By Hugo Francisco de Souza Nov 23 2023 Reviewed by Danielle Ellis, B.Sc.
In a research study published in Sustainable Agriculture, researchers evaluated teredinids as a potentially nutritious and sustainable future food source. They developed a pilot aquaculture system for these colloquially named 'naked clams' and elucidated their nutritional value when compared to conventional 'blue foods' such as blue mussels. Their findings reveal that naked clams are rich in beneficial nutrients, including monounsaturated fatty acids and vitamin B12, while containing protein content comparable to the blue mussels. Study: Naked Clams to open a new sector in sustainable nutritious food production. Image Credit: Andreea Photographer/Shutterstock.com
Encouragingly, tailored microencapsulated algal feeds on which the naked clams were grown were found to have a profound impact on their nutritional composition, thereby allowing for the missing essential nutrients to be added in future research. Together, these findings highlight the use of naked clams as an ideal future food source, both for humans and environmental health. Why do we need sustainable food?
Human land use, especially within the agricultural sector, represents the highest single source of greenhouse gas emissions (mainly methane and nitrous oxide) in the world today. The United Nations (UN) has identified current agriculture and livestock production trends as significant barriers to the global effort to curb greenhouse gas emissions and warned that they may prevent nations from meeting their global warming mitigation targets.
In recent years, environmentally conscious individuals have shifted their consumption patterns away from conventional red meat towards' blue foods', nutrient sources derived from marine and aquatic organisms. These foods present a much smaller land, water, and carbon footprint than their terrestrial counterparts while being arguably more nutritious. The rising global adoption of blue foods, while hitherto common in coastal regions, has resulted in recent booms in the 'urban' aquaculture industry, providing a sustainable yet lucrative livelihood opportunity to its employees.
Of the numerous organisms under the 'blue foods' umbrella, bivalves, a cohort including clams and mussels, stand out as exceptional sources of proteins and essential micronutrients. Unfortunately, given their relatively high production cost, slow maturation, growth rate, and high susceptibility to infection and disease, most aquaculture farmers shy away from bivalve rearing in favor of more profitable (yet less nutritious) sectors, including salmon farming.
Teredinids, also known as 'naked clams' or 'shipworms,' are mollusks adapted for boring into wood, which forms the bulk of their diet. Unlike conventional bivalves, teredinids have a much faster growth rate (the fastest of all known bivalves), and lower production costs. However, they have seldom been researched for their potential as a sustainable source of blue food protein. Interestingly, Australian Aboriginals have farmed these animals as a food source for centuries.
"Teredo navalis, the species of aquaculture potential used in our study, can grow at 1.5–2 mm per day, far outstripping conventional 'large-shelled' bivalves such as mussels, which typically grow at 0.1–0.2 mm per day" About the study
The present study aims to set the groundwork for naked clam aquaculture by developing an aquaculture setup and evaluating the nutritional composition of the clams under different dietary regimes, thereby establishing if dietary fortification could be used as a means to supplement the clams' inherent nutritional benefits further. Related StoriesGlobal food trade improves diets but red meat imports raise health concernsEmulsifiers and heart health: a prospective cohort study reveals associationsExploring nature's palette: The promising future of natural food colorants
Wild Teredo navalis samples were obtained from the north-eastern United States coast (Gloucester Harbour, MA, USA) by placing Eastern pine (Pinus strobus) panels in the water and allowing colonization of T. navalis larvae over the course of 10 months. At the time of collection, the larvae were approximately 9-month-old adults. Mytilus edulis (blue mussels) were obtained from a commercial farming facility in Shetland, Scotland, for use in nutritional comparisons. The M. edulis samples were two-year-old adults who had been reared on a wild marine plankton diet.
To test the dietary regimes' impacts on T. navalis nutritional content, lipid-walled microcapsules were produced using the ultrasonic atomization of a premixed slurry comprised of 30% powdered Schizochytrium algae and an antibacterial waxy encapsulant. T. navalis were exposed to three dietary regimes – wood only (W), microcapsules + wood (MW), and Shellfish Diet 1800 + wood (SDW). Fecal expulsion was used as a proxy for feeding rate. Feces were measured daily via digital recordings and weekly via visual counting. Weekly countings were also used to measure fecal weight, and collected fecal pellets were subjected to electron microscopy (scanning [SEM]).
Nutritional profiling was carried out by homogenizing T. navalis tissue and comprised biochemical composition analyses, B12 content estimation, and lipid quantification. Analysis of variance (ANOVA) tests were used to contrast findings from the treatments (W vs. MW vs. SDW) and M. edulis samples. Study findings
Feeding efficacy experiments revealed that the microcapsule + wood diet resulted in significantly higher mean fecal weight (0.26 mg) compared to wood only (0.11) or Shellfish Diet 1800 + wood (0.13). Fecal production rates, however, were found to be significantly lower in the microcapsule + wood diet, suggesting that microcapsule supplementation could reduce commercial production costs, especially those involving tank maintenance.
SEM results depicted significant differences in the composition and structure of T. navalis reared on W compared to those raised on MW. Notably, MW-raised T. navalis were found to produce significantly lower pseudofeces than W-raised individuals, further reducing feed wastage and tank maintenance requirements.
Nutritional evaluations revealed that T. navalis presented higher ask contents than M. edulis corresponding to lower quantities of fats, carbohydrates, and proteins. However, microcapsule supplementation alleviated these deficits, with MW clams presenting 29% higher protein content than W clams. Concentrations of carbohydrates (19%) and lipids (3.8%) were similarly improved on microcapsule intervention.
"Analyses revealed that Naked Clams had significantly higher levels of B12 than blue mussels. The B12 content of Naked Clams fed on wood + microcapsules was 142 ± 9 (SE) µg B12 per 100 g DW, significantly greater than that of blue mussels at 81 ± 9 (SE) µg per 100 g D"
Microcapsule supplementation was not found to alter vitamin B12 concentrations between MW and W naked clams. However, the concentrations of polyunsaturated fatty acids (PUFAs), Docosahexaenoic acid (DHA), and Eicosapentaenoic acid (EPA) were significantly higher in the MW cohort. Conclusions
The current study presents the first demonstration of naked clam aquaculture as well as the scientific optimizations that can be employed to maximize yield and profits for prospective naked clam farmers. The study further assessed the nutritional composition of naked clams, and found that, while wild T. navalis does not meet the protein content of conventional blue mussels, the supplementation of algal microcapsules in T. navalis feed makes up for this observed demerit.
In contrast, naked clams were found to have significantly higher concentrations of essential nutrients such as vitamin B12 when compared to conventional blue food sources. Notably, naked clams respond well to diet-based fortification, as suggested by MW clams' significantly higher nutritional content than their W counterparts.
"Overall, this study has provided the experimental foundation for a new form of sustainable food production that could turn wood into a protein and nutrient source for mass market human consumption. Naked Clams are hardy, grow exceptionally fast, and can be produced in static saltwater systems. There is an opportunity here to build a completely new aquaculture sector and open up a wealth of avenues for sustainable food production and consumption."Journal reference: Willer, D.F., Aldridge, D.C., Mhrshahi, P. et al. Naked Clams to open a new sector in sustainable nutritious food production. npj Sustain. Agric. 1, 4 (2023). doi: https://doi.org/10.1038/s44264-023-00004-y
If you know a teacher, or you are a teacher, you’ll understand that many in the profession consider their jobs one of the best in the world, while also acknowledging it can be one of the most stressful.
Teaching in a war zone takes it to another level on both fronts.
But imagine teaching in a war zone in say the London Underground or the Paris or New York metros?
Well, that’s exactly what is happening in Kharkiv, Ukraine’s second largest city – a city attacked by Russia on a constant basis.
In 2023, the authorities banned children from being taught in regular school buildings here because of the threat they were under from missile strikes.
So Kharkiv city and its education department started working on a plan.
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That plan has concluded with the construction of six schools in six metro stations, teaching 4,800 children daily whose families haven’t fled the war.
Intrigued by this new educational experiment, as it’s still considered, we were told to meet at the University metro station in the centre of the city and wait to be taken to the school.
Soviet-era metro stations, and particularly the platforms, are universally grand and ornate, although Ukraine’s are slightly more modest.
Pedestrian walkways though are always crammed with florists, newspaper stands, mobile phone shops and cafes, and Kharkiv’s are no different.
What is different though is that next to the main platform entrance, an adjacent passageway has been sealed off by a white wall with three doors built into it.
We were ushered inside, past a guard and into a concourse with two desks.
In front of us, we could see a wide staircase leading to a long corridor. Above us, large, shiny silver metal tubes stretched into the distance, pumping in air from above ground.
Lining the corridor, we could see a series of white interconnecting cabins, all brightly lit, and from them, we could hear the sounds of children laughing, music, and teachers conducting class in this strange subterranean school.
Perhaps the only school in the world with one corridor.
A door to one of the classes opened, and in pairs, a class of six and seven-year-olds emerged – their teacher at the front and an assistant at the rear.
They’re heading to the bathroom for a toilet break, the staff must keep an eye on them.
If any of the children were to make it out of the school, they could easily get lost in the underground system.
The pupils are spread across seven classrooms with a mix of yellow and green desks and chairs, and walls decorated with bright pictures like rainbows, sunshine and sunflowers, to try to create a cheery atmosphere.
“At first, the children were bewildered by studying here, it felt unfamiliar to them, but interacting with each other and with their teachers helped them to adapt,” Iryna Tarasenko from Kharkiv’s education department told me.
Iryna is showing me around the school. They feel it’s their way of contributing to the war effort.
She said: “In the summer of 2023, the Defence Council didn’t permit children to study in regular school buildings, so, we had to find a solution. This is our frontline – our educational frontline.”
There are of course health concerns for both the teachers and the pupils spending so much time underground, so medical examinations are done on a regular basis.
It is an opportunity for doctors and behavioural specialists to monitor the effects of this war on them.
Dmytro Mitelyov is the neurologist on duty monitoring the children’s behaviour, checking for any signs of stress – physical and mental.
He gently asks each child how they’re feeling, and asks if they have any aches and pains.
“These are children who haven’t left Kharkiv since the war began, they live in a constant state of stress, multifaceted stress caused by a range of factors. They are exposed to things they see and hear, like alarms, explosions, and they feel it all,” Dmytro told me.
“When these children grow older, all the trauma they’ve endured during their formative years can, unfortunately, leave a lasting and serious imprint on their mental health. They haven’t had a healthy, carefree childhood – the kind where they can learn, play, and feel safe as children normally would.”
As the first group’s school day ends, children from one of Kharkiv’s most bombed districts, wrap up warm before being led to the surface to catch a school bus to their old school – which was hit by a missile.
It’s still where they meet their parents for normal pick-up.
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We jump on the bus with them for the journey past destroyed government buildings, shopping centres and restaurants.
When the air raid suddenly sounds, I look around to see how the children and teachers on this bus will react.
They barely flinch it’s so common.
“People have, to some extent, adapted,” one of the headmistresses, Olena Nikolienko, said.
“If we see missiles coming, heaven forbid, we’ll stop near a designated shelter, following our evacuation plan, and that’s where the children will go for cover.”
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Remember, these children are safe underground at school, up here they are not.
During the bus ride, 10-year-old Alisa began quietly sobbing. Her teacher told me her grandfather was killed four months ago on the frontline, and since then she has been prone to tears.
Alisa’s teacher comforted her and told her everything would be ok.
It feels like everyone here has to carry their own sadness.
Everyone.
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0:18
‘Ukraine war will end sooner under Trump’
Parents, standing in the first snowfall of the season, greet the children as they get off the bus.
The kids run off the bus, and start throwing snowballs at each other, enjoying this precious moment.
Joe Biden has met with Xi Jinping for the last time as US president, where the Chinese leader said he is “ready to work” with Donald Trump.
Speaking at the Asia-Pacific Economic Cooperation forum in Lima, Peru, Mr Biden said the US and China’s relationship should be about “competition, not conflict”.
“We haven’t always agreed, but our conversations have always been candid and always been frank,” he said.
“We’ve never kidded one another. These conversations prevent miscalculations, and they ensure the competition between our two countries will not veer into conflict.
“We’ve been level with one another. I think that’s vital.”
But despite Mr Trump’s proposed measures, Mr Xi said his country’s goal “of a stable, healthy and sustainable China-US relationship remains unchanged”.
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“Our commitment to mutual respect, peaceful coexistence and… cooperation as principles for handling China-US relations remains unchanged,” he added.
The Chinese president then said the country is “ready to work with the new US administration to maintain communication, expand cooperation and manage differences, so as to strive for a steady transition”.
Neither Mr Xi nor Mr Biden responded to a question about whether there were concerns about Mr Trump’s proposed tariffs.
The president-elect has also named several China hawks to his transition team, such as Senator Marco Rubio as secretary of state and Representative Mike Waltz as national security adviser.
Former heavyweight champion Mike Tyson says the health scare in June, which forced the postponement of his boxing match with Jake Paul, almost cost him his life.
“I almost died in June,” Tyson wrote on X, adding that he “had 8 blood transfusions. Lost half my blood and 25lbs in hospital”.
The 58-year-old, who lost to the YouTuber-turned-boxer in a unanimous points decision in Texas, tweeted that the situation was far worse than people had realised.
Following Tyson’s recovery, after reportedly suffering an ulcer flareup, he reflected on the result of the fight.
“This is one of those situations when you lost but still won… no regrets to get in the ring one last time,” he said.
That contrasts with Tyson’s comments after the match in which he refused to confirm whether it would be his last fight.
“It depends on the situation,” Tyson said before suggesting a fight with Paul’s older brother, Logan Paul, who was standing near him in the ring.
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Critics argued that the revised match – which involved fewer and shortened rounds, as well as heavier gloves – fell short of entertaining.
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Paul beats Tyson by unanimous decision
Some claimed it appeared more like a glorified sparring session.
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It was Tyson’s first sanctioned pro bout since 2005, when he lost to Kevin McBride and then went into retirement – only briefly reappearing for an exhibition match in 2020 against Roy Jones Jr.
Paul has plenty to prove
Paul, 27, still has plenty to prove. The social media influencer wants to be a championship fighter and compete for a championship belt within two years. “I think it could happen in the next 24 months,” Paul said.
“I truly, truly believe in my skills and my ability and my power. And the cruiserweight division is seemingly open for the taking on that timeline,” he added.
The only professional match he has lost so far has been to Tommy Fury, the less-accomplished brother of former heavyweight champion Tyson Fury.
But there are questions about when Paul will fight a contender in his prime, as opposed to former champions or mixed martial artists.
Intriguingly, in the days before his fight with Tyson, Paul mentioned super middleweight champion Canelo Alvarez, considered one of the best boxers in the world.
According to reports, the Texas bout earned Paul $40m (£31.7m) versus $20m (£15.8m) for Tyson.
Netflix said 60 million households worldwide viewed the contest on its streaming platform, and nearly 50 million tuned in to watch the undercard which saw Ireland’s Katie Taylor beat Puerto Rico’s Amanda Serrano.
Even so there were some technical glitches. More than 90,000 users reported problems on Netflix at its peak, according to the website Downdetector, which tracks outages.