Latest news with #ThomasDavies
Yahoo
2 days ago
- Health
- Yahoo
The Ocean Is Getting Darker, Threatening All That Lives Within
Almost all life in the ocean depends on the upper waters where sunlight filters in, known as the photic zone – but new research suggests this narrow window of valuable marine light is shrinking in oceans worldwide. In the past 20 years, marine scientists have found, more than a fifth of our oceans have been growing darker. Thomas Davies, a marine biologist from the University of Plymouth, and Tim Smyth, a marine biogeochemist from the University of Exeter, noticed that despite growing concerns from scientists about ocean darkening, nobody had really quantified its extent. "There has been research showing how the surface of the ocean has changed color over the last 20 years, potentially as a result of changes in plankton communities," Davies says. "Our results provide evidence that such changes cause widespread darkening that reduces the amount of ocean available for animals that rely on the Sun and the Moon for their survival and reproduction." Pairing NASA satellite data from 2003 to 2022 with numerical modeling, the duo has uncovered a pattern of the photic zone depth – which inherently constrains the habitat for most ocean life – shrinking across the years. The photic zone is the topmost layer of the ocean, where light from the Sun (including that reflected off the Moon) permeates the water. All marine organisms that photosynthesize – seagrasses, kelps, and most essential of all, phytoplanktons – must live in the shallower parts of this layer to harness the Sun's energy. So the many other organisms that depend on these primary producers – like corals, crustaceans, fish, and marine mammals – hang out in the photic zone too. The study found in nearly 10 percent of the world's oceans, the depth of the photic zone has shrunk by more than 50 meters (164 feet). This means that three-dimensional habitat has become a lot smaller, which leads to greater competition for resources. Even worse, in 2.6 percent of the ocean, the photic zone has reduced by more than 100 meters. "The ocean is far more dynamic than it is often given credit for. For example, we know the light levels within the water column vary massively over any 24-hour period, and animals whose behavior is directly influenced by light are far more sensitive to its processes and change," says Smyth. "If the photic zone is reducing by around 50 meters in large swathes of the ocean, animals that need light will be forced closer to the surface, where they will have to compete for food and the other resources they need. That could bring about fundamental changes in the entire marine ecosystem." A few factors affect the depth of the photic zone. Light that hits the ocean in a vertical nosedive, like equatorial rays shining in the middle of the day, can penetrate further into the water, with fewer photons reflecting off the surface. And the less resistance those plunging photons encounter, in the form of suspended sediment and organic matter, the further they can dive. That's why, in clear tropical waters, light can penetrate up to 80 meters deep. When entering the water at an angle, however, more light reflects off the surface, and photons that do break the surface have to travel farther on their way down. This results in a much narrower photic zone at the poles – less than 10 meters deep in some places. This may partially explain why some of the most prominent changes were seen in the photic zones of the Arctic and Antarctic. But sediment and other suspended matter, like algal blooms, make the water more opaque, affecting the depths that light can reach. This is what Davies and Smyth suspect is darkening the world's waters in recent decades. "A combination of nutrient, organic material, and sediment loading near the coasts and changes in global ocean circulation are probable causes of increases in primary and secondary productivity that have reduced light penetration into surface waters," they write in their research paper. In extreme cases, like the recent algal blooms across Australia's Great Southern Reef, a lack of light can lead to mass mortality events. But the world's photic zones aren't only shrinking near the coast, where we would expect excess runoff from human activities to cloud the waters, as is evident in the Baltic Sea and the eastern coasts of England and Scotland. Darkening was also prominent in the Gulf Stream and the poles, where climate change is rapidly changing the natural systems. "We also rely on the ocean and its photic zones for the air we breathe, the fish we eat, our ability to fight climate change, and for the general health and wellbeing of the planet," Davies says. "Taking all of that into account, our findings represent genuine cause for concern." This research was published in Global Change Biology. Your Salad Could Be Carrying Microplastics From Soil Into Your Body UN Warns: High Odds We'll Exceed 1.5°C Temp Rise by 2029 Earth's Crust Is Hiding Vast Reserves of Hydrogen – Here's How We Can Find It
New York Post
4 days ago
- Science
- New York Post
Earth's oceans are growing darker, threatening marine life worldwide: study
Oceans around the globe have become darker over the last two decades, leaving researchers fearful for their marine inhabitants, according to a new study. Professor Thomas Davies of the University of Plymouth said in a study published in the Global Change Biology journal there is growing concern for the marine ecosystem. Advertisement Satellite data from NASA's Ocean Color Web data portal showed 21% of the planet's oceans had darkened between 2003 and 2022. According to Davies, the majority of marine life lives in the photic zones of the ocean, which is where sufficient light penetrates to stimulate photobiological processes. The photic zone, which is 200 meters deep, is where global nutrients and carbon budgets sustain the planetary fish markets. This is the area where light reaches marine life that lives closer to the surface of the ocean. Advertisement These ocean inhabitants rely on both the moonlight and sunlight for hunting, mating, reproduction and other important milestones. 4 Oceans around the planet have been getting darker over the last two decades, which has left researchers fearful as to what will happen to their marine inhabitants. peangdao – 4 New research shows satellite data from NASA's Ocean Color Web data portal reveals that 21% of the planet's oceans had darkened between 2003 and 2022. Getty Images The upper level of the ocean is where microscopic organisms and different types of plankton live. Advertisement With the oceans beginning to darken, it will cause creatures that rely on light to begin moving closer to the surface, potentially creating a cramped living space. Using satellite data and an algorithm-derived measure of the attenuation of light in seawater, Davis was able to measure how deep each photic zone was around the world. 4 Most of marine life lives in the photic zone of the ocean, says Professor Thomas Davies of the University of Plymouth. University of Plymouth Among the darker oceans, 9% of their photic zones were 50 meters more shallow, and 3% of the oceans' photic zones were 100 meters more shallow. Advertisement The reasoning behind the darkening of oceans far offshore is less clear. 4 The photic zone is 200 meters deep, and it is where global nutrients and carbon budgets sustain the planetary fish markets. AP Global warming and changes in ocean currents are thought to be involved in this phenomenon, according to the study. Despite an overall darkening, about 10% of oceans, or 37 million square kilometers, have become lighter over the past 20 years, the study found. It also found that most coastal areas have seen an increase in light. However, the study found that this does not translate into a net reduction in photic zone depth near shorelines. Davies predicts the implications of ocean darkening could be severe for marine food webs, global fisheries and carbon and nutrient budgets.
Yahoo
4 days ago
- Health
- Yahoo
Earth's oceans are growing darker, threatening marine life worldwide: study
Oceans around the globe have become darker over the last two decades, leaving researchers fearful for their marine inhabitants, according to a new study. Professor Thomas Davies of the University of Plymouth said in a study published in the Global Change Biology journal there is growing concern for the marine ecosystem. Satellite data from NASA's Ocean Color Web data portal showed 21% of the planet's oceans had darkened between 2003 and 2022. According to Davies, the majority of marine life lives in the photic zones of the ocean, which is where sufficient light penetrates to stimulate photobiological processes. Rare Colossal Baby Sea Creature Caught On Camera For The First Time The photic zone, which is 200 meters deep, is where global nutrients and carbon budgets sustain the planetary fish markets. Read On The Fox News App This is the area where light reaches marine life that lives closer to the surface of the ocean. These ocean inhabitants rely on both the moonlight and sunlight for hunting, mating, reproduction and other important milestones. Spooky Deep-sea Fish Rarely Seen By Humans Caught On Camera In Shallow Water: 'Nightmare Fuel' The upper level of the ocean is where microscopic organisms and different types of plankton live. With the oceans beginning to darken, it will cause creatures that rely on light to begin moving closer to the surface, potentially creating a cramped living space. Using satellite data and an algorithm-derived measure of the attenuation of light in seawater, Davis was able to measure how deep each photic zone was around the world. Among the darker oceans, 9% of their photic zones were 50 meters more shallow, and 3% of the oceans' photic zones were 100 meters more shallow. The reasoning behind the darkening of oceans far offshore is less clear. Global warming and changes in ocean currents are thought to be involved in this phenomenon, according to the study. Despite an overall darkening, about 10% of oceans, or 37 million square kilometers, have become lighter over the past 20 years, the study found. It also found that most coastal areas have seen an increase in light. However, the study found that this does not translate into a net reduction in photic zone depth near shorelines. Davies predicts the implications of ocean darkening could be severe for marine food webs, global fisheries and carbon and nutrient article source: Earth's oceans are growing darker, threatening marine life worldwide: study
Fox News
4 days ago
- Health
- Fox News
Earth's oceans are growing darker, threatening marine life worldwide: study
Oceans around the globe have become darker over the last two decades, leaving researchers fearful for their marine inhabitants, according to a new study. Professor Thomas Davies of the University of Plymouth said in a study published in the Global Change Biology journal there is growing concern for the marine ecosystem. Satellite data from NASA's Ocean Color Web data portal showed 21% of the planet's oceans had darkened between 2003 and 2022. According to Davies, the majority of marine life lives in the photic zones of the ocean, which is where sufficient light penetrates to stimulate photobiological processes. The photic zone, which is 200 meters deep, is where global nutrients and carbon budgets sustain the planetary fish markets. This is the area where light reaches marine life that lives closer to the surface of the ocean. These ocean inhabitants rely on both the moonlight and sunlight for hunting, mating, reproduction and other important milestones. The upper level of the ocean is where microscopic organisms and different types of plankton live. With the oceans beginning to darken, it will cause creatures that rely on light to begin moving closer to the surface, potentially creating a cramped living space. Using satellite data and an algorithm-derived measure of the attenuation of light in seawater, Davis was able to measure how deep each photic zone was around the world. Among the darker oceans, 9% of their photic zones were 50 meters more shallow, and 3% of the oceans' photic zones were 100 meters more shallow. The reasoning behind the darkening of oceans far offshore is less clear. Global warming and changes in ocean currents are thought to be involved in this phenomenon, according to the study. Despite an overall darkening, about 10% of oceans, or 37 million square kilometers, have become lighter over the past 20 years, the study found. It also found that most coastal areas have seen an increase in light. However, the study found that this does not translate into a net reduction in photic zone depth near shorelines. Davies predicts the implications of ocean darkening could be severe for marine food webs, global fisheries and carbon and nutrient budgets.
Daily Mirror
5 days ago
- Science
- Daily Mirror
Ocean darkening' warning as fifth of the world's waters undergoes transformation
A new study has warned that a significant portion of the world's oceans is undergoing a mysterious process known as "ocean darkening" - and the consequences could be dire A staggering fifth of the world's oceans have plunged into darkness over the past two decades, a dramatic shift that could spell disaster for marine life worldwide. Oceanographic Magazine has reported on a major new study revealing that more than 75 million square kilometres of ocean - including vast coastal areas and open waters - have experienced what experts are chillingly terming "ocean darkening." This process, observed between 2003 and 2022, involves the photic zone - the sunlit upper layers of the ocean where a whopping 90% of all marine life flourishes - shrinking dramatically as less light penetrates the water. Alarmingly, researchers from the University of Plymouth and Plymouth Marine Laboratory report that over 9% of the ocean (an area larger than Africa) has seen photic zones retreat by more than 50 metres, while 2.6% has seen a drop of more than 100 metres. While the full implications remain uncertain, scientists fear it could affect "huge numbers of the planet's marine species and ecosystem services provided by the ocean as a whole.", reports the Express. However, it's not all doom and gloom. Around 10% of global oceans - some 37 million square kilometres - have actually grown lighter over the same period, with changes possibly linked to plankton communities, rainfall, and agricultural runoff. Dr Thomas Davies, Associate Professor of Marine Conservation at the University of Plymouth, explained:. "There has been research showing how the surface of the ocean has changed colour over the last 20 years, potentially as a result of changes in plankton communities. "But our results provide evidence that such changes cause widespread darkening that reduces the amount of ocean available for animals that rely on the sun and the moon for their survival and reproduction." He added: "We also rely on the ocean and its photic zones for the air we breathe, the fish we eat, our ability to fight climate change, and for the general health and wellbeing of the planet. Taking all of that into account, our findings represent genuine cause for concern." The team analysed two decades of satellite data using NASA's Ocean Colour Web, which breaks the global ocean into 9km-wide pixels. Light availability was then calculated using a high-tech algorithm to estimate photic zone depth. Among the most affected areas are the Arctic and Antarctic, and the Gulf Stream, which are already undergoing some of the most dramatic transformations on the planet due to climate change. Closer to home, the UK's waters have seen mixed results. The North Sea, Celtic Sea, parts of the English and Scottish east coasts, Wales, and the Irish Sea have darkened - while the English Channel and northern waters near Orkney and Shetland have brightened. Professor Tim Smyth, from the Plymouth Marine Laboratory, issued a stark warning about the underappreciated dynamism of the ocean: "The ocean is far more dynamic than it is often given credit for. For example, we know the light levels within the water column vary massively over any 24 hour period, and animals whose behaviour is directly influenced by light are far more sensitive to its processes and change." He went on to highlight the potential ecological impact, "If the photic zone is reducing by around 50 metres in large swathes of the ocean, animals that need light will be forced closer to the surface where they will have to compete for food and the other resources they need." Smyth stressed this could precipitate dramatic shifts in marine life: "That could bring about fundamental changes in the entire marine ecosystem." His remarks accompany the publication of a pivotal study, 'Darkening of the Global Ocean', recently featured in Global Change Biology.
