Monday, August 07, 2023

Exploring the self-organizing origins of life

Exploring the origins of life — *A new model describes the self-organization of catalysts involved in metabolic cycles.*

Catalytic molecules can form metabolically active clusters by creating and following concentration gradients—this is the result of a new study by scientists from the Max Planck Institute for Dynamics and Self-Organization (MPI-DS). Their model predicts the self-organization of molecules involved in metabolic pathways, adding a possible new mechanism to the theory of the origin of life.

The results can help to better understand how molecules participating in complex biological networks can form dynamic functional structures, and provide a platform for experiments on the origins of life.

One possible scenario for the origin of life is the spontaneous organization of interacting molecules into cell-like droplets. These molecular species would form the first self-replicating metabolic cycles, which are ubiquitous in biology and common throughout all organisms. According to this paradigm, the first biomolecules would need to cluster together through slow and overall inefficient processes.

Such slow cluster formation seems incompatible with how quickly life has appeared. Scientists from the department of Living Matter Physics from MPI-DS have now proposed an alternative model that explains such cluster formation and thus the fast onset of the chemical reactions required to form life.

"For this, we considered different molecules, in a simple metabolic cycle, where each species produces a chemical used by the next one," says Vincent Ouazan-Reboul, the first author of the study. "The only elements in the model are the catalytic activity of the molecules, their ability to follow concentration gradients of the chemicals they produce and consume, as well as the information on the order of molecules in the cycle," he continues.

Consequently, the model showed the formation of catalytic clusters including various molecular species. Furthermore, the growth of clusters happens exponentially fast. Molecules hence can assemble very quickly and in large numbers into dynamic structures.

"In addition, the number of molecule species which participate in the metabolic cycle plays a key role in the structure of the formed clusters," Ramin Golestanian, director at MPI-DS, summarizes, "Our model leads to a plethora of complex scenarios for self-organization and makes specific predictions about functional advantages that arise for odd or even number of participating species. It is remarkable that non-reciprocal interactions as required for our newly proposed scenario are generically present in all metabolic cycles."

In another study, the authors found that self-attraction is not required for clustering in a small metabolic network. Instead, network effects can cause even self-repelling catalysts to aggregate. With this, the researchers demonstrate new conditions in which complex interactions can create self-organized structures.

Overall, the new insights of both studies add another mechanism to the theory of how complex life once emerged from simple molecules, and more generally uncover how catalysts involved in metabolic networks can form structures.

The paper is published in the journal Nature Communications.

More information: Vincent Ouazan-Reboul et al, Self-organization of primitive metabolic cycles due to non-reciprocal interactions, Nature Communications (2023). DOI: 10.1038/s41467-023-40241-w

Journal information: Nature Communications

Provided by Max Planck Society

Enzymatic reactions: Researchers reveal a regulatory mechanism by which life controls and organizes itself

Mathematical theory predicts self-organized learning in real neurons

by RIKEN

An international collaboration between researchers at the RIKEN Center for Brain Science (CBS) in Japan, the University of Tokyo, and University College London has demonstrated that self-organization of neurons as they learn follows a mathematical theory called the free energy principle.

The principle accurately predicted how real neural networks spontaneously reorganize to distinguish incoming information, as well as how altering neural excitability can disrupt the process. The findings thus have implications for building animal-like artificial intelligences and for understanding cases of impaired learning. The study was published August 7 in Nature Communications.

When we learn to tell the difference between voices, faces, or smells, networks of neurons in our brains automatically organize themselves so that they can distinguish between the different sources of incoming information. This process involves changing the strength of connections between neurons, and is the basis of all learning in the brain.

Takuya Isomura from RIKEN CBS and his international colleagues recently predicted that this type of network self-organization follows the mathematical rules that define the free energy principle. In the new study, they put this hypothesis to the test in neurons taken from the brains of rat embryos and grown in a culture dish on top of a grid of tiny electrodes.

Once you can distinguish two sensations, like voices, you will find that some of your neurons respond to one of the voices, while other neurons respond to the other voice. This is the result of neural network reorganization, which we call learning. In their culture experiment, the researchers mimicked this process by using the grid of electrodes beneath the neural network to stimulate the neurons in a specific pattern that mixed two separate hidden sources.

After 100 training sessions, the neurons automatically became selective—some responding very strongly to source #1 and very weakly to source #2, and others responding in the reverse. Drugs that either raise or lower neuron excitability disrupted the learning process when added to the culture beforehand. This shows that the cultured neurons do just what neurons are thought to do in the working brain.

The free energy principle states that this type of self-organization will follow a pattern that always minimizes the free energy in the system. To determine whether this principle is the guiding force behind neural network learning, the team used the real neural data to reverse engineer a predictive model based on it. Then, they fed the data from the first 10 electrode training sessions into the model and used it to make predictions about the next 90 sessions.

At each step, the model accurately predicted the responses of neurons and the strength of connectivity between neurons. This means that simply knowing the initial state of the neurons is enough to determine how the network would change over time as learning occurred.

"Our results suggest that the free-energy principle is the self-organizing principle of biological neural networks," says Isomura. "It predicted how learning occurred upon receiving particular sensory inputs and how it was disrupted by alterations in network excitability induced by drugs."

"Although it will take some time, ultimately, our technique will allow modeling the circuit mechanisms of psychiatric disorders and the effects of drugs such as anxiolytics and psychedelics," says Isomura. "Generic mechanisms for acquiring the predictive models can also be used to create next-generation artificial intelligences that learn as real neural networks do."

More information: Nature Communications (2023). DOI: 10.1038/s41467-023-40141-z

Journal information: Nature Communications

Provided by RIKEN

The free-energy principle explains the brain

Physicists synthesize single-crystalline iron in the form likely found in Earth's core

by Bob Yirka , Phys.org

Physicists synthesize single-crystalline iron in the form that it likely has in Earth's core — *By compressing a specific crystalline orientation of iron in a diamond-anvil cell, researchers*

A team of physicists and geologists at CEA DAM-DIF and Universit´e Paris-Saclay, working with a colleague from ESRF, BP220, F-38043 Grenoble Cedex and another from the European Synchrotron Radiation Facility, has succeeded in synthesizing a single-crystalline iron in a form that iron has in the Earth's core.

In their paper published in the journal Physical Review Letters, the group describes how they used an experimental approach to synthesize pure single-crystalline ε-iron and possible uses for the material

In trying to understand Earth's internal composition, scientists have had to rely mostly on seismological data. Such studies have led scientists to believe that the core is solid and that it is surrounded by liquid. But questions have remained. For example, back in the 1980s, studies revealed that seismic waves travel faster through the Earth when traveling pole to pole versed equator to equator, and no one could explain why.

Most theories have suggested it is likely because of the way the iron in the core is structured. Most in the field agree that if the type of iron that exists in the core could be made and tested at the surface, such questions could be answered with a reasonable degree of certainty. But doing so has proven to be challenging due to fracturing during synthesis. In this new effort, the research team has found a way around such problems and in so doing have found a way to synthesize a type of iron that can be used for testing the properties of iron in Earth's core.

The work by the team involved compressing a sample of α-iron at 7GPa. Doing so caused its temperature to rise to approximately 800 Kelvin. That led to the transformation of its structure into γ-iron crystals. More pressure pushed the γ-iron to form into ε-structure iron—single crystals that are believed to be the same types as those in the iron at Earth's core.

The research team conducted experiments that showed the directionally-dependent elasticity of their ε-iron behaving as iron does in the Earth's core, with vibrations traveled faster along one axis of a sphere than along the other. They suggest their approach can be used for generating iron samples for testing theories regarding the makeup of Earth's core.

More information: Agnès Dewaele et al, Synthesis of Single Crystals of ε -Iron and Direct Measurements of Its Elastic Constants, Physical Review Letters (2023). DOI: 10.1103/PhysRevLett.131.034101

Journal information: Physical Review Letters

Reproducing core conditions suggests Earth's outer core less dense than liquid iron

It survived 'Stumptown.' Now an ancient redwood may finally be protected for good

by Cari Spencer, Los Angeles Times

In Sonoma County, near a community once called Stumptown because of the sprawling graveyard of cleaved trees left in the wake of California's early logging boom, one ancient redwood has repeatedly escaped the ax.

And now, after years of uncertainty, the behemoth known as the Clar Tree may be able to live out the rest of its lengthy life without fear of being felled.

The tree persevered, even as an estimated 95% of California's original redwood forest was chopped or burned in the centuries following European colonization. Named after a man who lived in the area in the late 19th century, the Clar Tree today stands resolute at 278 feet. It's one of the tallest trees in the county even after last winter's storms sheared off 30 feet.

The giant coast redwood, thought to be about 2,000 years old, is the last old-growth redwood remaining on a 394-acre property above the Russian River in Guerneville.

On Tuesday, Save the Redwoods League announced a plan to raise $6.5 million to buy the property from RMB Revocable Family Trust—which owns the acreage and planned to log a portion of it this year. The league says the landowner has given them a Sept. 30 deadline to complete the purchase.

It's a "short timeline and a significant lift," but there's no shortage of hope, said Sam Hodder, president and chief executive of the nonprofit conservation group. Since 1918, the league has secured protection for more than 216,000 acres of redwood forest.

"With 394 acres, we're not going to save the world. But the redwoods are such an iconic species, they're such a charismatic species, and if we can work to set this young redwood forest on our trajectory … then we can set a model for how we collectively steward our forests in a time of changing climate," Hodder said.

According to the league, if the deal closes, the land will be transferred to Sonoma County for long-term preservation and restoration with the support of the county's Agricultural Preservation and Open Space District.

The county could also work to make the area around the Clar Tree more accessible for visitors, as well as create a landing along the river to serve as a shady stopover for those traveling by kayak or canoe among the younger redwood groves. The proposed land deal would include one mile of Russian River frontage near Guerneville.

As the forest of coast redwoods and Douglas firs is housed in the ancestral lands of the Southern Pomo people, Haddon said, the league has met with representatives from the Federated Indians of Graton Rancheria to ensure their cultural interests are protected.

News of the potential sale comes as a relief to local community members who have been fighting for years to stop logging near the Russian River, Sonoma County Supervisor Lynda Hopkins said.

Late last fall, the California Department of Forestry and Fire Protection approved a contentious 224-acre logging plan submitted by Redwood Empire Sawmill to cut down about one-third of the trees on the property. Although the timber company acknowledged the Clar Tree's unique legacy, surrounding it with a 75-foot "no harvest" radius, many opponents asserted the buffer was not enough to protect the tree's expansive root system.

In the two years it took for the harvest plan to get approved, it drew hundreds of public comments in opposition. Objectors raised concerns with the destruction of wildlife habitat, as well as the potential for heightened risks of landslides and wildfires from the removal of more fire-resistant trees.

After the plan was approved, the Guerneville Forest Coalition filed a legal complaint against Cal Fire and Redwood Empire Sawmill, alleging the plan would cause irreparable harm to the Russian River ecosystem. The coalition also alleged that the public outcry had been largely disregarded, as if "thrown down a black hole," said one of its members, Colin Baptie.

Logging in the area has yet to proceed and the lawsuit is ongoing. Baptie said members of the coalition will meet with their attorney to decide what to do next.

But with the news of the possible purchase, Baptie said the coalition is "over the moon."

The property has come to represent hope for a state already racked by the impacts of a changing climate and the repercussions of human incursion into once-wild areas.

Ancient redwood forests are known to capture more carbon dioxide per acre than any other forest in the world. Just one acre can store up to 890 metric tons of carbon—the equivalent of pulling about 700 cars off the road for a year, according to research from Save the Redwoods League and Cal Poly Humboldt.

Younger forests have proved an impressive ally too. Recent research suggests that with 150 years of growth, regenerating redwood forests can store 30% as much carbon as their ancestors.

Above the Russian River, where the Clar Tree stands sentry over younger trees and stems sprouting from ancient tree stumps, the intergenerational forest provides a glimpse of what the future may one day hold.

"There's something very mystical of a forest growing out of the skeleton of the forest that once stood, that speaks to the resilience of nature and the will to live and survive and grow back," Hodder said. "It plants a seed of hope of how, together, we can protect and heal the young redwood forest and help it grow to be the old growth of the future."

Redwoods and climate change: Vulnerability, resilience, and hopeful potential in world's tallest trees

About 1 in 3 vertebrate species is used, eaten or traded by humans, study finds

by Gina Errico, Los Angeles Times

buffet — Credit: Unsplash/CC0 Public Domain

A cheetah pouncing on a gazelle. A bear snatching a fish out of the water with its claws. And the most dangerous predator of them all? A human and their pet bird dancing to Gangnam Style.

Scientists who set out to quantify humanity's impact on our 46,755 fellow species have found that we are the most prolific exploiters of animals—by far.

Compared to wild predators that have roughly the same body size as us and have similar appetites, we capture or kill nearly 100 times as many vertebrate species, on average.

Orcas, for instance, have a range that's similar to ours, along with comparable social behaviors. Yet of the 121 types of vertebrates eaten by the so-called killer whales, humans also consume 83 of them—along with 10,337 others in the ocean alone.

The situation is similar on land. Jaguars, the most fearsome cats of the Americas, eat nine different types of prey. Humans use all nine of those same species, plus 2,698 others that live in the territory where jaguars and people overlap.

"This is a clear look at who we are as a species and what we are doing," said Boris Worm, a marine conservation biologist at Dalhousie University in Canada and the study's senior author. "It gives you a sense for how unusual of a species humans are."

Unlike other animals, humans have developed a wide array of skills that allow us to survive in a variety of of environments. As a result, humans have access to a wider range of animal species than is typical for large vertebrates.

Another reason for our outsized degree of mayhem is that we don't just consume other species for food. We also use them to make clothing, produce traditional medicines, create souvenir trinkets and keep us company, among other things.

To understand the ways in which humans exploit other animals, Worm and his colleagues analyzed data from the International Union for Conservation of Nature, an organization that keeps track of wildlife species across the globe and how well their populations are faring. Each species is listed with its geographic range and preferred habitat, along with threats to themselves and the places where they live.

That allowed the researchers to identify all 14,663 of the species exploited by humans, and how they were used.

It turned out that only around 55% of our victim species are killed for food, most of them other mammals and fish. (Only wild animals were included with in the analysis, so livestock like chickens and cows didn't count.)

In addition, about 55% of exploited species are kept as pets, and another 8% or so— primarily birds, reptiles and amphibians—are used to make products. (The percentages add up to more than 100% because some species are used in multiple ways, the study authors said.)

"Humanity has grossly overshot its role as a predator," said study leader Chris Darimont, an ecologist and conservationist at the University of Victoria.

"Our pre-industrial ancestors may have engaged in sustainable harvesting behavior," Darimont said. But the fact that modern humans exploit nearly one-third of all living vertebrate species—and use so many for nonfood purposes—is an indisputable sign that we are out of balance from the natural world, he added.

In fact, after combing through the IUCN data, the researchers found that 13% of the species we exploit are either vulnerable, endangered or critically endangered. That figure was much higher than Worm said he expected to find.

The results were published last month in the journal Communications Biology.

This study is the first to focus on the direct impacts of human predation on other species. Reducing the use of other animals would be more sustainable for the planet as a whole, Darimont said.

Robbie Burger, a macroecologist at the University of Kentucky who was not involved in the study, said that although the IUCN has the most data on biodiversity, it doesn't account for all the ways humans encroach on other species.

The entertainment industry, social media and celebrity culture are all big drivers in nonfood uses of other species. For instance, when the Harry Potter book series became an international sensation, it fueled the illegal owl trade in countries such as India and Indonesia. Researchers believe the fictional mail-delivering owls prompted interest in having owls as house pets, leading to an increase in their removal from the wild.

"Humans are clearly a cultural species," Burger said, and "collections for pets, trophies and medicines are clearly products of culture."

Darimont agreed that the study doesn't capture all of the indirect effects of human activity on wildlife, such as habitat removal and introductions of invasive species. Taken together, these are even more damaging to other species than our direct animal exploitation, he said.

But in Worm's view, the study's bleak findings come with a silver lining.

"This study is giving us the tools to prioritize species conservation and change our practices," he said, adding that he hopes these results will encourage people to think twice about how they use other animals.

More information: Chris T. Darimont et al, Humanity's diverse predatory niche and its ecological consequences, Communications Biology (2023). DOI: 10.1038/s42003-023-04940-w

Journal information: Communications Biology

2023 Los Angeles Times.

Distributed by Tribune Content Agency, LLC.Humans found to prey on approximately one-third of all vertebrate species

Liquid metal may be a 'Terminator terror' in the global fight against pathogens

by Flinders University

A new liquid metal combination is shaping up as a potential secret weapon in the global fight against antimicrobial resistance, which is already rendering some antibiotic medications powerless against 'superbugs'.

Scientists from the U.S. and Australia led by Flinders University have developed a simple metallic coating treatment for bandages, medical devices and even drug nanoparticles which are capable of resisting and killing bacteria.

The researchers from Flinders University's Biomedical Nanoengineering Laboratory, University of Sydney and North Carolina State University say the new approach involves testing 'GaLM' nanoscale liquid metal particles which have improved biocompatibility and low cytotoxicity to cells which could be applied as safe and effective antimicrobial agents.

"Gallium in its liquid state (or 'GaLM') is one of the most promising candidates to be used as an antimicrobial agent, and can be used in many ways as a liquid metal," says Flinders University researcher Dr. Vi Khanh Truong, lead author of a new article in ACS Nano.

"The liquid state of GaLM enables it to be easily combined or functionalised with other components to create various forms of more efficient antimicrobial metals."

"As well gallium appears to be compatible with human cells in preparations and concentrations relevant to its antimicrobial activity, so could one day be administered orally or intravenous injection."

"This material's antimicrobial performance would also be activated by external stimuli (light, magnetic fields, and heat as well as others), resulting in novel solutions which can outperform antimicrobial mono-metallic nanoparticles and may lead to the next generation of antimicrobial and anti-inflammatory metal-based agents."

Led by international experts in the field, including Professor Michael Dickey from the US, Australian Research Ccouncil Laureate Professor Kourosh Kalantar-Zadeh and NHMRC Leadership Fellow Flinders University Professor Krasimir Vasilev—all authors on the new review article—research is expanding in metal-based antimicrobial strategies in a race to combat escalating threats of antimicrobial resistance (AMR).

With AMR leading to different types of bacterial, fungal and viral infections becoming untreatable, which can result in morbidity and mortality, phage (virus) therapy, immunotherapy, CRISPR-Cas technology and antibiotic combination therapy are other research approaches under way around the world.

The current strategies for infection control that rely on conventional synthetic antibiotics are increasingly failing, and the treatment "toolbox" is rapidly becoming exhausted, the new ACS article says.

"To make matters worse, the ability of bacteria to evolve to resist antibiotics provides a disincentive for pharmaceutical companies to pursue next-generation target antibiotics."

Dr. Truong, from the Flinders University Biomedical Nanoengineering Laboratory, says the ACS Nano study examines how combining gallium with other elements "expands the realm of GaLMs with tunable features."

"In contrast to solid-state particles, GaLM particles can dramatically transform their configurations in response to external stimuli. Interestingly, GaLMs in the liquid state can transform their shape around and inside cells."

"Moreover, in their liquid state, GaLMs can dissolve and sequester metallic elements that can later be released on demand via stimuli. This is especially useful for improving the efficiency of the release of drugs."

"Compared to solid metals, GaLMs appear to be benign for eukaryotes (indicating biocompatibility with human tissue) while retaining potent antimicrobial activity."

"It is important to highlight that the antimicrobial activity of GaLMs, in bulk and nano dimensions, is not limited to prokaryotes such as bacteria and cyanobacteria," he adds.

"In addition, GaLMs offer anti-inflammatory properties and we also examined the role of phase behavior and interfaces in nanoscale GaLMs on antibacterial properties."

More information: Vi Khanh Truong et al, Gallium Liquid Metal: Nanotoolbox for Antimicrobial Applications, ACS Nano (2023). DOI: 10.1021/acsnano.3c06486

Journal information: ACS Nano

Provided by Flinders University Super-charged textile repairs itself, monitors heart rhythm

Putting starch into bio-based polymer makes bioplastics more compostable

by Matt Davenport, Michigan State University

Researchers make a sustainable plastic more compostable — Inside this conditioned chamber in Rafael Auras’ lab at Michigan State University,

Researchers from Michigan State University's top-ranked School of Packaging have developed a way to make a promising, sustainable alternative to petroleum-based plastics more biodegradable.

A team led by Rafael Auras has made a bio-based polymer blend that's compostable in both home and industrial settings. The work is published in the journal ACS Sustainable Chemistry & Engineering.

"In the U.S. and globally, there is a large issue with waste and especially plastic waste," said Auras, MSU professor and the Amcor Endowed Chair in Packaging Sustainability.

Less than 10% of plastic waste is recycled in the U.S. That means the bulk of plastic waste ends up as trash or litter, creating economic, environmental and even health concerns.

"By developing biodegradable and compostable products, we can divert some of that waste," Auras said. "We can reduce the amount that goes into a landfill."

Another bonus is that plastics destined for the compost bin wouldn't need to be cleaned of food contaminants, which is a major obstacle for efficient plastic recycling. Recycling facilities routinely must choose between spending time, water and energy to clean dirty plastic waste or simply throwing it out.

"Imagine you had a coffee cup or a microwave tray with tomato sauce," Auras said. "You wouldn't need to rinse or wash those, you could just compost."

PLA and a 'sweet spot' for starch

The team worked with what's known as polylactic acid, or PLA, which seems like an obvious choice in many ways. It's been used in packaging for over a decade, and it's derived from plant sugars rather than petroleum.

When managed properly, PLA's waste byproducts are all natural: water, carbon dioxide and lactic acid.

Plus, researchers know that PLA can biodegrade in industrial composters. These composters create conditions, such as higher temperatures, that are more conducive to breaking down bioplastics than home composters.

Yet, the idea of making PLA compostable at home seemed impossible to some people.

"I remember people laughing at the idea of developing PLA home composting as an option," said Pooja Mayekar, a doctoral student in Auras' lab group and the first author of the new report. "That's because microbes can't attack and consume PLA normally. It has to be broken down to a point where they can utilize it as food."

Although industrial compost settings can get PLA to that point, that doesn't mean they do it quickly or entirely.

"In fact, many industrial composters still shy away from accepting bioplastics like PLA," Auras said.

In its experiments, supported by the U.S. Department of Agriculture and MSU AgBioResearch, the team showed that PLA can sit around for 20 days before microbes start digesting it in industrial composting conditions.

To get rid of that lag time and enable the possibility of home composting, Auras and his team integrated a carbohydrate-derived material called thermoplastic starch into PLA. Among other benefits, the starch gives composting's microbes something they can more easily chow down on while the PLA degrades.

"When we talk about the addition of starch, that doesn't mean we just keep dumping starch in the PLA matrix," Mayekar said. "This was about trying to find a sweet spot with starch, so the PLA degrades better without compromising its other properties."

Fortunately, postdoctoral researcher Anibal Bher had already been formulating different PLA-thermoplastic starch blends to observe how they preserved the strength, clarity and other desirable features of regular PLA films.

Working with doctoral student Wanwarang Limsukon, Bher and Mayekar could observe how those different films broke down throughout the composting process when carried out at different conditions.

"Different materials have different ways of undergoing hydrolysis at the beginning of the process and biodegrading at the end," Limsukon said. "We're working on tracking the entire pathway."

The team ran these experiments using systems that Auras and lab members, past and present, largely built from scratch during his 19 years with MSU. The equipment the researchers have access to outside their own lab in the School of Packaging also makes a difference.

"Working with Dr. Auras, the School of Packaging, MSU—it's great," Bher said. "Because, at some point, we want to be making actual products. We are using facilities around campus to make materials and test their properties. MSU offers a lot of resources."

"There's a reason why this is one of the best schools for packaging," Mayekar said.

More information: Pooja C. Mayekar et al, Breaking It Down: How Thermoplastic Starch Enhances Poly(lactic acid) Biodegradation in Compost─A Comparative Analysis of Reactive Blends, ACS Sustainable Chemistry & Engineering (2023). DOI: 10.1021/acssuschemeng.3c01676

Journal information: ACS Sustainable Chemistry & Engineering

Provided by Michigan State University Researchers make bioplastic sheets with pineapple stems from agricultural waste

Huge blue whale washes ashore in southern Chile

The blue whale washed up on a beach in Ancud, on Chiloe island in southern Chile, on August 5, 2023 — The blue whale washed up on a beach in Ancud, on Chiloe island in southern Chile, on

An enormous blue whale, considered the largest animal on Earth, has washed up onto a beach in southern Chile, probably after dying at sea, local authorities said Sunday.

Residents of the city of Ancud, on Chiloe island, first spotted the giant marine mammal Saturday on a Pacific ocean beach some 1,000 kilometers (620 miles) south of the capital Santiago.

Agents of the Chilean national fishing agency Sernapesca, sent to investigate, confirmed the carcass was that of "a large cetacean of the family of Balaenopteridae," they posted on the X platform formerly known as Twitter.

"We helped identify the specimen and, based on preliminary evidence, it is a blue whale," the agency added.

Sernapesca's regional director Cristian Hudson told local media that "given its condition, the whale must have died at sea some time ago and drifted in that state."

Environmental groups noted that the area's waters are heavily used by the fishing industry and maritime traffic, and they called for an investigation to determine whether the creature was the victim of a collision.

Government experts said the huge creature likely died at sea then floated for days before washing ashore — Government experts said the huge creature likely died at sea then floated for days before

According to the non-governmental Cetacean Conservation Center (CCC) of Chile, the family of Balaenopteridae, or rorquals, includes a variety of species, ranging from the nine-meter (30-foot) minke whale to the blue whale—which at up to 30 meters is considered the largest animal on Earth.

Carcass of 79-foot blue whale washes ashore in California

Water-stressed Iraq dries up fish farms

AUGUST 7, 2023
by Salam Faraj

Water supply in Iraq, which the UN ranks as one of the five countries most impacted by some effects of climate change, is in a dire state.

Iraqi villager Omar Ziad gazes at the cracked and barren earth where his fish farm once stood, lost to water conservation efforts during a devastating four-year drought.

As the alarming water crisis blamed mostly on climate change drags on, officials see the need for trade-offs in an effort to meet the country's demands.

Drastic government measures have restricted water use for some purposes, including crop irrigation, and authorities have cracked down on illegal practices they long ignored.

Since late May, unauthorized fish farms like Ziad's have become a target.

"I've worked in this industry since 2003," the 33-year-old said at his village of Al-Bu Mustafa in Iraq's central Babylon province.

He had watched helplessly as officials from the water resources ministry sealed his family's seven fish ponds.

Surrounded by fields and majestic palm trees, this was where Ziad, his father and seven brothers would rear carp, which Iraqis use to make their beloved grilled fish dish known as masguf.

At full capacity, the farm held about 50,000 fish and earned the family the equivalent of $1,300-2,600 a month, far more than many in the country.

"We would share the revenues", said Ziad, who also works as a teacher.

He added that they sold their fish "cheaply", but since all but five of the village's 80 fish ponds shut down, the price of carp has almost doubled, now selling at more than 8,000 dinars (around $6) per kilogram, he said.

Dry fish farms abound in Iraq following a crackdown on unauthorised ponds in an effort to conserve water.

'Strategic reserves'

From a bird's-eye view, the backfilled dry patches of land that replaced the ponds are marked out by unpaved roads.

The monotony of the barren landscape is occasionally interrupted by ponds that still hold water. These were spared because their owners had the necessary permits, according to Ziad.

Water supply in Iraq, which the United Nations ranks as one of the five countries most impacted by some effects of climate change, is in a dire state.

Declining rain over the past four years coupled with rising temperatures has brought water levels in the Tigris and Euphrates rivers to staggering lows, for which Baghdad also accuses upstream dams built by neighboring Turkey and Iran.

"The strategic water reserves in Iraq are at their lowest point" in nearly a century, said Khaled Shamal, spokesman for the water resources ministry.

A fishing boat is moored on the banks of a branch of the Euphrates River in the Iraqi town of Al-Hamza.

Some of Iraq's 43 million inhabitants share the blame, he told AFP, due to water-intensive "irrigation practices".

Shamal justified the crackdown on unauthorized fish farms by saying the ponds "increase the water surface susceptible to evaporation", provoke seepage into the soil, and contribute to "environmental pollution".

About half of Iraq's estimated 5,000 "unlicensed" fish farms have been closed, Shamal said, pointing out that authorities still allow mobile fish tanks which are submerged in rivers.

Plunging output

Ayad al-Talibi, president of the Iraqi association of fish farmers, said he accepted the shutting of unauthorized ponds but questioned whether the water that has been saved was "properly used".

Before the May crackdown, Iraq produced nearly one million metric tons of fish per year, but Talibi told public broadcaster Al-Ikhbariya that output has now plunged to 190,000 metric tons.

A man walks on a makeshift bridge over what is now a dry fish farm in the village of Al-Bu Mustafa.

Declining rain and rising temperatures have brought water levels in the Tigris and Euphrates rivers to staggering lows.

According to him, the sector employs two million Iraqis. "All of these families will migrate to the cities" which might struggle to accommodate them, he predicted.

The water crisis has also affected river fishing.

In Iraq's far south, high salinity has harmed fishing in the Shatt al-Arab waterway, where the Tigris and Euphrates converge before spilling into the Gulf.

As the flow of fresh water from the north decreases every year, the riverbed gradually fills with salt water.

Sailing the waters of Shatt al-Arab, fisherman Khdeir Aboud, 71, casts his net but expects no major catch.

Fresh water would once carry "all types of fish" but "with the salt water, there's nothing left", said the white-bearded man.

The meager pay he now makes "can't support a household", he lamented.

"Most fishermen have quit the trade for odd jobs. There are only a few old people left."

© 2023 AFP

Explore furtherDead fish wash up on riverbank in drought-hit Iraq

LA REVUE GAUCHE - Left Comment