UC Irvine biologists discover bees to be brew masters of the insect world

New study sheds light on the subterranean microbreweries of ground-nesting bees

Peer-Reviewed Publication

UNIVERSITY OF CALIFORNIA - IRVINE

Irvine, Calif., April 20, 2023 — Scientists at the University of California, Irvine have made a remarkable discovery about cellophane bees – their microbiomes are some of the most fermentative known from the insect world. These bees, which are named for their use of cellophane-like materials to line their subterranean nests, are known for their fascinating behaviors and their important ecological roles as pollinators. Now, researchers have uncovered another aspect of their biology that makes them even more intriguing.

According to a study published in Frontiers in Microbiology, cellophane bees “brew” a liquid food for their offspring, held in chambers called brood cells. The microbiome of these brood cells is dominated by lactobacilli bacteria, which are known for their role in fermenting foods like yogurt, sauerkraut and sourdough bread. The researchers found that these bacteria are highly active in the food provisions of cellophane bees, where they likely play an important role as a source of nutrients for developing larvae.

“This discovery is quite remarkable,” said Tobin Hammer, assistant professor of ecology & evolutionary biology and lead author. “We know that lactobacilli are important for fermentation of food, but finding wild bees that use them essentially the same way was really surprising. Most of the 20,000 species of bees get their nutrition from nectar and pollen, but for these cellophane bees, we suspect that lactobacilli are also really important. They have effectively evolved from herbivores into omnivores.”

The study also found that the food provisions of cellophane bees have much higher bacterial biomass compared to other bee species, matching the unusually fermentative smell that emanates from their brood cells. These uniquely rich, lactobacilli-dominated microbreweries of cellophane bees could have important implications for the health of the bees, as well as for the ecology of the ecosystems in which they live.

“It was intriguing to find that cellophane bees use a strategy called ‘spontaneous fermentation,’ which is how certain fermented foods like sauerkraut are made. Rather than passing on starter cultures from generation to generation, they use wild strains of lactobacilli that are ubiquitous in flowers,” said Hammer. “It suggests that fermentation-based symbioses like this one can evolve without domestication. What makes these bees special is that they’ve figured out how to create a favorable environment in which lactobacilli can grow really well.”

This study highlights the importance of studying the microbiomes of insects, which are often overlooked in favor of more familiar animals like birds and mammals, despite playing an enormous role in ecosystems the world over. By understanding the complex interactions between microbes and their insect hosts, scientists can gain new insights into the biology of these important animals and the ecosystems that they inhabit.

This study was a collaboration between researchers at Cornell University, the Smithsonian Tropical Research Institute, UC Riverside, Colorado State University and the University of Arizona. The National Science Foundation, the U.S. Department of Agriculture and the Simons Foundation provided support.

About the University of California, Irvine: Founded in 1965, UCI is a member of the prestigious Association of American Universities and is ranked among the nation’s top 10 public universities by U.S. News & World Report. The campus has produced five Nobel laureates and is known for its academic achievement, premier research, innovation and anteater mascot. Led by Chancellor Howard Gillman, UCI has more than 36,000 students and offers 224 degree programs. It’s located in one of the world’s safest and most economically vibrant communities and is Orange County’s second-largest employer, contributing $7 billion annually to the local economy and $8 billion statewide. For more on UCI, visit www.uci.edu.

Media access: Radio programs/stations may, for a fee, use an on-campus ISDN line to interview UCI faculty and experts, subject to availability and university approval. For more UCI news, visit news.uci.edu. Additional resources for journalists may be found at communications.uci.edu/for-journalists.

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JOURNAL

Frontiers in Microbiology

ARTICLE TITLE

Bee breweries: The unusually fermentative, lactobacilli-dominated brood cell microbiomes of cellophane bees

ChatGPT is still no match for humans when it comes to accounting

Massive crowd-sourced study comes from 327 co-authors at 186 institutions from 14 countries

Peer-Reviewed Publication

BRIGHAM YOUNG UNIVERSITY

 

IMAGE: IN A TEST OF CHATGPT'S ABILITY TO HANDLE ACCOUNTING ASSESSMENTS IT STILL COULDN'T COMPETE WITH THE STUDENT'S LEVEL. view more 

CREDIT: NATE EDWARDS/BYU PHOTO

Last month, OpenAI launched its newest AI chatbot product, GPT-4. According to the folks at OpenAI, the bot, which uses machine learning to generate natural language text, passed the bar exam with a score in the 90th percentile, passed 13 of 15 AP exams and got a nearly perfect score on the GRE Verbal test.

Inquiring minds at BYU and 186 other universities wanted to know how OpenAI’s tech would fare on accounting exams. So, they put the original version, ChatGPT, to the test. The researchers say that while it still has work to do in the realm of accounting, it’s a game changer that will change the way everyone teaches and learns — for the better.

“When this technology first came out, everyone was worried that students could now use it to cheat,” said lead study author David Wood, a BYU professor of accounting. “But opportunities to cheat have always existed. So for us, we’re trying to focus on what we can do with this technology now that we couldn’t do before to improve the teaching process for faculty and the learning process for students. Testing it out was eye-opening.”

Since its debut in November 2022, ChatGPT has become the fastest growing technology platform ever, reaching 100 million users in under two months. In response to intense debate about how models like ChatGPT should factor into education, Wood decided to recruit as many professors as possible to see how the AI fared against actual university accounting students.

His co-author recruiting pitch on social media exploded: 327 co-authors from 186 educational institutions in 14 countries participated in the research, contributing 25,181 classroom accounting exam questions. They also recruited undergrad BYU students (including Wood’s daughter, Jessica) to feed another 2,268 textbook test bank questions to ChatGPT. The questions covered accounting information systems (AIS), auditing, financial accounting, managerial accounting and tax, and varied in difficulty and type (true/false, multiple choice, short answer, etc.).

Although ChatGPT’s performance was impressive, the students performed better. Students scored an overall average of 76.7%, compared to ChatGPT’s score of 47.4%. On a 11.3% of questions, ChatGPT scored higher than the student average, doing particularly well on AIS and auditing. But the AI bot did worse on tax, financial, and managerial assessments, possibly because ChatGPT struggled with the mathematical processes required for the latter type.

When it came to question type, ChatGPT did better on true/false questions (68.7% correct) and multiple-choice questions (59.5%), but struggled with short-answer questions (between 28.7% and 39.1%). In general, higher-order questions were harder for ChatGPT to answer. In fact, sometimes ChatGPT would provide authoritative written descriptions for incorrect answers, or answer the same question different ways.

“It’s not perfect; you’re not going to be using it for everything,” said Jessica Wood, currently a freshman at BYU. “Trying to learn solely by using ChatGPT is a fool’s errand.”

The researchers also uncovered some other fascinating trends through the study, including:

• ChatGPT doesn’t always recognize when it is doing math and makes nonsensical errors such as adding two numbers in a subtraction problem, or dividing numbers incorrectly.
• ChatGPT often provides explanations for its answers, even if they are incorrect. Other times, ChatGPT’s descriptions are accurate, but it will then proceed to select the wrong multiple-choice answer.
• ChatGPT sometimes makes up facts. For example, when providing a reference, it generates a real-looking reference that is completely fabricated. The work and sometimes the authors do not even exist.

That said, authors fully expect GPT-4 to improve exponentially on the accounting questions posed in their study, and the issues mentioned above. What they find most promising is how the chatbot can help improve teaching and learning, including the ability to design and test assignments, or perhaps be used for drafting portions of a project.

“It’s an opportunity to reflect on whether we are teaching value-added information or not,” said study coauthor and fellow BYU accounting professor Melissa Larson. “This is a disruption, and we need to assess where we go from here. Of course, I’m still going to have TAs, but this is going to force us to use them in different ways.”

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JOURNAL

Issues in Accounting Education

DOI

10.2308/ISSUES-2023-013 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

People

ARTICLE TITLE

The ChatGPT Artificial Intelligence Chatbot: How Well Does It Answer Accounting Assessment Questions?

Elephant seals drift off to sleep while diving far below the ocean surface

Brainwave patterns show elephant seals take short naps while holding their breath on deep dives, averaging just 2 hours of sleep per day while at sea

Peer-Reviewed Publication

UNIVERSITY OF CALIFORNIA - SANTA CRUZ

 

IMAGE: ELEPHANT SEALS SLEEP ABOUT 10 HOURS A DAY ON THE BEACH, BUT DURING MONTHS-LONG FORAGING TRIPS AT SEA THEY AVERAGE JUST 2 HOURS OF SLEEP PER DAY. THESE 2-MONTH-OLD NORTHERN ELEPHANT SEALS ARE SLEEPING ON THE BEACH AT AÑO NUEVO STATE PARK. view more 

CREDIT: PHOTO BY JESSICA KENDALL-BAR, NMFS 23188

For the first time, scientists have recorded brain activity in a free-ranging, wild marine mammal, revealing the sleep habits of elephant seals during the months they spend at sea.

The new findings, published April 20 in Science, show that while elephant seals may spend 10 hours a day sleeping on the beach during the breeding season, they average just 2 hours of sleep per day when they are at sea on months-long foraging trips. They sleep for about 10 minutes at a time during deep, 30-minute dives, often spiraling downward while fast asleep, and sometimes lying motionless on the seafloor.

First author Jessica Kendall-Bar led the study as a UC Santa Cruz graduate student working with Daniel Costa and Terrie Williams, both professors of ecology and evolutionary biology at UCSC.

“For years, one of the central questions about elephant seals has been when do they sleep,” said Costa, who directs UCSC’s Institute of Marine Sciences. Costa’s lab has led the UCSC elephant seal research program at Año Nuevo Reserve for over 25 years, using increasingly sophisticated tags to track the movements and diving behavior of the seals during their foraging migrations, when they head out into the North Pacific Ocean for as long as 8 months.

“The dive records show that they are constantly diving, so we thought they must be sleeping during what we call drift dives, when they stop swimming and slowly sink, but we really didn’t know,” Costa said. “Now we’re finally able to say they’re definitely sleeping during those dives, and we also found that they’re not sleeping very much overall compared to other mammals.”

In fact, during their months at sea, elephant seals rival the record for the least sleep among all mammals, currently held by African elephants, which appear to sleep just two hours per day based on their movement patterns.

“Elephant seals are unusual in that they switch between getting a lot of sleep when they’re on land, over 10 hours a day, and two hours or less when they’re at sea,” said Kendall-Bar, who is currently a postdoctoral fellow at UC San Diego’s Scripps Institution of Oceanography.

Elephant seals are most vulnerable to predators such as sharks and killer whales when they are at the surface in the open ocean, so they only spend a minute or two breathing at the surface in between dives.

“They’re able to hold their breath for a long time, so they can go into a deep slumber on these dives deep below the surface where it’s safe,” Kendall-Bar said.

Kendall-Bar developed a system that can reliably record brain activity (as an electroencephalogram or EEG) in wild elephant seals during their normal diving behavior at sea. With a neoprene headcap to secure the EEG sensors and a small data logger to record the signals, the system can be recovered when the animals return to the beach at Año Nuevo.

“We used the same sensors you’d use for a human sleep study at a sleep clinic and a removable, flexible adhesive to attach the headcap so that water couldn’t get in and disrupt the signals,” Kendall-Bar said.

Cetaceans (whales and dolphins) and otariids (fur seals and sea lions) keep one side of their brains awake while the other is asleep (unihemispheric sleep). In most other mammals, including phocids (true seals) and humans, both hemispheres of the brain are asleep at the same time.

CREDIT

Graphic by Jessica Kendall-Bar

In addition to the EEG system, the seals carried time-depth recorders, accelerometers, and other instruments that allowed the researchers to track the seals’ movements along with the corresponding brain activity. The recordings show diving seals going into the deep sleep stage known as slow-wave sleep while maintaining a controlled glide downward, then transitioning into rapid-eye-movement (REM) sleep, when sleep paralysis causes them to turn upside down and drift downwards in a “sleep spiral.”

“They go into slow-wave sleep and maintain their body posture for several minutes before they transition into REM sleep, when they lose postural control and turn upside down,” Kendall-Bar said.

At the depths at which this happens, the seals are usually negatively buoyant and continue to fall passively in a corkscrew spiral “like a falling leaf,” Williams said. In shallower waters over the continental shelf, elephant seals sometimes sleep while resting on the seafloor.

“It doesn’t seem possible that they would truly go into paralytic REM sleep during a dive, but it tells us something about the decision-making processes of these seals to see where in the water column they feel safe enough to go to sleep,” said Williams, who directs the Comparative Neurophysiology Lab at UCSC.

In developing the new EEG instrument, Kendall-Bar first deployed it on elephant seals housed temporarily in the marine mammal facilities at UCSC’s Long Marine Laboratory. The next step was to deploy it on animals in the elephant seal colony at Año Nuevo Reserve north of Santa Cruz, where researchers could observe the animals on the beach.

“I spent a lot of time watching sleeping seals,” Kendall-Bar said. “Our team monitored instrumented seals to make sure they were able to reintegrate with the colony and were behaving naturally.”

Some of those seals took short excursions into the water, but to observe diving behavior the researchers used a translocation procedure developed by Costa’s lab. Juvenile female elephant seals outfitted with the EEG sensors and trackers were transported from Año Nuevo to Monterey and released on a beach at the southern end of Monterey Bay. Over the next few days, the animals would swim back to Año Nuevo across the deep Monterey Canyon, where their dive behavior is very similar to that seen during much longer foraging trips in the open ocean.

With data on brain activity and dive behavior from 13 juvenile female elephant seals, including a total of 104 sleep dives, Kendall-Bar developed a highly accurate algorithm for identifying periods of sleep based on the dive data alone. This enabled her to estimate sleep quotas for 334 adult seals using dive data recorded over several months during their foraging trips.

“Because of the dataset that Dan Costa has curated over 25 years of working with elephant seals at Año Nuevo, I was able to extrapolate our results to over 300 animals and get a population-level look at sleep behavior,” said Kendall-Bar, who now plans to use similar methods to study brain activity in other species of seals and sea lions and in human freedivers.

When elephant seals go into rapid-eye-movement (REM) sleep during deep dives, sleep paralysis causes them to turn upside down and drift downwards in a “sleep spiral.” This data-driven graphic shows sleeping postures every 20 seconds, with accompanying 30-second segments of EEG traces in the background.

CREDIT

Graphic by Jessica Kendall-Bar

Williams called Kendall-Bar’s work on the project a tour de force. “It’s an amazing feat to pull this off,” she said. “She developed an EEG system to work on an animal that’s diving several hundred meters in the ocean. Then she uses the data to create data-driven animations so we can really visualize what the animal is doing as it dives through the water column.”

The results may be helpful for conservation efforts by revealing a “sleepscape” of preferred resting areas, Williams said. “Normally, we’re concerned about protecting the areas where animals go to feed, but perhaps the places where they sleep are as important as any other critical habitat,” she said.

In addition to Kendall-Bar, Costa, and Williams, the coauthors of the paper include Daniel Lozano, Rachel Holser, Theresa Keates, Roxanne Beltran, Patrick Robinson, and Taiki Adachi at UC Santa Cruz; Ritika Mukherji at University of Oxford; Julie Pitman at Sleep Health MD in Santa Cruz; Daniel Crocker at Sonoma State University; Oleg Lyamin at UCLA; and Alexei Vyssotski at the University of Zurich and Swiss Federal Institute of Technology. This work was funded in part by the National Science Foundation and the Office of Naval Research.

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JOURNAL

Science

DOI

10.1126/science.adf0566 

ARTICLE TITLE

Brain activity of diving seals reveals short sleep cycles at depth

ARTICLE PUBLICATION DATE

21-Apr-2023

Reducing fatigue and errors among nurses working night shifts

Short exposure to bright light could help shift workers generally combat fatigue

Peer-Reviewed Publication

MCGILL UNIVERSITY

Nurses exposed to 40 minutes of bright light before their night shifts feel less fatigued and make fewer errors at work, according to a study led by McGill University. The nurses also slept better after their shifts.

“Healthcare workers are experiencing high levels of fatigue due to staffing shortages, difficult schedules, and heavy workloads. Further, the cost of medical errors has been estimated at tens of billions of dollars per year in North America,” says Jay Olson, the senior author of the recent study in Sleep Health, who completed his PhD at McGill University and is now a Postdoctoral Fellow at the University of Toronto. “Our study shows that feasible changes, such as getting light exposure before the night shift, may help reduce fatigue and its effects on performance at work, something which could benefit both the nurses and their patients.”

Light exposure leads to a significant reduction in errors

Building on a previous study, the researchers recruited close to 60 nurses at the McGill University Health Centre. The nurses worked schedules that rotated between day and night shifts within the same week.

During an initial 10-day observation period, nurses in the experimental group made a total of 21 errors, ranging from giving the wrong medication dose to accidental needle pricks. However, when given 40 minutes of bright light exposure from a portable light box before their night shifts, the nurses made only 7 errors — a reduction of 67%. This confirmed the results of a previous feasibility study where the researchers saw a similar 62% reduction in the number of errors at work. In contrast, nurses in the control group who changed their diet to improve their alertness showed only a 5% reduction in errors.

The researchers also found that nurses who followed the evening light intervention reported larger improvements in fatigue compared to those in the control group. In addition, the nurses who reported higher levels of fatigue made more errors at work.

Small changes could make a big difference to many shift workers

“Interventions like the one we studied are relevant to a large population of workers, since between a quarter and a third of the world’s employees do some form of shift work,” adds Mariève Cyr, the first author on the paper, a fourth-year medical student at McGill University. “Although we focused on nurses working rotating schedules, our results may apply to other types of shift workers as well.”

The researchers are conducting workshops on practical fatigue management at hospitals and other workplaces and have launched a website that shift workers can use to adapt the interventions to their own schedules.

The study

“An evening light intervention reduces fatigue and errors during night shifts: A randomized controlled trial” by Mariève Cyr et al was published in Sleep Health.

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JOURNAL

Sleep Health

DOI

10.1016/j.sleh.2023.02.004 

ARTICLE TITLE

An evening light intervention reduces fatigue and errors during night shifts: A randomized controlled trial

ARTICLE PUBLICATION DATE

19-Apr-2023

Researchers develop safety monitoring system for construction sites

ViPER+ accurately tracks workers’ location on job site to enhance safety

Peer-Reviewed Publication

UNIVERSITY OF HOUSTON

 

IMAGE: ALIREZA ANSARIPOUR MONITORS DATA FROM THE EXPERIMENT IN HOUSTON ON HIS COMPUTER OUTSIDE THE TRACKING ZONE. view more 

CREDIT: UNIVERSITY OF HOUSTON

University of Houston computer scientists have developed a new system to keep construction workers safe at job sites. Their findings and process are laid out in a study published in the research journal Applied Sciences.

According to the Occupational Safety and Health Administration, 4,764 workers died on the job in 2020. Employees in construction and extraction occupations accounted for 20% of those deaths. Many were struck by a vehicle or mobile machinery on construction sites. Although the construction industry has enlisted the help of safety experts, a great number of fatalities and injuries still occur.

“The point of our research project was to enhance safety of workers and equipment on a construction site by tracking their location,” said Alireza Ansaripour, a computer science doctoral student at UH and first author of the study. “By tracking their location, we can monitor location-based policies related to the safety of workers and equipment in construction sites.”

These location-based safety policies are created during the planning stage of the construction site such as when Internal Traffic Control Plans are made. These policies define safe areas for workers and equipment or define a safe distance between them when equipment is operating in the construction site. ViPER+ automates the monitoring of these policies and detects any violations of the policies while workers and equipment are working.

ViPER+ utilizes ultra-wideband technology for location tracking. “These radios use large bandwidths to communicate, which enables them to perform location tracking more accurately compared to other wireless radios,” Ansaripour said. “This was the technology we used to track the locations of workers and equipment.”

The team’s ViPER+ system surmounts challenges of other ultra-wideband based real-time safety monitoring systems primarily because it overcomes non-line of sight situations. These are instances in which trucks, construction loaders and other equipment block the signal between the transmitter and receiver in ultra-wideband radio transmissions.

Ansaripour and his colleagues implemented a correction method in their localization, or location tracking algorithm to reduce the error caused by non-line of sight.

Construction truck with a ultra-wideband tag that allows students to monitor its location.

CREDIT

University of Houston

Testing ViPER+ in Construction Zones

ViPER+ is an updated and improved version of the group’s initial system ViPER. The greatest difference between the two is the enhanced location tracking on ViPER+, which is more accurate in non-line of sight situations.

The team tracked locations through tags and anchors. Tags are small ultra-wideband radio transmitters, mounted to workers and vehicles to monitor their locations. Anchors are ultra-wideband receivers that receive signals from tags. The researchers then collected data from anchors to their computer server and estimated the location of vehicles and people in a construction site.

They tested their system twice in actual construction zones in Houston that was cordoned off for their experiment. But instead of real construction workers, students had to play that part.

“In our evaluation, all four construction workers had tags mounted. We also had one vehicle, either a truck or bulldozer with multiple tags on it, and another static vehicle was used to create a non-line of sight situation.”

The first evaluation was in 2019 when researchers set up tags in an area about 8,600 square feet called the tracking zone. Four students operated as workers in the tracking zone while Ansaripour was managing the data flow of the system and made sure the experiment ran smoothly. In 2022, a similar scenario was set up but at a different construction site.

“Alireza is one of those students with brilliant ideas and the work ethic to see these ideas to fruition,” said Omprakash Gnawali, associate professor of computer science at the UH College of Natural Sciences and Mathematics and co-author of the study. “Having that combination is important to get these technical projects to be successful.”

Graphical rendering of the experiment in which the red box indicates where the truck is not allowed to enter.

CREDIT

University of Houston

Future Improvements

Future changes to the system include ironing out user design issues such as alerting construction workers when they are too close to moving machinery.

“We also have an issue creating a tracking zone that covers all of a construction site, not just a portion of it,” said Ansaripour. “There are still some improvements that need to be made for this to become a commercial product, but our work provides insight on how a real-time safety monitoring system can be used for safety tracking in construction sites.”

Other authors of the study include UH’s Milad Heydariaan, and from the University of Nebraska-Lincoln, corresponding author Kyungki Kim and Hafiz Oyediran.

This research project was funded through the National Cooperative Highway Research Program (NCHRP) Idea of the National Academy of Sciences under the award NCHRP-206.

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JOURNAL

Applied Sciences

DOI

10.3390/app13031581 

ARTICLE TITLE

ViPER+: Vehicle Pose Estimation Using Ultra-Wideband Radios for Automated Construction Safety Monitoring

Tiny plastic particles also find their way into the brain

Mechanism for breaching the blood-brain barrier described for the first time

Peer-Reviewed Publication

MEDICAL UNIVERSITY OF VIENNA

The study was carried out in an animal model with oral administration of MNPs, in this case polystyrene, a widely-used plastic which is also found in food packaging. Led by Lukas Kenner (Department of Pathology at MedUni Vienna and Department of Laboratory Animal Pathology at Vetmeduni) and Oldamur Hollóczki (Department of Physical Chemistry, University of Debrecen, Hungary) the research team was able to determine that tiny polystyrene particles could be detected in the brain just two hours after ingestion. The mechanism that enabled them to breach the blood-brain barrier was previously unknown to medical science. "With the help of computer models, we discovered that a certain surface structure (biomolecular corona) was crucial in enabling plastic particles to pass into the brain," Oldamur Hollóczki explained.

Researching impact on health
The blood-brain barrier is an important cellular barrier that prevents pathogens or toxins from reaching the brain. The intestine has a similar protective wall (intestinal barrier), which can also be breached by MNPs, as various scientific studies have demonstrated. Intensive research is being conducted on the health effects of plastic particles in the body. MNPs in the gastrointestinal tract have already been linked with local inflammatory and immune reactions, and the development of cancer. "In the brain, plastic particles could increase the risk of inflammation, neurological disorders or even neurodegenerative diseases such as Alzheimer's or Parkinson's," said Lukas Kenner, pointing out that more research is needed in this area.

Restrict the use of MNPs
Nanoplastics are defined as having a size of less than 0.001 millimetres, while at 0.001 to 5 millimetres, some microplastics are still visible to the naked eye. MNPs enter the food chain through various sources including packaging waste. But it is not just solid food that plays a role, but liquids too: according to one study, anyone who drinks the recommended 1.5-2 litres of water per day from plastic bottles will end up ingesting around 90,000 plastic particles a year in the process. However, drinking tap water instead can – depending on the geographical location – help reduce this figure to 40,000. "To minimise the potential harm of micro- and nanoplastic particles to humans and the environment, it is crucial to limit exposure and restrict their use while further research is carried out into the effects of MNPs," Lukas Kenner explained. The newly discovered mechanism by which MNPs breach protective barriers in the body has the potential to advance research in this area decisively.

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JOURNAL

Nanomaterials

DOI

10.3390/nano13081404 

ARTICLE TITLE

Micro- and Nanoplastics Breach the Blood–Brain Barrier (BBB): Biomolecular Corona’s Role Revealed

ARTICLE PUBLICATION DATE

19-Apr-2023

Arctic ice algae heavily contaminated with microplastics

Melosira arctica has ten times higher concentration of plastic particles than surrounding seawater

Peer-Reviewed Publication

ALFRED WEGENER INSTITUTE, HELMHOLTZ CENTRE FOR POLAR AND MARINE RESEARCH

 

IMAGE: ON A POLARSTERN EXPEDITION IN THE ARCTIC, RESEARCHERS LED BY BIOLOGIST MELANIE BERGMANN FROM THE ALFRED WEGENER INSTITUTE ARE INVESTIGATING HOW MUCH MICROPLASTIC IS IN AGGREGATES OF THE ICE ALGA MELOSIRA ARCTICA AND THE SEAWATER DIRECTLY NEXT TO ICE FLOES. view more 

CREDIT: ALFRED-WEGENER-INSTITUT / MARIO HOPPMANN

The alga Melosira arctica, which grows under Arctic sea ice, contains ten times as many microplastic particles as the surrounding seawater. This concentration at the base of the food web poses a threat to creatures that feed on the algae at the sea surface. Clumps of dead algae also transport the plastic with its pollutants particularly quickly into the deep sea - and can thus explain the high microplastic concentrations in the sediment there. Researchers led by the Alfred Wegener Institute have now reported this in the journal Environmental Science and Technology.

It is a food lift for bottom-dwelling animals in the deep sea: the alga Melosira arctica grows at a rapid pace under the sea ice during spring and summer months and forms metre-long cell chains there. When the cells die and the ice to whose underside they adhere melts, they stick together to form clumps that can sink several thousand metres to the bottom of the deep sea within a single day. There they form an important food source for bottom-dwelling animals and bacteria. In addition to food, however, these aggregates also transport a dubious cargo into the Arctic deep sea: microplastics. A research team led by biologist Dr Melanie Bergmann from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) has now published this in the journal Environmental Science and Technology.

“We have finally found a plausible explanation for why we always measure the largest amounts of microplastics in the area of the ice edge, even in deep-sea sediment,” Melanie Bergmann reports. Until now, the researchers only knew from earlier measurements that microplastics concentrate in the ice during sea ice formation and are released into the surrounding water when it melts. „The speed at which the Alga descends means that it falls almost in a straight line below the edge of the ice. Marine snow, on the other hand, is slower and gets pushed sideways by currents so sinks further away. With the Melosira taking microplastics directly to the bottom, it helps explain why we measure higher microplastic numbers under the ice edge”, explains the AWI biologist.

On an expedition with the research vessel Polarstern in summer 2021, she and a research team collected samples of Melosira algae and the surrounding water from ice floes. The partners from Ocean Frontier Institute (OFI), Dalhousie University and the University of Canterbury then analysed these in the laboratory for microplastic content. The surprising result: the clumps of algae contained an average of 31,000 ± 19,000 microplastic particles per cubic metre, about ten times the concentration of the surrounding water. “The filamentous algae have a slimy, sticky texture, so it potentially collects microplastic from the atmospheric deposition on the sea, the sea water itself, from the surrounding ice and any other source that it passes. Once entrapped in the algal slime they travel as if in an elevator to the seafloor, or are eaten by marine animals,” explains Deonie Allen of the University of Canterbury and Birmingham University who is part of the research team.

Since the ice algae are an important food source for many deep-sea dwellers, the microplastic could thus enter the food web there. But it is also an important food source at the sea surface and could explain why microplastics were particularly widespread among ice-associated zooplankton organisms, as an earlier study with AWI participation shows. In this way, it can also enter the food chain here when the zooplankton is eaten by fish such as polar cod and these are eaten by seabirds and seals and these in turn by polar bears.

The detailed analysis of plastic composition showed that a variety of different plastics are found in the Arctic, including polyethylene, polyester, polypropylene, nylon, acrylic and many more. In addition to various chemicals and dyes, this creates a mix of substances whose impact on the environment and living creatures is difficult to assess. “People in the Arctic are particularly dependent on the marine food web for their protein supply, for example through hunting or fishing. This means that they are also exposed to the microplastics and chemicals contained in it. Microplastics have already been detected in human intestines, blood, veins, lungs, placenta and breast milk and can cause inflammatory reactions, but the overall consequences have hardly been researched so far,” reports Melanie Bergmann. “Micro and nano plastics have basically been detected in every place scientists have looked in the human body and within a plethora of other species. It is known to change behaviours, growth, fecundity and mortality rates in organisms and many plastic chemicals are known toxins to humans,” says Steve Allen, OFI Dalhousie University, a research team member.

Moreover, the Arctic ecosystem is already threatened by the profound environmental upheavals caused by the climate crisis. If the organisms are now additionally exposed to microplastics and the chemicals they contain, it can weaken them further. “So, we have a combination of planetary crises that we urgently need to address effectively. Scientific calculations have shown that the most effective way to reduce plastic pollution is to reduce the production of new plastic,” says the AWI biologist and adds: “This should therefore definitely be prioritised in the global plastics agreement that is currently being negotiated.” That is why Melanie Bergmann is also accompanying the next round of negotiations, which will begin in Paris at the end of May.

Original Publication:

Bergmann, M., Allen, S., Krumpen, T., Allen, D., 2023. High levels of microplastics in the Arctic ice alga Melosira arctica, a vector to ice-associated and benthic food webs. Environmental Science and Technology. DOI: https://doi.org/10.1021/acs.est.2c08010

Information for editorial offices:

EMBARGOED until 12:00 CEST (06:00 am US Eastern Time, 11:00 London Time) on Friday, 21 April 2023. 

Printable images can be found in this collection until the end of the embargo: https://multimedia.awi.de/medien/pincollection.jspx?collectionName=738688f0fec1806bc1d0814218a705c7#1681817422433_2 and then in the online version of this press release at https://www.awi.de/ueber-uns/service/presse.html

Video footage of the sampling for the study can be found here: https://we.tl/t-9p7yre7Ro1

Your contact at the Alfred Wegener Institute is Dr. Melanie Bergmann (Tel.: +49 (0) 471 4831-1739, e-mail: Melanie.Bergmann@awi.de. At the cooperating institutes your contacts are: Dr. Deonie Allen, Research fellow at University of Birmingham, UK/ Canterbury University, New Zealand; email: deonie.castle@canterbury.ac.nz ; Phone: +64 (0)22 095 5171 and Dr. Steve Allen, Research fellow at Ocean frontiers Institute (Dalhousie University), Canada; Phone: +64 (0)22 095 5171; email: steveascotland@gmail.com.

In the press office of the Alfred Wegener Institute, Dr. Folke Mehrtens (Tel.: 0471 4831-2007; E-Mail: medien@awi.de) will support you.

Follow the Alfred Wegener Institute on Twitter (https://twitter.com/AWI_Media), Instagram (https://www.instagram.com/awiexpedition/) and Facebook (www.facebook.com/AlfredWegenerInstitute).

The Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) conducts research in the Arctic, Antarctic and oceans of the high and mid-latitudes. It coordinates polar research in Germany and provides major infrastructure to the international scientific community, such as the research icebreaker Polarstern and stations in the Arctic and Antarctica. The Alfred Wegener Institute is one of the 18 research centres of the Helmholtz Association, the largest scientific organisation in Germany.

 

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JOURNAL

Environmental Science & Technology

DOI

10.1021/acs.est.2c08010 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

High levels of microplastics in the Arctic ice alga Melosira arctica, a vector to ice-associated and benthic food webs

ARTICLE PUBLICATION DATE

21-Apr-2023