Scientists organize to tackle crisis of coral bleaching

by Laura Arenschield, The Ohio State University

Bleached coral in the Red Sea. Credit: Anna Roik

An international consortium of scientists has created the first-ever common framework for increasing comparability of research findings on coral bleaching.


"Coral bleaching is a major crisis and we have to find a way to move the science forward faster," said Andréa Grottoli, a professor of earth sciences at The Ohio State University and lead author of a paper on guidelines published TBD in the journal Ecological Applications.

The common framework covers a broad range of variables that scientists generally monitor in their experiments, including temperature, water flow, light and others. It does not dictate what levels of each should be present during an experiment into the causes of coral bleaching; rather, it offers a common framework for increasing comparability of reported variables.

"Our goal was to create a structure that would allow researchers to anchor their studies, so we would have a common language and common reference points for comparing among studies," said Grottoli, who also is director of the consortium that developed the common framework.

Coral bleaching is a significant problem for the world's ocean ecosystems: When coral becomes bleached, it loses the algae that live inside it, turning it white. Coral can survive a bleaching but being bleached puts coral at higher risk for disease and death. And that can be catastrophic: Coral protects coastlines from erosion, offers a boost to tourism in coastal regions, and is an essential habitat to more than 25% of the world's marine species.

Bleaching events have been happening with greater frequency and in greater numbers as the world's atmosphere—and oceans—have warmed because of climate change.

"Reefs are in crisis," Grottoli said. "And as scientists, we have a responsibility to do our jobs as quickly, cost-effectively, professionally and as well as we can. The proposed common framework is one mechanism for enhancing that."

The consortium leading this effort is the Coral Bleaching Research Coordination Network, an international group of coral researchers. Twenty-seven scientists from the network, representing 21 institutions around the world, worked together as part of a workshop at Ohio State in May 2019 to develop the common framework.

The goal, Grottoli said, is to allow scientists to compare their work, make the most of the coral samples they collect, and find ways to create a common framework for coral experimentation.

Their recommendations include guidelines for experiments that help scientists understand what happens when coral is exposed to changes in light or temperature over a short period of time, a moderate period, and long periods. The guidelines include a compendium of the most common methods used for recording and reporting physical and biological parameters in a coral bleaching experiment.

That such a framework hasn't already been established is not surprising: The scientific field that seeks to understand the causes of and solutions for coral bleaching is relatively young. The first reported bleaching occurred in 1971 in Hawaii; the first wide-spread bleaching event was reported in Panama and was connected with the 1982-83 El Niño.

But experiments to understand coral bleaching didn't really start in earnest until the 1990s—and a companion paper by many of the same authors found that two-thirds of the scientific papers about coral bleaching have been published in the last 10 years.

Researchers are still trying to understand why some coral species seem to be more vulnerable to bleaching than others, Grottoli said, and setting up experiments with consistency will help the science move forward more quickly and economically.

"Adopting a common framework for experiments around coral bleaching would make us more efficient as a discipline," Grottoli said.

"We'd be able to better collaborate, and to build on one another's work more easily. It would help us progress in our understanding of coral bleaching—and because of climate change and the vulnerability of the coral, we need to progress more quickly."


Explore further  Guam avoids severe coral bleaching predicted for this year
More information: A.G. Grottoli et al, Increasing comparability among coral bleaching experiments, Ecological Applications (2020). DOI: 10.1002/eap.2262

Journal information: Ecological Applications


Provided by The Ohio State University

3-D printed corals, new bioreactors to boost microalgae production for biofuels

by Fintan Burke, From Horizon Magazine, 

Horizon: The EU Research & Innovation Magazine
The structure of coral polyps provide an ideal habitat for colonies of Symbiodinium sp. algae to grow. Credit: Dr Wangpraseurt

Using light as an energy source, photosynthetic microalgae can be used to produce products like biofuels and cosmetics. But algae grown in a reactor block out the light on which they feed. New reactor designs could solve this problem and help the industry move forward.


Photosynthetic algae—tiny algae that use light to grow—offer an alternative to traditional fossil fuels. The small amount of lipids each cell produces can be harvested to produce biofuel for the transport industry.

Currently, there are two main designs to grow the algae: either through an outdoor artificial 'pond' or through a closed 'photobioreactor' – usually a transparent tube or bag.

Both have their problems. Although an open pond can be big enough for industrial production, it is difficult to control the pond's temperature and the water can easily get infected with unwanted bacteria.

An indoor photobioreactor reduces both these risks, but few designs can be used for industrial production. In both types, the photosynthetic microalgae begin to block out the light as they grow.

"Often what you have is too much light at the surface of the culture and too little light as you go deeper," said Dr. Daniel Wangpraseurt, a marine scientist at Cambridge University in the UK, who is researching how best to grow microalgae.

Efficiently producing biofuels starts by finding the best way possible to grow microalgae. "What we would like to do is to use a strain that produces lots of lipids that can then be converted to biodiesel," said Dr. Wangpraseurt. The better a strain can grow in a bioreactor, the larger the yield of biofuel.

Coral reefs

Dr. Wangpraseurt and his BioMIC-FUEL project took inspiration from how microalgae grow on tropical coral reefs. By recreating coral structures, he and his team hoped to recreate the best conditions for biofuel production.

The skeleton structure of the coral Stylophora pistillata (left) is reflected in the 3D printed material (right). Credit: Dr Wangpraseurt

As Dr. Wangpraseurt explains, these corals have a unique structure that allows photosynthesising algae to thrive in an environment with a lot of competition for space and light. For example, the coral skeleton is made from calcium carbonate, which allows the coral to scatter light in a way that it can reach dense microalgae growing on it.


The next step was to create a 3-D printing technique that could replicate the shape of corals, including their unique light-scattering chemical structure. This involved working with bioengineers with expertise in 'printing' cells in artificial organ research.

Researchers investigating how to recreate liver tissue were able to advise Dr. Wangpraseurt's team on how to recreate fine structures and details found on the surface of corals. A 'bio-ink' loaded with nutrients and chemicals was designed to help the microalgae grow well within the 3-D tissue construct.

"There's lots of different things that end up in this cocktail that we call bio-ink—one of the most time-consuming aspects was to tune this bio-ink to be beneficial for the growth of the algae," said Dr. Wangpraseurt.

This allowed them to create artificial structures that had similar strength, softness, and light-scattering qualities as natural corals. After finding the right mix, Dr. Wangpraseurt and colleagues were able to grow microalgae up to 100 times as dense as those found in natural corals.

Dr. Wangpraseurt says that work is underway to optimise the technology and scale it up so that businesses can use it.

Light

Right now, businesses looking for an indoor bioreactor still have few options—the technology still runs into problems such as controlling the light and nutrients in the reactor, and minimising contamination risk.

"Companies in the past tried solving this issue and have come to some solutions, but not something at scale," says Yonatan Golan, the CEO of Brevel, a small company based in Israel developing a large-scale photobioreactor.

A large bioreactor (left) and smaller labscale bioreactors (right). Credit: Yonatan Golan, Brevel

As Golan explains, adding lights into the reactor creates extra niches for unwanted bacteria to grow and contaminate the reactor. Extra cleaning elements can be installed in the reactor, though this then causes shadows within the bioreactor, reducing the amount of light for the microalgae.

Brevel's bioreactor design uses patented lighting and cleaning techniques to illuminate the photobioreactor inside while reducing the risk of infection by bacteria. The new lighting techniques mean that light in the reactor can be both smaller and brighter, without heating up the bacterial mixture. Digital image analysis and online monitoring means that the Brevel photobioreactor is also more automated than other photobioreactors available to industry.

Their results are already promising. They were able to reduce the cost of growing photomicroalgae by 90% and produce yields 200 times higher than state-of-the-art outdoor photobioreactors.

Salmon

The bioreactor has applications beyond biofuel. Salmon grown in fish farms do not have the pink colour seen in the wild. To compensate, salmon farmers add an artificial pigment called astaxanthin to feed that gives farmed salmon meat a pinkish hue.

As Golan explains, this synthetic pigment is made from petrochemicals, which researchers note is not approved to be directly consumed by people, though is safe to eat in farmed fish. This pigment constitutes 10% of the final price of salmon.

The scaled-up Brevel bioreactor can make this same pigment at the same price organically, and at the same price as the synthetic version. Organically made pigment is also proven to be safe to eat directly and is naturally higher in antioxidants. Its price is likely to fall as time goes on, Golan adds. The company is also looking at producing products for the nutrition and cosmetics industry.

Next year, Golan hopes to build the first photobioreactor factory and hire more engineers. He believes that microalgae also make sustainable business sense.

"We can actually make a profit from the high value (nutrition and cosmetics) products and be left with the biomass which contains proteins and lipids," he said. "These can be either for the protein market, or it's possible to produce biofuel from them."


Explore further  3-D-printed corals could improve bioenergy and help coral reefs

Provided by Horizon: The EU Research & Innovation Magazine

Climate change presents new challenges for the drinking water supply

by Helmholtz Association of German Research Centres

The Rappbode Reservoir in the Harz region is Germany's largest drinking water reservoir. Credit: André Künzelmann

The Rappbode Reservoir in the Harz region is Germany's largest drinking water reservoir, supplying around one million people with drinking water in areas including the Halle region and the southern part of the state of Saxony-Anhalt. Water temperatures in the reservoir now have the potential to increase significantly due to climate change. If average global warming reaches between 4 and 6 degrees by the year 2100, as the current trend suggests, temperature conditions in the Rappbode Reservoir will become comparable to those in Lake Garda and other lakes south of the Alps. In an article in Science of the Total Environment magazine, a team of researchers led by the Helmholtz Centre for Environmental Research (UFZ) writes that the reservoir's operators could partially offset the impacts this will have on the drinking water supply—to do so, they would have to change the way the reservoir is managed.


The impacts of climate change can already be seen in the Rappbode Reservoir: Over the past 40 years, the water surface temperature in the reservoir has increased by around 4 degrees in the summer months. This trend could continue, as has now been demonstrated by a team of researchers led by Dr. Karsten Rinke, who researches lakes at UFZ. Working on the basis of a lake model developed by US researchers, the team took into account potential reservoir management strategies to forecast the impacts climate change could have on water temperatures and on the lake's physical structure, which control the stratification and seasonal mixing of the body of water. Their research looked at three scenarios for future greenhouse gas emissions. The so-called "representative concentration pathways" (RCPs) describe whether greenhouse gas emissions will be halted (RCP 2.6), will continue to rise (RCP 6.0) or even continue to increase unabated (RCP 8.5) by 2100. According to the Intergovernmental Panel on Climate Change IPCC, the latter case would result in average global warming of more than 4 degrees by the end of this century.

For the RCP 2.6 and RCP 6.0 scenarios, the study's authors projected that the average temperature on the water surface of the Rappbode Reservoir is set to increase by 0.09 degrees or 0.32 degrees respectively every decade by the year 2100. This would correspond to a total increase of around 0.7 degrees (RCP 2.6) and around 2.6 degrees (RCP 6.0) by the end of this century. As expected, the increase in temperatures would be the highest under the RCP 8.5 scenario, which would see the water temperature increasing by 0.5 degrees every decade or approx. 4 degrees by 2100.

However, in terms of using drinking water, what happens in the deeper strata of the reservoir—i.e., at depths of 50 meters and below—is more serious, as this is where raw water is taken out before being treated to prepare it as drinking water. It is true that impacts by 2100 would be relatively minor under the RCP 2.6 and RCP 6.0 scenarios, as the water temperature would continue to be around 5 degrees year-round. However, water temperatures will increase significantly under the RCP 8.5 scenario—by nearly 3 degrees by the end of the century. As a result, the water in the depths of the reservoir would warm to around 8 degrees. "This would turn a reservoir in Germany's northernmost highlands into a body of water comparable to Lake Maggiore or Lake Garda nowadays," says UFZ scientist Rinke. An increase of this magnitude would have consequences because it would significantly accelerate the speed of biological metabolic processes.


"A temperature increase to 8 degrees nearly doubles oxygen demand, that is the amount of oxygen organisms consume during their respiration and degradation processes," says lead author Chenxi Mi, who is focusing on climate impacts on the Rappbode Reservoir in his doctorate at UFZ. Increased oxygen consumption will place an additional pressure on the water's oxygen budget, because the duration of summer stagnation—the phase of stable temperature stratification in lakes in which the deep water is closed off to oxygen supply from the atmosphere—is already extending due to climate change. Plus, warmer water is also unable to absorb as much oxygen. Potential consequences include intensified dissolution of nutrients and dissolved metals from the sediment, algae growth and an increase in blue-green algae.

In other words, the 8.5 scenario would have impacts on the drinking water supply if it were to occur. The reservoir's operators draw the raw water from the lowermost strata for good reason, as the water there is cold and contains only low levels of suspended substances, dissolved metals, algae, bacteria and potentially pathogenic microorganisms. If the oxygen content there decreases more rapidly due to the rising water temperature, the risk of contamination increases, for example due to substances released from the sediment and greater bacteria growth. Treating the water would therefore require a greater effort on the part of the operators, and they would have to deal with higher demands in terms of the treatment capacity they would need to reserve. "This means preventing the deep water from warming is also worthwhile from the perspective of the drinking water supply, and the ideal way to do this is ambitious climate policies that limit warming," says Rinke.

But the operators are not completely powerless against the warming of the deep water in the reservoir. The model simulations set up by Rinke's team show that a share of the heat can be exported by using a clever system to withdraw the water. This has to do with the water that is released to the downstream waters that is, the water that is withdrawn and drains into the water course below the reservoir in order to keep the discharge conditions there stable. This so-called downstream discharge would need to be withdrawn not from the lower strata as it has been thus far but rather from near the surface.

"This approach would allow the additional heat caused by climate change to be released again," Rinke explains. However, he adds, it would be impossible to prevent the deep water from heating up if the air temperature increases beyond 6 degrees. "Even though operators have had to cope more with a shortage of water due to the very dry years we've had recently, it's just as important to think about the quality of the water. In terms of reservoir management, we definitely have options and can respond to new conditions caused by climate change. In this way, we can alleviate certain negative impacts through climate adaptation measures."

The operators of the Rappbode Reservoir at the Talsperrenbetrieb Sachsen-Anhalt company are aware of this. They have been working closely together with Karsten Rinke and his team of researchers at UFZ for many years to assess the impacts of climate change and discussed about potential options for adapting the Rappbode Reservoir. The Talsperrenbetrieb is already planning new infrastructures that will make it possible to implement the new management strategies.


Explore further

Polar ice, atmospheric water vapor biggest drivers of variation among climate models

More information: Chenxi Mi et al, Ensemble warming projections in Germany's largest drinking water reservoir and potential adaptation strategies, Science of The Total Environment (2020). DOI: 10.1016/j.scitotenv.2020.141366

Journal information: Science of the Total Environment

Provided by Helmholtz Association of German Research C

Changes in fire activity are threatening

 more than 4,400 species globally

by Lito Vilisoni Wilson, University of Melbourne

Wildfire near a windfarm northeast Spain. Credit: Lluis Brotons

Changes in fire activity are putting at risk more than 4,400 species across the globe, says a new paper led by the University of Melbourne, involving 27 international researchers.

"Those species include 19 percent of birds, 16 percent of mammals, 17 percent of dragonflies and 19 percent of legumes that are classified as critically endangered, endangered or vulnerable," said lead author, Dr. Luke Kelly, a Senior Lecturer in Ecology and Centenary Research Fellow. "That's a massive number of plants and animals facing threats associated with fire."

The paper, "Fire and biodiversity in the Anthropocene," published in Science, found that the species categorized as threatened by an increase in fire frequency or intensity, include the orangutan in Indonesia and mallee emu-wren in Australia.

"Recent fires have burned ecosystems where wildfire has historically been rare or absent, from the tropical forests of Queensland, Southeast Asia and South America to the tundra of the Arctic Circle," Dr. Kelly said.

"Very large and severe fires have also been observed in areas with a long history of recurrent fire, and this is consistent with observations of longer fire seasons and predictions of increased wildfire activity in the forests and shrub lands of Australia, southern Europe and the western United States."

The research team also found a striking example from Australia: the total area burnt by bushfires in the eastern seaboard from August 2019 to March 2020, 12.6 million hectares, was unprecedented in scale.

However, some species and ecosystems are threatened when fire doesn't occur. Frequent fires, for example, are an important part of African savanna ecosystems and less fire activity can lead to shrub encroachment, which can displace wild herbivores such as wildebeest that prefer open areas.

"Understanding what's causing changes in different places helps us to find effective solutions that benefit people and nature," Dr. Kelly said.

Researchers, including 27 authors from a combined 25 institutions around the world (including six authors from the University of Melbourne), identified three main groups of human drivers as transforming fire activity and its impacts of biodiversity: global climate change, land-use and biotic invasions. This means that people and governments around the world need to act and confront the diverse changes to the environment that are occurring.

"It really is time for new, bolder conservation initiatives," Dr. Kelly said. "Emerging actions include large-scale habitat restoration, reintroductions of mammals that reduce fuels, creation of low-flammability green spaces and letting bushfires burn under the right conditions. The role of people is really important: Indigenous fire stewardship will enhance biodiversity and human well-being in many regions of the world."

Michael Clarke, Professor of Zoology at La Trobe University, who supported the study, echoed Dr. Kelly's call, saying "Our research highlights the magnitude of the challenge fire poses to animals, plants and people, given worsening climatic conditions—a conclusion echoed in the recent Royal Commission report into last summer's fires."


Explore further  Threatened species hit hard by Australia's bushfires
More information: Luke T. Kelly et al. Fire and biodiversity in the Anthropocene, Science (2020). DOI: 10.1126/science.abb0355
Journal information: Science
Provided by University of Melbourne

Humans are changing fire patterns, and it's threatening 4,403 species with extinction

by Luke Kelly, Annabel Smith, Katherine Giljohann and Michael Clarke, The Conversation

The Leadbeater’s possum, one of thousands of species threatened by changing fire regimes. Credit: Shutterstock

Last summer, many Australians were shocked to see fires sweep through the wet tropical rainforests of Queensland, where large and severe fires are almost unheard of. This is just one example of how human activities are changing fire patterns around the world, with huge consequences for wildlife.

In a major new paper published in Science, we reveal how changes in fire activity threaten more than 4,400 species across the globe with extinction. This includes 19% of birds, 16% of mammals, 17% of dragonflies and 19% of legumes that are classified as critically endangered, endangered or vulnerable.

But, we also highlight the emerging ways we can help promote biodiversity and stop extinctions in this new era of fire. It starts with understanding what's causing these changes and what we can do to promote the "right" kind of fire.

How is fire activity changing?

Recent fires have burned ecosystems where wildfire has historically been rare or absent, from the tropical forests of Queensland, Southeast Asia and South America to the tundra of the Arctic Circle.

Exceptionally large and severe fires have also been observed in areas with a long history of fire. For example, the 12.6 million hectares that burnt in eastern Australia during last summer's devastating bushfires was unprecedented in scale.

This extreme event came at a time when fire seasons are getting longer, with more extreme wildfires predicted in forests and shrublands in Australia, southern Europe and western United States.

But fire activity isn't increasing everywhere. Grasslands in countries such as Brazil, Tanzania, and the United States have had fire activity reduced.

Extinction risk in a fiery world

Fire enables many plants to complete their life cycles, creates habitats for a wide range of animals and maintains a diversity of ecosystems. Many species are adapted to particular patterns of fire, such as banksias—plants that release seeds into the resource-rich ash covering the ground after fire.

But changing how often fires occur and in what seasons can harm populations of species like these, and transform the ecosystems they rely on.

We reviewed data from the International Union for Conservation of Nature (IUCN) and found that of the 29,304 land-based and freshwater species listed as threatened, modified fire regimes are a threat to more than 4,403.

Most are categorised as threatened by an increase in fire frequency or intensity.




For example, the endangered mallee emu-wren in semi-arid Australia is confined to isolated patches of habitat, which makes them vulnerable to large bushfires that can destroy entire local populations.

Likewise, the Kangaroo Island dunnart was listed as critically endangered before it lost 95% of its habitat in the devastating 2019-2020 bushfires.

However, some species and ecosystems are threatened when fire doesn't occur. Frequent fires are an important part of African savanna ecosystems and less fire activity can lead to shrub encroachment. This can displace wild herbivores such as wildebeest that prefer open areas.

How humans change fire regimes

There are three main ways humans are transforming fire activity: global climate change, land-use and the introduction of pest species.

Global climate change modifies fire regimes by changing fuels such as dry vegetation, ignitions such as lightning, and creating more extreme fire weather.

What's more, climate-induced fires can occur before the dominant tree species are old enough to produce seed, and this is reshaping forests in Australia, Canada and the United States.

Humans also alter fire regimes through farming, forestry, urbanisation and by intentionally starting or suppressing fires.

Introduced species can also change fire activity and ecosystems. For example, in savanna landscapes of Northern Australia, invasive gamba grass increases flammability and fire frequency. And invasive animals, such as red foxes and feral cats, prey on native animals exposed in recently burnt areas.

Importantly, cultural, social and economic changes underpin these drivers. In Australia, the displacement of Indigenous peoples and their nuanced and purposeful use of fire has been linked with extinctions of mammals and is transforming vegetation.

The post-fire landscape in Flinders Chase National Park, Kangaroo Island, three months after an extremely large and severe bushfire last summer. Credit: Luke Kelly

We need bolder conservation strategies

A suite of emerging actions—some established but receiving increasing attention, others new—could help us navigate this new fire era and save species from extinction. 

They include:
managed wildfire—let some fires burn naturally in fire-prone ecosystems where fire has been absent for too long, suppressing only under specific conditions

deployment of rapid response teams to enact targeted fire suppression and emergency conservation management, including providing animal refuges, reseeding to promote plant regeneration and large-scale habitat restoration

reintroduction of grazing and digging animals that regulate fire regimes by reducing fuel loads, for the benefit of whole ecosystems

Indigenous fire stewardship, and continuing and reinstating cultural burning in a modern context. This boosts biodiversity, ecosystems and human well-being

green firebreaks or greenbelts, which comprises low-flammability land uses such as parkland and open vegetation to help reduce fire spread, while providing refuges for wildlife.

Where to from here?

The input of scientists will be valuable in helping navigate big decisions about new and changing ecosystems.

Empirical data and models can monitor and forecast changes in biodiversity. For example, new modelling has allowed University of Melbourne researchers to identify alternative strategies for introducing planned or prescribed burning that reduces the risk of large bushfires to koalas.

New partnerships are also needed to meet the challenges ahead.

At the local and regional scale, Indigenous-led fire stewardship is an important approach for fostering relationships between Indigenous and non-Indigenous organisations and communities around the world.

And international efforts to reduce greenhouse gas emissions and limit global warming are crucial to reduce the risk of extreme fire events. With more extreme fire events ahead of us, learning to understand and adapt to changes in fire regimes has never been more important.


Explore further 

Changes in fire activity are threatening more than 4,400 species globally
Provided by The Conversation 

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Covid and pollution: intimately linked, compound threat

by Amélie Bottollier-Depois

Researchers hold air pollution responsible for a range of diseases and studies suggest it can make Covid-19 deadlier

Lockdowns may have temporarily cleared up the skies above big cities this year but experts warn that air pollution remains a Covid-19 threat multiplier, as well a health hazard that will far outlast the pandemic.

As governments ordered temporary confinement measures to battle multiple virus waves, several studies have charted a marked increase in air quality in the US, China, and Europe.

In Spain, for example, levels of atmospheric nitrous oxide (NO2)—associated with a host of lung conditions—plummeted 62 percent during the spring lockdown period.

France and Italy saw falls of 52 and 48 percent, respectively, according to the European Environment Agency.

Since air pollution kills roughly seven million worldwide people each year, such falls are bound to have prevented deaths.

Paola Crippa, assistant professor at Notre Dame's Department of Civil and Environmental Engineering and Earth Sciences, told AFP that lockdowns probably prevented around 2,190 air pollution-linked deaths in Europe and 24,200 in China.

"When we consider the long-term effect too—avoided chronic respiratory problems, cardiovascular diseases, lung cancers and ischaemic heart diseases because of lower levels of air pollution—the number of averted fatalities is much larger," she said.

Factfile on the impact of air pollution on human health

In Europe, as many as 29,000 long-term air pollution fatalities may have been averted, she said, with up to 287,000 in China.

Lauri Myllyvirta, lead analyst at the Centre for Research on Energy and Clean Air (CREA), said that unless there is an immediate rebound in pollution levels, populations would benefit long term from the cleaner lockdown air.

"The long-term exposure of pretty much everyone in Europe would have been reduced because much less fossil fuels were burned in 2020," he told AFP.

'Particular danger'

The lives saved by cleaner air are all the proof campaigners need to continue to push for better air quality regulation going forward, even and especially once the pandemic ends.

But there is a more pressing reason to act, according to research.

One study published recently in the journal Cardiovascular Research found that long-term exposure to fine PM2.5 particulate matter could be linked to a 15 percent higher risk of dying from Covid-19.
  

Activist groups like Extinction Rebellion are already pressuring authorities over air pollution

In east Asia, that figure is closer to 30 percent, the study found.

This is because the novel coronavirus and PM2.5 both cause severe lung conditions, so one compounds the other in patients sick with Covid-19.

"They do the same thing: the vasculature inflammation in the lungs, secondary pneumonia, hypertension and also triggering (heart attacks) and heart failure," Thomas Munzel, from the University of Mainz's Centre for Cardiology, told AFP.

And since air pollution exposure makes pre-existing lung conditions more likely, "when you have already cardiovascular disease you are in particular danger when you get an infection with Covid," he said.

Double hit

Recent analysis of air quality across more than 3,000 US counties showed that an increase in airborne particulate matter of 1 microgram/m3 corresponded with an 11 percent increased risk of dying of Covid-19.

Authors of the study, published earlier this month in Science Advances, warned against overreacting to the findings, stressing that far more work was needed on this budding area of research.

Heavy air pollution in cities like Delhi can have serious health consequences for inhabitants

One thing that remains unclear is what impact exposure to air pollution has on people infected with SARS-CoV-2.

"I'm pretty convinced short term reduction of air pollution has an impact, but we don't have the data yet," said Munzel.

Clues are beginning to emerge on how air pollution interacts with the coronavirus, particularly as to the role of the ACE-2 receptor, which facilitates entry in to cells.

Described in the Journal of Infection back in Spring as the "double hit hypothesis", the idea is that fine pollution particles damage this receptor and make it easier for the virus to infect more cells.

This scenario could potentially be compounded by chronic NO2 exposure, which is known to weaken the lungs.

And with the arrival of winter—"pollution season" as Myllyvirta put it—experts have called for continued vigilance as the world grabbles with the second Covid-19.


Explore further

Study estimates exposure to air pollution increases COVID-19 deaths by 15% worldwide

© 2020 AFP

Air quality up in some EU cities during pandemic lockdown

People wearing face masks to prevent the spread of coronavirus sit on a street bench in downtown Madrid, Spain, Monday, Nov. 23, 2020. Spanish Prime Minister Pedro Sanchez says a national COVID-19 vaccination plan will be launched in January. (AP Photo/Manu Fernandez)

Air quality significantly improved in European metropolitan areas such as Milan and Madrid because of lockdown restrictions imposed to curb the spread of the coronavirus pandemic, European Union officials said Monday.

The improvements were particularly notable for the pollutant nitrogen dioxide (NO2) and fine particulate matter, which both can have a serious impact on people's health.

An EU report on air quality published Monday showed that among metropolitan areas with the largest NO2 concentrations, Barcelona's levels sank by 59% during the early spring compared to the year before. NO2 levels in Madrid dropped by 47%.

In Italy, NO2 pollution in Milan fell by 54% and in Rome by 39%. Levels in many other metropolitan areas across Europe, especially western Germany, Belgium and the Netherlands, also dropped by significant margins.

"Now we realize that this is, of course, temporary and that we should not be reaching air quality standards by locking down society," said Hans Bruyninckx, the executive director of the European Environmental Agency.

""But it indicates that if we can keep pushing quality standards and if we can keep innovating in those sectors, that indeed serious benefits to society, to human health are there," he added.

Lockdown measures in several EU member states during the first wave of the pandemic had a major impact on economic activity, dramatically reducing road and air transport plus shipping. That all affected the air quality in the regions.

European Commissioner for Environment and Oceans Virginijus Sinkevicius speaks during a media conference on the air quality in Europe for 2020 at EU headquarters in Brussels, Monday, Nov. 23, 2020. (Kenzo Tribouillard, Pool via AP)

European Commissioner for Environment and Oceans Virginijus Sinkevicius speaks during a media conference on the air quality in Europe for 2020 at EU headquarters in Brussels, Monday, Nov. 23, 2020. (Kenzo Tribouillard, Pool via AP)

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© 2020 The Associated Press. All rights reserved. 

Shift in atmospheric rivers could affect Antarctic sea ice, glaciers

by American Geophysical Union

Peterman Island, Graham Land, Antarctica. A new study finds that atmospheric rivers in the Southern Hemisphere have been gradually shifting toward the South Pole for the past 40 years, a trend which could lead to increased rates of ice melt in Antarctica. Credit: McKay Savage, CC-BY-2.0.

Weather systems responsible for transporting moisture from the tropics to temperate regions in the Southern Hemisphere have been gradually shifting toward the South Pole for the past 40 years, a trend which could lead to increased rates of ice melt in Antarctica, according to new research.

Atmospheric rivers are long, narrow jets of air that carry huge amounts of water vapor from the tropics to Earth's continents and polar regions. The new study finds atmospheric rivers in the Southern Hemisphere are shifting due in part to ozone depletion, greenhouse gas emissions and natural variations in sea surface temperature.

This shift of atmospheric rivers may affect moisture and heat transported into Antarctica, said Weiming Ma, an atmospheric scientist at UCLA and lead author of the new study published in the AGU journal Geophysical Research Letters, which publishes high-impact, short-format reports with immediate implications spanning all Earth and space sciences.

"The most important implication of our finding is that due to this shift, more atmospheric rivers are expected to make landfall over Antarctica, which will have effects on the surrounding sea ice and glaciers on the continent," Ma said.

A River from Thin Air

Atmospheric rivers form when warm, turbulent air from the tropics encounter cold fronts in mid-latitude regions. The narrow band between these two competing air masses grows thick with condensed water vapor as temperatures drop in the region of saturated air.

Sometimes measuring thousands of kilometers in length, these cloud systems can contribute up to 60% of the annual precipitation in some regions, such as California, Chile and western Europe.

In the past, scientists have used simulations to predict the future occurrence of atmospheric rivers over western Europe, showing that these weather patterns are likely to become more common under a warming climate. However, since their direction and movement are determined in large part by Earth's jet streams, and as the westerly jet is expected to shift toward the North Pole in future climate models, researchers predict that atmospheric rivers will likely move poleward as well.


But the new study found atmospheric rivers in the Southern Hemisphere have already been following this trend, steadily creeping toward the South Pole for at least the last four decades. Using simulations based on multiple models and datasets spanning back to 1979, the researchers looked for broad trends and potential mechanisms that might explain observed patterns.

A Cloudy Outlook

According to modeling results from the new study, at least part of the observed trend can be explained by increases in greenhouse gas emissions and ozone depletion over Antarctica and their corresponding effect on temperature gradients between the equator and South Pole; however, the shift also appears to be driven by natural, long-term changes in sea surface temperatures.

"We found evidence for cooling over the equatorial Pacific and the Southern Ocean, which is caused by a pattern called the inter-decadal Pacific Oscillation," said Ma. "This is a natural pattern that takes place over multiple decades and one that isn't driven by human activity."

These cooler patterns in sea surface temperature pull the westerly jet stream further south, pushing atmospheric rivers along with them. It's unclear exactly how this might affect rain and snowfall patterns over South America, but it seems likely that portions of Antarctica will experience increased rates of ice melt as a result, according to the researchers.

"Global sea level change depends critically on the fate of the Antarctic ice sheet, and that ice is impacted by how many atmospheric rivers hit Antarctica and how strong they are," said Marty Ralph, the director for the Center for Western Weather and Water Extremes at the Scripps Institution of Oceanography, who was not involved in the new study.

While atmospheric rivers over East Antarctica have been associated with increased snowfall accumulation in some years, they seem to have the opposite effect on the other side of the continent. According to research published in 2019 that used a similar dataset, an average of only 12 atmospheric rivers a year make their way across the western portion of Antarctica, yet they contribute up to 40% of the summer ice melt in some areas and appear to be responsible for the majority of ice melt in winter and in high-elevation glaciers.

Large ice melts in West Antarctica are still fairly rare, occurring only a few times each decade. However, scientists warn that increasing temperatures due to global climate warming and the shifting occurrence of atmospheric rivers in the southern hemisphere will likely cause the frequency and severity of those melting events to increase in the near future.


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More information: Weiming Ma et al, Poleward Shift of Atmospheric Rivers in the Southern Hemisphere in Recent Decades, Geophysical Research Letters (2020). DOI: 10.1029/2020GL089934

Journal information: Geophysical Research Letters

Provided by American Geophysical Union

Greenhouse gas levels at new high, despite Covid-19 measures

by Nina Larson

The WMO warned that the industrial slowdown due to the pandemic had not curbed record concentrations of the greenhouse gases that are trapping heat in the atmosphere

Greenhouse gases in the atmosphere, the main driver of climate change, hit record highs last year and have continued climbing in 2020 despite measures to halt the COVID-19 pandemic, the UN said Monday.

World Meteorological Organization (WMO) chief Petteri Taalas meanwhile welcomed several countries' vows to focus on climate-friendly technologies as they seek to revive their economies after the coronavirus crisis.

Speaking to journalists, he also voiced optimism at US president-elect Joe Biden's pledge to return his country to the Paris climate accord, saying he hoped it "might have the domino effect (and) motivate also some other countries."

But the United Nations agency dashed notions that the lockdowns and other measures to rein in the pandemic could by themselves repair some of the damage of ever-growing greenhouse gas emissions in recent decades.

While emissions have shrunk this year, the WMO warned this had not curbed record concentrations of the greenhouse gases that are trapping heat in the atmosphere, raising temperatures, causing sea levels to rise and driving more extreme weather.

"The lockdown-related fall in emissions is just a tiny blip on the long-term graph," Taalas said.

"We need a sustained flattening of the curve."

The WMO's main annual Greenhouse Gas Bulletin said preliminary estimates pointed to daily carbon dioxide (CO2) emissions falling by as much as 17 percent globally during the most intense period of the shutdowns.

The annual impact was expected to be a drop of between 4.2 and 7.5 percent, it said.

But this will not cause concentrations of CO2 in the atmosphere to go down, it said, warning the impact on concentrations was "no bigger than the normal year to year fluctuations."

Still rising

CO2 concentrations will continue to rise, albeit at a slightly reduced pace, the WMO said, adding that the pace would be no more than 0.23 parts per million (ppm) per year slower than the previous trajectory—well within the 1.0 ppm natural inter-annual variability.

Emissions are the main factor that determine the amount of greenhouse gas levels but concentration rates are a measure of what remains after a series of complex interactions between atmosphere, biosphere, lithosphere, cryosphere and the oceans.

The WMO said lockdowns, border closures, flight groundings and other measures to rein in the coronavirus crisis had indeed cut emissions of many pollutants

CO2 is by far the most important long-lived greenhouse gas in the atmosphere related to human activities, and is responsible for roughly two-thirds of the Earth's warming.


The WMO's Bulletin listed the atmospheric concentration of CO2 in 2019 at 410 ppm, up from 407.8 ppm in 2018, and said the rise had continued this year.

Taalas pointed out that the world breached the global threshold of 400 ppm in 2015, voicing alarm that "just four years later, we crossed 410 ppm."

"Such a rate of increase has never been seen in the history of our records."

The UN agency said that since 1990, there had been a 45-percent increase in so-called radiative forcing, which is the warming effect on the climate by greenhouse gases.

Five million years ago

"Carbon dioxide remains in the atmosphere for centuries and in the ocean for even longer," Taalas said.

"The last time the Earth experienced a comparable concentration of CO2 was three to five million years ago," he said.

The second most prevalent greenhouse gas in the atmosphere is methane—emitted in part from cattle and fermentation from rice paddies—which is responsible for around 16 percent of warming.

In 2019, methane levels were at 260 percent of pre-industrial levels, at 1,877 parts per billion (ppb).

The rise from 2018's measurement was slightly lower than the previous annual increase, but still higher than the 10-year average, WMO said.

Concentrations of nitrous oxide, the third major greenhouse gas which is caused largely by agricultural fertilisers, meanwhile stood at 332 ppb last year, or 123 percent above pre-industrial levels.

Its rise from 2018 to 2019 was also lower than that observed from 2017 to 2018, but on a par with the average annual growth rate over the past decade.


Explore further  Greenhouse gas concentrations in atmosphere reach yet another high

© 2020 AFP

Choked, strangled and drowned. How balloons and plastic bags are killing marine animals

by Adriana Brasileiro

Credit: CC0 Public Domain

In Florida, a critically endangered Kemp's ridley sea turtle was entangled in a plastic bag that had become filled with sand. The plastic bag had wrapped around the turtle's neck, which likely led it to drown or suffocate

In another Florida case, a recently hatched sea turtle was found with two plastic balloons in its gastrointestinal tract, causing a blockage that potentially led to the animal's death.

Balloons, plastic bags, recreational fishing line and food wrappers are killing thousands of marine animals as they eat plastic items that later perforate internal organs, or become entangled and drown, Oceana said in a new report.

The conservation group surveyed dozens of government agencies, organizations and institutions to paint a grim picture of the impact of plastic on marine mammals and sea turtles in the United States. Oceana compiled data on plastic ingestion and entanglements, and called the growing plastic problem "an unfolding disaster" for marine animals in U.S. waters.

"Single-use plastics are simply everywhere, so this was an attempt to quantify the damage to marine life in the U.S., even if this is only a snapshot," said Kimberly Warner, the author of the report and a senior scientist at Oceana.

The organization found that plastics ranged in size and type, from microplastics that were perforating the gastrointestinal tract of a baby sea turtle to DVD cases and huge plastic sheets that had been swallowed by whales.

The organization found records of almost 1,800 animals from 40 different species swallowing plastic or becoming entangled between 2009 and 2019. The data was provided by 51 marine life organizations and government agencies such as NOAA Fisheries Marine Mammal Stranding Network, the Florida Fish and Wildlife Conservation Commission, the Sanibel-Captiva Conservation Foundation and the National Sea Turtle Stranding and Salvage Network Coordinator in the Southeast Fisheries Science Center.

The report didn't include marine debris such as commercial fishing gear, which means the problem is considerably worse than Oceana's report indicates, Warner said.

Scientists estimate that 15 million tons of plastic wash into the ocean every year, or about two garbage trucks' worth of plastic every minute, Oceana said. With plastic production expected to quadruple by the year 2050, some expect there will be more plastic than fish in the world's oceans.

Of the 1,792 animals that swallowed or became entangled in plastic, 861 were sea turtles, including all six U.S. species, and 931 were marine mammals from 34 different species, Oceana said.

The biggest problem was animals consuming plastic. Marine animals often mistake plastic for food or inadvertently swallow plastic while feeding or swimming.

"The result is that it can obstruct their digestion or lacerate their intestines, and all of this can interfere with their ability to feed and obtain the nourishment they need. These problems can lead to an animal's starvation and death," the report said.

Oceana found records of 700 Florida manatees that suffered from plastic entanglement or ingestion between 2009 and 2018. Nearly all of them had swallowed plastic, mostly plastic fishing line.


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©2020 Miami Herald
Distributed by Tribune Content Agency, LLC

Researchers record largest aggregation of fishes in abyssal deep sea

by University of Hawaii at Manoa

Cutthroat eels (Ilyophis arx, Family Synaphobranchidae) swarming at a small bait package deployed on the summit of an unnamed abyssal seamount in the southwestern Clarion Clipperton Zone at a depth of 3083 m. 

Credit: Deep Sea Fish Ecology Lab, Astrid Leitner and Jeff Drazen, Department of Oceanography, SOEST University of Hawaii Manoa, DeepCCZ expedition

The largest aggregation of fishes ever recorded in the abyssal deep sea was discovered by a team of oceanographers from the University of Hawai'i at Mānoa (UH, U.S.), Monterey Bay Aquarium Research Institute (MBARI, U.S.) and the National Oceanography Centre (NOC, UK). Their findings were published recently in Deep-Sea Research.

"Our observations truly surprised us," said Astrid Leitner, lead author on the study, who conducted this work as graduate researcher in the UH Mānoa School of Ocean and Earth Science and Technology (SOEST). "We had never seen reports of such high numbers of fishes in the sparsely-populated, food-limited deep-sea."

The researchers, including Leitner, Jennifer Durden (NOC) and professors Jeffrey Drazen (Leitner's doctoral research advisor) and Craig Smith, made the observation on an expedition to the Clarion Clipperton Zone (CCZ). The CCZ is a large region stretching nearly from Hawai'i to Mexico, which is being explored for deep sea mining of nodules containing metals such as copper, cobalt, zinc and manganese.

Abyssal seamounts, deep underwater mountains whose summits are 9,800 ft (3,000 m) below the sea surface, dot the deep seascape and are some of the least explored habitats on the planet. During the expedition, the research team sampled three of these seamounts and their surrounding plains as part of an effort to establish an ecological baseline prior to extraction activities.

Cutthroat eels (Ilyophis arx, Family Synaphobranchidae) swarming at a small bait package deployed on the summit of an unnamed abyssal seamount in the southwestern Clarion Clipperton Zone at a depth of 3083 m. 

Credit: Deep Sea Fish Ecology Lab, Astrid Leitner and Jeff Drazen, Department of Oceanography, SOEST University of Hawaii Manoa, DeepCCZ expedition

On the summit of one of the three previously unmapped and completely unexplored seamounts, the team captured on video a swarm of 115 cutthroat eels (Family Synaphobranchidae) at a small bait package containing about two pounds (1 kg) of mackerel. A few eels were caught in a baited trap and identified to be of the species Ilyophis arx, a poorly known species with fewer than 10 specimens in fish collections worldwide.

These eels were observed at the top of all of the seamounts, but not on the surrounding abyssal plain. The findings provide evidence for an abyssal seamount effect (where these mountains can support much higher numbers of animals than other surrounding habitats), and also indicate these eels are likely to be seamount specialists.

After returning from the expedition, the team determined they had documented the highest number of fishes ever been recorded at one time in the abyssal ocean—almost double the previous record.

"If this phenomenon is not just isolated to these two seamounts in the CCZ, the implications on deep sea ecology could be widespread," said Leitner, who is now a postdoctoral researcher at the Monterey Bay Aquarium Research Institute. "Our findings highlight how much there is still left to discover in the deep sea, and how much we all might lose if we do not manage mining appropriately."

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More information: Astrid B. Leitner et al, Synaphobranchid eel swarms on abyssal seamounts: Largest aggregation of fishes ever observed at abyssal depths, Deep Sea Research Part I: Oceanographic Research Papers (2020). 

DOI: 10.1016/j.dsr.2020.103423

Provided by University of Hawaii at Manoa