Permafrost runs like a frozen belt of soil and sediment around Earth’s northern arctic and sub-arctic tundra. As permafrost thaws, microorganisms are able to break down thousands of years-old accumulations of organic matter. This process releases a number of greenhouse gases. One of the most critical gasses is methane; the same gas emitted by cattle whenever they burp and fart.

Because of this, scientists and public agencies have long feared methane emissions from permafrost to rise in step with global temperatures. But, in some places, it turns out that methane emissions are lower than once presumed.

In a comprehensive new study by a collaborative from the University of Gothenburg, Ecole Polytechnique in France and the Center for Permafrost (CENPERM) at the University of Copenhagen, researchers measured the release of methane from two localities in Northern Sweden. Permafrost disappeared from one of the locations in the 1980’s, and 10-15 years later in the other.

The difference between the two areas shows what can happen as a landscape gradually adapts to the absence of permafrost. The results show that the first area to lose its permafrost now has methane emissions ten times less than in the other locality. This is due to gradual changes in drainage and the spread of new plant species. The study’s findings were recently published in the journal Global Change Biology.

"The study has shown that there isn’t necessarily a large burst of methane as might have been expected in the wake of a thaw. Indeed, in areas with sporadic permafrost, far less methane might be released than expected," says Professor Bo Elberling of CENPERM (Center for Permafrost), at the University of Copenhagen’s Department of Geosciences and Natural Resource Management.

Water, plants and microbes all play a role

According to Professor Elberling, water drainage accounts for why far less methane was released than anticipated. As layers of permafrost a few meters deep begin to disappear, water in the soil above begins to drain.

"Permafrost acts somewhat like the bottom of a bathtub. When it melts, it's as if the plug has been pulled, which allows water to seep through the now-thawed soil. Drainage allows for new plant species to establish themselves, plants that are better adapted for drier soil conditions. This is exactly what we’re seeing at these locations in Sweden," he explains.

Grasses typical of very wet areas with sporadic permafrost have developed a straw-like system that transports oxygen from their stems down into to their roots. These straws also act as a conduit through which methane in the soil quickly find its way to the surface and thereafter into the atmosphere.

As the water disappears, so do these grasses. Gradually, they are replaced by new plant species, which, due to the dry soil conditions, do not need transport oxygen from the surface via their roots. The combination of more oxygen in the soil and reduced methane transport means that less methane is produced and that the methane that is produced can be better converted to CO2 within the soil.

"As grasses are outcompeted by new plants like dwarf shrubs, willows and birch, the transport mechanism disappears, allowing methane to escape quickly up through soil and into the atmosphere," explains Bo Elberling.

The combination of dry soil and new plant growth also creates more favorable conditions for soil bacteria that help break methane down.

"When methane can no longer escape through the straws, soil bacteria have more time to break it down and convert it into CO2," Bo Elberling elaborates.

As a result, one can imagine that as microorganisms reduce methane emissions, the process will lead to more CO2 being released. Yet, no significant increase in CO2 emissions was observed by the researchers in their study. This is interpreted as being the result of the CO2 balance, which is more heavily determined by plant roots than the CO2 released from the microorganisms that break down methane. Crucially, even though methane ends up as CO2, it is considered less critical in climate change context as methane is at least 25 more potent greenhouse gas as compared to CO2.

Infobox

Areas of sporadic permafrost cover the southern part of the Arctic around the globe, where the temperature is typically between minus five and zero degrees. This means that a rise in temperature can cause the permafrost to completely disappear.

 

Future precipitation will be decisive

According to Professor Elberling, the future’s greatest unknown is the amount of future precipitation. Because, while thawing permafrost makes it easier for soil to drain in areas with sporadic permafrost, increased rainfall or poor drainage can prevent an area from drying. Where the latter is the case, we shouldn’t expect a corresponding drying out and reduction in methane being released.

"The balance between precipitation and evaporation will be crucial for the release and absorption of greenhouse gases. However, predicting Arctic precipitation is fraught with uncertainty. In some areas we’re seeing increased precipitation, while in others, things are drying out - especially in the summer," says Elberling.

The study focuses on data from two localities in northern Sweden. As such, Professor Elberling is cautious about concluding that analogous conditions extend to other areas with similar permafrost, such as in Canada or Russia.

The study contributes to a new understanding of a process that must be taken into account whenever future methane emissions are assessed in permafrost-affected areas.

"In their most recent report on the Arctic’s future methane budget, the IPCC (Intergovernmental Panel on Climate Change) has not considered the conditions highlighted by us in the study. Our study reverses the general perception that thawed permafrost is to be consistently associated with increased levels of methane being released," Professor Elberling concludes. 

Lead author Mats Björkman from University of Göteborg adds:

“Our research shows that methane emissions from areas where permafrost thaws are not the same everywhere. The new observations represent an important component of a more comprehensive picture of the climate impact in the Arctic. Our results also underscore the importance of including hydrological, vegetation, and microbial changes when studying the long-term effects of permafrost thawing and disappearing.”

 In the future Mats Björkman wants to determine which areas will either get wetter or drier and see how they are affected when the permafrost thaws.

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JOURNAL

Global Change Biology

DOI

10.1111/gcb.16137 

ARTICLE TITLE

Reduced methane emissions in former permafrost soils driven by vegetation and microbial changes following drainage

What happens when plants have stress reactions to touch

Peer-Reviewed Publication

LUND UNIVERSITY

 

IMAGE: THE RESEARCHERS IN THE LAB view more 

CREDIT: JOHAN JOELSSON

A 30-year-old genetic mystery has been solved. It has previously been established that touch can trigger stress reactions in plants. However, the molecular models for explaining this process have been quite spartan so far. Now researchers at Lund University in Sweden have found genetic keys that explain how plants respond so strongly to mechanical stimuli. Cracking this code could help lead to higher yields and improved stress resistance in crops in the future.

When you water your garden plants, they react directly at a biochemical level. When a knife edge cuts a rhubarb stalk, thousands of genes are activated, and stress hormones are released. 

Unlike humans, plants can not feel pain, but they still react strongly to mechanical stimuli from human touch, hungry animals, wind and rain, for example. These external factors lead to the plant's molecular defense system being activated quickly, which in turn can contribute to plants becoming more resistant and flowering later. 

Although the phenomenon has been known since Darwin, there are still many question marks. A new study published in Science Advances has examined the complex regulating networks that affect how the plant's defenses are strengthened by external influences.

“We exposed the plant thale cress to soft brushing, after which thousands of genes were activated and stress hormones were released. We then used genetic screening to find the genes that were responsible for this process”, explains Olivier Van Aken, biology researcher at Lund University.

Previous studies have shown that the plant hormone jasmonic acid is an important mediator in touch signaling. It has also been known that jasmonic acid is only part of the plant's complex network of touch-sensitive responses, and that there are several unidentified pathways that have not yet been unveiled. After extensive laboratory work, the researchers were able to identify three new proteins that play a key role in the plants' response to touch.

“Our results solve a scientific mystery that has eluded the world's molecular biologists for 30 years. We have identified a completely new signaling pathway that controls a plant's response to physical contact and touch. Now the search for more paths continues”, says Essam Darwish, biology researcher at Lund University.

What possible applications will the new results have? Olivier Van Aken is also studying a centuries-old Japanese agricultural technology that involves trampling grain during the growth phase, to obtain more abundant harvests. The researchers believe that there is a lot of hidden knowledge about how mechanical stimuli can lead to higher yields and improved stress resistance in crops. Knowledge that in the long run can change modern agriculture at its core.

“Given the extreme weather conditions and pathogen infections that climate change leads to, it is of utmost importance to find new ecologically responsible ways to improve crop productivity and resistance”, concludes Olivier Van Aken.

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JOURNAL

Science Advances

DOI

10.1126/sciadv.abm2091 

ARTICLE TITLE

Touch signaling and thigmomorphogenesis are regulated by complementary CAMTA3- and JA-dependent pathways

Disclaimer: AAAS and Eurek

Crystal Palace dinosaurs: how we rediscovered five missing sculptures from the famous park

Published: May 20, 2022 

THE CONVERSATION

The iconic Iguanodon sculptures of the Crystal Palace Dinosaurs. 

Witton and Michel (2022), CC BY-SA


This summer sees our love for dinosaurs manifest in two major releases: the David Attenborough documentary Prehistoric Planet, and Jurassic World: Dominion. Such multi-million dollar projects are a far cry from the first attempts to bring dinosaurs to life in people’s imagination.

Perhaps the most famous of these took place almost 170 years ago at Crystal Palace Park, in south-east London, where over 30 life-sized sculptures of prehistoric animals, including dinosaurs, revealed extinct life to the public for the first time.

Much like the unveiling of Jurassic Park’s computer generated dinosaurs in 1993, the Crystal Palace dinosaurs stunned visitors. This historic site still enjoys hundreds of thousands of visitors each year.

Our new book, The Art and Science of the Crystal Palace Dinosaurs, reveals that neglect of the site allowed seven – almost a fifth – of the original sculptures to disappear. It was thought the original park had 32 sculptures, of which only 29 originals (with one replica, making 30) stand today. We showed 37 once existed.

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The lost statues include the tapir-like Palaeotherium magnum, three delicate llama-like Anoplotherium gracile, two Jurassic pterodactyls, and a female giant deer. It’s unknown when and how each vanished, but dereliction, site redevelopment and perhaps vandalism may be responsible.

Built as part of the Crystal Palace Park project, the dinosaurs were unveiled in 1854 and completed in 1855. Although books and magazines brought dinosaurs to the attention of the rich and educated in the early 1800s, fossils were an interest reserved for the upper tiers of society. The sculptures, crafted by a team led by Benjamin Waterhouse Hawkins, aimed to introduce prehistoric life to the wider public.

Map of the Geographical Court as originally planned. 

Image by Mark P. Witton and Ellinor Michel.

Working with geologists David Thomas Ansted and Joseph Campbell, Hawkins created a learning experience one part spectacle and one part enlightenment: the “Geological Court”. This showcase of geological and palaeontological science allowed visitors to walk through geological time.

The largest of Hawkins’ sculptures were the dinosaurs, reaching over 10m long. Mock geological features contained hundreds of tonnes of rocks sourced from all over the UK. This was expensive blockbuster edutainment.

For all the mockery cast on the sculptures for their scientific inaccuracy today, at the time they were cutting edge representations of extinct species – and a major hit with the public. But budget issues saw the site fall into disrepair from 1870 onward. Degraded and patchy records mean the full extent of the original display is uncertain.
An 1853 image of the Crystal Palace palaeontological sculpture workshed. Several now missing models are indicated by red arrows: the Palaeotherium magnum (left) and three Anoplotherium gracile (right). The surviving A. gracile is marked with a blue arrow. Image in public domain, modified by Mark P. Witton and Ellinor Michel.

Virtually no physical remains of the missing sculptures exist. Only archive photographs, illustrations and texts prove their existence. For example, the image above shows several models that no longer exist.

From these sources, we also re-identified one sculpture at the park – an alleged giant deer fawn – as Anoplotherium gracile, which resembles a gazelle and is the sole surviving representative of what was once a group of four statues.

If we know almost 20% of this unique Victorian site was allowed to vanish so quietly, what else might be missing?

A history at risk of extinction

While the Victorian artistry and creative engineering that went into creating the Geological Court is celebrated today, the site has long suffered from a lack of conservation.

The unchanging nature of the concrete displays, now numerous generations behind the latest palaeontological findings, gives a sense the they will always be here. But visit the site today and it’s obvious many of the displays are still crumbling.

Weathering, vandalism and redevelopment mean the Geological Court is a blend of originals and replicas of structures destroyed in the mid-20th century.

The state of the southern corner of the Geological Court as of 2021. This portion of the site has received some minor maintenance since this photo was taken. 

Photo by Mark P. Witton

There is hope. The Friends of Crystal Palace Dinosaurs charity was established in 2013, and the entire site is now Grade 1 listed and on the official Heritage At Risk Register by Historic England.

But the Geological Court’s status is a precarious one. Without urgent conservation the sculptures face major deterioration.

As you enjoy the digital descendants of Hawkins’ dinosaurs when they hit our screens this summer, spare a thought for their Victorian ancestors. To lose what remains of these displays, that changed the way many people thought about life on Earth, would be tragic.

Authors

Mark P. Witton
Research Fellow in Palaeontology, University of Portsmouth

Ellinor Michel
Scientific Associate, Natural History Museum

Disclosure statement

Mark P. Witton is the co-author of The Art and Science of the Crystal Palace Dinosaurs, out now on Crowood Press.

Ellinor Michel is the co-author of The Art and Science of the Crystal Palace Dinosaurs, out now on Crowood Press.

New discovery of missing Victorian

dinosaurs at world’s first Jurassic Park

Book Announcement

UNIVERSITY OF PORTSMOUTH

 

IMAGE: THE LONGEST SCULPTURE IN THE PARK IS MEGALOSAURUS, THE ORIGINAL CARNIVOROUS DINOSAUR. THIS RESTORATION SHOWS THE ARTISTIC SKILL AND SCIENTIFIC CONSIDERATION THAT WENT INTO EACH MODEL THROUGH ITS MUSCULAR, POWERFUL LIMBS, ENLARGED, HEAD-SUPPORTING SHOULDERS AND FINELY DETAILED JAWS. view more 

CREDIT: MARK P. WITTON

• New insights about the world’s first life-sized models of dinosaurs have been revealed.
• A new book provides missing evidence that seven - almost a fifth - of the world-famous Crystal Palace Dinosaurs have disappeared.
• The lost sculptures include the tapir-like Palaeotherium magnum, three delicate llama-like Anoplotherium gracile, two Jurassic pterodactyls, and a female giant deer.

Evidence for numerous missing models at the world-famous Crystal Palace Dinosaurs and re-identification of a sculpture as one of the park’s “lost species” are revealed in a new book, The Art and Science of the Crystal Palace Dinosaurs (The Crowood Press).

The Crystal Palace Dinosaurs were a series of over 37 Grade 1 listed sculptures of prehistoric animals and geological displays arranged in a simulated “walk through time”, which were unveiled to the public as part of the famous Crystal Palace Park in 1854.

It was thought the original park had 32 life-sized sculptures, of which 30 (29 originals and one replica) and a handful of geological displays survive today. The new research adds five lost mammal sculptures to that list, showing that 37 sculptures once existed.

This globally significant historic site, which includes iconic depictions of monumental dinosaurs, regal extinct mammals, serpentine marine reptiles and giant amphibians, captured a snapshot of palaeontology from a golden era of scientific discovery in the mid-19th century. Today, they are internationally recognised as a milestone in the portrayal of extinct life and the history of science.

The book’s co-author, Dr Mark Witton, a leading palaeontological artist and researcher at the University of Portsmouth, said: “We’ve uncovered a lot of new insights into the Dinosaurs and their park home in this project, but the evidence for so many lost models blew us away. They weren’t small, obscure sculptures either, but included pony-sized, tapir-like Palaeotherium magnum and a horse-sized female Megaloceros. More amazingly, we found lots of evidence for a hitherto overlooked species, ”Anoplotherium gracile”, which we call Xiphodon gracilis today. 

“There were originally four Xiphodon but only one model survives, mislabeled as a Megaloceros fawn. Happily, we have photos and illustrations of these lost models that show us what they looked like, but their existence also exposes large gaps in the documented history of the site. It means that, in total, eight original models have been lost, with only one successfully replaced - a standing Anoplotherium commune.”

Using new archive sources, the authors have revealed how grand the site was in its heyday before almost 20 per cent of the original constructed animal sculptures went missing in following decades, mostly under unknown circumstances. In addition, 14 planned extinct animal sculptures were never made due to funding restrictions.

Several mysteries about how the non-dinosaur animal models were manufactured have also been answered. Using new analysis of historic images, the authors discovered that the smaller sculptures were probably built indoors and moved around with carts, sometimes in pieces, to be assembled on site. The largest models, including the dinosaurs, were assembled in place, under tents to protect them from poor weather.

Co-author Dr Ellinor Michel, an evolutionary biologist at the Natural History Museum London, said: “This book celebrates these classic scientific artworks and explores their history, their conception as a wider part of the Crystal Palace project, their execution using unorthodox building materials, their reception by 19th century and modern critics, and their enduring mysteries.

“These sculptures and landscapes have been a gateway to the wondrous ideas of Deep Time and to teaching us how scientific ideas come to life since 1854. These Victorian creations can still teach us a lot today about science, art and history. I hope this book will continue to bring those important messages to many generations of curious minds.”

The book, which is published by The Crowood Press, includes hundreds of historic and modern photos and original paintings that offer a detailed study of the art and science behind each sculpture, and covers:

• How prehistoric life and the geological record was reconstructed at life-size for the first time in the 1850s, detailing how the models and their associated geological landscape were rationalised from scientific data before being rendered in iron and concrete.
• How palaeoartists and palaeontologists view them today, with a discussion of their historical reconstructions and the debates about the animals over time.  
• An evaluation of the roles performed by the site’s consultant, the historically controversial scientist Richard Owen, and its visionary artist, Benjamin Waterhouse Hawkins.

Dr Witton said: “The Crystal Palace Dinosaurs are the world’s first major palaeoart project and they played a significant role in making geological sciences accessible to the public. This is the most detailed and complete history of these world-famous sculptures yet, reinforcing their status as masterworks of education and palaeoartistry.”

Unfortunately, conservation risks have faced generations of custodians keeping the display intact, and the challenges still face the site today.

Dr Michel, who is co-founder and chair of the Friends of Crystal Palace Dinosaurs, said: “The need for greater care, maintenance and research in the Geological Court is even more urgent than anyone knew as the site has suffered more damage than we thought. Through this book, we want to show the importance of conserving these endangered sculptures for the next generation.”

All authors’ royalties from the book will support the charity Friends of Crystal Palace Dinosaurs to help in the conservation and interpretation of the models. 

ART AND SCIENCE OF THE CRYSTAL PALACE DINOSAURS

MARK WITTON ELLINOR MICHEL

£30.00

The Crystal Palace Dinosaurs, a series of thirty-seven incredible sculptures of prehistoric animals and geological displays, were unveiled to the public as part of the famous Crystal Palace Park in 1854. The display, which includes iconic depictions of rhinoceros-like dinosaurs, regal extinct mammals, serpentine marine reptiles and giant, frog-like amphibians, captured a snapshot of palaeontology from a golden era of scientific discovery in the mid-nineteenth century. Today, they are internationally recognized as a milestone in our portrayals of extinct life. This book celebrates these classic scientific artworks and explores: their history, their conception as a wider part of the Crystal Palace project, their execution using unorthodox building materials, their reception by nineteenth century and modern critics, and their enduring mysteries. Hundreds of historic and modern photos and original paintings show modern scientific visions of the extinct animals restored. Written in collaboration with and in support of the Friends of Crystal Palace Dinosaurs charity, this superb book gives the most detailed and complete history of these world-famous sculptures yet, reinforcing their status as masterworks of education and palaeoartistry.

 

CAPTION

Cover of The Art and Science of the Crystal Palace Dinosaurs.

CREDIT

The Crowood Press

ABOUT THE AUTHORS

Mark P Witton is a leading palaeontological artist, author and researcher at the University of Portsmouth, UK. He has produced artwork for museums and universities worldwide, including Natural History Museum, London, and American Museum of Natural History, and acted as a consultant for documentaries and films, including the Walking with Dinosaurs franchise. He has written numerous books on palaeontology and palaeoart, including The Palaeoartist’s Handbook and Recreating an Age of Reptiles for Crowood. After learning about Crystal Palace Dinosaurs as a child, he is thrilled to have made this contribution to the scholarship of this important, unique site.

Ellinor Michel is an evolutionary biologist, ecologist and taxonomist at the Natural History Museum, London. Her work extends to palaeoclimates and scientific nomenclature. It was her interest in the history and philosophy of science that led her to co-found and chair the Friends of Crystal Palace Dinosaurs. The Dinosaurs have been a gateway to the wondrous ideas of Deep Time and to teaching us how scientific ideas come to life since 1854, she hopes this book will continue to bring those important messages to many generations of curious minds.

Art and Science of the Crystal Palace Dinosaurs - The Crowood Press

California shellfish farmers adapt to climate change

San Diego State University and Oregon State University researchers probe growers’ strategies for keeping the sustainable industry resilient as oceans turn more acidic

Peer-Reviewed Publication

SAN DIEGO STATE UNIVERSITY

 

IMAGE: SHELLFISH GROWERS AT HOG ISLAND OYSTER FARM IN TOMALES BAY, NORTHERN CALIFORNIA. view more 

CREDIT: COURTESY OF REMY HALE/HOG ISLAND OYSTER CO.

Because of their proximity to the ocean, Californians get to enjoy locally-sourced oysters, mussels, abalone and clams. Most of the shellfish consumed here come from aquaculture farms along the coast — from San Diego to Humboldt County. And because the animals are filter feeders that siphon tiny plankton out of seawater, growing them is environmentally sustainable. 

But due to rising greenhouse gas emissions, the ocean has become more acidic, conditions hostile to shellfish growth.

“There have been calls across the state and across the U.S. to increase aquaculture output because it's so sustainable. But then at the same time, it's a very vulnerable industry,” said Melissa Ward, a postdoctoral fellow at San Diego State University. 

In a new study, SDSU and Oregon State University researchers interviewed California shellfish growers to find out how they perceive ocean acidification, and to learn what strategies they think will help their operations adapt to changing environmental conditions. 

“This study is fairly unique in that we're getting information directly from the people who are being affected by change and learning directly from their experiences,” said geographer Arielle Levine, director of the sustainability program in SDSU’s College of Arts and Letters.. 

Ward added: “They're on the front lines of observing climate change and they also are going to be most well-suited to describe what they think they need to adapt to those changes.”

Growing threat

Burning coal, oil and natural gas emits carbon dioxide and other greenhouse gases into the atmosphere. About a third of that CO2 is absorbed by the ocean, reducing pH levels. 

As the water becomes more acidic, the calcium carbonate shellfish need for their shells is less abundant.

“And so they're basically running out of building blocks to build shell with,” said Ward. “And that can be particularly challenging for a very very small shellfish that’s just forming.” 

Most shellfish are spawned in land-based hatcheries. When they’re about the size of a fingernail, they’re moved to floating nurseries in the ocean. 

“And at that point, they're just sort of subjected to whatever conditions and whatever food floats by in the water,” said Ward.

If the water is acidic, the baby shellfish may grow more slowly, or even die, making it harder for aquaculture farms to remain viable. 

Strategies for adaptation

Interviews with shellfish growers revealed that while they are concerned about the impact of ocean acidification on their operations, they often lack the scientific instrumentation to know when it’s happening.

Growers also worry about other environmental threats such as warmer water, heavy rainfall and pollution — which all contribute to the spread of marine diseases — as well as toxic algal blooms. 

“Sometimes, growers would lose 90, 100% of their shellfish in a given area, and they won't really know why,” said Ward. “It's sort of a story of multiple stressors;  you can imagine a time when the water is particularly warm or there's a rainfall event, and ultimately you may reach a tipping point that the shellfish in the water just can't remain resilient to.”

Many growers said they need access to scientific resources to pinpoint the environmental factors involved in large die-off events, and to potentially prevent them. 

Policy change

All of the shellfish growers felt that regulatory and permitting requirements for shellfish operations need to be adjusted to respond to the rapidly changing environment. For example, it might be wise to diversify a shellfish operation by growing a new species that is better adapted to ocean acidification. But obtaining the required permits for that can be onerous.

“California is likely the hardest state to get a permit for shellfish aquaculture, which is seemingly at odds with the messaging that's coming down from the top,” Ward said. While state leaders recognize that shellfish aquaculture is sustainable and an opportunity for economic growth, it can take years and hundreds of thousands of dollars for a grower to obtain a permit for a new species. “And they just can't afford that time and money,” she added. 

“We need to maintain the environmental protections that we have in California, but if we really want the industry to be resilient to environmental change, we have to kind of allow for flexibility in farm management.”

Another adaptive strategy identified by shellfish growers was a need for more networking opportunities — not only with other growers, but also with managers, scientists and policymakers — to share information and best practices for adapting to environmental change.

The study is published in the journal Ocean & Coastal Management. The researchers hope it will serve as a roadmap for improving the resilience of the aquaculture industry in California. 

“This work really draws a connection between environmental change that's happening and will continue to happen, and how that's not just affecting the species in the ocean, but also the people who rely on these species,” said Levine.

 

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About San Diego State University 

San Diego State University is a major public research institution that provides transformative experiences for its more than 36,000 students. SDSU offers bachelor’s degrees in 96 areas, master’s degrees in 84 fields and doctorates in 23 areas, with additional certificates and programs at regional microsites. SDSU ranks as the number 1 California State University in federal research support, as one of the top public research universities in California. In addition to academic offerings at SDSU, SDSU Imperial Valley and SDSU Georgia, SDSU Global Campus offers online training, certificates and degrees in areas of study designed to meet the needs of students everywhere. Students participate in transformational research, international experiences, sustainability and entrepreneurship initiatives, internships and mentoring, and a broad range of student life and leadership opportunities. SDSU is committed to inclusive excellence and is known for its efforts in advancing diversity and inclusion. SDSU is nationally recognized for its study abroad initiatives, veterans’ programs and support of LGBTQA+ students, as well as its powerhouse Division I Athletics Program. About 50% of SDSU’s undergraduate and graduate students are students of color. The university resides on Kumeyaay land and was most recently recognized as an Asian American Native American Pacific Islander-Serving Institution (AANAPISI). SDSU is also a long-standing Hispanic-Serving Institution (HSI). The university’s rich campus life and location offers opportunities for students to lead and engage with the creative and performing arts, career and internship opportunities with SDSU’s more than 491,000 living alumni, and the vibrant cultural life of the greater San Diego and U.S.- Mexico region.

 

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JOURNAL

Ocean & Coastal Management

DOI

10.1016/j.ocecoaman.2022.106155 

METHOD OF RESEARCH

Survey

SUBJECT OF RESEARCH

Animals

ARTICLE TITLE

California shellfish farmers: Perceptions of changing ocean conditions and strategies for adaptive capacity

ARTICLE PUBLICATION DATE

16-May-2022

COI STATEMENT

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Acoustic sensors pinpoint shooters in urban setting #ASA182

Modeling and optimizing sensor networks for a specific environment will help missions narrow in on shooter locations

Reports and Proceedings

ACOUSTICAL SOCIETY OF AMERICA

 

IMAGE: LUISA STILL, OF SENSOR DATA AND INFORMATION FUSION, WILL DISCUSS THE IMPORTANT FACTORS IN DETERMINING SHOOTER LOCALIZATION ACCURACY AT THE 182ND ASA MEETING. view more 

CREDIT: LUISA STILL

DENVER, May 23, 2022 – During a gunshot, two sound events occur: the muzzle blast and the supersonic shock wave. Acoustic sensors, such as single or arrays of microphones, can capture these sounds and use them to approximate the location of a shooter.

As part of the 182nd Meeting of the Acoustical Society of America at the Sheraton Denver Downtown Hotel, Luisa Still, of Sensor Data and Information Fusion, will discuss the important factors in determining shooter localization accuracy. Her presentation, "Prediction of shooter localization accuracy in an urban environment," will take place May 23 at 12:45 p.m. Eastern U.S.

In an urban setting, buildings or other obstacles can reflect, refract, and absorb sound waves. The combination of these effects can severely impact the accuracy of shooter localization. Preemptively predicting this accuracy is crucial for mission planning in urban environments, because it can inform the necessary number of sensors and their requirements and positions.

Still and her team used geometric considerations to model acoustic sensor measurements. This modeling, combined with information on sensor characteristics, the sensor-to-shooter geometry, and the urban environment, allowed them to calculate a prediction of localization accuracy.

"In our approach, the prediction can be interpreted as an ellipse-shaped area around the true shooter location," said Still. "The smaller the ellipse-shaped area, the higher the expected localization accuracy."

The group compared their accuracy prediction to experimental performance under various geometries, weapons, and sensor types. The localization accuracy depended significantly on the sensor-to-shooter geometry and the shooting direction with respect to the sensor network. The smaller the distance between the shooting line and a sensor, the more accurate they could be with their prediction of the source. Adding more sensors increased the accuracy but had diminishing returns after a certain point.

"Each urban environment is too individual (e.g., in terms of layout, building types, vegetation) to make a general recommendation for a sensor set up," said Still. "This is where our research comes in. We can use our approach to recommend the best possible setup with the highest accuracy for a given location or area."

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Diamond mirrors for high-powered lasers

Diamonds can withstand the heat from high-powered, continuous beam lasers

Peer-Reviewed Publication

HARVARD JOHN A. PAULSON SCHOOL OF ENGINEERING AND APPLIED SCIENCES

 

IMAGE: ILLUSTRATION OF A HIGH-POWERED CONTINUOUS LASER HITTING NANOSTRUCTURES ON A DIAMOND MIRROR. view more 

CREDIT: (CREDIT: LONCAR LAB/HARVARD SEAS)

Just about every car, train and plane that’s been built since 1970 has been manufactured using high-power lasers that shoot a continuous beam of light. These lasers are strong enough to cut steel, precise enough to perform surgery, and powerful enough to carry messages into deep space. They are so powerful, in fact, that it’s difficult to engineer resilient and long-lasting components that can control the powerful beams the lasers emit. 

Today, most mirrors used to direct the beam in high-power continuous wave (CW) lasers are made by layering thin coatings of materials with different optical properties. But if there is even one, tiny defect in any of the layers, the powerful laser beam will burn through, causing the whole device to fail. 

If you could make a mirror out of a single material, it would significantly reduce the likelihood of defects and increase the lifespan of the laser. But what material would be strong enough?

Now, researchers at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) have built a mirror out of one of the strongest materials on the planet: diamond. By etching nanostructures onto the surface of a thin sheet of diamond, the research team built a highly reflective mirror that withstood, without damage, experiments with a 10-kilowatt Navy laser. 

"Our one-material mirror approach eliminates the thermal stress issues that are detrimental to conventional mirrors, formed by multi-material stacks, when they are irradiated with large optical powers,” said Marko Loncar, the Tiantsai Lin Professor of Electrical Engineering at SEAS and senior author of the paper. “This approach has potential to improve or create new applications of high-power lasers.” 

The research is published in Nature Communications. 

Loncar’s Laboratory for Nanoscale Optics originally developed the technique to etch nanoscale structures into diamonds for applications in quantum optics and communications. 

“We thought, why not use what we developed for quantum applications and use it for something more classical,” said Haig Atikian, a former graduate student and postdoctoral fellow at SEAS and first author of the paper. 

Using this technique, which uses an ion beam to etch the diamond, the researchers sculpted an array of golf-tee shaped columns on the surface on a 3-milimeter by 3-milimeter diamond sheet. The shape of the golf tees, wide on top and skinny on the bottom, makes the surface of the diamond 98.9% reflective. 

“You can make reflectors that are 99.999% reflective but those have 10-20 layers, which is fine for low power laser but certainly wouldn’t be able to withstand high powers,” said Neil Sinclair, a research scientist at SEAS and co-author of the paper. 

To test the mirror with a high-power laser, the team turned to collaborators at the Pennsylvania State University Applied Research Laboratory, a Department of Defense designated U.S. Navy University Affiliated Research Center.

There, in a specially designed room that is locked to prevent dangerous levels of laser light from seeping out and blinding or burning those in the adjacent room, the researchers put their mirror in front of a 10-kilowatt laser, strong enough to burn through steel.  

The mirror emerged unscathed. 

“The selling point with this research is that we had a 10-kilowatt laser focused down into a 750-micron spot on a 3-by-3-millimeter diamond, which is a lot of energy focused down on a very small spot, and we didn’t burn it,” said Atikian. “This is important because as laser systems become more and more power hungry, you need to come up with creative ways to make the optical components more robust.”

In the future, the researchers envision these mirrors being used for defense applications, semiconductor manufacturing, industrial manufacturing, and deep space communications. The approach could also be used in less expensive materials, such as fused silica. 

Harvard OTD has protected the intellectual property associated with this project and is exploring the commercialization opportunities.

The research was co-authored by Pawel Latawiec, Xiao Xiong, Srujan Meesala, Scarlett Gauthier, Daniel Wintz, Joseph Randi, David Bernot, Sage DeFrances, Jeffrey Thomas, Michael Roman, Sean Durrant and Federico Capasso, the Robert L. Wallace Professor of Applied Physics and Vinton Hayes Senior Research Fellow in Electrical Engineering at SEAS. 

This research was performed in part at the Center for Nanoscale Systems (CNS), a member of the National Nanotechnology Coordinated Infrastructure Network (NNCI), which is supported by the National Science Foundation under NSF award no. 1541959. It was supported in part by the Air Force Office of Scientific Research (MURI, grant FA9550-14-1-0389), the Defense Advanced Research Projects Agency (DARPA, W31P4Q-15-1-0013), STC Center for Integrated Quantum Materials and NSF Grant No. DMR-1231319.

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JOURNAL

Nature Communications

DOI

10.1038/s41467-022-30335-2 

CAPTION

Zoomed SEM image of the mirror (Credit: Loncar Lab/Harvard SEAS)

CREDIT

(Credit: Loncar Lab/Harvard SEAS)