Scientists seek new ways to save mussel power in Cornwall
Scientists from the Environment Agency are exploring new ways to monitor water following a decline in mussels. Daymer Bay, at the mouth of the Camel estuary in Cornwall, is one of 20 sites around the country where Atlantic Blue mussels play a role in measuring coastal pollution. Annually, in early spring, mussels are collected and samples tested.In response to a decline in these shellfish, the Environment Agency is working with other organisations to explore alternatives.
Paul Elsmere, from the Cornwall analysis and reporting team, said mussels are "brilliant" because " they're filtering up to 25 litres a day... they bioaccumulate or concentrate those chemicals and substances in their flesh. "The other important thing is... they don't break down those chemicals so what you see in the environment is what you see in the mussel flesh as well." A decline in the numbers of mussels has been seen throughout the north east Atlantic. He said factors that impacted this could be climate change, over fishing, predation and chemicals in the water.
Mussels from Daymer Bay make their way to a Bodmin lab where they are cleaned, measured and have their flesh removed to be sent to other labs to be analysed.Scientists are exploring a new technique called passive monitoring which uses thin film membranes to absorb chemicals and pollutants present in the water. If successful these may replace the need for using mussels. Mr Elsmere said passive monitoring techniques being trialled in Hampshire were a "promising development".
The Environment Agency said the effectiveness of passive sampling devices was being compared to other methods. It said it was working with the Centre for Environment, Fisheries and Aquaculture Science, and if successful it could transform its approach to monitoring chemicals in coastal waters.Further trials are planned to start in the Plymouth Sound area at the end of this year.
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Telegraph
3 hours ago
- Telegraph
Scientists invent way to make farmed salmon healthier and better for you
Scientists have invented a way to make farmed salmon healthier. Feeding fish with a new type of rapeseed oil, which includes a natural red pigment, makes pink seafood richer in omega-3 oils and filled with more antioxidants, a study has found. The pinkness of a fish, whether shrimp, trout or salmon, comes from consumption of a chemical called astaxanthin, which is produced by some algae in the wild. Wild fish eat this in their diet and become pink as a result, but farmed fish do not and as a result have naturally grey flesh. These fish are therefore fed synthetic versions of this chemical to make the aesthetically pleasing hue consumers desire. But a genetically modified variant of the crop, which is spliced with genes from the scarlet flax flower, creates a plant that naturally produces seeds rich in astaxanthin. DNA, which powers the pigment-making pathway, was injected into the crop's own genome and small batches were grown at trial sites in the US and UK. Published in the Plant Biotechnology journal, data show that in each gram of seed from this new crop, there are 136 micrograms of colourful pigments. More than a third (47 micrograms) is astaxanthin. Giving this to fish in their diet to make them pink, instead of the current synthetic astaxanthin, would make the salmon healthier and better to eat, scientists say. In another experiment by the same scientists at Rothamsted University, oil made from these plants was given to 120 rainbow trout in four tanks. The study was later published in the journal Aquaculture. These animals grew just as big and were richer in health chemicals such as omega-3, the study found. Prof Johnathan Napier, a plant biotechnology pioneer who led the work at Rothamsted, told The Telegraph: 'The plant-based source of the pigment is accumulated and delivers benefits to the fish. 'In particular, it can help reduce the build-up of pro-inflammatory molecules. 'We are also hoping to see if having diets in which the plant-derived astaxanthin is present makes them more resistant to disease (especially lice) and stress – that work is ongoing.' The fish which eat the new oil are healthier, he said, and the humans that eat the fish are also set to benefit from the change. Prof Napier said: 'One would hope that fish being fed this diet would be more healthy [sic],' 'Astaxanthin helps to reduce oxidation, and therefore protects the fish's metabolic state as well as protecting the healthy omega-3s and then we consume and get health benefits for ourselves. 'And there is also an additional potential benefit from having the astaxanthin in your diet, as an antioxidant.' The scientists who invented the new plant used genetic modification techniques to create the astaxanthin-rich rapeseed oil. It is not possible to grow this crop commercially in the UK because the UK still uses the EU legislation prohibiting genetically modified (GM) foods. GM foods are allowed in the US and Prof Napier believes fish and farmers over there will be able to benefit from this new product in less than ten years. Red tape around the use of GM foods in UK agriculture, he believes, is stifling the market and also preventing foods which Prof Napier said: 'Tax revenue is being used to fund millions of pounds' worth of fundamental research in UK universities and institutes. 'But the potential arising from any useful discoveries is not correctly captured or exploited because of regulatory burdens. 'In the specific example of GM crops, we are still lumbered with the EU regulations, so we are double-whammied.'
BBC News
7 hours ago
- BBC News
'There's a huge amount that we don't understand': Why sperm is still so mysterious
How do sperm swim? How do they navigate? What is sperm made of? What does a World War Two codebreaker have to do with it all? The BBC untangles why we know so little about this mysterious cell. With every heartbeat, a man can produce around 1,000 sperm – and during intercourse, more than 50 million of the intrepid swimmers set out to fertilise an egg. Only a few make it to the final destination, before a single sperm wins the race and penetrates the egg. But much about this epic journey – and the microscopic explorers themselves – remains a mystery to science. "How does a sperm swim? How does it find the egg? How does it fertilise the egg?" asks Sarah Martins da Silva, clinical reader of diabetes endocrinology and reproductive biology at the University of Dundee in the UK. Almost 350 years on from the discovery of sperm, many of these questions remain surprisingly open to debate. Using newly developed methods, scientists are now following sperm on their migration – from their genesis in the testes all the way to the fertilisation of the egg in the female body. The results are leading to groundbreaking new discoveries, from how sperm really swim to the surprisingly big changes that occur to them when they reach the female body. "Sperm – or spermatozoa – are 'very, very different' from all other cells on Earth," says Martins da Silva. "They don't handle energy in the same way. They don't have the same sort of cellular metabolism and mechanisms that we would expect to find in all other cells." Due to the huge range of functions demanded of spermatozoa, they require more energy than other cells. Plus sperm need to be flexible, to be able to respond to environmental cues and varying energetic demands during ejaculation and the journey along the female tract, right up until fertilisation. Sperm are also the only human cells which can survive outside the body, Martins da Silva adds. "For that reason, they are extraordinarily specialised." However, due to their size these tiny cells are very difficult to study, she says. "There's a lot we know about reproduction – but there's a huge amount that we don't understand." One fundamental question that remained unanswered over almost 350 years of research: what exactly are sperm? "The sperm is incredibly well-packaged," says Adam Watkins, associate professor in reproductive and developmental physiology at Nottingham University in the UK. "We typically thought of the sperm as a bag of DNA on a tail. But as we've started to realise, it's quite a complex cell – there's a lot of [other] genetic information in there." The science of sperm began in 1677, when Dutch microbiologist Antoni van Leeuwenhoek looked through one of his 500 homemade microscopes and saw what he called "semen animals". He concluded, in 1683, that it wasn't the egg that contained the miniature and entire human, as previously believed, but that man comes "from an animalcule in the masculine seed". By 1685, he had decided that each spermatozoon contains an entire miniature person, complete with its own "living soul". Almost 200 years later, in 1869, Johannes Friedrich Miescher, a Swiss physician and biologist, was studying human white blood cells collected from pus left on soiled hospital bandages when he discovered what he called "nuclein" inside the nuclei. The term "nuclein" was later changed to "nucleic acid" and eventually became "deoxyribonucleic acid" – or "DNA". Aiming to further his studies of DNA, Miescher turned to sperm as his source. Salmon sperm, in particular, were "an excellent and more pleasant source of nuclear material" due to their particularly large nuclei. He worked in freezing temperatures, keeping laboratory windows open, in order to avoid deterioration of salmon sperm. In 1874, he identified a basic component of the sperm cell that he called "protamine". It was the first glimpse of the proteins that make up sperm cells. It took another 150 years, however, for scientists to identify the full protein contents of sperm. Since then, our understanding of sperm has moved on leaps and bounds. But much still remains a mystery, says Watkins. As scientists have started to better understand early embryonic development, he adds, they are realising that sperm doesn't just pass the father's chromosomes on, but also epigenetic information, an extra layer of information that affects how and when the genes should be used. "It can really influence how the embryo develops and potentially the lifelong trajectory of the offspring that those sperm generate," says Watkins. Sperm cells begin to form from puberty onwards, made in vessels within the testicles called seminiferous tubules. "If you look inside the testes where the sperm are made, it starts as just a round cell that looks pretty much like anything else," says Watkins. "Then it undergoes this dramatic change where it becomes a sperm head with a tail. No other cell within the body changes its structure, its shape, in such a unique way." It takes sperm about nine weeks to reach maturity within the male body. Unejaculated sperm cells eventually die and are reabsorbed into the body. But the lucky ones are ejaculated – and then the adventure begins. After ejaculation, each of these tiny cells must propel themselves forward (alongside their 50 million competitors) using their tail-like appendages to swim for the egg. And while you may have seen plenty of videos of tadpole-like sperm swimming around, in fact scientists are only just beginning to understand how sperm really swim. It was previously thought that the sperm's tail – or flagellum – moved side to side like that of a tadpole. But in 2023, researchers at the University of Bristol in the UK found that sperm tails follow the same template for pattern formation discovered by mathematician and World War Two codebreaker Alan Turing. In 1952, Turing realised that chemical reactions can create patterns. He proposed that two biological chemicals moving and reacting with each other could be used to explain some of nature's most intriguing biological pattern formations – including those found in fingerprints, feathers, leaves and ripples in sand – an idea known as his "reaction-diffusion" theory. Using 3D microscopy, the Bristol researchers discovered that a sperm's tail – or flagellum – undulates, generating waves that travel along the tail to drive it forward. This is significant as understanding how sperm move can help scientists to understand male fertility. So, now the sperm are on the move. They travel through the cervix, into the womb and up the oviducts – tubes that eggs travel down to reach the womb, known as the fallopian tubes in human females – in search of the egg. But here we hit another gap in knowledge, because scientists don't fully understand how sperm actually find their way to the egg. Spermatozoa which are healthy and take the right route are rare. Many take a wrong turn in the maze that is the female body – and never even make it near the goal line. For the ones that do find their way to the fallopian tubes, scientists think that they may be guided by chemical signals emitted by the egg. One recent theory is that sperm may use taste receptors to "taste" their way to the egg. Once the sperm find the egg, the challenge is not over. The egg is surrounded by a triplicate coat of armour: the corona radiata, an array of cells; the zona pellucida, a jelly-like cushion made of protein; and finally the egg plasma membrane. The sperm cells have to fight their way through all the layers, using chemicals contained in their acrosome, a cap-like structure on the head of a sperm cell containing enzymes that digest the egg cell coating. However, what prompts the release of these enzymes remains a mystery. Next the sperm use a spike on their "head" to try and break their way in to the egg, thrashing their tails to force themselves forwards. Finally, if one sperm makes contact with the egg membrane, it is engulfed and can complete fertilisation. Human cells are diploid. This means they contain two complete sets of chromosomes, one from each parent. If more than one sperm were to fuse with the egg, a condition called polyspermy would arise. Nondiploid cells – ones with the incorrect number of chromosomes – would develop, a condition lethal to a growing embryo. To prevent this from happening, once a sperm cell has made contact with it, the egg quickly employs two mechanisms. First, its plasma membrane rapidly depolarises – meaning it creates an electrical barrier that further sperm cannot cross. However, this only lasts a short time before returning to normal. This is where the cortical reaction comes in. A sudden release of calcium causes the zona pellucida – the egg's "extracellular coat" – to become hardened, creating an impenetrable barrier. So, of millions of sperm that set out on the journey, only one – at most – gets to do its job. The sperm's epic journey culminates in its fusion with the egg. Today, researchers are still attempting to uncover the identity and role of cell surface proteins that could be responsible for sperm-egg recognition, binding and fusion. In recent years, several proteins have been identified – albeit in mice and fish – as being crucial for this process, but many of the molecules involved remain unknown. So, for now, how the sperm and egg recognise each other, and how they fuse are yet more mysteries that remain unsolved. One way researchers are hoping to shed light on sperm is by studying species other than our own, says Scott Pitnick, a professor of biology at Syracuse University in New York. Human sperm cells are microscopic, so we can't see them with the naked eye. But some fruit fly species produce sperm cells 20 times their own body length. That would be like a man producing sperm the length of a 40m (130ft) python. Pitnick engineers the heads of fruit fly sperm so that they glow. This means he can watch them as they travel through dissected female fly reproductive tracts, revealing new details about fertilisation at the molecular level. "Why do males in some species make a few giant sperm?" asks Pitnick. "The answer, it turns out, is because females have evolved reproductive tracts that favour them." That's "not really much of an answer", he adds, because it's just the redirects the question: why have females evolved this way? "We still don't understand that at all." But it does teach us that sperm as they exist in the male body is only half the story, says Pitnick. "There's a massive sex bias historically in science. There's been this obscenely biased male focus on male traits. But it turns out that what's driving the system is female evolution – and males are just trying to keep up." Sperm, Pitnick says, are the most diverse and rapidly evolving cell type on Earth. Why sperm have undergone such dramatic evolution is a mystery that has stumped biologists for more than a century. "It turns out the female reproductive tract is this incredibly, rapidly evolving environment," says Pitnick, "and we don't know much about what sperm do inside the female. That is the big, hidden world. I think the female reproductive tract is the greatest unexplored frontier for sexual selection, theory and speciation [the process by which new species are formed]." The fruit fly's long-tailed sperm, suggests Pitnick, could be considered an ornament – much like a deer's antlers or a peacock's tail. Ornaments are a "sort of a weapon in evolution", explains Pitnick. More than just a defence from predators, ornaments like antlers and horns often have two roles to play. "A lot of these weapons are about sex, and usually male-male competition. The [fruit fly's] long sperm flagellum really meets the definitional criteria of an ornament. We think the female tract has traits that bias fertilisation in favour of some sperm phenotypes over others." We know a lot about pre-mating sexual selection, Pitnick says. "Say, it's prairie chickens dancing out on a grassland, or a bird of paradise displaying in a rainforest. It's motion, it's colour, it's smells?" Processing this sensory input, explains Pitnick, leads to decision making – whether the pair mate or not. But, Pitnick says, the sexual selection that goes on inside the female after mating – and how this drives the evolution of sperm – largely remains a mystery. "We still understand very little about the genetics of ornaments and preferences," he says. To fully understand sperm, we need to think about how the entire lifecycle of the sperm – and the female body, explains Pitnick, plays a huge role in the sperm's development. "Sperm are not mature when they finish developing in the testes, they're not done developing." Complex – and critical – interactions occur between the sperm and the female reproductive tract, he says. "We're now spending a lot of time studying what we call post-ejaculatory modifications to sperm across the whole animal kingdom." Even as scientists are unravelling the many and varied processes a sperm goes through in order to achieve fertilisation, other research is leading to real concern about the current state of human sperm. Men produce close to a trillion sperm during one lifetime, so it might be hard to imagine that sperm are in trouble. But research suggests sperm counts – the number of sperm in a sample of semen – are tumbling globally and the decline appears to be accelerating. More like this:• How pollution is causing a male fertility crisis• Pre-eclampsia: The deadly mystery scientists can't solve• Fewer than half of IVF cycles are successful. These scientists are trying to change that According to a 2023 report published by the World Health Organisation (WHO), around one in six adults worldwide experience infertility – and male infertility contributes to roughly half of all cases. (It's also worth noting that many people around the world are not having as many children as they want for other reasons too, such as the prohibitive cost of parenthood, as a recent United Nation population Fund report highlighted). Pollution, smoking, alcohol, poor diet, lack of exercise and stress are all thought to impact male infertility. Yet for the majority of men with fertility problems, the cause remains unexplained. (Read more about the decline in sperm quality around the world). "With all those moving parts, there are so many things that could go wrong," says Hannah Morgan, a post-doctoral research associate in maternal and fetal health at the University of Manchester, UK. "It could be a mechanism: it doesn't swim very well, so it can't get to the egg. Or it could be something more intricate within the head of the sperm, or other regions of the sperm. It's so specialised in so many different ways, that lots of little things can go wrong." One way to see if a man may be infertile is to look inside the sperm, says Morgan. "How does the DNA look? How is it packaged? How fragmented is it? To break open the sperm, there's a whole range of stuff you could look at. But what is a good or bad measurement? We don't actually know." Perhaps by unravelling the mystery of sperm and how they function, Morgan says, we might begin to understand male infertility too. -- For trusted insights into better health and wellbeing rooted in science, sign up to the Health Fix newsletter, while The Essential List delivers a handpicked selection of features and insights. For more science, technology, environment and health stories from the BBC, follow us on Facebook, X and Instagram.
Daily Mail
8 hours ago
- Daily Mail
Toilet paper over or under? Scientist FINALLY settles the debate - so, do you agree with their method?
It's a cause of arguments in households around the world. And over 150 years since the toilet roll was invented, the question of how exactly it should be oriented still triggers furious debate. In the 'over' position, the next square of toilet paper is facing the user, while in the 'under' position, the next square of toilet paper is facing the wall. Now, a scientist has settled the debate once and for all. Dr Primrose Freestone, professor of clinical microbiology at the University of Leicester, says the 'under' orientation is actually safer and more effective, despite the image in the original toilet paper patent. The researcher points out that the 'over' method requires a second hand to touch the toilet roll. This increases the risk of the paper being contaminated before it reaches our nether-regions – which in turn means greater risk of infection. 'There is more handling of the toilet roll from the over position,' Professor Freestone told MailOnline. Imagine you are on the toilet doing your business, and the toilet roll is in the 'over' position (with the next square facing you). In this scenario, you need to use one hand to hold the toilet roll to stop it from rotating forward, and the other hand to actually tear off the next bit of paper. In contrast, in the 'under' position, you can pin the next sheet against the wall with one hand as you simultaneously tear it off, according to the academic. So you don't have to use the second hand in the process at all – and the overall risk of transferring hand bacteria to the paper is reduced. Especially for women, accidental transfer of bacteria from the hand to the genital area can increase the risk of infection. And women generally tend to use more paper for men – for number ones and number twos. 'For the under position, there is less likely to be whole roll contamination,' Professor Freestone told MailOnline. 'You can pin the sheets against the toilet wall without having to touch the exterior of the roll.' Why is the 'under' position better for toilet roll? Unlike the 'over' position, the 'under' position (with the next square of toilet paper facing the wall) requires only one hand, not two. When you enter the bathroom, both hands are immediately exposed to high-touch surfaces potentially teeming with harmful bacteria - such as the doorknob and the toilet seat. So using just one hand instead of two, you are at best halving the risk of bacterial transfer from the hand to the toilet paper that you're about to use. Especially for women, accidental transfer of bacteria from the hand to the nether-regions can risk getting an infection. When people enter the bathroom, both hands are immediately exposed to high-touch surfaces likely teeming with harmful bacteria – including the doorknob and the toilet seat. So by touching the paper with just one hand instead of two, we are potentially halving the risk of bacterial transfer from the hand to the unused toilet paper. Of course, both hands have the potential to transfer bacteria onto toilet paper during a bathroom break – but by only using one hand throughout the whole process, we can reduce the risk of this transfer. Also, using two hands risks the spread of bacteria from the wiping hand to the other hand – because they are brought into close proximity to each other. 'If someone who has wiped say once and the faecal matter has soaked through the layers of toilet paper and makes hand contact, the presumably right hand that did the wiping will likely be contaminated,' Professor Freestone said. 'Then that right hand may contaminate anything it touches as the toilet user reaches for more toilet paper which they then fold for wipe two, possibly touching the left hand as it does so.' According to Professor Freestone, her advice is even more pertinent in public toilets, where there may be multiple sites of heavy faecal contamination all over the toilet door, stall and seat. 'This is why it is so important to wash your hands after going to the toilet, and not to eat, drink or use a phone in the toilet, either,' she told MailOnline. Dated 1891, a drawing for US Patent No. 465588A (left) features a toilet roll clearly positioned unmistakably in the over orientation Interestingly, the original patent for toilet paper more than 150 years ago shows a toilet roll in the over, not under, position. The patent from September 15, 1891 was filed by the inventor of perforated toilet paper sheets, New York business man Seth Wheeler. According to various surveys, around 70 per cent of people prefer the over position and 30 per cent the under position. There's also the argument that the under position reduces the chances of a cat or small child from pulling at the toilet paper. But the over position does have alleged advantages, such as giving you more transparency over how many square you are tearing off. When was toilet paper invented? In the 14th century, perfumed paper sheets were 'manufactured' for the Hongwu dynasty, but only the royal family and the imperial court had access to them. Around the same time in Europe, people used rags to clean up after a trip to the loo. Rich Europeans used wool, hemp or even lace. But commoners used whatever cloth they had including their sleeves. The first mention of toilet paper appeared in Europe in the 16th century in a text by French writer Rabelais. In North America, throughout the 1700s, people were still wiping with whatever they had on hand - even seashells. But by the 1800s, paper was becoming more widely available, and finally in 1857, a New Yorker named Joseph Gayetty introduced and first patented toilet paper. He called it 'Medicated Paper for the Water-Closet' and Gayetty's name was printed on every sheet. His medicated paper contained aloe and was sold in packages of 500 sheets for 50 cents. Seth Wheeler of Albany, New York, obtained the earliest US patents for toilet paper rolls and dispensers, dated 1881. Included in the patent, are Seth's declarations on his new product: 'Be it known that I, SETH WHEELER, of the city and county of Albany, and State of New York, have invented certain new and useful Improvements in Toilet-Paper Rolls.'
