All living organisms rely on iron as an essential nutrient. In the ocean, iron’s abundance or scarcity means all the difference as it fuels the growth of plankton. A new study from the Woods Hole Oceanographic Institution identifies an unexpectedly large source of iron to the North Atlantic—meltwater from glaciers and ice sheets, which may stimulate plankton growth. This source is likely to increase as melting of the Greenland ice sheet escalates under a warming climate.
With data from 73 ice and sediment core monitoring sites around the world, scientists have recently reconstructed Earth's temperature history back to the end of the last Ice Age. The analysis reveals that the planet today is warmer than it's been during 70 to 80% of the last 11,300 years.
Like the extraterrestrial creature in the movie Alien, the "extremophile" red alga Galdieria sulphuraria can survive brutal heat and resist the effects of toxins. Scientists were previously unsure of how a one-celled alga acquired such flexibility and resilience. But recently they made an unexpected discovery: Galdieria's genome shows clear signs of borrowing genes from its neighbors.
A continental-scale chemical survey in the waters of the eastern U.S. and Gulf of Mexico is helping researchers determine how distinct bodies of water will resist changes in acidity. The study, which measures varying levels of carbon dioxide and other forms of carbon in the ocean. According to the survey, different regions of coastal ocean will respond to an influx of carbon dioxide in different ways.
Researchers steering a remote-controlled submarine around the world's deepest known hydrothermal vents have collected numerous samples from depths reaching more than 3 miles below the sea's surface between the Cayman Islands and Jamaica. They believe that laboratory analysis in the coming months will reveal some new life forms that have evolved in the pitch-black vent areas of the Cayman Trough, where mineral-rich fluid gushes from volcanic chimneys.
When migrating, sockeye salmon typically swim up to 4,000 miles into the ocean and then, years later, navigate back to the upstream reaches of the rivers in which they were born to spawn their young. Scientists have long wondered how salmon find their way to their home rivers over such epic distances. A new study suggests that salmon find their home rivers by sensing the rivers' unique magnetic signature.
Researchers recently found that nitrogen entering the ocean—whether through natural processes or pollution—boosts the growth and toxicity of a group of phytoplankton that can cause the human illness “amnesic shellfish poisoning”. Commonly found in marine waters off the North American West Coast, these diatoms produce a potent toxin called domoic acid. When these phytoplankton grow rapidly into massive blooms, high concentrations of domoic acid put human health at risk if it accumulates in shellfish.
British researchers have unveiled a futuristic Antarctic research base that can move, sliding across the frozen surface to beat the shifting ice and pounding snow that doomed its predecessors. Its builders hope that the Halley VI Research Station, the sixth facility to occupy the site on the Brunt Ice Shelf, can adapt to the unpredictable ice conditions.
In another blow to the "Everything is Everywhere" tenet of bacterial distribution in the ocean, scientists at the Marine Biological Laboratory have found "bipolar" species of bacteria that occur in the Arctic and Antarctic, but nowhere else. And, surprisingly, they found even fewer bipolar species than would turn up by chance if marine bacteria were randomly distributed everywhere.
After years of searching, scientists and broadcasters say they have captured video images of a giant squid in its natural habitat deep in the ocean for the first time. Japanese public broadcaster NHK released photographs of the giant squid this week ahead of Sunday's show about the encounter. The Discovery Channel will air its program on Jan. 27.
In the past week, researchers with the West Antarctic Ice Sheet Divide (WAIS) project, the Whillans Ice Stream Subglacial Access Research Drilling (WISSARD) project and the Pine Island Glacier (PIG) project each announced they had achieved these various milestones. In each case, the successes were based on innovative drilling technologies and promise to open new scientific vistas for Antarctic research.
Atmospheric nuclear testing in the 1950s and 1960s produced significant amounts of uranium-236. This isotope readily dissolves in seawater, giving researchers today the opportunity to investigate ocean currents by monitoring its concentration. Until recent advances in heavy ion mass spectrometry, however, this type of detection was considered impossible.
The rapid retreat of sea ice in the Arctic has attracted the attention of top naval officials who have recently held an Arctic Summit at the Office of Naval Research to discuss their reponse to what will likely be a increased volume of human activity in the region. Although the meeting did not discuss policy, it did highlight the many potential areas of impact, from oil drilling to tourism.
Gaping crevasses that penetrate upward from the bottom of the largest remaining ice shelf on the Antarctic Peninsula make it more susceptible to collapse, according to researchers who spent the last four Southern Hemisphere summers studying the massive Larsen C Ice Shelf. But the team, which used radar technology to study the composition of the ice shelf, also identified structures that contributed to the shelf’s resilience.
Vast amounts of methane are stored under the ocean floor, and anaerobic oxidation of methane coupled to sulfate respiration prevents the release of this gas. Though discovered decades ago, the mechanism for how microorganisms performed this reaction has remained a mystery. According to recent findings, a single microorganism can do this on its own, and does not need to be carried out in collaboration with a bacterium as previously thought.
To keep cellular systems running all cells need fuel. For certain ocean-dwelling microorganisms, methane can be such a fuel. But researchers studying these creatures had previously assumed that the methane they consumed was used as a carbon source. However, recent studies have surprisingly shown that is not the case and will force scientists to reevaluate the microorganisms’ role in inactivating environmental methane.
In the future, warmer waters could significantly change ocean distribution of populations of phytoplankton, tiny organisms that could have a major effect on climate change. Researchers have recently shown that by the end of the 21st century, warmer oceans will cause populations of these marine microorganisms to thrive near the poles and shrink in equatorial waters.
A new NASA study shows that from 1978 to 2010 the total extent of sea ice surrounding Antarctica in the Southern Ocean grew by roughly 6,600 square miles every year, an area larger than the state of Connecticut. However, this growth rate is not nearly as large as the decrease in the Arctic, which has scientists questioning the reasons for the growth. Atmospheric circulation may be one cause.
A research team from the University of California, Santa Barbara and Portland State University has retrieved a sensor containing previously unavailable data about changes in chemistry or acidification in the remote waters of McMurdo Sound in Antarctica. The device collected data through June, when the battery expired in the harsh polar sea.
A U.K. research team has recently determined that the geometry of channels beneath the ice can be a strong control on ice behaviour, temporarily hiding the signals of retreat. The findings, which provide the first simulation of past ice-sheet retreat and collapse over a ten thousand year period in Antarctica, shed new light on what makes ice stable or unstable and will help refine predictions of future ice extent and global sea-level rise, the researchers say.
While the North Pole has been losing sea ice over the years, the water nearest the South Pole has been gaining it. Antarctic sea ice hit a record 7.51 million square miles in September, just days after reports of the biggest loss of Arctic sea ice on record. Climate change skeptics have seized on this example, but scientists say the skeptics are misinterpreting what's happening and why.
Water does not forget, says Prof. Boris Koch, a chemist at the Alfred Wegener Institute for Polar and Marine Research. With the combination of some new techniques, Koch and colleagues can now identify and retrace some of the biomolecular tracks left by living organism. This dissolved organic matter, detectable with mass spectrometry, is one of the largest active, organic carbon reservoirs on earth.
Our greenhouse gas emissions up to now have triggered an irreversible warming of the Earth that will cause sea levels to rise for thousands of years to come, new research has show. The results come from a study which sought to model sea-level changes over millennial timescales, taking into account all of the Earth's land ice and the warming of the oceans.
Emerging from the investigation of a mysterious nitrogen-fixing microbe that has a very small genome, an international team of investigators has found that certain type of photosynthetic bacteria not only provides nitrogen to its host single-cell algae, it appears now to be the most widespread nitrogen-fixing organism in the oceans.
According to a new study that measured the rate at which bacteria in the Gulf of Mexico ate the oil and gas discharged by the broken Deepwater Horizon well, at least 200,000 tons of hydrocarbons were consumed by gulf bacteria over a five month period.