Shrinking to survive: Clownfish adapt to climate change by getting smaller
The researcher, who focuses extensively on these questions of size, recently made a surprising discovery: Clownfish can shrink during marine heatwaves, which increases their short-term chances of survival.
To obtain these results, published Thursday, May 22, in Science Advances, the researchers donned their wetsuits to observe breeding pairs of Pacific clownfish living in the coral reefs of Kimbe Bay, Papua New Guinea. At that time, between February and August 2023, a severe global coral bleaching event was underway, during which sea temperatures in the study area exceeded 32°C.
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France 24
a day ago
- France 24
Restoring sea floor after mining may not be possible, researchers warn
One of the last wild zones on the planet, the sea floor is a coveted frontier for companies and countries eager to access minerals that are in high demand for emerging technologies such as electric cars. Particularly coveted are potato-sized nodules containing cobalt, nickel, copper and manganese, that are found in abundance on the seabed in the central Pacific Ocean. Companies eager to vacuum up these polymetallic nodules say they can do it with minimal risk to the deep-sea environment. But ocean defenders have battled against what they see as the advent of an industry that will threaten isolated ecosystems that are not yet well understood. That threat was underscored by European scientists who presented findings this week on the sidelines of a meeting in Kingston, Jamaica of the International Seabed Authority, which is trying to finalize future rules for seabed mining. "If we remove nodules from the seabed, we do not know what we lose, only that it's lost forever," was one of the conclusions of DEEP REST, a sea floor conservation research project. The DEEP REST study cautioned against using seabed restoration "as a management action for impacted habitats." "So far, all the restoration operations we have attempted within our DEEP REST project have been short-term. And what we observed, is that in the given time, that is to say a few years, the ecosystems do not recover," said Jozee Sarrazin, a researcher at the French Institute for Ocean Science, or Ifremer. "If restoration is possible, it will take a very long time, and at the moment we don't have the data to be able to say if that will be 100 years or 1000 years," the DEEP REST coordinator told AFP. Despite the pressure, the cold, the total darkness, and the lack of nutrition sources at the bottom of the ocean, it is teeming with life. The number of species who live on the deep seabed is not yet known but estimated to be in the millions. Soft corals, sea anemone Broad swathes of the Pacific Ocean where polymetallic nodules are found shelter fauna such as sponges, soft corals or sea anemones. The fauna "only exists in these areas because they need the hard substrate of the nodule to attach," said Matthias Haeckel of the German research center GEOMAR, which presented results of the MiningImpact project in Kingston this week. Vacuuming up these nodules and spreading sediment over the impacted areas reduces population densities, biodiversity and the functioning of ecosystems, MiningImpact's study found. "To make the story short, in the end, we're talking about recovery times of thousands of years," Haeckel said. The nodules themselves form over millions of years. Some research on restoration efforts is underway but the results are not yet in. "We designed artificial nodules made of deep-sea clay and we placed them at different sites" at depths of about 4,500 meters (14,700 feet), Sabine Gollner, a biologist at the Royal Netherlands Institute for Sea Research, told AFP. "But when you take into account the slow growth rates in the deep sea, the slow processes, it will take quite some more years to find out if restoration is effective and to what degree," she said. Massive deposits of sulfide -- a type of mineral deposit found in underwater vents that spit out seawater heated by magma -- should be off-limits, the researchers suggest. These types of underwater geysers are teeming with astonishing and unique biodiversity. "If we extract massive sulfides near active vents, we know what we lose, and we must prevent loss," the DEEP REST study says. But according to Gollner, it would be good to incorporate restoration goals into the mining code being negotiated by the International Seabed Authority's member states. "It's good to include it but with a clear statement that at this moment in time, it cannot be taken into account to reach agreed environmental goals," she said. "For example, a contractor shouldn't be allowed to use that argument to mine a larger area." © 2025 AFP
Euronews
4 days ago
- Euronews
Healthy babies born in UK using DNA from three people
In a groundbreaking advance, eight healthy babies have been born in the UK using a revolutionary technique that combines DNA from three different people to prevent the inheritance of rare and often fatal genetic diseases. It's an innovation made possible by a 2016 change in British law. Though banned in the United States and many other countries, the technique is also permitted in Australia. The news 'marks an important milestone,' said Dr. Zev Williams, who directs the Columbia University Fertility Centre but was not involved in the work. 'Expanding the range of reproductive options will empower more couples to pursue safe and healthy pregnancies'. Why mitochondrial diseases are so dangerous Most of our DNA comes from the nucleus of a cell, inherited from both mother and father. But there's also some DNA outside of the cell's nucleus, in structures called mitochondria - tiny energy-producing structures that come only from the mother. When mitochondrial DNA carries dangerous mutations, it can lead to severe and often untreatable conditions in children, from seizures and muscle weakness to organ failure and early death. Screening embryos during IVF can sometimes detect these mutations - but not always. As a result of these rare and uncertain cases, scientists have been developing a pioneering workaround: replacing the mutated mitochondria with healthy ones from a donor egg. The mother's genetic material is extracted and inserted into a donor egg that has had its own nucleus removed, keeping the donor's mitochondria intact but none of her traits. The resulting embryo contains DNA from three people: the mother, the father, and a third-party mitochondrial donor. Outcomes and early results from the UK study Researchers from Newcastle University in the UK and Monash University in Australia, writing in the New England Journal of Medicine, reported that they applied the technique to embryos from 22 women. Eight healthy babies have been born so far, and one woman remains pregnant. One of the babies showed slightly elevated levels of abnormal mitochondria - but not high enough to cause disease, experts say. Still, doctors will continue to monitor development. Dr. Andy Greenfield, a reproductive health expert at the University of Oxford, called the work 'a triumph of scientific innovation,' and said the method of exchanging mitochondria would only be used for a small number of women for whom other ways of avoiding passing on genetic diseases, like testing embryos at an early stage, was not effective. While the term 'three-parent baby' makes headlines, the amount of donor DNA involved is tiny - less than 1 per cent of the child's genome. "If you had a bone marrow transplant from a donor... you will have much more DNA from another person,' noted stem cell expert Robin Lovell-Badge. So far, 35 families in the UK have been approved to use the technique, which is closely regulated. Critics have voiced concerns over the long-term effects of heritable genetic changes, which is partly why the US currently prohibits clinical research into such methods. Federal restrictions have blocked the FDA from even considering applications involving embryos altered in this way But for families like Liz Curtis', the technique offers something they never had before: hope. Her daughter Lily died of a mitochondrial disease in 2006 at just eight months old. She said the diagnosis 'turned our world upside down, and yet nobody could tell us very much about it, what it was or how it was going to affect Lily.' Curtis later founded the Lily Foundation in her daughter's name to raise awareness and support research into the disease, including the latest work done at Newcastle University. 'It's super exciting for families that don't have much hope in their lives,' Curtis said.
Euronews
08-07-2025
- Euronews
How climate change is threatening your glass of milk
A single day of extreme heat can cut milk production by 10 per cent. And it doesn't stop there – the effects of heat stress on dairy cows can linger for more than a week. That's the finding from a comprehensive assessment of how rising global temperatures affect livestock, published this week in Science Advances. Researchers focused on Israel, considered one of the world's most innovative dairy-producing countries because of its high milk production per cow and use of advanced technologies. Even there, widespread adoption of fans, ventilation and water-spraying systems only mitigated half the losses – and less on the hottest days. 'Even the most high-tech, well-resourced farms are deploying adaptation strategies that may be an insufficient match to climate change,' co-author Eyal Frank said in a release. What happens to cows during high heat? The research team tracked more than 130,000 cows over 12 years, using detailed weather records and farm surveys. The threshold for heat stress quickly became clear. When 'wet-bulb' temperatures exceed 26°C, milk yields begin to fall steeply. Unlike ambient air temperature, wet-bulb readings reflect the humidity present on especially hot days. Cows exposed to these muggy conditions – an effect the researchers compared to a 'steam bath' – can need more than 10 days to recover fully. While nearly all farms in the study had invested in some form of cooling, the systems proved only partly effective. At a wet-bulb temperature of 20°C, cooling cut losses in half. At 24°C, that figure dropped to 40 per cent. Still, the cooling equipment paid off. It took just 18 months on average for farmers to pay back the costs of installing the equipment. Global losses and uneven impacts Using the Israeli data as a benchmark, the researchers modelled future losses in the world's top 10 dairy-producing countries. Without cooling, average daily milk yields could decline by 4 per cent by the middle of the 21st century. But India, Pakistan and Brazil are expected to see steeper drops – as much as 4 per cent per cow per day. Even with cooling, these countries could still lose 1.5 to 2.7 per cent of their milk yields. For low-income farmers and producers in hot climates, the costs of adaptation may be unaffordable. 'Adaptation is costly, and farmers need to carefully balance the benefits they obtain versus the costs. This is why we see some investment in cooling measures, but not a complete insulation of cows from their environment, which would be far too costly to implement,' said Ayal Kimhi, associate professor at the Hebrew University of Jerusalem. And milk itself isn't the only concern. Heat stress affects animalwell-being and behaviour in several ways, fromfertility patterns to their ability tosurvive at all. Farmers are already on the front lines Extreme weather is no longer a distant threat for farmers. Around the world, producers are already battling more frequent floods, heatwaves and unpredictable rainfall. In Europe, rural farmers have voiced support for green policies, citing the impact they have witnessed on crop yields and their daily lives. Some have described themselves as the 'first affected' by climate change. Climate-linked disruptions have also put some of Europe's favourite crops – including cocoa, coffee and wheat –at risk. Evenbananas, a global kitchen staple, are under pressure, as flooding, heat and degraded soils shrink suitable growing regions. Milk may be next. Even though cows are particularly vulnerable to heat, most countries are not adequately preparing for livestock losses or supporting the farmers most at risk, according to the study's authors. They warn that future-proofing dairy production will depend not just on better cooling systems, but on broader reforms, from improved animal welfare to policy support that helps farmers in hot, low-income regions to adapt. 'Policymakers should look into more strategies to not only cool cows but reduce stressors, like confinement and calf separation,' said lead author Claire Palandri. 'Stressors make cows more sensitive to heat and less resilient.' Without faster action, the effects of climate change won't just reshape what farmers grow. They could also upend what we eat and drink. 'Climate change will have wide-ranging impacts on what we eat and drink,' said Frank. 'Including that cold glass of milk.'
