Thursday, February 09, 2023

Biosensors change the way water contamination is detected


Social scientist and synthetic biologist collaborate to tackle a global challenge

Peer-Reviewed Publication

NORTHWESTERN UNIVERSITY

A family in rural Kenya tests water quality 

IMAGE: A FAMILY IN RURAL KENYA FIELD TEST THE POINT-OF-USE FLUORIDE BIOSENSORS. view more 

CREDIT: CREDIT: JANET BARSOLAI

EVANSTON, Ill. --- Scientists from Northwestern University have collaborated on the implementation of an accurate, low-cost and easy-to-use test for detecting toxic levels of fluoride in water.

The new biosensor device developed at Northwestern has been field tested in rural Kenya, providing evidence that water testing for fluoride can be easily used outside of a lab and accurately interpreted by nonexperts.

Worldwide, it is estimated that tens of millions of people live in areas where the water supply is contaminated with toxic levels of naturally occurring fluoride, a colorless, odorless and tasteless substance. The scale of the issue has been difficult to measure because of the high cost or complexity of available testing options.

A major step toward addressing global health concerns over access to safe drinking water, the new proven testing method is the result of a rare collaboration between researchers in the fields of anthropology and synthetic biology.

Study findings will be published by NPJ Clean Water on Feb. 8, 2023, at 10 a.m. GMT/4 a.m. CST. After publishing the paper can be accessed here.

The study was co-led by Northwestern anthropologist Sera Young and synthetic biologist Julius Lucks. Young is an associate professor of anthropology and global health studies at Weinberg College of Arts and Sciences and a faculty fellow at the Institute for Policy Research (IPR). Lucks is professor and associate chair of chemical and biological engineering at McCormick School of Engineering. Lucks is also co-director of the Northwestern Center for Synthetic Biology, where Young is also a faculty member.

Young and Lucks say it is the first time they have collected field data together, and it shows what’s possible when social scientists and synthetic biologists put their heads together to address global challenges.

The project builds upon and finds a unique intersection for prior research conducted by both Lucks and Young, who are married.

In 2017, Young and colleagues developed the Water Insecurity Experiences Scales to provide a measurement of global water insecurity that takes human experiences into account. Young partnered with the Gallup World Poll to publish estimates for half of the globe using the WISE scale in 2022 in Lancet Planetary Health.

Prompted by Young’s research, Lucks and his lab began to investigate naturally occurring biosensors — molecules used by microbes to sense for the presence of contaminants. In 2020, they published work on repurposing biosensors in a cell-free synthetic biology system, allowing the detection of harmful water contaminants such as fluoride in the field, naming the technology platform ROSALIND.

To further Young’s research on improving global water security, the latest iteration of the Lucks Lab’s ROSALIND technology improved the speed and usability of the device to allow for easy transport to locations where harmful levels of fluoride are a safety concern.

The research team collected 57 water samples from 36 households in rural Kenya to evaluate the accuracy of the fluoride concentration measurement when compared with the gold-standard method of fluoride photometer. They also designed their studies to examine whether test results would be easily interpreted by non-expert users, a key indicator that the technology can have meaningful impact in addressing the global water crisis.

Results were excellent, showing that the point-of-use had an 84% chance of correctly predicting fluoride levels above the World Health Organization limit of more than 1.5 parts per million.

The tests also were found to be highly usable, with only 1 of 57 tests with an interpretation discrepancy between the user and scientific team.

“This is a whole new way to measure water quality,” Young said. “The study shows that we can get a test into people’s hands that is based on some very complex biology but works very simply.”

“It also points to the feasibility of such tests for other chemicals like lead and PFAS,” Lucks said.

Potential next steps for the point-of-use fluoride test could include mapping where geogenic fluoride is located globally.

Closer to home in Chicago, Young and Lucks are interested in investigating the usability of an at-home test for rapidly detecting lead in water, and in leveraging this study as a model for interfacing social sciences with synthetic biology to increase the impact of synthetic biology innovations.

The study, “The accuracy and usability of point-of-use fluoride biosensors: a field study in Nakuru County, Kenya,” will appear online Feb. 8, 2023, in Nature Partner Journals: Clean Water.

This work was supported by the Carnegie Corporation; Northwestern University’s Institute for Policy Research and the Crown Family Center for Jewish and Israel Studies; the support of the American people provided to the Feed the Future Sustainable Intensification Innovation Lab through the United States Agency for International Development Cooperative Agreement AID-OAA-L-14-00006; and the United States Army Contracting Command W52P1J-21-9-3023.

Artificial sweetener as wastewater tracer

New study by the University of Vienna shows what the sweetener acesulfame reveals about groundwater flows

Peer-Reviewed Publication

UNIVERSITY OF VIENNA

Acesulfame is a sweetener in sugar-free drinks and foods. As it cannot be metabolised in the human body, the sweetener ends up in wastewater after consumption and remains largely intact even in sewage treatment plants. A new study by the University of Vienna shows that the persistence of the sweetener varies with temperature as the concentration of the sweetener in wastewater varies with the seasons. The environmental geosciences team analysed how groundwater flows can be traced based on these seasonal fluctuations. Since residues of the sweetener end up in drinking water, acesulfame serves as an indicator of the origin and composition of our drinking water. The study has now been published in the journal Water Research.

The sugar substitute acesulfame is one of the most commonly used sweeteners in Europe. It is almost 200 times sweeter than sugar and temperature-stable, making it suitable for sugar-free baking and for sweetening most diet lemonades. Because the human body does not metabolise the substance, it ends up in wastewater when consumed in large quantities and remains there even after treatment, but in fluctuating concentrations. The new study by the University of Vienna shows that the substance is broken down to varying degrees over the year depending on the temperature. "For a long time, it was assumed that the potassium salt of acesulfame is not degraded at all in wastewater treatment plants. This is still true, but only in the cold season," explains Thilo Hofmann, deputy head of the Centre for Microbiology and Environmental Systems Science at the University of Vienna. "There were already initial indications that at least partial biodegradation takes place in summer. We can prove this in our study and systematically show for a longer period of time how the concentration of the sweetener in the water changes with the seasons."

Sweetener acesulfame: indicator for the flow paths of wastewater treated in sewage treatment plants

Acesulfame is a widely used indicator of wastewater discharges into surface waters and groundwater: since this sweetener is not completely degraded both in wastewater treatment plants and in the environment – after it has been discharged into water bodies with the treated wastewater – a detection of the substance in water indicates that and how much treated wastewater has entered groundwater, rivers or lakes. "If you follow the traces of the substance, you can ultimately trace flow paths of the wastewater and its mixing with groundwater," Hofmann explains. With the knowledge of seasonal fluctuations in the degradation of the substance, acesulfame becomes an even more meaningful tracer.

Computer models of groundwater flows enable risk prevention

"Our study shows that the seasonally fluctuating concentration of acesulfame can be used to better visualise and understand the processes in the subsurface, i.e. groundwater flows," says Hofmann. Wastewater components in drinking water can be recorded as well as the flow velocity of the groundwater and the mixing ratios of groundwater and river water. The environmental geoscientists evaluated river and groundwater samples that were collected regularly over eight years in a pre-alpine catchment. The research team linked their analyses to computer models that calculate water flows in the subsurface. "Such computer models are the key to risk prevention, because they can be used to understand how much river water and how much groundwater end up in the population's drinking water and how to optimise the operation of waterworks," adds the head of the research group. 

Traces of the sweetener end up in drinking water

The sweetener acesulfame thus lays a tracer trail from wastewater to river and groundwater and finally to our drinking water. "The fact that acesulfame is not degraded is basically a good thing for us hydrogeologists, because we can draw valuable information from it," says Hofmann. He adds: "However, this fact also makes us aware of our lifestyle being reflected in the wastewater and thus also in the drinking water: The sugar substitute we consume ends up back in our drinking water – albeit heavily diluted, of course."

New evolutionary insights from stepping outside the lab

In order to study fruit fly phenotypes, EMBL´s Crocker group uses unusual approaches to uncover surprising results

Peer-Reviewed Publication

EUROPEAN MOLECULAR BIOLOGY LABORATORY

Crocker Lab Fruit Fly 

IMAGE: EMBL SCIENTISTS JUSTIN CROCKER AND LAUTARO GANDARA USED FOOD SOURCES INCORPORATING FRUIT GROWN IN AND AROUND EMBL IN THEIR EXPERIMENTS THAT BRIDGE NATURAL AND LAB ENVIRONMENTS TO UNDERSTAND THE EVOLUTION OF PHENOTYPES. view more 

CREDIT: EMBL/ KINGA LUBOWIECKA

Most of his career, Justin Crocker, EMBL Heidelberg Group Leader, has been working at the interface of development and evolution. In two new studies led by Crocker, scientists have shown how using non-standard laboratory conditions and synthetic biology approaches can help us understand fundamental mechanisms that regulate the development and evolution of phenotypes.

In this, they are part of the growing field of phenomics – the systematic study of an organism’s traits and how they vary and change during development as well as in response to the environment. Phenotypic evolution becomes particularly interesting in light of global concerns such as climate change, where many animals are under pressure to adapt quickly to fast-changing environments.

The significance of studying phenotypes

Phenotypes are the observable characteristics of an organism – features such as behaviour, appearance, metabolism, gene expression patterns, etc. They result from interactions between the genotype – the information contained in DNA, and the environment. The phenotypes any organism exhibits often depend on precise decisions regarding which genes are expressed where and when.

In the two publications, the Crocker group and their collaborators provide novel insights into some of the key processes that determine the robustness of phenotypes and the appearance of new phenotypes during development. 

This knowledge can help researchers better understand how diversity emerges during evolution in animals, and perhaps even predict ecological and environmental patterns of change in the phenotypes of wild animal populations.

Studying phenotypes in laboratories vs “the wild”

Biologists often study organisms under well-standardised laboratory conditions to ensure rigour and reproducibility. However, this also increases the risk of missing effects that only become apparent outside of these narrow ranges of conditions.

Using fruit-fly embryos and a variety of other model systems, Crocker and his team have been demonstrating  the importance of moving beyond standardised laboratory conditions and challenging established assumptions when it comes to understanding the development and evolution of phenotypes. 

The team used food sources incorporating fruit grown in and around the EMBL Heidelberg campus in their experiments that bridge natural and lab environments to understand the evolution of phenotypes.

In their experiments, they found that the loss of a certain epigenetic mark, the H3K4 monomethylation, led to changes in behaviour, gene expression, metabolism, and even rates of offspring production.

“This epigenetic mark is present throughout the genome, but its deletion seems to have little to no impact on gene expression, which led scientists to hypothesise that it doesn’t play a major role in normal development and function,” said first co-author Albert Tsai, team leader at the Centre de Recherche en Biologie cellulaire de Montpellier (CRBM), former postdoc in the Crocker lab.

H3K4 monomethylation is found ubiquitously in almost every cell’s nucleus. “That led us to question why there is such an evolutionary drive to create these marks if it’s actually doing nothing,” said Tsai. The Crocker group was sure that they were missing something.

The scientists observed that the loss of H3K4 monomethylation led to changes, especially when the fruit-flies were fed on natural food sources, including fruit collected in and around the EMBL campus. In the absence of this mark, certain traits became sensitive to environmental conditions and to different genetic backgrounds. When exposed to high temperatures or when certain background genes were mutated, the organisms likewise responded differently. 

“It challenges the current paradigm of standardising experiments as much as possible to focus on very specific conditions,” said Tsai. “We need to come up with controlled ways of bringing more natural environments into the lab.”

Synthetic biology and the study of phenotypes

In a second study, Crocker and his team questioned how new phenotypes emerge in the first place. This is a central question in evolutionary biology – for organisms to accumulate small changes that would be selected by the environment, there must be a way to continuously, quickly, and easily introduce variation in phenotypes.

While our genomes often accumulate small changes – called mutations – over time, these don’t always result in changes in phenotypes, or observable traits.

The team began by studying the expression of various genes in fruit fly embryos with point mutations – single-nucleotide DNA changes – in enhancer regions of the genome. “What we quickly started to appreciate was that while gene expression levels changed in these mutants, it always remained within the same regions,” said Rafael Galupa, first author of the paper and former postdoc in the Crocker lab. In other words, if a gene is usually active in the gut, for example, its expression levels increased or decreased as a result of the mutations, but did not shift to a different tissue, e.g. the muscle. “So we started wondering, what does it take to get expression elsewhere?” said Galupa, who is currently on his way to establishing his independent lab in Centre de Biologie Intégrative, Toulouse (France). “Ultimately in the course of evolution, how do you get new functions?”

Next, the team introduced completely random sequences into the genome instead. In a natural context, random DNA sequences may arise in the genome due to viruses, or transposons – mobile genetic elements that actively move between different parts of the genome. 

To the researchers’ surprise, with their synthetic DNA approach, they found that random sequences easily drove gene expression, and in all parts of the embryo.

 “We have been talking about doing this for a long time, and everybody thought it was a bit crazy. Then we just went ahead and did it,” said Crocker. “In the field we often think about how expression is generated, how to activate genes, etc. This study makes us think that if any random sequence can drive expression, and we have a genome with millions of sequences – maybe the question is not so much how do you generate expression but how do you repress or control it.”

In future studies, the Crocker lab will continue to look deeply into the mechanisms that connect genotype and environment to phenotypes.

How do sustainable behaviors spread? The solutions of the new ERC Consolidator Grant Green Tipping

Grant and Award Announcement

UNIVERSITÀ DI BOLOGNA

Alessandro Tavoni 

IMAGE: GREEN TIPPING IS A NEW RESEARCH PROJECT LED BY ALESSANDRO TAVONI, PROFESSOR AT THE DEPARTMENT OF ECONOMICS AT THE UNIVERSITY OF BOLOGNA, AND FUNDED BY THE EUROPEAN RESEARCH COUNCIL (ERC) WITH A CONSOLIDATOR GRANT WORTH EUR 1.8 MILLION. view more 

CREDIT: UNIVERSITY OF BOLOGNA

To meet the challenge of ecological transition, technological solutions and economic decisions are not enough. Behavioural changes, both individual and societal, are also needed. But how can these changes be fostered? How widespread does a new positive behaviour have to be for even the most sceptical to commit to it?

This is the topic that Green Tipping will focus on. This new project is led by Alessandro Tavoni, professor at the Department of Economics at the University of Bologna, and was funded by the European Research Council (ERC) with a Consolidator Grant worth EUR 1.8 million.

"We know that it is very difficult to get people to abandon long-established behaviours, including those that are perpetuating dependence on fossil fuels, and this limits the effectiveness of policy choices, preventing the changes that would be necessary," Tavoni explains. "To overcome this obstacle, we are studying solutions to promote the adoption of positive behaviour in a targeted manner in order to reach a threshold beyond which a new sustainable behaviour spreads autonomously across the entire population."

In these cases, it is referred to as Social Tipping Interventions (STI), i.e. actions that promote positive changes that can spread across society. This is an emerging field of analysis that until now has only been analysed on a theoretical level or with small-scale experiments. The aim of Green Tipping is to explore these tools to find solutions for large-scale sustainable changes in individual and social behaviour.

"During the project, we will identify the conditions necessary to abandon widespread but climate-damaging social norms, and then test their effectiveness on a number of representative samples in different countries," explains Tavoni. "From the data gathered, we will then be able to fine-tune the identified solutions with controlled group experiments on specific targets, and then assess their social diffusion potential in the real world."

New economic model finds Fracture Liaison Services are highly effective

The newly developed model to estimate the health benefits and budget impact of Fracture Liaison Services (FLS) is an important tool to drive the prioritization of FLS provision within healthcare systems

Peer-Reviewed Publication

INTERNATIONAL OSTEOPOROSIS FOUNDATION

Extra cost and quality of life year gains of Fracture Liaison Services (FLS) compared to current practice by year 

IMAGE: THE BARS IN THE FIGURE INDICATE THE EXCESS TOTAL COST (IE, HEALTH AND SOCIAL CARE COSTS AS WELL AS THOSE REQUIRED FOR FRACTURE LIAISON SERVICE [FLS] OPERATION) IN LOCAL CURRENCY OF FLSS ABOVE THE TOTAL COST UNDER CURRENT PRACTICE PER YEAR. THE ORANGE LINE TRACKS THE NUMBER OF ADDITIONAL QUALITY-ADJUSTED LIFEYEARS (QALY) GAINED BY IMPLEMENTING FLSS (IE, ABOVE THOSE EXPECTED TO BE ACHIEVED WITHOUT THEM) PER YEAR. ADAPTED FIG. 2 OF PINEDO-VILLANUEVA ET AL. EXPECTED BENEFITS AND BUDGET IMPACT FROM A MICROSIMULATION MODEL SUPPORT THE PRIORITISATION AND IMPLEMENTATION OF FRACTURE LIAISON SERVICES. DOI: 10.1002/JBMR.4775 view more 

CREDIT: FROM PINEDO-VILLANUEVA ET AL. EXPECTED BENEFITS AND BUDGET IMPACT FROM A MICROSIMULATION MODEL SUPPORT THE PRIORITISATION AND IMPLEMENTATION OF FRACTURE LIAISON SERVICES. DOI: 10.1002/JBMR.4775

New research reveals that widespread Fracture Liaison Service (FLS) implementation would benefit patient outcomes, manifested in a significant reduction in subsequent fragility fractures and gains in quality of life, whilst at the same time reducing hospital bed days, surgeries, need for institutional social care, and their associated costs.

With populations ageing, the burden of fragility fractures on healthcare systems around the world is on the rise, resulting in a spiral of increased patient disability, loss of independence, and early mortality within the older population. Given that patients with a fragility fracture are at substantially high risk of subsequent fractures, effective secondary fracture prevention is of critical importance. In this regard, FLS have been shown to be an optimal way to systematically identify, assess, treat, and monitor patients who have recently sustained a fragility fracture, and they have been proven to reduce the risk of subsequent fractures in numerous studies and reviews.

Associate Professor Kassim Javaid, Lecturer in Metabolic Bone Disease and Honorary Consultant Rheumatologist, NDORMS, University of Oxford, UK, co-author of the study, stated:

“Although FLSs are highly effective in reducing the risk of subsequent fragility fractures and improving patient outcomes, the majority of healthcare settings that manage adult fracture patients do not have an FLS in place. In the European Union for example, 50% of countries reported FLS coverage in less than 10% of hospitals. We know that a major barrier to sustainable effective FLS implementation is a lack of national, regional, and local policy prioritisation and reimbursement. This new model makes visible both the invisible costs of fragility fracture and the expected net benefits from systematic FLS provision to patients and their families, clinicians, healthcare systems, and wider society. The flexibility of the model allows its implementation across different types of healthcare systems and populations and provides clear outputs tailored to a wide audience, giving decision makers critical information based on their local data to appropriately prioritise local implementation of FLS for patient benefit.”  

The microsimulation model estimates the impact of FLSs compared to current practice for men and women 50 years of age or older with a fragility fracture. It provides estimates for health outcomes that include subsequent fractures avoided and quality-adjusted life years (QALYs), as well as resource use, and health and social care costs, including those necessary for FLSs to operate, over five years. 

Based on an exemplar country the size of the United Kingdom, FLSs were estimated to lead to a reduction of 13,149 subsequent fractures and a gain of 11,709 QALYs over the first five years of FLS implementation. Hospital bed days would be reduced by 120,989 and surgeries by 6,455, whilst 3,556 person-years of institutional social care would be avoided. Expected costs per QALY gained placed FLSs as highly cost-effective at £8,258 per QALY gained over the first five years alone.

Associate Professor Rafael Pinedo-Villanueva, Senior Health Economist, NDORMS, University of Oxford, first author of the study, explains:

“With healthcare budgets being limited and increased pressures on healthcare providers, policy makers need to make informed decisions based not only on necessary investments but also on expected benefit to patients, impact on healthcare resource use, and cost impacts before they can prioritise secondary fracture prevention in relation to other health priorities. This model acts as a calculator for all these relevant outcomes and can be run for any country or region. When run with values for a country the size of the United Kingdom, it shows that the initial investment in FLS implementation, where extra costs are concentrated in the first year, is worthwhile. The costs then drop significantly thereafter as we see gains in QALYs over time as more and more fractures are avoided.”

“Further work to develop country-specific models is currently underway, and we expect that this will deliver crucial national-level data that can then be used to inform policy makers at the country level.”

The development of the model was carried out by experts from the University of Oxford and supported by the International Osteoporosis Foundation (IOF) Capture the Fracture® initiative, a programme which works to drive the implementation and sustainability of FLS worldwide, and which offers best-practice guidance and recognition to more than 800 FLS in all regions of the world. 

Professor Cyrus Cooper, IOF President and co-author, concluded:

“This important model, essentially an ‘FLS cost and benefit’ calculator, provides significant evidence that secondary fracture prevention through FLS service provision is highly cost effective, with significant benefits for patients, their families, the healthcare system, and society as a whole.”

###

Further reading
•    Rafael Pinedo-Villanueva, Edward Burn, Christopher Maronga, Cyrus Cooper, M. Kassim Javaid. Expected benefits and budget impact from a microsimulation model support the prioritisation and implementation of Fracture Liaison Services doi: 10.1002/jbmr.4775
•    What is a Post-Fracture Care Coordination Program / Fracture Liaison Service 
•    Policy report: Capture the Fracture® Partnership Guidance for Policy Shaping

About Capture the Fracture®
Capture the Fracture® (CTF) is a multi-stakeholder initiative, led by the International Osteoporosis Foundation (IOF), to facilitate the implementation of Post-Fracture Care (PFC) Coordination Programs, such as Fracture Liaison Services (FLS), for secondary fracture prevention. The CTF initiative, which celebrated its 10th year of service in 2022, aims to drive changes at local and regional levels to prioritize secondary fracture prevention. It sets global best practice standards and offers recognition for Fracture Liaison Services (FLS) through its Best Practice Framework. CTF also provides essential resources and documentation to build the case for prioritization of secondary fracture prevention and to help drive the implementation and quality improvement of FLS. Mentorship programs that support the development of FLS at the local level are also offered.

The Capture the Fracture® Partnership, a global initiative launched in 2020, is a collaboration between the International Osteoporosis Foundation (IOF), the University of Oxford, Amgen and UCB, amplifying the Capture the Fracture programme launched in 2012. It seeks to address the global health burden of osteoporosis through five interconnected pillars, following a comprehensive, top-down and bottom-up approach, and aligning stakeholders at the international, national and local level in prioritized countries across the Asia Pacific, Europe, Latin America and the Middle East. The aim is to prioritize PFC and drive more rapid uptake of PFC coordination programs around the world.

Currently, the CTF network includes 813 FLS in 53 countries worldwide. FLS are invited to apply for free assessment and recognition via the CTF website’s online Best Practice Framework application platform. https://www.capturethefracture.org   #CaptureTheFracture

About IOF
The International Osteoporosis Foundation (IOF) is the world's largest nongovernmental organization dedicated to the prevention, diagnosis, and treatment of osteoporosis and related musculoskeletal diseases. IOF members, including committees of scientific researchers as well as more than 300 patient, medical and research organizations, work together to make fracture prevention and healthy mobility a worldwide heath care priority. https://www.osteoporosis.foundation   @iofbonehealth

About NDORMS 
The largest European academic department in its field, NDORMS is part of the Medical Sciences Division of the University of Oxford. It runs a multi-disciplinary programme of research and teaching, supported by an extensive grant portfolio. The Department is a growing community of over 500 staff, approximately 100 post-graduate students, more than 30 professors, several university lecturers, and senior researchers. Its highly skilled team has expertise in a broad range of areas, including orthopaedic surgery, inflammation, immunology, rheumatology, medical statistics, epidemiology, data science and clinical trials. The research work at NDORMS takes place across three world-leading research institutes: the Botnar Institute for Musculoskeletal Sciences, the Kennedy Institute for Rheumatology and the Kadoorie Centre. The co-location with NHS services at Oxford's Nuffield Orthopaedic Centre (NOC) puts the department in an excellent and rare position, where basic researchers work alongside clinicians. This substantially improves NDORMS’ research capability, improving access for researchers to patients, and facilitates the interaction between clinicians and scientists, which is essential for successful translational research. https://www.ndorms.ox.ac.uk/

Marine reserves unlikely to restore marine ecosystems

Study on carnivorous fish from shallow rocky sea bottoms

Peer-Reviewed Publication

UNIVERSITY OF BARCELON

Marine reserves unlikely to restore marine ecosystems 

IMAGE: THE STUDY USED VISUAL CENSUSES AND THE ANALYSIS OF STABLE ISOTOPES TO DETERMINE THE ABUNDANCE AND TROPHIC NICHE OF CARNIVOROUS FISH IN MARINE RESERVES AND AREAS OPEN TO FISHING view more 

CREDIT: LLUÍS CARDONA - UNIVERSITY OF BARCELONA

Protected marine areas are one of the essential tools for the conservation of natural resources affected by human impact —mainly fishing—, but, are they enough to recover the functioning of these systems? A study published in the ICES Journal of Marine Science, led by researchers from the Biodiversity Research Institute (IRBio) of the University of Barcelona, in collaboration with researchers from the Group of Ecosystem Oceanography (GRECO) of the Oceanographic Center of the Balearic Islands, highlights the limitations of marine reserves in restoring food webs to their pristine state prior to the impact of intensive fishing.

Protected marine areas are one of the essential tools for the conservation of natural resources affected by human impact —mainly fishing—, but, are they enough to recover the functioning of these systems? A study published in the ICES Journal of Marine Science, led by researchers from the Biodiversity Research Institute (IRBio) of the University of Barcelona, in collaboration with researchers from the Group of Ecosystem Oceanography (GRECO) of the Oceanographic Center of the Balearic Islands, highlights the limitations of marine reserves in restoring food webs to their pristine state prior to the impact of intensive fishing.

“This study shows that with only the small-scale marine reserves, it is not enough to conserve the functionality of marine ecosystems. In areas with an intense fishing pressure, both professional and recreational, exploited areas have more influence on small reserves”, says lecturer Lluís Cardona, from the Department of Evolutionary Biology, Ecology and Environmental Sciences of the Faculty of Biology and IRBio, and first signatory of the article.

The study is also signed by the researchers Fabiana Saporiti, Asunción Borrell and Àlex Aguilar (IRBIO-UB), and it includes the participation of the experts Joan Moranta and Olga Reñones (IEO-CSIC), and Adam Gouraguine, from Newcastle University (United Kingdom).

Study on carnivorous fish from shallow rocky sea bottoms

The researchers analysed, through underwater visual censuses, the number and size of carnivorous fish living on shallow rocky bottoms in the Mediterranean Sea and in temperate areas of the Atlantic Ocean, with the aim of assessing the effects of protection from fishing in marine reserves. They later used the technique of stable isotope analysis of carbon and nitrogen to see whether there had been a change in the diet of the species and, thus, in the food web.

In the Mediterranean, the samples were obtained in the Cabrera National Park (Majorca), in areas where this activity has been banned since 1991. These samples were compared to those from the west side of Majorca, where this activity is allowed. On the other hand, the samples from the Atlantic were obtained in the Cies Islands, a small archipelago that belongs to the Atlantic Islands of Galicia National Park, where certain types of fishing have been prohibited since 2002 (except for small-scale artisanal fishing), and other areas in the mouth of the adjacent Ria de Vigo, which are open to all fishing.

Effects on number and size of fish, but not on trophic structure

The results show a larger biomass and size of carnivorous fish from shallow rocky bottoms in the analysed marine reserves, compared to areas open to fishing. The most extreme examples were the dusky grouper (Epinephelus marginatus) in the Balearic Islands, and the sargo (Diplodus sargus) in Galicia, since the individuals larger than 45cm, as in the first case, and 26cm, in the second case, could only be found in the protected areas.

Apart from the positive effects, the study shows that the protection of fishing did not cause any significant change in the trophic structure of the carnivorous fish community in any of those two regions, although there were some changes in the diet of some species. According to the researchers, this indicates that the effects of the marine reserves in the Mediterranean Sea and the north-eastern areas of the Atlantic Ocean are “insufficient to help reconstruct the populations of some carnivorous fish and restore the size structure, as well as to provoke changes in the diet of certain species, but they are unlikely to induce the recovery of the trophic structure of pristine ecosystems prior to the intensification of fishing”.

The impact of the absence of sharks, dolphins and seals

These results would be explained due to the lack of large carnivorous fish and other highly mobile species, such as seals and coastal sharks, which are at the top of the food chain and have been affected by human exploitation. “Marine reserves favour the recovery of species such as the dusky grouper, but not other highly mobile and large species such as sharks, dolphins and seals. Even species such as the sea bass have problems recovering in Galicia’s marine reserves. The lack of these species is what prevents the emergence of differences in food webs between reserves and areas open to fishing, in the Mediterranean and the Atlantic, beyond the recovery of the biomass of some sedentary species”, says Lluís Cardona.

As a result, according to the researchers, the aims of the marine networks in regions where mobile predators have been depleted or have become extinct have to be rethought in “more realistic terms than the recovery of pristine conditions prior to intensive fishing, although in marine reserves some of the characteristics of the historical trophic structure, such as biomass and size structure of certain sedentary species, can be recovered".

In this sense, Luís Cardona thinks the focus of the future conservation of marine ecosystems regarding fishing has to be on “reducing the impact on highly mobile and large species in the areas that are open to fishing, since marine reserves alone can do little to protect these species”.

However, researchers note that the situation could be different in areas where human pressure has been lower and where there is still part of the original diversity of larger and highly mobile carnivorous fish, such as in the north-eastern Pacific Ocean, where populations of most of these species remain in good conditions thanks to the conservation measures applied throughout the territory.

  

The absence of highly mobile predators such as seals and sharks in marine reserves means that the original trophic structure of the fish community cannot be restored.

CREDIT

Manel Gazo - UNIVERSITY OF BARCELONA


How did ancient extreme climate affect sand in the deep sea?

Peer-Reviewed Publication

STANFORD UNIVERSITY

Geologists are interested in the sedimentary cycle – erosion from mountains that forms sand that is carried out to the ocean – because it’s foundational for understanding how the planet works.

It’s also crucial for understanding the global sand budget and planning offshore operations like oil extraction, wind farms, and carbon sequestration. Now, researchers have taken a broad look at ancient Earth’s sedimentary cycle during an extremely hot period in search of clues about the impacts of extreme climate events.

By synthesizing global data on deep-sea sand deposits, researchers identified a signal or “fingerprint” of extreme climate change from about 50 million years ago: turbidite deposits. These deposits, evidence of ancient rapid submarine water currents, are thought to be caused by the downslope transport of sediment that has accumulated at the top of the continental slope.

“This suggests that extreme weather events and exacerbated global climatic conditions contributing to increased erosion of landscapes could amplify delivery of sand into the deep ocean,” said Stanford University adjunct lecturer Zack Burton, PhD ’20, lead author on a study detailing the findings published Feb. 8 in Nature Scientific Reports.

High seas

The research challenges a long-held notion that sea-level changes are the dominant influence on sand deposits in the deep sea. When sea level is low, there’s a better chance for sediment eroded off mountains to find its way to the deep sea. Many researchers have theorized that high seas prevent sand from being deposited to deep seas because coastal plains and underwater continental shelves could be barriers to sand reaching deep waters.

But according to the study authors’ compilation of 59 instances of early Eocene turbidite systems active 56 million to 48 million years ago, climatic conditions and tectonic activity may be more important than sea-level changes for deep-sea sand deposition.

“We suspected this was true, but we hadn’t realized the magnitude of examples that have been documented in the literature,” said senior study author Stephan Graham, the Welton Joseph and Maud L’Anphere Crook Professor in the Stanford Doerr School of Sustainability. “There were many more of those deep-water deposits than we had realized.”

In the paper, the researchers present a conceptual model suggesting that conditions like intense precipitation and integrated river drainages can cause abundant sand-rich deep-marine deposits despite exceptionally high sea levels.

Hothouse planet

Earth during the early Eocene 56 million to 48 million years ago had the highest sea levels – with oceans over 200 feet above current levels – since before the sudden mass extinction of three-quarters of the planet’s plant and animal species about 66 million years ago. There were rainforests in the Arctic, and alligators lived in the Dakotas.

While some of these conditions may be unfathomable, present-day climate change is giving us glimpses of the extreme climate events that besieged the early Eocene.

“As the Earth gets hotter and hotter because CO2 increases the greenhouse effect and sea level rises even further, then we would expect the increasing intensity of storms, higher precipitation rates – based on climate modeling by other people – to have much more impact in terms of sediment getting to the deep sea,” Graham said.

While that may not be relevant anytime soon, the power of turbidity currents shouldn’t be underestimated for future-proofing the next generations. The sediment-laden flows known as turbidity currents are like the devastating glowing avalanches that cascade down erupting volcanoes, Graham said.

Researchers first found out about turbidity currents because they were snapping transatlantic telegraph cables in 1929. “They’re very powerful submarine flows of tremendous scale,” Burton said.

With this synthesis of turbidity deposits from such a critical time in Earth’s history, the researchers hope others will continue speculating about the aspects of warmer climates that may be impacting the global sedimentary cycle.

“Other factors, like human interactions with sedimentary systems and the terrestrial world we all live in, are combining to influence movement of sediment,” Burton said. “I think it’s hard to consider from an everyday perspective, just because we don’t see these systems – they’re part of the beautiful mystery of the deep ocean which we know so little about.”

Stanford co-authors include Tim McHargue and alumni Chris Kremer (now at Brown University), Jared Gooley (now at the U.S. Geological Survey Alaska Science Center), Chayawan Jaikla (now at Microsoft), and Jake Harrington. The research was supported by the Stanford Project on Deep-water Depositional Systems and Basin Processes and Subsurface Modeling programs.

 ‘Game-changing’ findings for sustainable hydrogen production: University of Surrey

Peer-Reviewed Publication

UNIVERSITY OF SURREY

Hydrogen fuel could be a more viable alternative to traditional fossil fuels according to University of Surrey researchers who have found that a type of metal-free catalysts could contribute to the development of cost-effective and sustainable hydrogen production technologies. 

The study has shown promising results for the use of edge-decorated nano carbons as metal-free catalysts for the direct conversion of methane, which is also a powerful greenhouse gas, into hydrogen. Among the nano carbons investigated, nitrogen-doped nano carbons presented the highest level of performance for hydrogen production at high temperatures. 

Crucially, the researchers also found that the nitrogen-doped and phosphorous-doped nano carbons had strong resistance to carbon poisoning, which is a common issue with catalysts in this process. 

Dr Neubi Xavier Jr, the Research Fellow who performed the material science simulations, said: 

"Our results suggest that using edge-decorated nano carbons as catalysts could be a game-changer for the hydrogen industry, offering a cost-effective and sustainable alternative to traditional metal catalysts. At the same time, this process gets rid of methane, which is a fossil fuel involved in global warming." 

Hydrogen fuel is a clean and renewable energy source that has the potential to reduce carbon emissions and decrease our dependence on fossil fuels. When used as a fuel, hydrogen can power vehicles, generate electricity, and heat buildings. The only by-product of hydrogen fuel is water vapour, making it an environmentally friendly alternative to traditional fossil fuels. 

However, the production of hydrogen fuel is currently reliant on fossil fuels, which creates carbon emissions in the process, and metal catalysts, which mining and manufacturing are energy intensive and can negatively affect the environment. Therefore, the development of sustainable hydrogen production methods and catalytic materials is crucial to realising the full potential of hydrogen fuel as a clean energy source. 

The research was conducted by a team led by Dr Marco Sacchi from the University of Surrey, an expert in the field of sustainable energy and computational chemistry, who combined quantum chemistry, thermodynamics and chemical kinetics to determine the most efficient edge decoration for hydrogen production. 

Dr Sacchi said: 

"One of the biggest challenges with catalysts for hydrogen production is that they can get poisoned by carbon. But our study found that nitrogen and phosphorous-doped nano carbons are pretty resistant to this problem. This is a huge step forward for sustainable hydrogen production."

The full article can be found in ACS Applied Materials & Interfaces. 

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· Reference: First Principles Microkinetic Modelling Unravelling the Performance of Edge-Decorated Nanocarbons for Hydrogen Production from Methane; Neubi F. Xavier Jr et al; ACS Applied Materials & Interfaces; January 2023; 10.1021/acsami.2c20937.