Microbes conquer the next extreme environment: Your microwave

Radiation-resistant microbiome inside microwaves resembles that on solar panels

Frontiers

Since the industrial revolution, microbes have successfully colonized one novel type of habitat after another: for example marine oil spills, plastic floating in the oceans, industrial brownfields, and even the interior of the International Space Station.

However, it turns out that one extreme environment harboring a specialized community of highly adapted microbes is much closer to home: inside microwaves. This finding has now been reported for the first time in a study in Frontiers in Microbiology by researchers from Spain. It’s not only important from the perspective of hygiene, but could also inspire biotechnological applications – if the strains found inside microwaves can be put to good use in industrial processes that require especially hardy bacteria.

“Our results reveal that domestic microwaves have a more ‘anthropized’ microbiome, similar to kitchen surfaces, while laboratory microwaves harbor bacteria that are more resistant to radiation,” said Daniel Torrent, one of the authors, and a researcher at the start-up Darwin Bioprospecting Excellence SL in Paterna, Spain.

Torrent and colleagues sampled microbes from inside 30 microwaves: 10 each from single-household kitchens, another 10 from shared domestic spaces, for example corporate centers, scientific institutes, and cafeteria, and 10 from molecular biology and microbiology laboratories. The aim behind this sampling scheme was to see if these microbial communities are influenced by food interactions and user habits.

They used two complementary methods to inventorize the microbial diversity: next generation sequencing and cultivation of 101 strains on five different media.

A biodiverse microbiome right at home

In total, the researchers found 747 different genera within 25 bacterial phyla. The most frequently encountered phyla were Firmicutes, Actinobacteria, and especially Proteobacteria.

They found that the composition of the typical microbial community partly overlapped between shared domestic and single-household domestic microwaves, while laboratory microwaves were quite different. The diversity was lowest in single-household microwaves, and highest in laboratory ones.

Members of genera Acinetobacter, Bhargavaea, Brevibacterium, Brevundimonas, Dermacoccus, Klebsiella, Pantoea, Pseudoxanthomonas and Rhizobium were found only in domestic microwaves, whereas Arthrobacter, Enterobacter, Janibacter, Methylobacterium, Neobacillus, Nocardioides, Novosphingobium, Paenibacillus, Peribacillus, Planococcus, Rothia, Sporosarcina, and Terribacillus were found only in shared-domestic ones.

Nonomuraea bacteria were isolated exclusively from laboratory microwaves. There, Delftia, Micrococcus, Deinocococcus and one unidentified genus of the phylum Cyanobacteria were also common, found in significantly greater frequencies than in domestic ones.

The authors also compared the observed diversity with that in specialized habitats reported in the literature. As expected, the microbiome in microwaves resembled that found on typical kitchen surfaces.

“Some species of genera found in domestic microwaves, such as Klebsiella, Enterococcus and Aeromonas, may pose a risk to human health. However, it is important to note that the microbial population found in microwaves does not present a unique or increased risk compared to other common kitchen surfaces,” said Torrent.

Parallel evolution

However, it was also similar to the microbiome in an industrial habitat: namely, on solar panels. The authors proposed that the constant thermal shock, electromagnetic radiation, and desiccation in such highly irradiated environments has repeatedly selected for highly resistant microbes, in the same manner as in microwaves.

“For both the general public and laboratory personnel, we recommend regularly disinfecting microwaves with a diluted bleach solution or a commercially available disinfectant spray. In addition, it is important to wipe down the interior surfaces with a damp cloth after each use to remove any residue and to clean up spills immediately to prevent the growth of bacteria,” recommended Torrent.

 

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Journal

Frontiers in Microbiology

DOI

10.3389/fmicb.2024.1395751 

Article Title

The microwave bacteriome: biodiversity of domestic and laboratory microwave ovens

Article Publication Date

8-Aug-2024

 

Concern for children is key driver of advertising complaints

Care for the wellbeing of children is a commonly cited reason for people making a formal complaint about an advert, a study shows

University of Edinburgh

Concern for children is key driver of advertising complaints

Care for the wellbeing of children is a commonly cited reason for people making a formal complaint about an advert, a study shows.

The representation of children and potential harm caused to them from seeing offensive adverts accounted for 46 per cent of the grounds for complaints to the Advertising Standards Authority (ASA), according to a study.

The research considered thousands of customer grievances relating to ads from the non-profit sector.

Graphic portrayals – such as violence, sexual acts or disease – also appear highly problematic, accounting for a further 20 per cent of complaints.

Some depictions of crime, weapons and drugs were also sources of offence.

A team at the University of Edinburgh analysed 9055 complaints received over a six-year period about adverts from the not-for-profit, third and public sectors – such as charities, government bodies and pressure groups.

They focused the study on the non-commercial sector where use of shock appeals to attract attention or connect with audiences is more prevalent and where such tactics result in more complaints.

Adverts from this sector may also be perceived by consumers as tolerable, due to the ultimately good cause of the organisations, experts suggest.

The complaints related to adverts in a range of media – including television, print and online.

Charities had the most complained-about adverts, with 38 per cent of the complaints, followed by governmental organisations at 29 per cent.

Campaigns from medical and children’s charities triggered many offence or harm-based complaints.

The data used covered the period 2009 to 2015 and the associated regulatory response in the form of the ASA’s adjudications.

Researchers found a prevalence of offence and harm-based complaints in the non-commercial sector with 62 per cent of all complaints under that category, compared with the commercial sector in which complaints about misleadingness prevail.  

The representation of children was the top complained-about issue with 4,157 complaints during the six-year period.

Of the 9,055 complaints, only 138 (1.5 per cent) were upheld and 629 (6 per cent) were upheld in part.

Researchers say this raises questions about possible bias of the advertising regulator and whether it is protecting advertisers, likely based on the idea that their messaging is justified within the non-profit context.  

The study calls on advertisers to test their advertisements with intended and unintended audiences, including relevant vulnerable groups and parents, and to carefully schedule and position their advertisements to targeted audiences in order to minimise offence and harm caused, particularly to children.

It also urges the advertising regulator to consider whether its management of the non-commercial sector may need to differ from the commercial contexts.

Dr Kristina Auxtova, of the University of Edinburgh Business School, who led the study, said: “The findings help us understand the breadth of sources of offence and harm in non-profit and public sector advertising. It is crucial for advertisers and regulators to understand what the public perceives to be offensive or harmful and for regulators to be able to respond to and regulate issues of contemporary concern.”

The study is published in the Journal of Nonprofit and Public Sector Marketing (link /doi/full/10.1080/10495142.2024.2345908). The research was supported by an ESRC grant.

 

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Journal

Journal of Nonprofit & Public Sector Marketing

DOI

10.1080/10495142.2024.2345908 

Subject of Research

People

Article Title

Offensive and Harmful Advertising: A Content Analysis of Official Complaints

Major M7.1 Earthquake Strikes Japan; "Megaquake" Alert Issued

GeologyHub

A major magnitude 7.1 earthquake just struck a mere 3 miles offshore of Japan. This generated a tsunami, and caused the ground to shake for 22 seconds. Alongside this, an alert was issued which warned of an increased likelihood of an even larger megathrust earthquake occurring from the Nankai subduction zone. However, I believe this alert to be misleading, which I will explain in today's video. Note: This video's thumbnail image may show up as one of two separate images depending on who views it. They may be one of the two following images... 

 

‘Hearing’ Temperature: Uncovering a hidden human ability to perceive temperature through sound

Reichman University

 

image: 

A questionnaire examined people’s beliefs about cross-modal perception, participants' perceptual ability was tested in an online 2AFC task using recordings captured in an ambisonic facility. The recordings were also used to train a machine learning model to perform the same classification.

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Credit: IVCHER INSTITUTE FOR BRAIN COGNITION AND TECHNOLOGY, REICHMAN UNIVERSITY

Scientists from the Ivcher Institute for Brain, Cognition, and Technology (BCT Institute) at Reichman University (IDC Herzliya) explored a largely unrecognized perceptual ability and utilized machine learning to clarify the dynamics of cross-modal perception; the experience of interactions between multiple different sensory modalities. In a recently published study, the team investigated the possibility for humans to detect the thermal properties of water (water temperature) through its sound, and whether or not it happens consciously. Harnessing principles of multisensory integration (the way the brain combines information from various sensory modalities to form a unified perception of the environment), the team explored the potential of multisensory thermal perception. They also employed a pre-trained deep neural network (DNN) and a classification algorithm (a support vector machine) to examine whether machine learning could successfully and consistently classify audio recordings of water at different temperatures being poured, and create a mapping of these thermal properties physically encoded in sound.

 

“Temperature perception is pretty unique in comparison to other sensory experiences,” says Dr. Adi Snir, postdoctoral fellow at the BCT Institute and co-author of the study. “For vision and hearing we have dedicated sensory ‘organs’ like the eyes and ears, with temperature we rely on specialized receptors in the skin that respond to various temperature ranges which we experience as heat and coolness, but in the animal kingdom we know for example that snakes can actually ‘see’ body heat which allows them to identify prey ”. The question of whether multisensory perception of temperature extends to humans has been posed before. “Previous studies have explored this on a behavioral level” states Prof. Amir Amedi, founding Director of the BCT Institute. “These studies have shown that humans can hear a difference between hot liquids and cold liquids being poured, but not how or why this is possible” he explains.

 

The researchers set out first to replicate previous findings and confirm this surprising perceptual ability, as well as clarify whether or not this ability is innate or acquired, a question that has long been the subject of much debate. “We also wanted to investigate whether or not people are consciously aware of these differences in the sound properties of thermal differences” says Snir, “and also explore what characteristics of the sounds themselves allow for differentiation in perception” he adds. To accomplish this, the team used a pre-trained deep neural network (DNN) to characterize recordings of various temperatures of water being poured, a machine learning algorithm to classify the thermal properties of the water, and computational analysis of the auditory features of each recording. “What we saw is that participants were consistently able to discern water temperature through its sound, even when they didn’t believe that they could, which tells us this is likely an implicit skill acquired through exposure to auditory cues throughout life” Amedi explains, “simultaneously the machine learning model which was trained on recordings of hot and cold water showed a high accuracy in classifying the sounds”.

 

The results of the study demonstrate that humans have an ability to learn complex sensory mappings from everyday experiences, and that machine learning can help to clarify subtle perceptual phenomena. “The next step is to look into whether or not people will develop novel sensory maps in the brain for this experience, the way they do for vision, touch, and hearing” Amedi states. “In theory recent claims by Elon Musk regarding Neuralink creating superhuman abilities could become reality if you couple this same method with brain stimulation” he adds.

Scientists from the Ivcher Institute for Brain, Cognition, and Technology (BCT Institute) at Reichman University (IDC Herzliya) explored a largely unrecognized perceptual ability and utilized machine learning to clarify the dynamics of cross-modal perception; the experience of interactions between multiple different sensory modalities. In a recently published study, the team investigated the possibility for humans to detect the thermal properties of water (water temperature) through its sound, and whether or not it happens consciously. Harnessing principles of multisensory integration (the way the brain combines information from various sensory modalities to form a unified perception of the environment), the team explored the potential of multisensory thermal perception. They also employed a pre-trained deep neural network (DNN) and a classification algorithm (a support vector machine) to examine whether machine learning could successfully and consistently classify audio recordings of water at different temperatures being poured, and create a mapping of these thermal properties physically encoded in sound.

 

“Temperature perception is pretty unique in comparison to other sensory experiences,” says Dr. Adi Snir, postdoctoral fellow at the BCT Institute and co-author of the study. “For vision and hearing we have dedicated sensory ‘organs’ like the eyes and ears, with temperature we rely on specialized receptors in the skin that respond to various temperature ranges which we experience as heat and coolness, but in the animal kingdom we know for example that snakes can actually ‘see’ body heat which allows them to identify prey ”. The question of whether multisensory perception of temperature extends to humans has been posed before. “Previous studies have explored this on a behavioral level” states Prof. Amir Amedi, founding Director of the BCT Institute. “These studies have shown that humans can hear a difference between hot liquids and cold liquids being poured, but not how or why this is possible” he explains.

 

The researchers set out first to replicate previous findings and confirm this surprising perceptual ability, as well as clarify whether or not this ability is innate or acquired, a question that has long been the subject of much debate. “We also wanted to investigate whether or not people are consciously aware of these differences in the sound properties of thermal differences” says Snir, “and also explore what characteristics of the sounds themselves allow for differentiation in perception” he adds. To accomplish this, the team used a pre-trained deep neural network (DNN) to characterize recordings of various temperatures of water being poured, a machine learning algorithm to classify the thermal properties of the water, and computational analysis of the auditory features of each recording. “What we saw is that participants were consistently able to discern water temperature through its sound, even when they didn’t believe that they could, which tells us this is likely an implicit skill acquired through exposure to auditory cues throughout life” Amedi explains, “simultaneously the machine learning model which was trained on recordings of hot and cold water showed a high accuracy in classifying the sounds”.

 

The results of the study demonstrate that humans have an ability to learn complex sensory mappings from everyday experiences, and that machine learning can help to clarify subtle perceptual phenomena. “The next step is to look into whether or not people will develop novel sensory maps in the brain for this experience, the way they do for vision, touch, and hearing” Amedi states. “In theory recent claims by Elon Musk regarding Neuralink creating superhuman abilities could become reality if you couple this same method with brain stimulation” he adds.

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Journal

Frontiers in Psychology

DOI

10.3389/fpsyg.2024.1353490 

Method of Research

Experimental study

Subject of Research

People

Article Title

“Hearing temperatures: employing machine learning for elucidating the cross-modal perception of thermal properties through audition”

 

‘FoMO’ is a key risk factor for mental health and burnout at work

Peer-Reviewed Publication

University of Nottingham

Fear of missing out (FoMO) is a key risk factor for employee mental health and, along with information overload, may increase burnout, according to new research.

Researchers from the University of Nottingham’s Schools of Psychology and Medicine analysed survey data from 142 employees to investigate the ‘dark side’ of digital working and found that employees who are worried about missing out on information and are overloaded by it are more likely to suffer stress and burnout. The results have been published today in SAGE Open.

Elizabeth Marsh, PhD student from the School of Psychology led the quantitative study and said: “The digital workplace is now recognised as a key strategic asset in organisations that enables worker productivity and flexibility in context of hybrid working. However, the potential downsides in terms of worker well-being also need to be considered, especially given the proliferation of digital communication channels and tools since Covid.”

This new study connects to previous work which revealed that employees who are more mindful in the digital workplace are better protected against stress, anxiety and overload.

In this research FoMO is defined as anxiety about missing out on both important information and updates, as well as opportunities for relationships and interactions. FoMO has long been a term used in relation to social media, and now this new research shows it is an effect that is being felt in the workplace.

The participants in the study were surveyed about their experiences of the dark side effects of the digital workplace which were identified as; stress, overload, anxiety and fear of missing out and how these affected their wellbeing.

The results showed that among the dark side effects, those relating to information – both feeling overloaded by it and fearing missing out on it - proved particularly detrimental for well-being both directly and by elevating overall stress related to digital working.  

Elizabeth adds: “The glut of information flowing through channels such as email, intranets or collaboration tools can lead workers to worry about missing out on it as well as succumbing to overload as they strive to keep up. To help people cope with information overwhelm, serious and sustained attention should be given to both optimising information management and supporting information literacy.”

The research makes some practical suggestions for employers which include investing in practices to optimise the amount and flow of information to employees. The findings could also be used by HR departments to consider policy and training options that would support the end-users of the digital workplace to better access, manage and consume information in a way that is conducive to well-being as well as productivity.

Dr Alexa Spence, Professor of Psychology adds: “Consideration of the digital workplace in work and job design is essential to not only employee productivity but also well-being in modern organisations. Where this is lacking, elevated stress and burnout as well as poorer mental health may result. Our findings indicate the information ecosystem as an important area for attention both inside organisations and among the research community.” 

The research was funded by ESRC-MGS (Economic and Social Research Council - Midland Graduate School).

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Journal

SAGE Open

DOI

10.1177/21582440241268830 

Method of Research

Experimental study

Subject of Research

People

Article Title

Overloaded by Information or Worried About Missing Out on It: A Quantitative Study of Stress, Burnout, and Mental Health Implications in the Digital Workplace

Article Publication Date

9-Aug-2024

 

High-speed trains face icy challenges: new study assesses overhead contact system adaptability

Maximum Academic Press

 

image: 

Influence of ice-covered condition on PCS.

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Credit: Chinese Journal of Electrical Engineering

A pivotal study assesses the ice-covered environmental adaptability of overhead contact systems in high-speed railways, vital for ensuring the continuous and safe collection of electrical energy. The research introduces a dynamic model to simulate and analyze the pantograph-catenary system's performance under different icing conditions, presenting a new approach to evaluate and improve system resilience.

The operation of high-speed railways is frequently jeopardized by icy conditions, which can cause significant mismatches in the interaction between the pantograph and catenary systems. The ice-covered overhead conductors lead to more intense fluctuations in contact force and increased incidence of arcing, undermining both safety and service reliability. Addressing these challenges necessitates an in-depth analysis of how overhead contact systems perform and adapt under icy environments.

In a collaborative scholarly endeavor, experts from Southwest Jiaotong University, alongside the National Rail Transit Electrification and Automation Engineering Technology Research Center, unveil their insights (DOI: 10.23919/CJEE.2024.000058) within the esteemed pages of the Chinese Journal of Electrical Engineering, on June 30, 2024. The study pioneers a novel methodology for evaluating the adaptability of overhead contact systems amidst diverse ice-covered conditions.

This pioneering research erects a holistic evaluative scaffold for the overhead contact system's (OCS's) icy ordeals, essential for the high-speed rail's continuous operation. Through dynamic simulation of the pantograph-catenary system (PCS), the scholars carefully calculated the complex response of the PCS under various ice loads. The model adeptly seizes critical metrics—contact force and arcing propensity—revealed system equilibrium and dependability. The research's highlight lies in the sensitivity coefficient's inception, a quantifiable indicator of the OCS's environmental responsiveness. Together with an incisive analysis of five OCS prototypes, provides an unassailable framework for evaluating their adaptability, guiding the design of stronger railway frameworks.

Dr. Guangning Wu, an IEEE Fellow and venerated academic, praised this research for its transformative potential in high-speed rail's maintenance. "The advent of the OCS sensitivity coefficient is a quantum leap, providing us with precise standards for assessing the environmental impact of railway systems," he notes. "This work is set to redefine the fortitude of overhead contact systems in climes of extremity."

The research is poised to redefine railway infrastructure's blueprint and upkeep, particularly in icy climes. By pinpointing the OCS structures most adept at braving the frost and deciphering their environmental sensitivity, rail stewards can marshal precise enhancements. This preemptive strategy not only fortifies high-speed rail's operational integrity and alacrity but also charts a course for economic infrastructure stewardship, curtailing the specter of service standstills and their pecuniary reverberations.

###

References

DOI

10.23919/CJEE.2024.000058

Original Source URL

https://doi.org/10.23919/CJEE.2024.000058

Funding information

Supported by China State Railway Group Co., Ltd. (L2022G006), Chengdu Guojia Electrical Engineering Co., Ltd. (NEEC-2022-A04), and Natural Science Foundation of Sichuan Province (2022NSFSC1863).

About Chinese Journal of Electrical Engineering

Chinese Journal of Electrical Engineering (CJEE), published quarterly, is a peer-reviewed international academic journal in English. It is sponsored and published by China Machinery Industry Information Institute (China Machine Press) and co-technically sponsored by IEEE Power Electronics Society. It is indexed by ESCI, Ei Compendex, Scopus, INSPEC, CSCD (Chinese Science Citation Database) and DOAJ.

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Journal

Chinese Journal of Electrical Engineering

DOI

10.23919/CJEE.2024.000058 

Article Title

Ice-Covered Environmental Adaptability Assessment for Overhead Contact System in High-Speed Railways

 

New study defines the novel relationships among heparan and chondroitin sulfate and associated proteins involved in drug abuse

Findings provide a new focus for the investigation of therapeutics

Boston University School of Medicine

(Boston)—Substance use disorder is a major concern with few therapeutic options. In 2019, close to 20.4 million people were diagnosed with substance use disorder, and nearly 71,000 people died of an overdose, with cocaine and methamphetamine (meth) responsible for approximately 15,000 deaths that year.  

 

A new study from researchers at Boston University Chobanian & Avedisian School of Medicine and the Scripps Research Institute reveals how altered molecules and related neurobiological mechanisms operate during substance abuse. These findings open avenues for developing new therapeutic targets and treatment strategies to improve quality of life for drug addicts.

 

“The altered pathways and associated molecular mechanisms we found will strengthen our fundamental knowledge of the neurobiology of addiction. The expression patterns we reported and their functional roles need to be further characterized to unravel the biological implication of drug abuse in the brain,” explained co-corresponding author Joseph Zaia, PhD, professor of biochemistry & cell biology at the school.

 

The researchers performed mass spectrometry-based glycomic and proteomic analysis to understand the effects of cocaine and meth on two brain regions critically involved in drug addiction: the lateral hypothalamus and the striatum. They observed that cocaine and meth significantly altered glycan and sulfate contents and compositions for heparan sulfate and chondroitin sulfate disaccharides known to be involved in neuronal processes, and thus, likely contribute to drug-induced neural plasticity in these brain regions.

 

“Notably, altering the levels of these sulfated glycans in the experimental models ameliorated anxiety and prevented the expression of preference for cocaine during cocaine withdrawal. Taken together, this data supports the role of sulfated glycans and associated proteins in stimulants abuse and suggest that their manipulation can represent a novel therapeutic strategy,” adds first author Manveen K Sethi, PhD, research assistant professor of biochemistry & cell biology at the school.

 

These findings appear online in the journal Molecular Cellular Proteomics.  

 

Funding for this study was provided by NIH grants P41GM104603, R21HL131554, U01CA221234, DA053801, DA036241, DA048882.

 

 

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DOI

10.1016/j.mcpro.2024.100803 

Method of Research

Experimental study

Subject of Research

Cells

Article Title

Comprehensive Glycomic and Proteomic Analysis of Mouse Striatum and Lateral Hypothalamus Following Repeated Exposures to Cocaine or Methamphetamine

Article Publication Date

1-Aug-2024

Disclaimer: A

 

Non-biting midges help us understand how to protect Lake Balaton

What was Lake Balaton like in its natural state, and when did it change?

Peer-Reviewed Publication

Eötvös Loránd University

 

image: 

What was Lake Balaton like in its natural state, and when did it change? Can its near-natural condition still be restored? These are the questions the researchers from ELTE Science Faculty's Paleoenvironment and Climate Change Research Group sought to answer in their latest study, where they also made specific recommendations for the protection of the lake.

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Credit: Photo: Eniko Magyari / Eötvös Loránd University

What was Lake Balaton like in its natural state, and when did it change? Can its near-natural condition still be restored? These are the questions the researchers from ELTE Science Faculty's Paleoenvironment and Climate Change Research Group sought to answer in their latest study, where they also made specific recommendations for the protection of the lake.

According to the recently adopted Nature Restoration Law (NRL) by the EU, member states are required to restore at least 30% of the habitats covered by the law by 2030. But what could be the target state for Lake Balaton?

Many may recall blue-green algae blooms from their childhood, when the toxins produced by the algae mass caused skin irritation and created a less-than-ideal water surface for vacationers. In the 1970s and 1980s, Central Europe's largest shallow lake, Balaton, received uncontrolled nutrient loads, leading to eutrophication—initially causing the spread of aquatic plants and later algae blooms. However, Lake Balaton is one of the few lakes worldwide where successful water quality protection measures, starting in 1994, led to significant improvements in its condition, albeit with a decade-long delay.

Researchers were optimistic about the lake's future until 2019,

when, despite low nutrient loads, recurring summer algae blooms began. This is due to internal phosphorus loading, where previously settled phosphorus compounds dissolve back into the water from oxygen-depleted sediments. Although recent summer droughts have raised concerns about the lake's water level, it is important to note that these phosphorus backflows are related to the high summer water levels maintained in the lake. To understand why we should not be alarmed by occasional low water levels and what can be done to protect Balaton, we need to look into the geological recent past.

The lake, which formed around 17,000 years ago and has had a more or less continuous water surface for about 10-11,000 years, has experienced numerous water level changes throughout its history. In their recently published article in the July issue of Science of the Total Environment, the Paleoenvironment and Climate Change Research Group associated with the Climate Change National Laboratory and Élvonal grant, led by Enikő Magyari, examined the last 500 years of Lake Balaton, analyzing changes in the lake's macroinvertebrate fauna up to the end of the Ottoman period. The goal was to reconstruct the lake's natural, pre-human impact fauna in the Szemes Basin, thus establishing a reference state for conservation purposes. The researchers particularly examined the chironomid fauna, whose tiny, water-dwelling larvae are sensitive indicators of environmental changes. Their community composition alters if, for example, the sediment's grain size changes, if there is a sudden decrease in available oxygen, if significant amount of organic deby is deposited on the lake bed, or if fish populations suddenly increase and consume the slow-moving, detritus-eating species.

Interestingly, the most intense and irreversible changes in the macroinvertebrate fauna occurred during the economic boom between the first and second world wars (post-Trianon), a period of extensive lake construction and recreational use, between 1925 and 1940. During this time, the chironomid community completely transformed, with the Stempellina species, characteristic of the lake, disappearing from several basins. Following a temporary dominance of an oxygen-tolerant species (Chironomus balatonicus), a predatory chironomid species (Procladius choreus) became dominant from 1940.

The changes in the chironomid fauna since the 1470s coincide with deforestation around the lake, increased shoreline erosion, and the onset of strict water level regulation, which limited water level fluctuations. The size of the chironomid population has significantly decreased since 1940, and researchers found no evidence that the reduction in nutrient loads since 1994 impacted the chironomid fauna. However, they demonstrated a strong correlation between the increase in benthivorous fish populations and the decline in the chironomid population, indicating that fish stocking also had a significant impact. Due to the overstocked and over-maintained fish populations, chironomids, which play a crucial role in phosphorus removal, cannot perform this vital ecosystem service. Remember, Lake Balaton would naturally be an oligotrophic-mesotrophic system, with limited capacity to support fish fauna.

What does an oligotrophic-mesotrophic system mean? The term oligotrophic refers to water with low nutrient levels, primarily nitrogen and phosphorus. In contrast, mesotrophic waters have more nutrients and exhibit a slight increase in biological production. Lake Balaton is characterized by a west-east meso-oligotrophic gradient, with higher biological production near the Zala inflow, such as in the Keszthely area, and very low production near Siófok.

Therefore, researchers suggest that the fish fauna should be reasonably reduced.

They understand that regulated fishing is a major tourist attraction at Balaton, but hope their research will help people understand the principles of sustainable functioning of ecosystems like Lake Balaton and agree on the necessity of regulations to enjoy the lake's recreational activities for longer.

And what is the natural state we can set as a goal?

The researchers proposed that the reference lake state for restoration should be between 1740 and 1900,

after the high summer water levels characteristic of the Ottoman period, when the lake's water regime was similar to today's. They emphasized that the natural characteristic of Central Europe's largest shallow lake is natural water level fluctuation, and its natural biotic communities are adapted to this, so we should not fear occasional low summer water levels concerning the lake's wildlife.

According to the recently adopted Nature Restoration Law (NRL) by the EU, member states are required to restore at least 30% of the habitats covered by the law by 2030. But what could be the target state for Lake Balaton?

Credit

Photo: Eniko Magyari / Eötvös Loránd University

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Journal

Science of The Total Environment

DOI

10.1016/j.scitotenv.2024.174191. 

Article Title

Large shallow lake response to anthropogenic stressors and climate change: Missing macroinvertebrate recovery after oligotrophication (Lake Balaton, East-Central Europe)