It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
Tuesday, December 01, 2020
TPU scientists develop eco-friendly hydrogel for agriculture
Scientists of Tomsk Polytechnic University, in cooperation with the Czech colleagues have developed a new hydrogel for agriculture. It is meant to retain moisture and fertilizers in soil. The difference of the new hydrogel from other formulations is that it is made entirely of natural components and degrades in soil into nontoxic products to humans, animals, and plants. The research results are published in the Journal of Cleaner Production (IF: 7, 246; Q1).
Hydrogels are used in agriculture and forestry to retain moisture in soil, which directly affects germination. They are also used in combination with fertilizers as hydrogels reduce volatilization of fertilizers and therefore control fertilizer release.
"Due to the hydrogels, plants require less watering and fertilization. On the one hand, it is important for fresh water conservation on the planet, on the other hand, it reduces the harmful effect of fertilizers to the soil. Most of the hydrogels available on the market are made of polyacrylamide and polyacrinolintrile. They are not fully biodegradable, that is why they are considered potential soil contaminants. Even though the components themselves are not toxic, their commercial formulations contain residual amounts of acrylamide, which is a neurotoxic and carcinogen substance. We used whey protein and alginic acid as primary components in our research work. These are affordable, natural and completely non-toxic components. This is the main advantage of our hydrogel," Antonio Di Martino, one of the article authors, associate professor of the TPU Research School of Chemistry & Applied Biomedical Sciences, says.
The process of obtaining the hydrogel suggested by the authors of the research is simple: the primary components must be mixed in a solution, dried, and compressed into a tablet. In contact with liquids, the substance swells and becomes gel-like.
"We also added urea in the mixture which is a well-known fertilizer. Over time, the hydrogel degrades in soil gradually and evenly releasing the fertilizer. Moreover, the hydrogel itself degrades into carbon and nitrogen over time, while nitrogen is a widely used macronutrient in agriculture and an essential structural material for plants. The laboratory experiments showed that the hydrogel can be used a few more times after a full release of moisture," Antonio Di Martino notes.
In the future, the scientists will continue experimenting and searching for new materials for a controlled application of fertilizers in soil.
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The scientists from Tomas Bata University in Zlín (the Czech Republic), Dairy Research Institute (the Czech Republic), and Research Institute for Soil and Water Conservation (the Czech Republic) took part in the research project.
An escape route for seafloor methane
Leakage from frozen layers was a puzzle, but a new study shows how the potent greenhouse gas breaks through icy barriers.
Methane, the main component of natural gas, is the cleanest-burning of all the fossil fuels, but when emitted into the atmosphere it is a much more potent greenhouse gas than carbon dioxide. By some estimates, seafloor methane contained in frozen formations along the continental margins may equal or exceed the total amount of coal, oil, and gas in all other reservoirs worldwide. Yet, the way methane escapes from these deep formations is poorly understood.
In particular, scientists have been faced with a puzzle. Observations at sites around the world have shown vigorous columns of methane gas bubbling up from these formations in some places, yet the high pressure and low temperature of these deep-sea environments should create a solid frozen layer that would be expected to act as a kind of capstone, preventing gas from escaping. So how does the gas get out?
A new study helps explain how and why columns of the gas can stream out of these formations, known as methane hydrates. Using a combination of deep-sea observations, laboratory experiments, and computer modeling, researchers have found phenomena that explain and predict the way the gas breaks free from the icy grip of a frozen mix of water and methane. The findings are reported today in the journal PNAS, in a paper by Xiaojing (Ruby) Fu SM '15, PhD '17, now at the University of California at Berkeley; Professor Ruben Juanes at MIT; and five others in Switzerland, Spain, New Mexico, and California.
Surprisingly, not only does the frozen hydrate formation fail to prevent methane gas from escaping into the ocean column, but in some cases it actually facilitates that escape.
Early on, Fu saw photos and videos showing plumes of methane, taken from a NOAA research ship in the Gulf of Mexico, revealing the process of bubble formation right at the seafloor. It was clear that the bubbles themselves often formed with a frozen crust around them, and would float upward with their icy shells like tiny helium balloons.
Later, Fu used sonar to detect similar bubble plumes from a research ship off the coast of Virginia. "This cruise alone detected thousands of these plumes," says Fu, who led the research project while a graduate student and postdoc at MIT. "We could follow these methane bubbles encrusted by hydrate shells into the water column," she says. "That's when we first knew that hydrate forming on these gas interfaces can be a very common occurrence."
But exactly what was going on beneath the seafloor to trigger the release of these bubbles remained unknown. Through a series of lab experiments and simulations, the mechanisms at work gradually became apparent.
Seismic studies of the subsurface of the seafloor in these vent regions show a series of relatively narrow conduits, or chimneys, through which the gas escapes. But the presence of chunks of gas hydrate from these same formations made it clear that the solid hydrate and the gaseous methane could co-exist, Fu explains. To simulate the conditions in the lab, the researchers used a small two-dimensional setup, sandwiching a gas bubble in a layer of water between two plates of glass under high pressure.
As a gas tries to rise through the seafloor, Fu says, if it's forming a hydrate layer when it hits the cold seawater, that should block its progress: "It's running into a wall. So how would that wall not be preventing it from continuous migration?" Using the microfluidic experiments, they found a previously unknown phenomenon at work, which they dubbed crustal fingering.
If the gas bubble starts to expand, "what we saw is that the expansion of the gas was able to create enough pressure to essentially rupture the hydrate shell. And it's almost like it's hatching out of its own shell," Fu says. But instead of each rupture freezing back over with the reforming hydrate, the hydrate formation takes place along the sides of the rising bubble, creating a kind of tube around the bubble as it moves upward. "It's almost like the gas bubble is able to chisel out its own path, and that path is walled by the hydrate solid," she says. This phenomenon they observed at small scale in the lab, their analysis suggests, is also what would also happen at much larger scale in the seafloor.
That observation, she said, "was really the first time we've been aware of a phenomenon like this that could explain how hydrate formation will not inhibit gas flow, but rather in this case, it would facilitate it," by providing a conduit and directing the flow. Without that focusing, the flow of gas would be much more diffuse and spread out.
As the crust of hydrate forms, it slows down the formation of more hydrate because it forms a barrier between the gas and the seawater. The methane below the barrier can therefore persist in its unfrozen, gaseous form for a long time. The combination of these two phenomena -- the focusing effect of the hydrate-walled channels and the segregation of the methane gas from the water by a hydrate layer -- "goes a long way toward explaining why you can have some of this vigorous venting, thanks to the hydrate formation, rather than being prevented by it," says Juanes.
A better understanding of the process could help in predicting where and when such methane seeps will be found, and how changes in environmental conditions could affect the distribution and output of these seeps. While there have been suggestions that a warming climate could increase the rate of such venting, Fu says there is little evidence of that so far. She notes that temperatures at the depths where these formations occur -- 600 meters (1,900 feet) deep or more -- are expected to experience a smaller temperature increase than would be needed to trigger a widespread release of the frozen gas.
Some researchers have suggested that these vast undersea methane formations might someday be harnessed for energy production. Though there would be great technical hurdles to such use, Juanes says, these findings might help in assessing the possibilities.
"The problem of how gas can move through the hydrate stability zone, where we would expect the gas to be immobilized by being converted to hydrate, and instead escape at the seafloor, is still not fully understood," says Hugh Daigle, an associate professor of petroleum and geosystems engineering at the University of Texas at Austin, who was not associated with this research. "This work presents a probable new mechanism that could plausibly allow this process to occur, and nicely integrates previous laboratory observations with modeling at a larger scale."
"In a practical sense, the work here takes a phenomenon at a small scale and allows us to use it in a model that only considers larger scales, and will be very useful for implementing in future work," Daigle says.
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The research team included Joaquin Jimenez-Martinez at the Swiss Federal Institute of Aquatic Science and Technology; Than Phon Nguyen, William Carey and Hari Vinaswanathan at Los Alamos National Laboratory; and Luis Cueto-Felgueroso at the Technical University of Madrid. The work was supported by the U.S. Department of Energy.
Written by David L. Chandler, MIT News Office
Caribbean coral reefs under siege from aggressive algae
An aggressive, golden-brown, crust-like alga is rapidly overgrowing shallow reefs, taking the place of coral that was damaged by extreme storms and exacerbating the damage caused by human activity
IMAGE: ORANGE PEYSSONNELID ALGAL CRUSTS SPREADING OVER A LOBE OF ORBICELLA ANNULARIS AT 14-METER DEPTH ON THE TEKTITE REEF ON THE SOUTHERN SHORE OF ST. JOHN, U.S. VIRGIN ISLANDS. view more
CREDIT: IMAGE COURTESY OF PETER EDMUNDS.
Baltimore, MD--Human activity endangers coral health around the world. A new algal threat is taking advantage of coral's already precarious situation in the Caribbean and making it even harder for reef ecosystems to grow.
Just-published research in Scientific Reports details how an aggressive, golden-brown, crust-like alga is rapidly overgrowing shallow reefs, taking the place of coral that was damaged by extreme storms and exacerbating the damage caused by ocean acidification, disease, pollution, and bleaching.
For the past four years, the University of Oxford's Bryan Wilson, Carnegie's Chen?Ming Fan, and California State University Northridge's Peter Edmunds have been studying the biology and ecology of peyssonnelid algal crusts, or PAC, in the U.S. Virgin Islands, which are out-competing coral larvae for limited surface space and then growing over the existing reef architecture, greatly damaging these fragile ecosystems.
"This alga seems to be something of an ecological winner in our changing world," described lead author Wilson, noting that the various other threats to coral communities make them more susceptible to the algal crusts.
Edmunds first took note of the crusts' invasive growth in the wake of category 5 hurricanes Irma and Maria when they were rapidly taking over spaces that had been blasted clean by the storms.
Corals are marine invertebrates that build large exoskeletons from which reefs are constructed. To grow new reef structures, free-floating baby corals first have to successfully attach to a stable surface. They prefer to settle on the crusty surface created by a specific type of friendly algae that grows on the local rocks. These coralline crustose algae, or CCA, acts as guideposts for the coral larvae, producing biochemical signals along with their associated microbial community, which entice the baby coral to affix itself.
What puzzled the researchers is that both the destructive PAC and the helpful CCA grow on rocks and create a crust, but PAC exclude coral settlement and CCA entices it. What drives this difference?
The team set out to determine how the golden-brown PAC affects Caribbean coral reefs, and found that the PAC harbors a microbial community that is distinct from the one associated with CCA, which is known to attract corals.
"These PAC crusts have biochemical and structural defenses that they deploy to deter grazing from fish and other marine creatures," explained Fan. "It is possible that these same mechanisms, which make them successful at invading the marine bio-space, also deter corals."
More research is needed to elucidate the tremendous success that the algal crusts are having in taking over Caribbean reef communities and to look for ways to mitigate the risk that they pose.
"There is a new genomic and evolutionary frontier to explore to help us understand the complexity of organismal interactions on the reef, both mutualistic and antagonistic," added Fan.
Edmunds concluded: "The coral and their ecosystem are so fragile as it is. They are under assault by environmental pollution and global warming. We have made their lives so fragile, yet they are sticking in there. And now this gets thrown into the mix. We don't know if this is the straw that breaks the camel's back, but we need to find out."
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This work was funded by a Long Term Research in Environmental Biology grant and a Rapid Response Research grant from the U.S. National Science Foundation.
Research was completed under permits issued by the Virgin Islands National Park.
The Carnegie Institution for Science (carnegiescience.edu) is a private, nonprofit organization headquartered in Washington, D.C., with three research divisions throughout the U.S. Since its founding in 1902, the Carnegie Institution has been a pioneering force in basic scientific research. Carnegie scientists are leaders in plant biology, developmental biology, astronomy, materials science, global ecology, and Earth and planetary science.
UN to issue first-ever global report on harmful algal blooms
After 7 years' work, 100+ experts in 112 countries deliver 1st global assessment of HABs, synthesizing three decades of data
IMAGE: MORE THAN 100 SCIENTISTS IN 112 COUNTRIES CONTRIBUTED TO A SYNTHESIS AND ANALYSIS OF HARMFUL ALGAL BLOOM DATA GATHERED FROM 1985 TO 2018 -- A FIRST-EVER BIG DATA APPROACH TO... view more
CREDIT: MELVIL JAPAN
A seven-year analysis of almost 10,000 Harmful Algal Blooms (HAB) events worldwide over three decades will be published by the HAB Programme of UNESCO's Intergovernmental Oceanographic Commission.
More than 100 scientists in 112 countries contributed to the synthesis and analysis of HAB data gathered from 1985 to 2018 -- a first-ever big data approach to detecting changes in the costly phenomenon's global distribution, frequency, and intensity.
The authors detail the health and economic damages caused by harmful microalgae, including:
Bioaccumulation of toxins in seafood (the most dominant HAB problem, broken down by both region and by algae species)
Toxic or non-toxic microalgae blooms causing discoloured water, scum, mucilage or foam, harming tourism and/or fisheries
Mass fish kills, including in aquaculture operations
High biomass, causing closures of e.g. beaches or desalination plants
The researchers also examine whether and how rising marine resource exploitation and other factors affect HAB events.
The work assesses the occurrence of toxin-producing and other harmful microalgae, and the status and probability of change in HAB frequencies, intensities, and range resulting from environmental change at the local and global scale.
Publication of the key findings in a prominent journal will be followed by a complete set of 13 papers to be published in a special edition of Harmful Algae.
Databases mined
Thousands of microalgae species form the foundation of aquatic food chains, help control atmospheric CO2 levels, and produce roughly half of the world's oxygen.
The troublemakers are approximately 200 species that can produce potent toxins or cause harm through their sheer biomass, plus a similar number of non-toxic species that can harm fish gills, impair the beauty of the sea with strange colours, scums and foams, or deplete oxygen.
The study involved mining the global Harmful Algae Event Database (HAEDAT), consisting of 9,503 events with one or more impacts on human society, together with the Ocean Biodiversity Information System (OBIS), which contains 7 million microalgal records including 289,668 toxic algal species occurrences.
Due to differences in the levels of monitoring worldwide, trends within the HAEDAT database were examined regionally and corrected for sampling effort using OBIS phytoplankton species records as a proxy.
The work creates the first-ever baseline to facilitate future tracking and detection of changes in the world's HAB problems, and to help manage the problems in future.
The only existing database of information about harmful algal events from around the world, summarized into 'events' associated with a management action or negative economic / ecological impact. Includes cases of non-toxic water discolorations, mucilage, anoxia or other damage to fish.
A database on the geographic range of harmful algal species
HAEDAT and OBIS are both components of the IOC International Oceanographic Data and Information Exchange Programme (IODE).
The IOC-UNESCO Taxonomic Reference List of Harmful Microalgae
Includes formally accepted names of 150+ planktonic or benthic microalgae that have been proven to produce toxins. The number of species in the list has doubled over the years.
The work will help future researchers determine:
1. The distribution of HAB species, HAB events, and toxins globally
2. How the geographic distribution, characteristic, frequency and intensity of HABs are changing and if these changes are attributable to global change
3. How climate change and other factors alter the impacts of HABs -- on human health, ecosystems, economics, food and water security
With more than 100 expert contributors from 112 countries, the work is piloted by 18 principal authors from 14 countries (including two from Australia, two from France, three from the USA):
· Gustaaf M. Hallegraeff, University of Tasmania, Australia
· Donald M. Anderson, Woods Hole Oceanographic Institution, USA
· Catherine Belin, IFREMER, France
· Marie-Yasmine Bottein, Ecotoxicologie et Développement Durable expertise, France
· Eileen Bresnan, Marine Scotland, UK
· Mireille Chinain, Institut Louis Malardé-UMR241, Tahiti
· Henrik Enevoldsen, Intergovernmental Oceanographic Commission of UNESCO, University of Copenhagen, Denmark
· Mitsunori Iwataki, University of Tokyo, Japan
· Cynthia H. McKenzie, Fisheries and Oceans Canada, Canada
· Inés Sunesen, CONICET - UNLP, Argentina
· Grant C. Pitcher, University of Cape Town, South Africa
· Pieter Provoost, Intergovernmental Oceanographic Commission of UNESCO, Oostende, Belgium
· Anthony Richardson, CSIRO Oceans and Atmosphere, and University of Queensland, Australia
· Laura Schweibold, Institut Universitaire Européen de la Mer, France
· Patricia A. Tester, Ocean Tester, USA
· Vera L. Trainer, National Oceanic and Atmospheric Administration, USA
· Aletta T. Yñiguez, University of the Philippines, Philippines
· Adriana Zingone, Stazione Zoologica Anton Dohrn, Italy
"The most frequently asked questions about Harmful Algal Blooms (HABs) are if they are increasing and expanding, and what are the mechanisms behind observed trends," the authors say.
"Indeed a global expansion of HABs and its causes have long been debated. Eutrophication, human-mediated introduction of alien harmful species, climatic variability, and aquaculture have all been mentioned as possible causes of an expansion and intensification of HABs. Our research sheds an authoritative light on the problem and will help guide responses to it for decades to come."
The IOC Intergovernmental Panel on HABs began the Global HAB Status Report in 2013.
The work is linked with the International Panel on Climate Change (IPCC) reporting mechanism, which increasingly is focusing on the biological impacts of climate change.
IOC UNESCO project partners include the International Atomic Energy Agency (IAEA), the International Council for Exploration of the Sea (ICES), the North Pacific Marine Science Organization (PICES) and the International Society for the Study of Harmful Algae (ISSHA). The initiative receives financial support from the Government of Flanders/FUST-DIPS.
Interested media and other parties may apply for advance, embargoed access to the papers, approximately one week prior to publication. Please email tc@tca.tc with the subject line: Advance access, UN HAB report
The Intergovernmental Panel on Harmful Algal Blooms (IOC-IPHAB), part of the Intergovernmental Oceanographic Commission of UNESCO, initiated the development of the Global HAB Status Report in Paris in April 2013, developed with the support of the Government of Flanders within the IOC International Oceanographic Data and Information Exchange (IODE) Programme, which manages both the Harmful Algae Event Data Base (HAEDAT) and the Ocean Biodiversity Information System (OBIS). Partners include ICES, PICES and IAEA.
OBIS focuses on the global distribution of all marine species including those HAB species that are toxic to humans and fish as covered by the IOC-UNESCO Taxonomic Reference list of Harmful MicroAlgae (a subset of the World Register of Marine Species), while HAEDAT holds information specifically on the HAB events that have adversely impact on human society, whether by high biomass (clogging of fishing nets, beach closures), aquaculture fish kills, or seafood toxin events leading to shellfish farm closures, human poisonings or even death.
IMAGE: DEVELOPING SEA URCHIN LARVAE ARE AFFECTED BY CHEMICALS FROM MARINE MICROPLASTICS. LEFT - NOT TREATED. RIGHT - TREATED. view more
CREDIT: EVA JIMENEZ-GURI
Plastics in the ocean can release chemicals that cause deformities in sea urchin larvae, new research shows.
Scientists soaked various plastic samples in seawater then removed the plastic and raised sea urchin embryos in the water.
The study, led by the University of Exeter, found that urchins developed a variety of abnormalities, including deformed skeletons and nervous systems.
These abnormalities were caused by chemicals embedded in the plastics leaching out into the water, rather than the plastics themselves.
The plastic-to-water ratio in the study would only be seen in severely polluted places, but the findings raise questions about the wider impact of plastic contaminants on marine life.
"We are learning more and more about how ingesting plastic affects marine animals," said Flora Rendell-Bhatti, of the Centre for Ecology and Conservation on Exeter's Penryn Campus in Cornwall.
"However, little is known about the effects of exposure to chemicals that leach into the water from plastic particles.
"This study provides evidence that contamination of the marine environment with plastic could have direct implications for the development of larvae, with potential impacts on wider ecosystems.
"Our work contributes to the growing evidence that we all need to help reduce the amount of plastic contamination released into our natural environment, to ensure healthy and productive ecosystems for future generations."
Dr Eva Jimenez-Guri, also of the Centre for Ecology and Conservation, added: "Many plastics are treated with chemicals for a variety of purposes, such as making them mouldable or flame retardant.
"If such plastics find their way to the oceans, these chemicals can leach out into the water.
"Plastics can also pick up and transport chemicals and other environmental contaminants, potentially spreading them through the oceans."
The study used pre-production "nurdles" (pellets from which most plastics are made) from a UK supplier, and also tested nurdles and "floating filters" (used in water treatment) found on beaches in Cornwall, UK.
For the tests, each plastic type was soaked in seawater for 72 hours, then the plastic was removed.
Analysis of the water showed all samples contained chemicals known to be detrimental to development of animals, including polycyclic aromatic hydrocarbons and polychlorinated biphenyls.
Water from the different kinds of plastic affected urchin development in slightly different ways, though all sample types led to deformity of skeletons and nervous systems, and caused problems with gastrulation (when embryos begin to take shape).
The study also raised urchin embryos in water that had contained "virgin" polyethylene particles that had not been treated with additive chemicals or collected any environmental pollutants.
These urchins developed normally, suggesting that abnormalities observed in other samples were caused by industrial additives and/or environmentally adsorbed contaminants - rather than the base plastics themselves.
Nurdles and floating filters are not waste products, so they are not deliberately discarded, but the study highlights the importance of preventing their accidental release.
The researchers say most plastics may have similar effects as those in the study, so the findings emphasise the importance of finding alternatives to replace harmful additives, and reducing overall marine plastic pollution.
CAPTION
The skeleton (green) and nervous system (magenta) of sea urchin larvae are affected by chemicals from microplastics. Left - not treated. Right - treated.
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The study team included the Stazione Zoologica Anton Dohrn (Naples, Italy) and the Institute of Oceanology at the Polish Academy of Sciences (Sopot, Poland).
It was funded by the European Union's Horizon 2020 programme and the Natural Environment Research Council.
The paper, published in the journal Environmental Pollution, is entitled: "Developmental toxicity of plastic leachates on the sea urchin Paracentrotus lividus."
Even razor clams on sparsely populated Olympic Coast can't escape plastics, study finds
IMAGE: RESEARCHERS FOUND MICROPLASTICS IN PACIFIC RAZOR CLAMS ON WASHINGTON'S SPARSELY POPULATED OLYMPIC COAST -- PROOF, THEY SAY, THAT EVEN IN MORE REMOTE REGIONS, COASTAL ORGANISMS CAN'T ESCAPE PLASTIC CONTAMINATION. view more
CREDIT: BRITTA BAECHLER | PORTLAND STATE UNIVERSITY
Portland State University researchers and their collaborators at the Quinault Indian Nation and Oregon State University found microplastics in Pacific razor clams on Washington's sparsely populated Olympic Coast -- proof, they say, that even in more remote regions, coastal organisms can't escape plastic contamination.
Microplastics are pieces of plastic smaller than 5 millimeters that are either intentionally produced at that size, or break down from synthetic clothing, single-use plastic items, or other products. These particles enter the environment and pervade freshwater and marine environments, soils and even the air we breathe.
Britta Baechler, the study's lead author and a recent graduate of PSU's Earth, Environment and Society doctoral program, analyzed the concentrations of microplastics in razor clams collected from eight beaches along the Washington coast and, after surveying recreational clam harvesters,estimated the annual microplastic exposure of those who eat them.
The Pacific razor clam is one of the most sought-after shellfish in Washington. The state's Department of Fish and Wildlife said that during a recent season, the recreational razor clam fishery saw more than 280,000 digger trips with diggers harvesting 4 million clams for the season. It's also a key first food, cultural resource, and vital source of income for members of the Quinault Indian Nation.
During the study, a total of 799 suspected microplastics were found in the 138 clam samples, 99% of which were microfibers. On average, clams had seven pieces of plastic each.
Clams from Kalaloch Beach, the northernmost site near the mouth of Puget Sound, contained significantly more microplastics than clams from the other seven sites. Though the study did not explore the reasons behind this, Baechler noted that there were no major differences in land cover types between Kalaloch and the other sites, but Kalaloch is the closest in proximity of all sites to the densely populated Seattle metro area.
Baechler's team compared whole clams -- minimally processed as if being consumed by an animal predator -- and cleaned clams -- gutted, cleaned of sand debris and grit, and prepared as if being eaten by a person. They found that in thoroughly cleaned clams, the amount of microplastics was reduced by half.
Baechler said this bodes better for people -- 88% percent of the survey respondents reported cleaning clams before eating them -- than for ocean predators that aren't afforded the luxury of cleaning clams prior to consumption.
Surveys of 107 recreational harvesters determined the average number of razor clams consumed per meal and the number of meals containing clams each year. Combining consumption information with the average number of microplastics per clam, the researchers estimated Olympic Coast razor clam harvester-consumers were exposed to between 60 and 3,070 microplastics per year from razor clams for those who thoroughly cleaned their clams before eating them, or between 120 and 6,020 microplastics a year for those who ate them whole without removing the guts, gills or other organs.
"We don't know the exact human health impacts of microplastics we inevitably ingest through food and beverages," said Baechler, who now works as an ocean plastics researcher at Ocean Conservancy. "Our estimates of microplastic exposure from this single seafood item are, for context, far lower than what we likely take in from inhalation, drinking bottled water and other sources, but no amount of plastic in our marine species or seafood items is desirable."
Baechler and Elise Granek, a professor of environmental science at PSU, said that everyone has a role to play in reducing plastic pollution in the marine environment -- from plastic producers and product designers who can develop effective upstream pollution control solutions to consumers who can make substitutions in their daily lives to reduce their plastic footprints.
"We all have become dependent on plastics for our clothing and packaging, and the more plastic we use, the more likely it's going to end up in our drinking water, our food and our air," Granek said. "All of us have a responsibility to do what we can to limit the amount of plastic that we're using."
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The study's findings were published in the journal Frontiers in Marine Science. Co-authors include Granek; Scott Mazzone, marine and shellfish biologist for the Quinault Indian Nation; Max Nielsen-Pincus, associate professor of environmental science at PSU; and Susanne Brander, assistant professor of fisheries and wildlife at Oregon State University.
Guam's most endangered tree species reveals universal biological concept
IMAGE: UNIVERSITY OF GUAM RESEARCH ASSOCIATE BENJAMIN DELOSO EXAMINES A BI-PINNATELY COMPOUND LEAF OF GUAM'S FLAME TREE. THE ENDANGERED SERIANTHES NELSONII TREE MAKES A LEAF THAT USES THIS SAME DESIGN.... view more
CREDIT: UNIVERSITY OF GUAM
Newly published research carried out at the University of Guam has used a critically endangered species to show how trees modify leaf function to best exploit prevailing light conditions. The findings revealed numerous leaf traits that change depending on the light levels during leaf construction.
"The list of ways a leaf can modify its shape and structure is lengthy, and past research has not adequately looked at that entire list," said Benjamin Deloso, lead author of the study.
The results appear in the October issue of the journal Biology (doi:10.3390/biology9100333).
Terrestrial plants are unable to move after they find their permanent home, so they employ methods to maximize their growth potential under prevailing conditions by modifying their structure and behavior. The environmental factor that has been most studied in this line of botany research is the availability of light, as many trees begin their life in deep shade but eventually grow tall to position their leaves in full sun when they are old. These changes in prevailing light require the tree to modify the manner in which their leaves are constructed to capitalize on the light that is available at the time of leaf construction.
"One size does not fit all," Deloso said. "A leaf designed to perform in deep shade would try to use every bit of the limited light energy, but a leaf grown under full sun needs to refrain from being damaged by excessive energy."
The research team used Guam's critically endangered Serianthes nelsonii tree as the model species because of the complexity of its leaf design. This tree's leaf is classified as a bi-pinnate compound leaf, a designation that means a single leaf is comprised of many smaller leaflets that are arranged on linear structures that have a stem-like appearance. The primary outcome of the work was to show that this type of leaf modifies many whole-leaf traits in response to prevailing light conditions. Most literature on this subject has not completely considered many of these whole-leaf traits, and may have under-estimated the diversity of skills that compound leaves can benefit from while achieving the greatest growth potential.
This study provides an example of how plant species that are federally listed as endangered can be exploited for non-destructive research, helping to highlight the value of conserving the world's threatened biodiversity while demonstrating a universal concept.
The study was a continuation of several years of research at the University of Guam designed to understand the ecology of the species. The research program has identified recruitment as the greatest limitation of species survival. Recruitment is what botanists use to describe the transition of seedlings into larger juvenile plants that are better able to remain viable. Considerable seed germination and seedling establishment occur in Guam's habitat, but 100% of the seedlings die. Extreme shade is one of the possible stress factors that generate the seedling mortality. Testing this possibility by providing outplanted seedlings with a greater range of sunlight transmission than the 6% recorded in this study may provide answers to the extreme shade stress hypothesis.
The latest results have augmented the team's earlier research that demonstrated how a specialized leaf gland enables rapid leaflet movement when the light energy is excessive. This skill of being able to change the leaflet's orientation is an instantaneous behavior that mitigates the damage that may result from excessive sunlight exposure.
"Just because the tree can't move itself, that doesn't mean it can't move its leaves to avoid stress," Deloso said.
Serianthes nelsonii was listed on the Endangered Species Act in 1987. A formal plan to recover the species was published in 1994 and called for research to more fully understand the factors that limit success of the species. This latest publication adds to the expanding knowledge that the University of Guam is generating to inform conservation decisions into the future.
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Further Reading:
Deloso, B.E. and T.E. Marler. 2020. Bi-pinnate compound Serianthes nelsonii leaf-level plasticity magnifies leaflet-level plasticity. Biology 9: 333; doi:10.3390/biology9100333.
Biodiesel made from discarded cardboard boxes
Development of a microorganism that doubles the yield of biodiesel precursor production using genetic scissors and based on the principles of evolution; expected to reduce fine dust release and reduce greenhouse gas emissions
IMAGE: CONCEPTUAL DIAGRAM FOR PRODUCING BIOFUELS USING MICROORGANISMS AS RAW MATERIALS FOR WOOD-BASED BIOMASS view more
CREDIT: KOREA INSTITUE OF SCIENCE AND TECHNOLOGY(KIST)
Automobile exhaust emitted by fossil-fuel-based vehicles, especially those operating on diesel, is known to be a major source of fine dust and greenhouse gases . Using biodiesel instead of diesel is an effective way of coping with climate change caused by greenhouse gases while reducing fine dust emission. However, the current method of producing biodiesel by chemically processing vegetable oil or waste cooking oil-such as palm or soybean oil-is limited because of the unreliable availability of raw materials.
Therefore, there is an active effort to develop biofuels by converting lignocellulosic biomass generated as a by-product of farming or logging, instead of consuming raw materials derived from food crops. Lignocellulosic biomass is an economical and sustainable raw material that can be converted to eco-friendly motor fuel through microbial metabolism.
Dr. Sun-Mi Lee and her team at the Clean Energy Research Center of the Korea Institute of Science and Technology (KIST) have announced that they have developed a novel microorganism capable of producing biodiesel precursors from lignocellulosic biomass such as discarded agricultural by-products, waste paper, and cardboard boxes. This microorganism has achieved the product yield twice of what was obtainable from its predecessors.
This novel microorganism can produce biodiesel precursors during the process of metabolizing sugars contained in the lignocellulosic biomass that it feeds on. The sugar contained in lignocellulosic biomass is generally composed of 65-70% glucose and 30-35% xylose. While microorganisms that exist in nature are effective in producing diesel precursors by metabolizing glucose, they do not feed on xylose, thus limiting the yield of the raw materials.
To solve this problem, the KIST research team developed a new microorganism that can produce diesel precursors by effectively metabolizing xylose as well as glucose. In particular, the metabolic pathway of the microorganism was redesigned using genetic scissors to prevent interference with the supply of coenzymes essential for producing diesel precursors. The ability to metabolize xylose was improved by effectively controlling the process of evolution in a laboratory, for instance, by selecting and cultivating only those microorganisms that delivered excellent performance.
This confirmed the possibility of producing diesel precursors using all sugar components including xylose from lignocellulosic biomass, and the product yield was almost doubled, compared to that obtained in previous studies which employed metabolic pathways having unresolved coenzyme issues.
"Biodiesel is an effective alternative fuel that can reduce greenhouse gas and fine dust emissions without restricting the operation of existing diesel-fueled vehicles, and we developed a core technology that can improve the economic efficiency of biodiesel production," said Dr. Sun-Mi Lee of KIST. "At a time like this, when we feel climate change in our bones due to frequent typhoons and severe weather phenomena, expanded supply of biofuels that help us cope with climate change most quickly and effectively will facilitate the expansion of related industries and the development of technology."
CAPTION
Xyloxic metabolic pathways introduced in diesel raw material production strains
This study was carried out with a grant from the Ministry of Science and ICT (MSIT), as part of the Institutional R&D Program of KIST and the New and Renewable Energy Research Program of the Korea Energy Technology Evaluation and Planning, and it was published in the most recent edition of Global Change Biology Bioenergy (Top 0.55% in the field of JCR).
Tree rings provide evidence for climate regime shifts
Tree rings, with their special characteristics of precise dating, annual resolution, long time series and climate sensitivity, have been widely considered a useful proxy for past climate variations.
Researchers at the Institute of Botany of the Chinese Academy of Sciences have given an overview on using tree rings to identify climate regime shifts in a perspective paper entitled "Tree rings circle an abrupt shift in climate," which was published in Science on Nov. 26.
In the paper, Prof. ZHANG Qi-Bin and Dr. FANG Ouya provided background in the field and discussed its advances. They also referenced a paper reporting a recent climate regime shift to a hotter and drier climate over inner East Asia, which was written by lead author ZHANG Peng from South Korea and published in the same issue of Science.
"Careful attention is required when using tree rings to reconstruct a specific climate variable over a large geographical region," said Prof. ZHANG Qi-Bin. "Signals from the macroclimate must be extracted efficiently while removing the nonclimate noise embedded in the tree rings."
Changes in climate have dramatic effects on natural ecosystems and human society. Less well understood is whether these changes are irreversible beyond a certain tipping point, that is, whether they represent a climate regime shift.
Scientists worldwide are alarmed about the potential risks of abrupt climate changes and their impacts on ecosystems and society, yet it is still difficult to identify the exact occurrence of climate regime shifts.
To judge whether climate systems undergo regime shifts from one steady state to another, scientists must understand the natural range of climate variability over a time scale that is much longer than the new regime.
ZHANG Peng et al. compiled tree-ring width data from 76 sites throughout inner East Asia and successfully screened 20 sites with strong signals of summer heatwave frequency and soil moisture content.
They found that the magnitude of the warm and dry anomalies compounding in the past two decades is unprecedented over the past 260 years. They further illustrated that the heatwaves and droughts became tightly coupled, which is likely caused by a pronounced enhancement of land-atmosphere coupling along with anthropogenic climate change.
However, it is still challenging for scientists to disentangle the interaction of climate variables and clarify whether these interactions generate negative or positive feedbacks, according to Prof. ZHANG Qi-Bin and Dr. FANG.
Furthermore, spatial differences related to climate regime shifts are worthy of study.
Using tree-ring data as a proxy for past climate variability and forest dynamics, Prof. ZHANG Qi-Bin's lab has long been engaged in investigating the responses of tree growth to multiple dimensions of climate change and ecological disturbances, and in exploring spatial and temporal patterns of forest health.
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Natural resources governance -- responsibilization of citizens or forcing responsibility on them?
The possibilities of citizens to participate in natural resource governance are increasing. Responsive and collaborative models of natural resource governance can open up new opportunities, but can also lead to unreasonable responsibilization, or even force responsibility on under-resourced organisations and individuals. This is the conclusion made in studies published in the Special Issue of Journal of Forest Policy and Economics, entitled Responsibilization in Natural Resource Governance and edited by Professor of Natural Resources Governance Irmeli Mustalahti from the University of Eastern Finland and Professor of Natural Resources & Environment Arun Agrawal from the University of Michigan.
The studies included in the Special Issue deal with natural resources governance in Indonesia, India, Mexico, Nepal, Tanzania and Russia, and show that natural resources governance involves a plethora of different actors for whom responsibilization has become more the rule than the exception. Often, local communities were given increasing responsibility for natural resources governance - without being given appropriate resources or operating conditions. In some cases, responsibilization had changed from mildly persuasive, to demanding, then to forced responsibility.
"The shift from responsibilization to forcing responsibility on local communities can be described as symbolic violence. Obligations and demands dictated from above are often a form of soft and invisible violence that can lead to corruption, social inequalities and exhaustion of natural resources," says Professor Irmeli Mustalahti.
The term symbolic violence was coined by Pierre Bourdieu, a sociologist and philosopher who observed and identified symbolic violence in nearly all power structures that societies have.
"In Finland, too, responsibilization has become an important objective, a tool for enhancing efficiency," says Professor Mustalahti.
She points out that some structures of governance and top-down demands do not necessarily support the well-being of citizens but instead force responsibility on them and are, in fact, manifestations of symbolic violence. Young people, too, are affected. This is a theme addressed also by the ALL-YOUTH research project which is supported by the Strategic Research Council coordinated at the Academy of Finland.
Professor Mustalahti and Professor Agrawal point out in their article that responsibilization and forced responsibility is not an issue in natural resources governance alone; the education and health care sectors are also affected. For example obligations can be transferred or reassigned to local communities, patients or students without giving them proper resources and operating conditions. In public discourse, forcing responsibility on citizens has been justified for reasons pertaining to climate, economy and labour policy.
"In order to support responsible and collaborative governance of natural resources, we need to have better understanding of citizens' skills and abilities, and of social structures and agency. Citizens must have adequate operating conditions, and tasks assigned to them must be in line with their resources and possibilities to influence," says Professor Mustalahti.
