Sunday, October 24, 2021

Northern lakes warming six times faster in the past 25 years

YORK UNIVERSITY

Oneida Lake — IMAGE: ICE BREAKUP ON ONEIDA LAKE IN NEW YORK view more
CREDIT: PHOTO BY PROFESSOR LARS RUDSTAM, CORNELL UNIVERSITY

TORONTO, Oct. 21, 2021 – Lakes in the Northern Hemisphere are warming six times faster since 1992 than any other time period in the last 100 years, research led by York University has found.

Lake Superior, the most northern of the Great Lakes which straddles the Canada/United States border, is one of the fastest warming lakes, losing more than two months of ice cover since ice conditions started being recorded in 1857. In Lake Suwa, in Japan, ice formed close to 26 days later per century since 1897 and is now only freezing twice every decade, while Grand Traverse Bay in Lake Michigan had one of the fastest ice-off trends, melting about 16 days earlier per century.

“We found that lakes are losing on average 17 days of ice cover per century. Alarmingly, what we found is that warming in the past 25 years, from 1992 to 2016, was six times faster than any other period in the last 100 years,” says Associate Professor Sapna Sharma of the Faculty of Science at York University, who led the study with Professor David Richardson at the State University of New York at New Paltz and climate scientist Iestyn Woolway, PhD, of the European Space Agency Climate Office, United Kingdom.

The researchers re-assessed ice trends of 60 lakes for the first time since 2004 for 60 lakes by studying ice phenology records ranging from 107 to 204 years old from prior to the Industrial Revolution. “Many of our lakes may be approaching a tipping point to ice-free conditions which will have vast cultural and ecological implications,” says Sharma.

On average, these lakes were freezing 11 days later and thawing 6.8 days earlier. Extremely warm winters over the last several decades have contributed to the increasing rate of ice loss, especially in larger lakes and in southern and coastal regions.

“In addition, we found that the duration of winter ice cover has decreased, particularly since 1995, to the point where some lakes are beginning to have more winters with minimal or even no ice cover. For example, some deep lakes in Switzerland and Germany, which historically used to freeze each winter, have permanently lost their ice cover in the past few decades,” says Richardson.

Of the lakes studied, 40 are in North America including Lakes Michigan and Superior, Detroit Lake in Minnesota, Lakes Monona and Mendota in Wisconsin, Cazenovia and Oneida lakes in New York, and several in Ontario – Lake Simcoe, Lake Nipissing and Lake of Bays – 18 in Europe, and two in Asia – Lake Baikal in Siberia, Russia, and Lake Suwa in Japan.

“The findings were in line with our expectations as air temperature has increased over recent decades,” says Woolway. “Air temperature is one of the most important climatic drivers of lake ice dynamics, owing to its additive effects on various components of the lake energy budget.”

Lake ice phenology is considered an important sentinel of climate change. A reduction in greenhouse gas emissions is necessary if increases in air temperature and decreases in lake ice cover are to be mitigated. The researchers say this would also help limit ecological, cultural, and socioeconomic consequences, including increased evaporation rates, warmer water temperatures, degraded water quality, and the formation of toxic algal blooms.

Records have been kept for several decades to centuries detailing lake ice-on and ice-off times because of its importance to refrigeration, transportation, recreation and cultural traditions, as well as economic impacts.

The paper, Loss of Ice Cover, Shifting Phenology, and More Extreme Events in Northern Hemisphere Lakes, was published in the October issue of the Journal of Geophysical Research: Biogeosciences.

CAPTION

Lake Kallavesi, spring 2021, Finland.

CREDIT

Photo by Johanna Korhonen, World Meteorological Organization

York University champions new ways of thinking that drive teaching and research excellence. Our students receive the education they need to create big ideas that make an impact on the world. Meaningful and sometimes unexpected careers result from cross-disciplinary programming, innovative course design and diverse experiential learning opportunities. York students and graduates push limits, achieve goals and find solutions to the world’s most pressing social challenges, empowered by a strong community that opens minds. York U is an internationally recognized research university – our 11 faculties and 25 research centres have partnerships with 200+ leading universities worldwide. Located in Toronto, York is the third largest university in Canada, with a strong community of 53,000 students, 7,000 faculty and administrative staff, and more than 300,000 alumni. York U's fully bilingual Glendon Campus is home to Southern Ontario's Centre of Excellence for French Language and Bilingual Postsecondary Education.

JOURNAL

Journal of Geophysical Research Biogeosciences

DOI

10.1029/2021JG006348

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Loss of Ice Cover, Shifting Phenology, and More Extreme Events in Northern Hemisphere Lakes

ARTICLE PUBLICATION DATE

21-Oct-2021

Disclaimer: AAAS and Eur

First-ever Africa-wide great ape assessment reveals human activity, not habitat availability, is greatest driver of ape abundance

GDP, roads, agricultural land, and human population density are the strongest factors predicting abundance

Peer-Reviewed Publication

WILDLIFE CONSERVATION SOCIETY

NEW YORK (21 October 2021) – The first-ever Africa-wide assessment of great apes – gorillas, bonobos and chimpanzees – finds that human factors, including roads, population density and GDP, determine abundance more than ecological factors such as forest cover.

The findings are published in the American Journal of Primatology by a team of scientists led by the Max Planck Institute for Evolutionary Anthropology, Wildlife Conservation Society (WCS), and other groups.

Authors looked at 156 sites in 20 countries, developing a model that spans the entire African great ape range to determine abundance, and to identify key factors influencing their distribution at this large scale. The highest densities of apes were found in Central Africa, and the lowest in West Africa.

Said the study’s lead author Isabel Ordaz-Németh of Max Planck Institute for Evolutionary Anthropology: “The findings reveal that the impact of human activities dominates over ecological factors in determining where great apes are still found today. This means that even if suitable habitat is still present at various locations, such as tropical rainforest, apes do not occur anymore or at much lower density, because of human activities.”

Ordaz-Németh added: “Furthermore, the relationship between GDP and great apes indicates a decline of great apes with more developed, larger economies.”

In addition, the study found that only 10.7 percent of the predicted great ape population was found in areas with high levels of legal protection (IUCN Category I and II protected areas).

Said co-author Fiona “Boo” Maisels of WCS: “This study mirrors the recent findings that elephant distribution across the African continent is now also mostly constrained by human activities, rather than environmental variables. Current great ape conservation strategies are largely focused on protected areas, but only one in ten great apes live in these areas. We must improve the protection for the remaining nine-tenths of great apes that are currently outside them, and assess the impacts of alternative policies, infrastructure development or stricter guidelines for resource extraction.”

An important question emerging from these results is whether we can find solutions for harmonizing economic development and the survival of great ape populations.

The authors note that recent assessments of African great ape populations have revealed drastic declines. To successfully protect these endangered species, it is essential to evaluate the effectiveness of policies and outcomes of different scenarios. These scenarios can include, for example, the impact of resource extraction sites, climate change, large scale land-planning, and the implementation of policies that are, for example, related to forest management, or carbon storage policies for climate change mitigation.

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WCS (Wildlife Conservation Society)

MISSION: WCS saves wildlife and wild places worldwide through science, conservation action, education, and inspiring people to value nature. To achieve our mission, WCS, based at the Bronx Zoo, harnesses the power of its Global Conservation Program in nearly 60 nations and in all the world’s oceans and its five wildlife parks in New York City, visited by 4 million people annually. WCS combines its expertise in the field, zoos, and aquarium to achieve its conservation mission. Visit: newsroom.wcs.org Follow: @WCSNewsroom. For more information: 347-840-1242.

JOURNAL

American Journal of Primatology

DOI

10.1002/ajp.23338

METHOD OF RESEARCH

Meta-analysis

SUBJECT OF RESEARCH

Animals

ARTICLE TITLE

Range-wide indicators of African great ape density distribution

ARTICLE PUBLICATION DATE

18-Oct-2021

COI STATEMENT

None

Disclaimer

Climate change lowers nutrition, increases toxicity at base of food web

Research looks at warming, browning effects on freshwater systems

Peer-Reviewed Publication

DARTMOUTH COLLEGE

Mesocosms — IMAGE: CONTROLLED OUTDOOR ENVIRONMENTS KNOWN AS “MESOCOSMS” WERE USED TO STUDY CLIMATE CHANGE IMPACTS ON NUTRITION AND TOXICITY ON THE AQUATIC FOOD WEB. view more
CREDIT: PHOTO CREDIT: PIANPIAN WU

HANOVER, N.H. – October 25, 2021 – Climate change impacts on freshwater systems can lower nutrition and increase toxicity at the base of the food web, according to research from Dartmouth College and the Swedish University of Agricultural Sciences.

The research, published in Scientific Reports, focused on the effects of warming water temperatures and browning—a discoloration of water caused by increased dissolved organic matter—using controlled outdoor environments known as mesocosms.

“Climate change scenarios predict increases in temperature and organic matter supply from land to water,” said Pianpian Wu, a postdoctoral fellow at Dartmouth and lead author of the study. “For the first time, we used manipulated mesocosm systems to test the effects of warming and browning.”

Under the expected climate scenario of more warming, changing precipitation patterns, and higher levels of dissolved organic matter, the study looked at the fate of nutritious polyunsaturated fatty acids and toxic methylmercury in the food chain.

The research found that a combination of warmer, browner water resulted in the higher transfer of methylmercury from water to phytoplankton at the base of food web. Lower concentrations of essential polyunsaturated fatty acids in phytoplankton were also observed.

Long-chain polyunsaturated fatty acids—such as omega-3 and omega-6—support the growth and survival of animal and plant life by providing energy and by regulating immune systems. Methylmercury is a form of mercury that is easily absorbed by living organisms and acts a potent neurotoxin.

“The reduction of polyunsaturated acids at the end of the mesocosm experiment with both warming and browning effects was concerning,” said Wu, who began the research as a PhD candidate at the Swedish University of Agricultural Sciences.

Phytoplankton are the main suppliers of polyunsaturated fatty acids in aquatic ecosystems. According to the study, the less nutritious phytoplankton that result from browning and warmer water cause higher-level organisms—such as zooplankton, fish, other wildlife, and humans—to be exposed to more methylmercury as they consume more to achieve fatty acid quotas.

“This study shows that the food quality at the base of aquatic food webs deteriorates with climate change,” said Kevin Bishop, professor at the Swedish University of Agricultural Sciences and the senior researcher of the study. “The research is important because it places food web investigations within the context of active global change processes.”

While previous research on browning and warming has been conducted in natural environments, this is the only study to rely entirely on controlled mesocosm environments.

The researchers used 24 thermally insulated plastic cylinders to test the effects of various levels of warming and browning under four different scenarios, including a reference scenario without any weathering effect. The mesocosms were controlled at subalpine conditions that are highly prone to climate change effects and relatively poor in dissolved organic matter.

“The use of mesocosms to investigate questions related to ecosystem effects of climate change is particularly important,” said Celia Chen, research professor at Dartmouth and a co-author of the study. “The effects of factors such as temperature and browning can be tested individually and in combination while controlling other environmental conditions. Mesocosms also eliminate the need to travel long distances for field investigations.”

The study was conducted at the WasserCluster Lunz research facility outside of Vienna using lake water from Lunzer See in Lower Austria.

According to the research team, the findings point to the importance of factoring consumption levels in addition to concentration levels when looking at the quality of the food web in freshwater systems.

Martin Kainz and Katharina Winter, from WasserCluster Lunz- Biologische Station; Fernando Valdés, Uppsala University; Siwen Zheng and Rui Wang, Tongji University; and Brian Branfireun, Western University all served as co-authors of the study.

JOURNAL

Scientific Reports

DOI

10.1038/s41598-021-95742-9

ARTICLE TITLE

Elevated temperature and browning increase dietary methylmercury, but decrease essential fatty acids at the base of lake food webs

ARTICLE PUBLICATION DATE

19-Aug-2021

Emergence of a novel reassortant avian influenza virus (H10N3) in Eastern China

Peer-Reviewed Publication

SCIENCE CHINA PRESS

Emergence of a Novel Reassortant Avian Influenza Virus (H10N3) in Eastern China — IMAGE: FIGURE. BIOLOGICAL CHARACTERISTICS OF THE NOVEL REASSORTANT H10N3 VIRUSES ISOLATED FROM CHICKEN IN EASTERN CHINA. 1) THE NOVEL REASSORTANT H10N3 ISOLATES BOUND TO BOTH AVIAN-TYPE (SAΑ-2,3-GAL) AND HUMAN-TYPE (SAΑ-2,6-GAL) RECEPTORS; 2) THE NOVEL REASSORTANT H10N3 AIVS WERE HIGHLY PATHOGENIC IN MICE; 3) THE NOVEL REASSORTANT H10N3 ISOLATES WERE TRANSMISSIBLE AMONG GUINEA PIGS VIA DIRECT CONTACT AND RESPIRATORY DROPLETS. view more
CREDIT: ©SCIENCE CHINA PRESS

The first known H10 avian influenza virus (AIV) was isolated from chicken in Germany in 1949 and has undergone multiple reassortment events during decades of circulation. Many H10-subtype AIVs, including H10N1, H10N2, H10N3, H10N6, H10N7, H10N8, and H10N9, are widely distributed in domestic and wild birds. H10-subtype AIVs circulate not only in poultry but have spread to mammals such as minks, pigs, and seals. Transmission of H10-subtype AIVs from birds to humans is uncommon but has occurred. The first reported human infections with a H10 subtype influenza virus occurred in Egypt in 2004. In subsequent surveillance, cross-species transmission of subtype H10 influenza virus has been detected occasionally. Remarkably, three patients were reportedly infected with the H10N8 subtype influenza virus in China in 2013, two of the infected patients died. The National Health Commission of the People's Republic of China confirmed the first case of human infection with H10N3 subtype AIV in Zhenjiang, Jiangsu Province, in April 2021. The epidemiological investigation did not find that the patient had a clear history of exposure to the live poultry market, and the H10N3 virus of the same genotype was not isolated locally, so the source of infection could not be determined. This poses a great challenge to prevent the recurrence of human infections with H10N3.

“Tracing the source of the human-origin H10N3 virus and systematic analysis of its biological characteristics are the prerequisites for preventing H10N3 from re-infecting humans.” said associate professor, Xiaoquan, Wang, the co-corresponding author of this work.

During surveillance activities for avian influenza in live bird markets (LBMs) in Eastern China from 2019 to 2021, the research team isolated several avian H10N3 viruses, and these strains were highly homologous to human-origin H10N3 strain. In this study, two avian-origin H10N3 viruses were first isolated from Jiangsu Province in December 2019, indicating that this type of virus has been silently circulating in poultry for at least 17 months before causing human infections. Phylogenetic analysis revealed that the HA and NA sequences, which belonged to the Eurasian lineage, were derived from H10N8 and H7N3, respectively, and were prevalent in Zhejiang province; whereas the internal genes of H10N3 were all derived from H9N2 AIVs. Interestingly, H9N2 AIVs have become dominant in LBMs in China in recent years and donate internal genes for human isolates such as H7N9, H10N8 and H5N6. The first species barrier is host cell attachment. AIVs preferentially bind to SAα-2,3-Gal, whereas human-adapted viruses have been shown to favor SAα-2,6-Gal. These H10N3 strains presented affinities to both avian-type and human-type receptors. AIVs can transmit to new species, but without long-term adaptation in mammals, most AIVs show low pathogenicity in mice. In this study, the two novel reassortant H10N3 isolates were highly pathogenic in mice and replicated efficiently in multiple organs without prior adaptation. AIV acquires the ability for continuous transmission between humans was the key to a pandemic. This study showed that infected guinea pig models could shed high virus loads through the respiratory tract and could transmit the virus via both direct contact and aerosols.

This finding illustrates that the novel reassortant H10N3 isolates exhibited comparable binding affinity for both avian-type and human-type receptors and lethal infection of mice. Furthermore, it displayed efficient transmission via both direct contact and aerosolization in guinea pig models, suggesting that the novel reassortant H10N3 subtype AIV poses a high threat to public health.

“LPAIVs usually cause no explicit symptoms in poultry; thus, human outbreaks may occur when poultry infections go unnoticed. Therefore, continuous surveillance for the emergence and evolution of novel AIVs in poultry and evaluation of their potential threat to public health is necessary.” said Prof. Xiufan Liu, the corresponding author of this work.

This work was supported by grants from the National Key Research and Development Project of China: 2016YFD0500202-1; National Natural Science Foundation of China: 31772755; National Key Research and Development Project of China: 2016YFD0501601; Jiangsu Provincial Natural Science Fund for Excellent Young Scholars (BK20170068); Earmarked Fund For China Agriculture Research System: CARS-40; Open Project Program of Jiangsu Key Laboratory of Zoonosis: R1808; Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD).

See the article:

Liu, K., Ding, P., Pei, Y., Gao, R., Han, W., Zheng, H., Ji, Z., Cai, M., Gu, J., Li, X., et al. (2021). Emergence of a novel reassortant avian influenza virus (H10N3) in Eastern China with high pathogenicity and respiratory droplet transmissibility to mammals. Sci China Life Sci 64, https://doi.org/10.1007/s11427-020-1981-5.

JOURNAL

Science China Life Sciences

DOI

10.1007/s11427-020-1981-5

Permanent Twitter ban of extremist influencers can detoxify social media

Removing extremist public figures from social media reduces the spread of offensive ideas and toxicity

Peer-Reviewed Publication

RUTGERS UNIVERSITY

Banning right-wing extremists from social media can reduce the spread of anti-social ideas and conspiracy theories, according to Rutgers-led research.

The study, published in the journal Proceedings of the ACM on Human-Computer Interaction, examined what happens after individual influencers with large followings are banned from social media and no longer have a platform to promote their extreme views.

“Removing someone from a platform is an extreme step that should not be taken lightly,” said lead author Shagun Jhaver, an assistant professor in the Department of Library and Information Science at Rutgers-New Brunswick. “However, platforms have rules for appropriate behavior, and when a site member breaks those rules repeatedly, the platform needs to take action. The toxicity created by influencers and their supporters who promote offensive speech can also silence and harm vulnerable user groups, making it crucial for platforms to attend to such influencers’ activities.”

The study examined three extremist influencers banned on Twitter: Alex Jones, an American radio host and political extremist who gained notoriety for promoting conspiracy theories; Milo Yiannopoulos, a British political commentator who became known for ridiculing Islam, feminism and social justice; and Owen Benjamin, an American “alt-right” actor, comedian and political commentator who promoted anti-Semitic conspiracy theories and anti-LGBT views.

The researchers analyzed more than 49 million tweets referencing the banned influencers, tweets referencing their offensive ideas, and all tweets posted by their supporters six months before and after they were removed from the platform.

Once they were denied social media access, posts referencing each influencer declined by almost 92 percent. The number of existing users and new users specifically tweeting about each influencer also shrank significantly, by about 90 percent.

The bans also significantly reduced the overall posting activity and toxicity levels of supporters. On average, the number of tweets posted by supporters reduced by 12.59 percent and their toxicity declined by 5.84 percent. This suggests that de-platforming can improve the content quality on the platform.

Researchers say the study indicates that banning those with extremist views who are promoting conspiracy theories minimizes contentious conversations by their supporters. The data from the study will help social media platforms make more informed decisions about whether and when to implement bans, which has been on the rise as a moderation strategy.

“Many people continue to raise concerns about the financial benefits from advertising dollars tied to content that spreads misinformation or conducts harassment,” said Jhaver. “This is an opportunity for platforms to clarify their commitment to its users and de-platform when appropriate. Judiciously using this strategy will allow platforms to address the problem of online radicalization, a worthy goal to pursue even if it leads to short-term loss in advertising dollars.”

Future research is needed to examine the interactions between online speech, de-platforming and radicalization and to identify when it would be appropriate to ban users from social media sites.

JOURNAL

Proceedings of the ACM on Human-Computer Interaction

DOI

10.1145/3479525

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Evaluating the Effectiveness of Deplatforming as a Moderation Strategy on Twitter

Hidden costs of global illegal wildlife trade

Peer-Reviewed Publication

UNIVERSITY OF ADELAIDE

Sulcata Tortoise — IMAGE: A VENDOR DISPLAY FEATURING A SULCATA TORTOISE AT A REPTILE TRADE CONVENTION IN FLORIDA, USA. view more
CREDIT: SUPPLIED BY ADAM TOOMES, THE UNIVERSITY OF ADELAIDE.

An international team of experts, including researchers from the University of Adelaide, has highlighted that the illegal and unsustainable global wildlife trade has bigger ramifications on our everyday lives than you might think.

In a paper published in Biological Conservation, the team of researchers investigated the many ways in which the trade negatively impacts species, ecosystems, and society – including people’s health, crime and our economies.

Co-author, Dr Oliver Stringham from the University of Adelaide said: “The Illegal or unsustainable wildlife trade is growing at a global level and the impacts are far-reaching.

“The trade in wild vertebrates alone is estimated to involve a quarter of terrestrial (land) species, while the trade in ocean life, invertebrates, plants, and fungi remains considerably overlooked and poorly documented.

“As a threat to targeted species, the trade represents one of the five major drivers of biodiversity loss and extinction at global scale.

“But these effects are just the tip of the iceberg.”

In their paper the researchers also describe the incidental effects of wildlife harvesting on other species. These include disrupted interactions between species and ecosystem structure, altering species composition, functioning, and services – such as seed dispersal, pollination and carbon storage. Many species also provide habitat for others and their loss results in habitat depletion.

The trade can further result in deliberate or accidental introduction of predators and pests in previously predator-free areas. This has an estimated cost of US$162.7 billion a year, and can cause havoc on the native systems through the spread of disease, and in extreme cases cause the extinction of native species.

The paper also discusses impacts for human health.

Dr Stringham said: “Two-thirds of emerging infectious disease outbreaks affecting humans, many leading to pandemics, have zoonotic origins, and of these, the majority originate in wildlife.”

There are also costs to eco-tourism. Deforestation of pristine areas can reduce space for recreation, and the global estimated net loss in ecosystem services, mainly due to logging and consequent habitat loss is estimated at US$20.2 trillion.

According to co-author of the paper PhD candidate Adam Toomes from the University of Adelaide, the legal yet unregulated trade can be just as detrimental as its illegal counterpart.

“A large diversity of species are not protected by international regulation and are traded without any formal documentation process, making it incredibly difficult to evaluate the associated costs and benefits,” he said.

“The trade is also highly dynamic, meaning that, in extreme cases, demand for a previously low-risk species can increase rapidly, outpacing relevant legislation.”

In a follow-up paper, the researchers outline a number of approaches and tools available to curb the trade. These include bans, quotas, protected areas, certification, captive-breeding and propagation, education and awareness.

Mr Toomes said, while it is clear urgent action is needed to close key knowledge gaps and regulate wildlife trade more stringently, policy and enforcement also needs to consider the livelihoods and communities depending on trade, to ensure a balance between these often-opposing views.

“Trade regulations that do not take this into consideration could increase vulnerability and poverty in certain areas that depend on it for food and income,” he said.

“With large differences in legislation, cultural drivers of trade and availability of species, there is no one-size fits all strategy. Each unique context warrants a variety of disciplines and actors dedicated to ensuring trade occurs sustainably.”