Articles tagged with Anoxia
A new method for the controlled cleavage of carbon-carbon double bonds in alkenes has been developed using CO₂ as an oxygen donor and visible light. This process replaces traditional oxidising substances with a safer and more sustainable approach, yielding ketones and carboxylic acids.
Researchers found that nitrogen oxide production is outpaced by consumption, resulting in little emissions from the Black Sea. The study identified microorganisms responsible for the turnover of this potent greenhouse gas, highlighting the importance of further research on nitrous oxide dynamics in marine environments.
Scientists discovered that tiny anoxic pockets on sand grains can carry out denitrification, a process removing human-derived nitrogen from coastal sands. These microenvironments, created by microbes consuming oxygen, account for up to one-third of total nitrogen loss in silicate shelf sands.
Researchers have refined the timing and duration of Ocean Anoxic Event 1a, an extreme environmental disruption that caused significant extinction among plankton. The study determined OAE 1a lasted for just over 1.1 million years, providing valuable insights into Earth's climate and ocean system.
A University of Maryland-led study found that burying wood in the right environmental conditions can stop its decomposition and help curb carbon dioxide emissions. The researchers analyzed a 3,775-year-old log and surrounding soil, revealing that it had lost less than 5% carbon dioxide thanks to the low-permeability clay soil.
Researchers found a link between ancient ocean oxygen depletion and the massive extinction of marine species during the Jurassic Period. The study provides insights into how human-made carbon emissions may lead to similar extinctions in the future.
Scientists from the University of Copenhagen have found that a chain reaction involving phosphorus recycling played a key role in ancient ocean anoxia. This self-amplifying loop led to rapid and prolonged marine anoxia, which could still pose a threat today due to human activities influencing nutrient dynamics.
A study published in Global Change Biology found that low deep-water oxygen concentrations lead to increased algae growth and further oxygen declines. This positive feedback cycle can result in frequent algal blooms, disrupting lake ecosystems and human health.
Scientists have identified key stages in the 'wave of death' - a high-amplitude wave that marks the transition to complete brain silence after oxygen deprivation. The study found that this critical event induces neuronal death throughout the cortex and can be reversible with timely resuscitation.
Researchers analyzed over 24 million assault-related injuries and found that 40% resulted in anoxia, with IPV accounting for 30-40% of neck contusions. The study aims to raise awareness of strangulation among medical providers and advocate for comprehensive screening in IPV patients.
Scientists found that oceanic deoxygenation played a significant role in the Triassic–Jurassic mass extinction, leading to widespread ecosystem disruption and species extinctions. The global extent of deoxygenation was surprisingly similar to today's levels.
The study reconstructs a nearly continuous record of marine oxygen levels through the Phanerozoic using a machine learning approach. Oxygen levels in deep continental shelf seawater were negatively correlated with the production rate of the oceanic crust over timescales of 10–100 million years.
Researchers studied ancient sediment and microfossils to understand the Ocean Anoxic Event 2 (OAE2), a significant environmental disruption that choked oxygen from oceans. The team proposes a new hypothesis for the Plenus Cold Event, which briefly interrupted intense greenhouse temperatures due to ocean acidification.
Rondaxe Lake's experience is just one of thousands worldwide as lakes lose oxygen due to warming, leading to conditions like hypoxia and anoxia. This phenomenon, exacerbated by seasonal stratification, threatens aquatic life and ecosystems.
A new study by researchers at University of California - Riverside found that the position of continents can have a devastating effect on deep ocean creatures. Continental movement can cause a sudden collapse in global water circulation, leading to a stark separation between oxygen levels in the upper and lower depths.
A recent study reveals that massive carbon emission during the Late Paleozoic Ice Age led to anoxic areal extent equivalent to 20% of the seafloor and significant biodiversity loss. The research team used geochemical signals, sedimentology, and climate modeling to simulate the effects of a 300,000-year warming event.
A new study describes a period of rapid global warming in an ice-capped world 304 million years ago, resulting in atmospheric carbon dioxide levels doubling and oceans becoming anoxic. Biodiversity dropped on land and at sea, with about 23% of the seafloor worldwide becoming anoxic dead zones.
Eukaryotes emerged in an anoxic environment in the ocean, and their mitochondria-bearing cells likely resulted from a merger between archaea and bacteria. This finding contradicts the long-held view that oxygenation of Earth's surface environment led to eukaryogenesis.
A new Stanford University study suggests that rising oxygen levels may have slowed down ancient ocean extinctions. The research found that oxygen levels beyond 40% of present atmospheric levels expanded viable ocean habitat and reduced extinction rates. This discovery has implications for understanding the fate of ocean creatures in to...
A recent study found that ancient oceans were more resilient to climate change than previously thought, with limited expansion of seafloor anoxia during the Paleocene Eocene Thermal Maximum. However, current human activities are expected to drive more rapid and expansive oxygen loss due to higher carbon emissions and nutrient pollution.
Researchers have discovered that ocean anoxic zones, which lack dissolved oxygen, are teeming with life and play a crucial role in the Earth's carbon cycle. The study found that microbes can still eat organic carbon but respiring sulfate, known as cryptic sulfur cycling, leading to more organic carbon deposits in sediments.
Researchers found that certain species of foraminifera can survive and thrive in anoxic environments with high levels of toxic hydrogen sulfide. The organisms exploit soluble organic material as a source of carbon and energy, playing a crucial role in anaerobic nutrient cycles.
Researchers from the University of Montana's Flathead Lake Biological Station have unlocked a mystery surrounding unique aquatic insects in the Flathead watershed. Subterranean stoneflies have been found to survive in low-oxygen environments, and their DNA has revealed a possible mechanism for this adaptation.
A new study by Stanford researchers links the Late Ordovician Mass Extinction to ocean deoxygenation, revealing severe and prolonged anoxic conditions. The findings suggest that low oxygen levels in modern oceans will put strain on many organism types, potentially leading to extinction.
Hagfish hearts can pump for 36 hours without oxygen, a phenomenon that could inspire new strategies for protecting the human heart during anoxia. Researchers found that glycerol enhances heart contraction during anoxia, raising questions about its role in hagfish physiology.
Researchers from Arizona State University study the Ediacaran-Cambrian transition and find a severe marine anoxic event coincided with the decline of early animals. The team integrated geochemical data and fossil records to precisely match evolutionary and environmental events, shedding light on this pivotal moment in Earth's history.
A team of researchers led by Maya Elrick found that a global marine anoxic event occurred during the Late Ordovician Mass Extinction, which lasted for at least 1 million years and coincided with the extinction of 85% of marine life. The study suggests that low oxygen concentrations in the ocean were a major driver of the mass extinction.
Researchers found a prolonged ocean anoxic event worldwide during the Late Ordovician mass extinction, coinciding with peak glaciation and suggesting global cooling may have driven ocean anoxia. This finding could support the theory that global cooling played a role in triggering the LOME.
Researchers discovered that ocean anoxia, a decrease in dissolved oxygen, played a key role in the Permian-Triassic mass extinction. The team's new technique allowed them to analyze uranium isotopes in carbonates, providing insights into global anoxia and its link to climate change.
Scientists developed a method to quantify past oxygen depletion in oceans using thallium isotope composition of ancient seafloor sediments. The analysis suggests up to half of the deep ocean was oxygen-depleted during Oceanic Anoxic Event 2, with modern trends showing similar rates of deoxygenation.
A recent study published in Science Advances estimated that up to half of the deep ocean became oxygen-depleted during Oceanic Anoxic Event 2, lasting for about half a million years. The researchers suggest that increased nutrient delivery fueled the production of organic matter, leading to oxygen loss.
A recent fossil site discovery reveals that low oxygen levels during the Early Jurassic led to a stressed marine ecosystem, with only a few species surviving. The study tracks how this event impacted local communities, including a collapse of fish populations and changes in species composition.
Scientists from the University of Exeter found that a 183 million-year-old oceanic oxygen depletion event ended after one million years due to increased atmospheric oxygen and rising fire activity. This study highlights the critical need to limit carbon emissions to prevent future anoxic events in the modern ocean.
A international research team has discovered a new biogeochemical process that explains the removal of dissolved iron from seawater in oxygen minimum zones. This process, which involves the reaction of iron with nitrate instead of oxygen, is essential for understanding nutrient availability and carbon fixation in the oceans.
Scientists have discovered that iron-rich, low oxygen waters played a key role in delaying the recovery of life on Earth after the Permian-Triassic Boundary extinction. The study found that while toxic sulphides were not present, the oceans were rich in iron, which restricted marine life recovery.
A new study suggests that estuaries like the Chesapeake Bay could be a significant source of atmospheric methane, potentially more so than previously thought. Methane release is linked to eutrophication and anoxia in these bodies of water.
A study on Caenorhabditis elegans reveals that mothers who experienced normoxic conditions early on tend to provision their young with more glycogen, equipping the embryos with tools to survive oxygen deprivation. This adaptation leads to improved hatchability and survival rates in offspring.
Low oxygen levels hampered life's recovery after the Permian-Triassic extinction, which wiped out 90% of species. Oxygen levels didn't return to pre-extinction levels until 5 million years later, when climate stability increased.
A new study found evidence of metazoans living in anoxic conditions using fluorescent tags and reproductive structures. However, no metazoans were alive or reproducing in the deepest part of the interface zone with minimal oxygen.
Researchers discovered that peat soils can act like gigantic batteries, using humic substances to accept electrons under anoxic conditions. When oxygen enters, these substances release electrons to oxygen, thereby regenerating their capacity to accept electrons and suppressing methane formation.
A new study links the end-Ordovician mass extinction to nutrient-driven anoxia in the global ocean. The research overthrows century-old knowledge on why marine animals faced their first major challenges, highlighting the tight coupling between life evolution and oxygen dynamics.
Researchers from Arizona State University developed a new geochemical technique to study the Earth's largest mass extinction event. The study found that the period of oceanic anoxia was much shorter than previously estimated, occurring at most tens of thousands of years before the extinction event.
Researchers found evidence of oxygen-poor ocean conditions lasting 2-4 million years after the first appearance of animals, suggesting fluctuating oxygen levels may have driven rapid evolutionary turnover during the Cambrian Period. This study provides new insights into how early life evolved and flourished on Earth.
Researchers found evidence of ancient ocean 'dead zones,' where oxygen levels were low, around 499 million years ago. This challenges the long-held assumption that oceans became oxygen-rich about 600 million years ago. The findings suggest that fluctuations in oxygen levels may have played a major role in shaping early animal evolution.
A new species of small fish, the bearded goby, has been found to eat jellyfish and thrive in an oxygen-depleted zone off the coast of southwest Africa. This unexpected predator-prey relationship puts jellyfish back into the food cycle.
Researchers have discovered small animals in the Mediterranean Sea that live their entire lives without oxygen and reproduce despite a complete absence of oxygen. These multicellular organisms possess organelles resembling hydrogenosomes found in anaerobic environments, challenging our current understanding of life on Earth.
Recent studies have shed new light on explosive volcanic eruptions in the ocean, a 300-million-year-old forest from the Andes, and innovative methods for dating sedimentary rocks. Researchers have discovered a unique eruption style dubbed 'Poseidic,' characterized by uninterrupted magma ascent, while fossil evidence supports an ecologi...
Researchers found glycolytic oscillations increase damage to heart during anoxia and ischemia. The study used a technique to image heart muscle cells with fluorescent dyes during severe anoxia.
Researchers studied organic carbon-rich sediments from an ancient seabed to learn about a devastating event when oxygen levels in the oceans dropped so low that one-third of marine life died. The studies found that volcanic activity triggered a biogeochemical cascade, leading to a decrease in atmospheric carbon dioxide levels.
The study found a significant decrease in delivery-related perinatal deaths in term infants, with a 38% reduction in overall mortality rates. The largest contributor was a decline in oxygen deprivation cases, which dropped by 48%.
A team of scientists from NOAA and Oregon State University have discovered widespread areas of low-oxygen water off the northwest coast, which may be causing deaths of marine animals that cannot escape. The study suggests that these conditions are associated with coastal upwelling and plankton production.
The study found that crucian carp store vast amounts of glycogen in their brain to survive anoxia, with levels reaching 15 times higher in February than July. This adaptation allows them to extend their survival time without oxygen by 150-fold.
The carp's extraordinary ability to adapt to low oxygen conditions allows it to thrive in environments where other fish would perish. Researchers have discovered that its blood has a higher affinity for oxygen than any other vertebrate, enabling the fish to maintain physical activity while oxygen supplies are limited.
Scientists discovered that massive underground coalfields, burned during the Toarcian Oceanic Anoxic Event, triggered a period of intense global warming and mass extinction. The new research sheds light on the consequences of current carbon-based fuel consumption.
Turtles have a natural mechanism to shut off energy-utilizing activities during anoxia, unlike humans. The discovery reveals potential targets for improving outcomes of cerebral stroke and cardiac infarct, as well as developing better anesthetics.
Researchers suggest that hydrogen sulfide gas, produced in the oceans through sulfate decomposition by sulfur bacteria, could have caused the largest mass extinction. The high levels of hydrogen sulfide would be toxic to most oceanic and terrestrial organisms, leading to a significant loss of life.