Latest news with #HelenFindlay
Yahoo
15-06-2025
- Science
- Yahoo
Ocean Acidity Has Reached Critical Levels, And We're All Under Threat
Ocean acidity is one of the key markers of Earth's health, because if it tips too far towards acidic then the results can be catastrophic – and a new study suggests the world's waters are now entering this danger zone. A team of scientists from the US and UK looked at what's known as the planetary boundary for ocean acidification, defined as a 20 percent drop in average surface aragonite saturation – that's the calcium carbonate material that many marine organisms use for shells and skeletons. Combining computer models with the latest field measurements, the researchers found that globally, the oceans were either very close to or beyond the boundary. Around 60 percent of deeper waters have gone beyond it, and 40 percent of surface waters. Given the damage already recorded, the team suggests the boundary should actually be set at a 10 percent drop in aragonite saturation – a level the ocean as a whole went past at the turn of the millennium. "Looking across different areas of the world, the polar regions show the biggest changes in ocean acidification at the surface," says biological oceanographer Helen Findlay from Plymouth Marine Laboratory (PML) in the UK. "Meanwhile, in deeper waters, the largest changes are happening in areas just outside the poles and in the upwelling regions along the west coast of North America and near the equator." While ocean acidification is not something you'll immediately notice as you gaze out across the sea from the shoreline, it has a profound effect. It damages coral reefs, makes waters inhospitable for shell-building creatures, and kills off or weakens other marine life. That then has a knock-on effect on the rest of the ecosystem. This acidification happens when carbon dioxide is absorbed by the ocean and reacts with water, and so the more greenhouse gases saturate the atmosphere, the more acidic the world's waters are going to become. "Most ocean life doesn't just live at the surface – the waters below are home to many more different types of plants and animals," says Findlay. "Since these deeper waters are changing so much, the impacts of ocean acidification could be far worse than we thought. "This has huge implications for important underwater ecosystems like tropical and even deep-sea coral reefs that provide essential habitats and nursing refuge for many species." Scientists have agreed on eight other planetary boundaries besides ocean acidification, and we've already crossed six of them. Ocean acidification would be the seventh, and shows the dire straits that Earth is now in. The researchers behind this latest study want to see a rapid response to the dangers, with targeted action taken in the areas most vulnerable to acidification – as well as protective measures for those areas that haven't been as badly affected so far. "Ocean acidification isn't just an environmental crisis – it's a ticking time bomb for marine ecosystems and coastal economies," says Steve Widdicombe from PML, who wasn't directly involved in the study. "From the coral reefs that support tourism to the shellfish industries that sustain coastal communities, we're gambling with both biodiversity and billions in economic value every day that action is delayed." The research has been published in Global Change Biology. Emperor Penguins Disappearing Faster Than Worst Estimates, Study Finds World Oceans Day: Scientists Freeze Coral to Save The Great Barrier Reef Volcanic Eruptions Can Create Ice in The Sky, And We Finally Know How
Yahoo
14-06-2025
- Science
- Yahoo
Yikes: We Just Crossed a Planetary Boundary 66 Million Years in the Making
Here's what you'll learn when you read this story: Planetary boundaries outline how far past pre-industrial conditions Earth can get before anthropogenic activity has detrimental effects on the environment. While we have been dangerously close to the ocean acidity boundary for some time, it is now being breached, and the shells of some organisms are dissolving because of chemical reactions that deprive them of calcium carbonate. The boundary for ocean acidity was originally at 20% post-industrial, but researchers have now moved it back to 10% as a call to action before entire ecosystems start to disappear. When the asteroid that triggered the end-Cretaceous Mass Extinction crashed to Earth (and decimated the dinosaurs), it hit rocks that released sulfur and caused pH levels in the oceans to plummet. Ocean acidity levels became intolerable and led to more than half of all marine life dying out. 66 million years later, it's happening again. This time, there is no asteroid—just us humans. Anthropogenic activity such as deforestation and the burning of fossil fuels has released enormous amounts of emissions, primarily in the form of carbon dioxide. That CO2 has caused ocean pH levels to fall off a cliff and has lead to a 30% increase in acidity, which underwater habitats ranging from coral reefs to the deep ocean. The planetary boundary for ocean acidification—the limit of what Earth can tolerate before the onset of destructive consequences—is a 20% drop in the concentration of calcium carbonate (a common base often found in things like limestone and seashells) from pre-industrialization levels. It was already looming by 2020, but until recently, we had not breached. Now, however, researchers at the UK's Plymouth Marine Laboratory (PML) are nervous. In an effort led by biological oceanographer Helen Findlay (who is also Chair off the North East Atlantic Acidification Hub and an Executive Council Member for the Global Ocean Acidification Observing Network), experts found that the ocean acidification boundary had already been crossed by as much as 60% of subsurface ocean waters located 200 meters (about 656 feet) below the surface. 'The planetary boundaries assessment defines nine large scale Earth-system processes and associated boundaries that, if crossed, could generate unacceptable environmental change,' Findlay and her team said in a study recently published in the journal Global Change Biology. Creatures that make their own shells through calcification rely on calcium and carbonate molecules already floating around in the ocean. Too much carbon dioxide can throw off this process. When CO2 is absorbed by seawater, it reacts with water molecules to form carbonic acid (H2CO3), which easily breaks apart into hydrogen (H+) ions and bicarbonate (HCO3-) ions. The lonely hydrogen ions lower the pH of water, and the bicarbonate ions bring their own problems. Species that make their own shells need carbonate ions (CO32-) to bond to calcium, but they can't access them if they're already locked up in bicarbonates. So, as the amount of CO2 in the ocean goes up, the number of available carbonate ions gos down, and the organisms end up in a sticky spot. And the problems don't stop there. As rising temperatures heat up the ocean, warmer oceans hold less oxygen. This warmer water is more buoyant and does not mix as well with deeper, colder and more oxygenated water, so the shorter supply is used up faster. More oxygen breathed in than replenished leads to a deficit of oxygen known as hypoxia. Less oxygen means calcifying organisms have to use more energy to build and maintain their shells, the additional exposure to conditions with low oxygen can be even more dangerous for them. Low enough pH levels can cause shells and exoskeletons to actually dissolve, which is what led Findlay to suggest that the boundary of 20% less calcium carbonate (than existed in pre-industrial times) should be reset to 10%. This adjustment should give the ocean life affected a chance to recover and flourish again. And if carbon emissions continue to rise, thing will continue to look bleaker and bleaker for marine life. A separate but alarming NOAA experiment showed that some species of pteropods—tiny mollusks (also known as sea butterflies for the wing-like appendages they use to swim) that produce their own shells—could soon find themselves unable to maintain the shells they need to survive. In the study, researchers placed pteropod shells in water with carbonate levels adjusted to reflect projected carbonate levels for the year 2100. The shells dissolved after only 45 days. And even in today's oceans, pteropod shells off the coast of Antarctica have already been found to be dissolving. It might seem inconsequential for such small creatures to vanish, but the reality is that pteropods—along with other organisms considered zooplankton—form the base of an extensive food web that could suffer immensely if disrupted. Organisms that do not calcify will feel the effects of ocean acidification in other ways. If there is a significant enough change in ocean chemistry, for example, it will become difficult for some species of fish to detect predators. Findlay also found that the polar oceans have experienced the most significant change at the surface level, but the most unnerving shifts in the subsurface have happened in low-latitude and subpolar regions. If deep-water corals are not able to build exoskeletons, entire ecosystems that depend on them for food and shelter could be wiped out. And ecosystem loss could lead to entire populations ending up isolated in smaller areas where they are more vulnerable to dying out. 'The main advancement lies in shifting from an assessment based primarily on the changing chemistry to a more holistic approach that considers uncertainties, regional variations, subsurface impacts and the biological consequences of exceeding the boundary,' she said. There may be no extinction-level asteroid headed for Earth anytime soon, but if carbon emissions continue at the current rate, we could be creating a lethal asteroid effect of our own. You Might Also Like The Do's and Don'ts of Using Painter's Tape The Best Portable BBQ Grills for Cooking Anywhere Can a Smart Watch Prolong Your Life?
Yahoo
09-06-2025
- Science
- Yahoo
‘Ticking timebomb': sea acidity has reached critical levels, threatening entire ecosystems
The world's oceans are in worse health than realised, scientists have said today, as they warn that a key measurement shows we are 'running out of time' to protect marine ecosystems. Ocean acidification, often called the 'evil twin' of the climate crisis, is caused when carbon dioxide is rapidly absorbed by the ocean, where it reacts with water molecules leading to a fall in the pH level of the seawater. It damages coral reefs and other ocean habitats and, in extreme cases, can dissolve the shells of marine creatures. Until now, ocean acidification had not been deemed to have crossed its 'planetary boundary'. The planetary boundaries are the natural limits of key global systems – such as climate, water and wildlife diversity – beyond which their ability to maintain a healthy planet is in danger of failing. Six of the nine had been crossed already, scientists said last year. However, a new study by the UK's Plymouth Marine Laboratory (PML), the Washington-based National Oceanic and Atmospheric Administration and Oregon State University's Co-operative Institute for Marine Resources Studies found that ocean acidification's 'boundary' was also reached about five years ago. 'Ocean acidification isn't just an environmental crisis – it's a ticking timebomb for marine ecosystems and coastal economies,' said PML's Prof Steve Widdicombe, who is also co-chair of the Global Ocean Acidification Observing Network. The study drew on new and historical physical and chemical measurements from ice cores, combined with advanced computer models and studies of marine life, which gave the scientists an overall assessment of the past 150 years. It found that by 2020 the average ocean condition worldwide was already very close to – and in some regions beyond – the planetary boundary for ocean acidification. This is defined as when the concentration of calcium carbonate in seawater is more than 20% below preindustrial levels. The deeper in the ocean they looked, the worse the findings were, the scientists said. At 200 metres below the surface, 60% of global waters had breached the 'safe' limit for acidification. 'Most ocean life doesn't just live at the surface,' said PML's Prof Helen Findlay. 'The waters below are home to many more different types of plants and animals. Since these deeper waters are changing so much, the impacts of ocean acidification could be far worse than we thought.' This had, she added, huge implications for important underwater ecosystems such as tropical and even deep-sea coral reefs that provided essential habitats and nursery grounds for the young of many species. As pH levels drop, calcifying species such as corals, oysters, mussels and tiny molluscs known as sea butterflies struggle to maintain their protective structures, leading to weaker shells, slower growth, reduced reproduction and decreased survival rates. Related: Surge in marine heatwaves costs lives and billions in storm damage – study The authors underlined that decreasing CO2 emissions was the only way to deal with acidification globally, but that conservation measures could and should focus on the regions and species that were most vulnerable. Jessie Turner, director of the International Alliance to Combat Ocean Acidification, who was not involved in the study, said: 'This report makes it clear: we are running out of time and what we do – or fail to do – now is already determining our future. 'We are coming to terms with an existential threat while grappling with the difficult reality that much suitable habitat for key species has already been lost. It's clear that governments can no longer afford to overlook acidification in mainstream policy agendas,' she said.
Irish Examiner
09-06-2025
- Science
- Irish Examiner
‘Ticking timebomb': Sea acidity at critical levels and threatens entire ecosystems
The world's oceans are in worse health than realised, scientists have said, as they warn that a key measurement shows we are 'running out of time' to protect marine ecosystems. Ocean acidification, often called the 'evil twin' of the climate crisis, is caused when carbon dioxide is rapidly absorbed by the ocean, where it reacts with water molecules leading to a fall in the pH level of the seawater. It damages coral reefs and other ocean habitats and, in extreme cases, can dissolve the shells of marine creatures. Until now, ocean acidification had not been deemed to have crossed its 'planetary boundary'. The planetary boundaries are the natural limits of key global systems – such as climate, water and wildlife diversity – beyond which their ability to maintain a healthy planet is in danger of failing. Six of the nine had been crossed already, scientists said last year. However, a new study by the UK's Plymouth Marine Laboratory (PML), the Washington-based National Oceanic and Atmospheric Administration and Oregon State University's Co-operative Institute for Marine Resources Studies found that ocean acidification's 'boundary' was also reached about five years ago. 'Ocean acidification isn't just an environmental crisis – it's a ticking timebomb for marine ecosystems and coastal economies,' said PML's Professor Steve Widdicombe, who is also co-chair of the Global Ocean Acidification Observing Network. The study drew on new and historical physical and chemical measurements from ice cores, combined with advanced computer models and studies of marine life, which gave the scientists an overall assessment of the past 150 years. It found that by 2020 the average ocean condition worldwide was already very close to – and in some regions beyond – the planetary boundary for ocean acidification. This is defined as when the concentration of calcium carbonate in seawater is more than 20% below pre-industrial levels. The deeper in the ocean they looked, the worse the findings were, the scientists said. At 200 metres below the surface, 60% of global waters had breached the 'safe' limit for acidification. 'Most ocean life doesn't just live at the surface,' said PML's Professor Helen Findlay. 'The waters below are home to many more different types of plants and animals. Since these deeper waters are changing so much, the impacts of ocean acidification could be far worse than we thought.' As pH levels drop, calcifying species such as corals, oysters, mussels and tiny molluscs known as sea butterflies struggle to maintain their protective structures, leading to weaker shells, slower growth, reduced reproduction and decreased survival rates. The authors said decreasing CO2 emissions was the only way to deal with acidification globally, but that conservation measures could and should focus on the regions and species that were most vulnerable. The Guardian
