Ireland's fishermen fear species migration as sea temperatures soar

by Callum PATON

Daragh McGuinness 23, always wanted to be a fisherman but fears climate change could

 wreck his hopes.

When he finished school Daragh McGuinness knew he wanted to join a fishing crew but now, at 23, he fears climate change may kill off the industry that has sustained his family for generations.

"It's a massive problem," he told AFP in the pilothouse of the Atlantic Challenge trawler, where he works as a deckhand, docked in the port of Killybegs in northwest Ireland.

"It could really finish the fishing, in Ireland anyway at least."

Soaring temperatures in the North Atlantic Ocean over the summer months have raised fears that fish could be pushed to colder waters, heaping pressure on the already struggling industry.

At the end of July, the US National Oceanic and Atmospheric Administration (NOAA) announced that average surface temperatures in the North Atlantic had reached a new record high of 24.9 degrees Celsius (76.8 degrees Fahrenheit).

The Atlantic Challenge, like many vessels sailing out of Killybegs, catches blue whiting and mackerel, which are highly prized on international markets, returning to port one or two days after a catch so produce is fresh.

"It would just concern you that you would be pushed further, too far north and then it wouldn't be viable to come back to Killybegs," McGuinness explained.

Sean O'Donoghue, chief executive of the Killybegs Fishermen's Organisation, said climate change was having a "dramatic effect" on white fish stocks such as cod which prefer colder waters.

Fishermen in Killybegs, northwest Ireland, fear sea temperature rises will force species to 

migrate to colder waters.

'Extreme'

He feared it was "only a matter of time" before so-called pelagic fish such as mackerel, blue whiting and herring move north permanently.

"If we continue with the warming of the waters, it is inevitable, the pelagic species will move totally out of the waters. And we could end up that we have very little fish," he said.

Among trends emerging, he added, were more mackerel being caught by the Icelandic fleet, while his members were catching more species like anchovies and sardines, which are typically found in warmer southern waters, prompting "overall concern".

The temperature record set in July was particularly worrying as it came weeks before the North Atlantic typically reaches peak temperatures in September.

In June, the NOAA recorded what it characterized as a Category 4 or "extreme" marine heat wave off the coasts of Ireland and the United Kingdom.

Glenn Nolan, who heads oceanographic and climate services at Ireland's Marine Institute, said the month saw "significant" temperatures, 4-5 degrees in excess of what would be normal off the country's coast in the summer months.

Boats are now bringing in more fish such as anchovies and sardines, which are usually

 found in warmer waters.

"When you're seeing a temperature at 24.5 or 21, as we saw in some of the coastal bays around the county of Galway... it's way above what you would ordinarily expect," he said.

Nolan said he expected a specific study attributing the spike in temperatures in June and July to climate change in due course.

Double whammy

The UN's Intergovernmental Panel on Climate Change (IPCC), which assesses the science related to climate change, has attributed the intensity of marine heat waves to global warming for decades, he noted.

"The IPCC have already looked at marine heat waves in general and they have high confidence that they can attribute them to manmade climate change," the Galway-based expert said.

Nolan said the extreme temperatures could create the conditions for changes to fish migration, and pointed to algal blooms in warm waters causing "problems typically for shellfish and finfish".

For Irish fishing, the situation is a double whammy, as the industry has been hit by lost EU fishing quotas after Brexit, the UK's departure from the bloc at the end of 2020.

Killybegs Fishermen's Organisation chief executive Sean O'Donoghue says climate 

change has added to the industry's woes caused by Brexit quotas.

EU member Ireland saw a 15-percent cut to fishing quotas by 2025 as part of the last-minute trade deal between London and Brussels.

"Unfortunately the deal that was done disproportionally hit Ireland," said O'Donoghue.

"The net effect of it is that Ireland is paying 40 percent of the transfer of fish to the UK (from the EU)."

He now wants to see changes to EU fisheries policy to reflect the impact of the Brexit cuts on Ireland's fleet and to mitigate the effects of climate change on his members' catch.

"We're not happy with the way things are on the Common Fisheries Policy at the moment. They need to be changed and Brexit and climate change have to be taken on board," O'Donoghue said.

© 2023 AFP

N. Atlantic ocean temperature sets record high: US agency

 

How our complex relationship with heat inhibits climate action

by Jennifer Ellen Good, The Conversation

Credit: CC0 Public Domain

Humans are a species borne of the heat, as hot and dry temperatures played a key role in our evolution, and many of us (at least in the United States) prefer to be in the heat.

We as a species have known for decades that the carbon-fueled actions of some nations meant that devastating heat and related extreme weather events were coming.

And yet, most of us did nothing.

The summer of 2023's unprecedented forest fires, floods and rising ocean temperatures are the consequences of collective inaction and while there are many reasons for these failures to act, humanity's complex relationship with heat is arguably a critical one.

The comfort, and dangers, of heat

At a fundamental level, heat is what allows for humans and the Earth's biological diversity to exist. A stable core body temperature facilitates human survival and the greenhouse effect facilitates all life on Earth. However, while heat may be essential to life, and desirable to many, too much heat is devastating.

One way to articulate this complex balance has been to use the metaphor of a fever. If a human's body temperature increases even a couple of degrees, then an illness is likely occurring. If a person's core body temperature increases only three to four degrees celsius it can be fatal. Likewise, a rise in planetary temperatures above just 1.5 C could be equally fatal.

A seemingly easy to understand threshold. However, in practice, communicating a 1.5 C tipping point has been extremely challenging. Humans generally struggle with disentangling short-term daily temperatures from a long-term climatic shift and as a result fluctuations in temperature have been easily misunderstood. And confusion over these questions are readily misused to question the veracity of an anthropogenically induced changing climate

All under one greenhouse?

An early attempt at circumventing our innate fondness for heat in climate change communications was through leveraging the term greenhouse effect—a phrase which notably removes heat from the equation altogether.

Knowledge of the greenhouse effect goes back to the mid-19th century. In the latter half of the 20th century, the term became an evocative label for what the burning of fossil fuels was doing to the planet.

But the term is inaccurate.

An animated overview of the basic principles of the greenhouse effect. While the term greenhouse effect may be useful in some cases, it is generally inaccurate when referring to anthropogenic climate change. Credit: NASA-JPL/Caltech

The greenhouse effect is the well-established phenomenon of the Earth's atmosphere trapping the sun's radiation and allowing the planet to be a warm and hospitable place. Using the greenhouse effect as a term referring to the warming of the planet due to the burning of fossil fuels conflated a naturally occurring and well-established phenomenon with an unfolding anthropogenic disaster to confusing results.

In response to this limitation, global warming increasingly became the terminology of choice for the changing climate—phasing out the banal inadvertent climate modification which had also been in use since the 1970s. So much so that by the 1990s, it became the single most used term. But this also had challenges.

Warming has a certain coziness and as climate change researchers Julia Corbett and Jessica Durfee highlighted, 'global warming needs a more salient metaphor that emphasizes its seriousness, immediacy and scientific credibility.'

Global warming was also a narrow term, as global average temperature increases would cause a range of extreme weather effects

In response to these limitations, the term climate change gradually came to replace global warming as the most widely accepted and used descriptor. Though more recently, this somewhat benign term has been altered again by some to more accurately address the urgency of the situation.

For example, in 2019 The Guardian moved from using climate change to the terms climate emergency, crisis or breakdown in response to climatic effects of ever-increasing severity.

This confused discourse has led to even further confusion and arguably hampered climate change mitigation efforts for decades.

Too much of a good thing

Research indicates that in the summer of 2022, over 60,000 people in Europe alone died from extreme heat. July 2023 was the hottest month ever recorded and it is increasingly looking like 2023 will be the hottest year on record. Heat-related deaths are mounting and the heat is being exacerbated by raging fires and extreme ocean temperatures.

Human beings, alongside all life, exist on Earth because of a delicate celestial balance of gases that trap the sun's warmth. For millions of years, this greenhouse effect has made Earth a miraculously habitable orb in the coldness of space.

While all human beings have a complex—and often positive—relationship with heat, in the Northern Hemisphere it is something which many of us particularly crave. However, the reckless pursuit of it (among other comforts) through the burning of fossil fuels has turned heat from a source of life to a harbinger of doom for all.

It is only through confronting this complex relationship—by accepting the inherent dangers of more heat—that we can hope to seriously pursue real action on fossil fuel emissions.

Provided by The Conversation 

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

NASA clocks July 2023 as hottest month on record ever since 1880

 

'In a sauna': Hong Kong's laborers swelter as temperatures rise

by Holmes CHAN

Wah, a 63-year-old pest control worker, told AFP it 'feels like it's raining' inside the 

protective suit his job requires.

Dressed in a full-body protective suit, an elderly pest control worker could last no more than 15 minutes spraying pesticide along a Hong Kong pavement before the summer heat became too much.

"The longer you work, the more it feels like it's raining inside the (suit)... it's just like being in a sauna," said Wah, 63, who asked to be identified only by his first name.

He emerged from his protective clothing drenched in sweat on a scorching August morning, with temperatures soaring to 32.2 degrees Celsius (90 degrees Fahrenheit) and humidity hitting 87 percent.

The month before, Hong Kong saw its third-hottest July on record, with the maximum daily temperature hitting 36.1 degrees Celsius. The top three warmest years in the city's history were all recorded after 2018.

Recently, the government advised employers to let workers take longer breaks on hotter days, but companies say the guidelines fail to consider the needs of different work environments.

Activists argue that without strong regulations, thousands of Hong Kong workers remain vulnerable to heat-related illnesses.

"Temperatures in 2022 broke multiple records, so we felt more support was needed," said social worker Fish Tsoi of Caritas Hong Kong.

Pest control worker Wah shows the temperature recorded inside the protective full-body 

suit his job requires.

She is part of a research team measuring the body temperatures of people toiling under extreme heat, especially the elderly like Wah and his six-person crew.

Last July, a pest control firm saw 20 of its workers quit because conditions were too tough, while 10 were hospitalized with heatstroke, she said.

"This situation did not just appear last year—it was years in the making," Tsoi said. "Nobody took proactive steps to respond."

'Slow' progress

Temperatures around the world are rising to unprecedented levels, with more frequent heat waves, which scientists have partly attributed to human-caused climate change.

A city infamous for its intense humidity levels, Hong Kong introduced a heat-stress warning system in May to help employers schedule "appropriate work-rest periods".

It has been issued more than 50 times since then.

A colour-coded system for heat guidelines is displayed on the side of a van in Hong Kong.

Greenpeace campaigner Tom Ng said the "biggest problem" was that employers who ignore the guidelines face no legal repercussions.

"In terms of how climate change affects Hong Kongers, outdoor workers are at the frontlines," he told AFP.

Emily Chan, a public health specialist at the Chinese University of Hong Kong, welcomed the guidelines but agreed more was needed.

She pointed to mainland Chinese cities, including neighboring tech hub Shenzhen, which mandate work stoppages and subsidies once temperature thresholds are reached.

"(Hong Kong) has been relatively slow in setting up protections," Chan said.

Labor minister Chris Sun said this month that his department had "stepped up inspections" and would issue warnings to employers when needed.

Despite the new system having no legal bite, the government can still sue employers "who just turn a blind eye", he said in May.

Hong Kong's government has advised employers to let workers take longer breaks on hot days, but there are no legal repercussions for those who do not.

Wah, who clocks six-day weeks for $8 an hour, said there is little he can do to avoid heat exhaustion besides operating his machinery in short bursts.

"If you do this for more than half an hour, the human body cannot withstand the temperature," he said.

'No recourse'

In each of the past four years, the city has logged fewer than two dozen cases of heatstroke-related work injuries and no deaths, according to labor officials, but activists dispute those statistics.

"The reality is (heatstroke) is not reported," said Fay Siu, who runs the Association for the Rights of Industrial Accident Victims.

Either the workers do not know they can report it or "the company may not recognize it", she told AFP.

She pointed to a 2018 case when a 39-year-old died after fainting at a construction site. An investigation found rhabdomyolysis—a potentially life-threatening type of muscle breakdown—"caused by high temperatures and signs of heatstroke".

Chart showing the average daily maximum air temperature in Hong Kong for July, 1997-2023.

"But the insurance company and his employer... pinned it on his personal medical conditions so it would not be categorized as a work injury," Siu said.

Her group has identified at least four cases of outdoor workers dying on days of extreme heat in the past year.

Siu said labor officials should do more to investigate or family members would be left with "no recourse".

In response, the Labor Department said there was no information indicating that workers were unable to report heatstroke-related work injuries, but agreed that cases with "mild symptoms" may go unreported.

"The number of registered cases may be lower than the actual number of symptomatic cases," the department told AFP in a statement.

"Based on the experience of the (department) in processing work injuries suspected to be relating to heat stroke, employers generally do not dispute their liabilities and would make compensation," they added.

For some, the government's new heat-stress warning system appears to have had limited impact.

A Hong Kong construction worker (R) takes a break from the heat.

Wah and his colleagues say they have seen few changes to their routine—especially since they risk having their pay docked if they are caught taking lengthy breaks.

Chuen, 70, said they usually continue working after a five-minute water break.

"That's how it goes," he said, sweating in the shade.

© 2023 AFP

Expert discusses heat exhaustion and heatstroke

  

Spanish city shatters heat record

An umbrella helped at the Xativa castle south of Valencia on Thursday.

Spain's eastern city of Valencia set a new temperature record on Thursday as the country baked under its third heat wave of the summer

The mercury soared to 46.8 degrees Celsius (116.2 Fahrenheit) at Valencia airport, shattering the previous record of 43.4 Celsius set on July 6, 1986, state weather agency Aemet said on social media.

The center of the Mediterranean port city was emptier than usual as many people stayed indoors to shelter from the heat, or escaped to the countryside or nearby beaches.

Those who did venture outside used fans and umbrellas to guard themselves against the scorching sun, or cooled themselves with water from fountains.

"This summer has been horrible... we cannot live in our apartment," Valencia resident Nazim Ali told AFPTV.

The local government opened an air-conditioned shelter to allow homeless people to escape the heat and access water, food and showers.

"At night we use the air-conditioning and a fan," said Roberto Gimenez, another resident.

"During the day we try to leave the house as late as we can if we don't have work to do, and go to the beach."

The record for the highest temperature in Spain—47.6 degrees Celsius —- was registered on August 14, 2021, at Aemet's weather station in La Rambla in the southern province of Cordoba.

The heat wave affecting most of central, southern and eastern Spain is expected to ease on Friday.

Scientists say heat waves have become more likely due to climate change.

As global temperatures rise over time, heat waves are predicted to become more frequent and intense, and their impacts more widespread.

© 2023 AFP

Record heat warning as forest fires rage in Spain and Portugal

Where summer heat hits hard: Mideast and North Africa

by AFP bureaux

Men cool off with a mist dispenser set up in a street in central Baghdad amid soaring 

temperatures.

Climate change has impacted the Middle East and North Africa where summer is already very hot. Many in Iraq, Syria, Tunisia and Saudi Arabia still labour in the heat.

A tool of the trade in Syria

Heat is a tool of the trade for blacksmith Murad Haddad in the city of Idlib in northwest Syria.

"We make everything by hand here. We get up early to try to avoid the extra heat we're exposed to as well as the flames," the 30-year-old told AFP.

He and his five brothers take it in turn to use skills handed down by their grandfather as they toil in torching temperatures.

As he strikes the glowing iron with his hammer, a tattoo on his forearm states categorically that "My life is painful".

From time to time he removes his shirt and wipes away the sweat dripping from his beard and drinks tea, standing under an ancient fan suspended from the ceiling.

"We work up close to the fire for five or six hours, until two or three in the afternoon. It consumes us," he said.

"The heat is killing us. I have six kids, and I can hardly look after them. But if I don't work, I can't make ends meet."

Hot food at 50°C in Baghdad

Maoula al-Tai is 30 and delivers takeaway food in Baghdad where he roams the city on a backfiring moped.

When the mercury rises above 50 degrees Celsius (122 Fahrenheit), as it did at the beginning of the week, he is one of the few to venture out onto deserted streets.

Saudi lifeguard Amani Al-Felfel at the Sunset Beach resort in the city of Khobar.

"Sometimes it hits 52, 53 or 54. That's not normal. Nobody can handle that!" he said.

To try to protect himself from the heat, Tai wears a balaclava that covers his nose and mouth.

The United Nations says Iraq is one of the five countries most impacted by some effects of climate change. It is now enduring its fourth consecutive year of drought.

A woman farmer in Tunisia

Munjia Deghbouj is 40, and she lives in the village of El Hababsa, in prosperous countryside in the Siliana region of northern Tunisia.

When she spoke to AFP at the end of July, the North African country was going through an intense and unusual heatwave, with temperatures hitting 50 degrees Celsius in the shade in the capital, Tunis.

She had to change her working hours in order to cope, and rose at dawn each day.

Then she walked for around seven kilometres (four and a half miles) to her field where she grows peppers and watermelons.

"I get up at four in the morning and get my basket ready as well as breakfast for my children," she said.

"I leave home at around five and work until two, and then I come home again on foot.

"We start work really early, planning to be home again once the temperature gets too hot."

Tunisia and other parts of North Africa have experienced wildfires during a scorching 

heatwave.

Backbreaking labour in Iraq

It was 51 degrees Celsius in Nasiriyah in southern Iraq at the start of the week. Atheer Jassim, in his 40s, makes a living delivering gas cylinders.

When he gets home after working in the heat all day, he often finds the house has no electricity. In Iraq, power cuts caused by load shedding can last up to 12 hours a day.

When fatigue gets too much for the father of eight, he "rests for five or six minutes. I splash water on my head, I rest, and then start again."

Jassim delivers gas bottles to private houses by carrying them from his van to his customers.

Despite the work being exhausting, he must keep on going because he wants his children to "finish their studies".

Long hot workday in Saudi

In eastern Saudi Arabia, beachfront resorts offer one way to beat the heat. But it means long days for the lifeguards tasked with keeping swimmers safe.

"We pay a lot of attention to our fitness level when we're working amid high summer temperatures," said Amani al-Felfel.

"We cooperate, so if one of us gets tired someone else will replace her."

Felfel has worked for more than a decade at a resort in the city of Khobar, where temperatures can top 50 degrees.

She works eight- or nine-hour shifts, patrolling the water on a jet ski and the beach on foot.

When she can, she ducks under the pool shower to wash away the sweat so she can stay awake and vigilant.

"When I go back home, I just ask for the coldest water I can ever have to make a shower with and relax, as I've had enough of the heat," she said.

© 2023 AFP

'No more water': Iraq drought claims lakeside resort

 

Climate change impacts are unraveling the fabric of society in the South-West Pacific, says report

by World Meteorological Organization (WMO)

Credit: Pixabay/CC0 Public Domain

Weather-related disasters and climate change impacts are unraveling the fabric of society in the South-West Pacific. Sea level rise threatens the future of low-lying islands while increasing ocean heat and acidification harms vital and vulnerable marine ecosystems, according to a new report from the World Meteorological Organization (WMO).

The State of the Climate in the South-West Pacific 2022 report provides a snapshot of climate indicators including temperatures, sea level rise, ocean heat and acidification, and extreme weather events in 2022. It also highlights the socio-economic risks and impacts on key sectors like agriculture.

The report, along with an interactive story map, is one of a series of five regional reports and a global report from WMO providing the latest climate insights to inform decision-making.

The three-year-long La Niña event had a clear influence on temperatures in 2022. But despite its temporary cooling influence, it was still a warm year for the region. The mean temperature in 2022 was 0.2 °C to 0.3 °C higher than during the last strong La Niña event in 2011.

"The El Niño, which followed three years of La Niña conditions, is very likely to continue during the rest of the year. This will have a big impact on the South-West Pacific region as it is frequently associated with higher temperatures, disruptive weather patterns and more marine heat waves and coral bleaching," said WMO Secretary-General Prof. Petteri Taalas.

Compared to 2021, the number of reported disaster events decreased; however, economic losses increased. Economic damage due to flooding was US$ 8.5 billion, almost triple compared to the previous year, with most of the damage attributable to a series of flooding events in Australia. Tropical Storms Megi and Nalgae caused devastating flooding in the Philippines.

"Early warning is one of the most effective ways of reducing damage from disasters, as it empowers people to make risk-informed decisions for food security, as well as other sectors," said Prof. Taalas.

"Despite continuous efforts to strengthen multi-hazard early warning systems, the present report clearly shows that there are still significant gaps to be addressed," he said.

"The Early Warnings for All initiative … is critical in the Pacific, which is characterized by distinct disaster risk hotspots that are intensifying and expanding as climate-related hydrometeorological disasters intensify," said Armida Salsiah Alisjahbana, Under-Secretary-General of the United Nations and Executive Secretary of the Economic and Social Commission for Asia Pacific.

"ESCAP and WMO, working in partnership, will continue to invest in raising climate ambition and accelerating the implementation of policy actions, which includes bringing early warnings to all in the region so that no one is left behind as our climate change crisis continues to evolve," she said.

The report shows how the agriculture sector is one of the most critical sectors affected by climate-related disasters, echoing the national adaptation plans of many countries in the South-West Pacific. Enhancing the resilience of food systems is therefore a high priority.

Blue Pacific

The report was released at the Third Pacific Ministerial Meeting on Meteorology (PMMM-3) and the First Development Partners and Donors Engagement Meeting in Fiji. The meetings, which are all interlinked, will be guided by the theme: "Sustaining Weather, Climate, Water and Ocean Services for a Resilient Blue Pacific."

The meetings gather Government Ministers, representatives from National Meteorological and Hydrological Services (NMHSs) in the Pacific, as well as those from development partners such as the Secretariat of the Pacific Regional Environment Programme (SPREP), WMO and the private sector, to strengthen climate and weather services in the Pacific.

"Our Pacific people are at the forefront of the impact of the triple planetary crises of climate change, biodiversity loss, and pollution. Our Pacific leaders have already declared a climate emergency, reaffirming that this is now the single greatest existential threat facing the Blue Pacific," said SPREP's Director-General Sefanaia Nawadra.

The WMO report says that sea-level rise rates were, in general, slightly higher than the global mean rate, reaching approximately 4 mm per year in several areas.

Despite La Niña conditions, marine heat waves occurred in various parts of the region. The most prominent and persistent marine heat waves occurred in a large area north-east of Australia and south of Papua New Guinea in the Solomon and Coral Seas, over a period of more than six months.

The ocean has taken up more than 90% of the excess heat in the climate system. Ocean warming contributes about 40% of the observed global mean sea-level rise through thermal expansion of seawater. It is altering ocean currents, indirectly altering storm tracks and affecting marine ecosystems.

Most of the regions in the South-West Pacific show upper-ocean (0–700 m) warming since 1993. Warming is particularly strong, with rates exceeding 2–3 times the global average warming rates, in the Solomon Sea and east of the Solomon Islands; in the Arafura, Banda and Timor Seas; east of the Philippines; along the southern coast of Indonesia and in the Tasman Sea, according to the report.

In Indonesia, satellite estimates of the area of a glacier in the western part of the island of New Guinea showed a total ice area in April 2022 of 0.23 km2, a decrease of about 15% from the previous assessment of 0.27 km2 in July 2021.

From 2016 to 2022, the average reduction in ice area was approximately 0.07 km2 per year. Measurements of ice thickness via a single stake show a reduction in thickness of 24 m from June 2010 to the beginning of 2021, and the estimated remaining ice thickness in December 2022 was just 6 meters.

Climate-related impacts and risks

La Niña conditions contributed to significant rainfall anomalies in the region. Most of the equatorial Pacific islands experienced drier-than-normal conditions, and Kiribati and Tuvalu suffered from significant water shortages at times during the year. At the other extreme, Australia suffered significant economic loss in association with severe floods.

In 2022, a total of 35 natural hazard events were reported in the South-West Pacific according to the International Disaster Database (EM-DAT), of which over 70% were flood events. These resulted in over 700 fatalities, of which over 70% were associated with storms.

Over 8 million people were directly affected by these hazards, and they caused total economic damage of close to US$ 9 billion. Storms were the leading cause of death and affected the greatest number of people in 2022, especially in the Philippines and Fiji.

A comparison of the economic losses from disasters in the South-West Pacific region in 2022 with the average over the past 20 years (2002–2021) shows that the losses associated with flooding in 2022 (an estimated US$ 8.5 billion) were more than four times the average.

In 2022, as an aggregate, flooding caused the highest economic losses in Australia, where the total was over US$ 8 billion, followed by Indonesia (over US$ 74 million) and the Philippines (over US$ 11 million).

Provided by World Meteorological Organization (WMO)

14 million people were hit with climate disasters in the South-West Pacific last year

Natural compound in white button mushrooms could benefit animal, human health

by Krista Weidner, Pennsylvania State University

Researchers in Penn State’s College of Agricultural Sciences have identified a compound in white button mushrooms that potentially can be beneficial for gut health in mammals. Credit: Pixabay

A team of researchers in Penn State's College of Agricultural Sciences has identified a compound in white button mushrooms that could potentially benefit gut health in mammals by activating a protective biological response.

"Our research showed that a biochemometric approach—modeling chemistry and biology data together—can lead to the discovery of new components of chemical mixture in foods that might be therapeutic for animal and human health," said Joshua Kellogg, assistant professor of metabolomics in the Department of Veterinary and Biomedical Sciences. The researchers published their findings in the Journal of Functional Foods.

Using cell-based assays and a molecular networking approach—a method that organizes molecules according to their structural similarity—the researchers found that the new compound they identified in white button mushrooms activates the aryl hydrocarbon receptor, or AHR, which is found in mammals including mice, pigs and humans.

Prior studies have demonstrated that when mice ingest mushrooms, the AHR either becomes antagonized or inhibited. The compound Kellogg's team identified activates AHR when applied to human and mouse-derived cell lines, which are cultured in the laboratory to test the molecular effects of certain variables.

"It's a delicate balancing act, which is why studying whole foods as well as individual compounds is essential," Kellogg said. "There are benefits to AHR activation as well as antagonism."

Kellogg said that AHR plays an important role in gut health. When activated, it can induce a cellular response to detoxify aryl hydrocarbons, which are known carcinogens, in the gut. When inhibited, AHR can help reduce tumor growth in certain cancers. AHR is also critical in other facets of promoting gut health, including maintaining the integrity of the mucosal lining of the gut and preventing bacteria from invading the gut.

The team's latest research builds on prior work by co-authors Andrew Patterson, professor of molecular toxicology, biochemistry and molecular biology, and Gary Perdew, H. Thomas & Dorothy Willits Hallowell Chair of Agricultural Sciences and director of the Center for Molecular Toxicology and Carcinogenesis. They previously looked at molecules called benzothiazoles and how they react with AHR.

"In our research, we recognized those benzothiazoles, but we also saw previously undiscovered molecules that were structurally related," Kellogg explained. "When we profiled the chemistry of these related structures, we wondered if they would also work with AHR. And we found that they do activate AHR."

The researchers' findings underscore the importance of studying the roles each chemical component plays in a whole food, according to Kellogg.

"Foods are complex chemical mixtures," Kellogg said. "What we do at our core is focus on ways to hunt for active chemistry in natural sources—plants, mushrooms, bacteria. We're interested in how chemical mixtures in foods react with AHR and could protect gut health in general."

Graduate student Xiaoling Chen, a member of the research team and lead author of the paper, is continuing the research by examining at molecular mixtures in other mushroom species.

The team also is applying the biochemometric approach to infectious disease research, Kellogg said. For example, they are screening various plants from regions across Pennsylvania for compounds that act against pathogenic bacteria. They have found phytochemicals—part of a plant's immune system that helps protect against viruses—in the plant Artemisia that seem to be effective at inhibiting the growth of mycobacteria that cause tuberculosis.

More information: Xiaoling Chen et al, Molecular networking identifies an AHR-modulating benzothiazole from white button mushrooms (Agaricus bisporus), Journal of Functional Foods (2023). DOI: 10.1016/j.jff.2023.105602

Journal information: Journal of Functional Foods 

Provided by Pennsylvania State University Broccoli consumption protects gut lining, reduces disease in mice, study shows