An unusual microorganism discovered in the open ocean forces scientists to rethink their understanding of how carbon and nitrogen cycle through ocean ecosystems…

An unusual microorganism discovered in the open ocean may force scientists to rethink their understanding of how carbon and nitrogen cycle through ocean ecosystems. A paper describing the new findings appears in the November 14 issue of the journal Science.

A research team led by Jonathan Zehr, a marine scientist at the University of California, Santa Cruz, characterised the new microbe by analysing its genetic material, even though researchers have not been able to grow it in the laboratory.

Zehr said that the newly described organism seems to be an atypical member of the cyanobacteria, a group of photosynthetic bacteria formerly known as blue-green algae.

"This research has revealed a big surprise about the microbiology of the oceans, and the complex integration of the ocean's nitrogen and carbon cycles," said Philip Taylor, section head in the National Science Foundation (NSF)'s Division of Ocean Sciences, which funded the work.

"The fact that nitrogen fixation in these abundant unicells is decoupled from photosynthesis is intriguing," said Taylor. "This unique adaptation brings up questions about the role of these abundant microbes in the ocean."

Unlike all other known free-living cyanobacteria, this one lacks some of the genes needed to carry out photosynthesis, the process by which plants use light energy to make sugars out of carbon dioxide and water.

The mysterious microbe can do something very important, though: It provides natural fertilizer to the oceans by "fixing" nitrogen from the atmosphere into a form useable by other organisms.

"For it to have such an unusual metabolism is very exciting," Zehr said. "We're trying to understand how something like this can live and grow with so many missing parts."

Earlier research by Zehr's group had revealed surprisingly large numbers of novel nitrogen-fixing cyanobacteria, including the one that is the focus of this study, in the open ocean.

Although 80 percent of Earth's atmosphere is nitrogen, most organisms cannot use it unless it is "fixed" to other elements to make molecules like ammonia and nitrate. Because nitrogen is essential for all forms of life, nitrogen fixation is a major factor controlling overall biological productivity in the oceans.

The new microbe is one of the most abundant nitrogen fixers in many parts of the ocean, Zehr said.

New DNA sequencing technology provided by 454 Life Sciences enabled rapid sequencing of the organism's genome. "I had begun to suspect that there was something missing in this organism's genome, and the genome sequencing confirmed that," said Zehr. The results showed that it is missing the entire set of genes needed for photosystem II and carbon fixation, essential parts of the molecular machinery that carries out photosynthesis in plants and cyanobacteria.

"That has multiple implications," Zehr said. "It must have a 'lifestyle' that's very different from other cyanobacteria. Ecologically, it's important to understand its role in the ecosystem and how it affects the balance of carbon and nitrogen in the ocean."

During photosynthesis, photosystem II generates oxygen by splitting water molecules. Because oxygen inhibits nitrogen fixation, most nitrogen-fixing cyanobacteria only fix nitrogen at night, or do it in specialised cells. The lack of photosystem II enables the new microbe to fix nitrogen during the day, Zehr said.

But without photosynthesis, it can't take carbon dioxide from the atmosphere and convert it into sugars. So it's not clear how the new microbe feeds itself. Either it has some way of feeding on organic matter in its environment, or it lives in close association with other organisms that provide it with food, Zehr said.

"It would make a perfect symbiont because it could feed nitrogen to its host and live on the carbon provided by the host," he said. Photosystem II is large complex of multiple proteins and chlorophyll molecules, but the team was unable to find any of the genes for the photosystem II core proteins. The genes for photosystem I appeared in the sequencing data, as did genes for both photosystems from the small numbers of contaminating cyanobacteria in the sample.

Zehr said that he plans to continue research on the new microbe and fill some gaps in the present knowledge. Efforts are currently underway to map the microbe's presence in the oceans and determine its global abundance. Zehr is also interested in how its metabolism differs from other known cyanobacteria. If it can be cultured, there may be ways to exploit this organism's unusual metabolism in biotechnology applications, he said.

Hubble Space Telescope has taken the first visible-light snapshot of a planet circling another star which has been a candidate for planet hunting ever since an excess of dust was discovered around the star in the early 1980s

NASA's Hubble Space Telescope has taken the first visible-light snapshot of a planet circling another star. Estimated to be no more than three times Jupiter's mass, the planet, called Fomalhaut b, orbits the bright southern star Fomalhaut, located 25 light-years away in the constellation Piscis Australis, or the "Southern Fish". Fomalhaut has been a candidate for planet hunting ever since an excess of dust was discovered around the star in the early 1980s by NASA's Infrared Astronomy Satellite, IRAS.

In 2004, the coronagraph in the High Resolution Camera on Hubble's Advanced Camera for Surveys produced the first-ever resolved visible-light image of the region around Fomalhaut. It clearly showed a ring of protoplanetary debris approximately 21.5 billion miles across and having a sharp inner edge.This large debris disk is similar to the Kuiper Belt, which encircles the solar system and contains a range of icy bodies from dust grains to objects the size of dwarf planets, such as Pluto.

Hubble astronomer Paul Kalas, of the University of California at Berkeley, and team members proposed in 2005 that the ring was being gravitationally modified by a planet lying between the star and the ring's inner edge. The sharp inner edge of the ring is also consistent with the presence of a planet that gravitationally "shepherds" ring particles. Independent researchers have subsequently reached similar conclusions.

Now, Hubble has actually photographed a point source of light lying 1.8 billion miles inside the ring's inner edge. Observations taken 21 months apart by Hubble's Advanced Camera for Surveys' coronagraph show that the object is moving along a path around the star, and is therefore gravitationally bound to it. The planet is 10.7 billion miles from the star, or about 10 times the distance of the planet Saturn from our sun.

The planet is brighter than expected for an object of three Jupiter masses. One possibility is that it has a Saturn-like ring of ice and dust reflecting starlight. The ring might eventually coalesce to form moons. The ring's estimated size is comparable to the region around Jupiter and its four largest orbiting satellites.

Future observations will attempt to see the planet in infrared light and will look for evidence of water vapour clouds in the atmosphere. This would yield clues to the evolution of a comparatively newborn 100-million-year-old planet. NASA's James Webb Space Telescope, scheduled to launch in 2013 will be able to make coronagraphic observations of Fomalhaut in the near- and mid-infrared. Webb will be able to hunt for other planets in the system and probe the region interior to the dust ring for structures such as an inner asteroid belt.

Water vapour is known to be the Earth's most abundant greenhouse gas, but the extent of its contribution to global warming has been debated. Using recent NASA satellite data, researchers have estimated more precisely...

Water vapour is known to be the Earth's most abundant greenhouse gas, but the extent of its contribution to global warming has been debated. Using recent NASA satellite data, researchers have estimated more precisely than ever the heat-trapping effect of water in the air, validating the role of the gas as a critical component of climate change.

Andrew Dessler, Texas, confirmed that the heat-amplifying effect of water vapour is potent enough to double the climate warming caused by increased levels of carbon dioxide in the atmosphere.

With new observations, the scientists confirmed experimentally what existing climate models had anticipated theoretically. The research team used novel data from the Atmospheric Infrared Sounder (AIRS) on NASA's Aqua satellite to measure precisely the humidity throughout the lowest 10 miles of the atmosphere. That information was combined with global observations of shifts in temperature, allowing researchers to build a comprehensive picture of the interplay between water vapour, carbon dioxide, and other atmosphere warming gases.

"Everyone agrees that if you add carbon dioxide to the atmosphere, then warming will result," Dessler said. "So the real question is, how much warming?"

The answer can be found by estimating the magnitude of water vapour feedback. Increasing water vapour leads to warmer temperatures, which causes more water vapour to be absorbed into the air. Warming and water absorption increase in a spiralling cycle.

Water vapour feedback can also amplify the warming effect of other greenhouse gases, such that the warming brought about by increased carbon dioxide allows more water vapour to enter the atmosphere. "The difference in an atmosphere with a strong water vapour feedback and one with a weak feedback is enormous," Dessler said.

Climate models have estimated the strength of water vapour feedback, but until now the record of water vapour data was not sophisticated enough to provide a comprehensive view of how water vapour responds to change in Earth's surface temperature. That's because instruments on the ground and previous space-based could not measure water vapour at all altitudes in Earth's troposphere - the layer of the atmosphere that extends from Earth's surface to about 10 miles in altitude.

AIRS is the first instrument to distinguish differences in the amount of water vapour at all altitudes within the troposphere. Using data from AIRS, the team observed how atmospheric water vapour reacted to shift in surface temperatures between 2003 and 2008. By determining how humidity changed with surface temperature, the team could compute the average global strength of the water vapour feedback.

"This new data set shows that as surface temperature increases, so does atmospheric humidity," Dessler said. "Dumping greenhouse gases into the atmosphere makes the atmosphere more humid. And since water vapour is itself a greenhouse gas, the increase in humidity amplifies the warming from carbon dioxide."

Specifically, the team found that if Earth warms 1.8 degrees fahrenheit, the associated increase in water vapour will trap an extra two watts of energy per square meter (about 11 square feet).

"That number may not sound like much, but add up all of that energy over the entire Earth surface and you find that water vapour is trapping a lot of energy," Dessler said. "We now think the water vapour feedback is extraordinarily strong, capable of doubling the warming due to carbon dioxide alone."

Because the new precise observations agree with existing assessments of water vapour's impact, researchers are more confident than ever in model predictions that Earth's leading greenhouse gas will contribute to a temperature rise of a few degrees by the end of the century.

"This study confirms that what was predicted by the models is really happening in the atmosphere," said Eric Fetzer, an Atmospheric Scientist, AIRS data, NASA's Jet Propulsion Laboratory, Pasadena, Calif. "Water vapour is the big player in the atmosphere as far as climate is concerned."

Aline of massive boulders, each up to 30 feet high and weighing almost 2,000 tons, on the western shore of Tonga could be evidence of the most powerful volcano-triggered tsunami ever, dwarfing even the 1883 Krakatau (Krakatoa) tsunami which is estimated to have been over 100 feet high. Matthew Hornbach, of the University of Texas Institute for Geophysics, gave a briefing on the boulders to other scientists at the Joint Annual Meeting of the Geological Society of America in Houston, Texas.

The boulders are such an unusual part of the Tongan landscape that tales of their origins appear in local folklore. According to one legend, the god Maui hurled the boulders ashore in an attempt to kill a giant man-eating fowl.

Called erratic boulders, these seven giant coral rocks are located 300 to 1,300 feet from the coast on Tongatapu, Tonga's main island. Because the island is flat, the boulders could not have rolled downhill from elsewhere. The boulders are made of the same reef material found just offshore, which is quite distinct from the island's volcanic soil. In fact, satellite photos show a clear break in the reef opposite one of the biggest boulders. And some of the boulders' coral animals are oriented upside down or sideways instead of toward the sun, as they are on the reef.

Hornbach says that the Tongatapu boulders may have reached dry land within the past few thousand years. Though their corals formed roughly 122,000 years ago, they are capped by a sparse layer of soil. And the thick volcanic soils that cover most of western Tongatapu are quite thin near the boulders. This suggests the area was scoured clean by waves in the recent past. Finally, there is no limestone pedestal at the base of the boulders, which should have formed as rain dissolved the coral if the boulders were much older.

Many tsunamis, like the one that struck on Boxing Day in 2004, are caused by earthquakes. But the boulders' location makes an underwater eruption or submarine slide a more likely culprit. A chain of sunken volcanoes lies just 20 miles west of Tongatapu. An explosion or the collapse of the side of a volcano such as that seen at the famous Krakatau eruption in 1883 could trigger a tremendous tsunami.

Another possibility is that a storm surge could have brought the boulders ashore. But that scenario isn't likely. No storms on record have moved rocks this big. Another possibility is that a monster undersea landslide caused the tsunami. But Hornbach's analyses of adjacent seafloor topography point to a volcanic flank collapse as the most probable source of such a wave.

"We think studying erratic boulders is one way of getting better statistics on mega-tsunamis," Hornbach says. "There are a lot of places that have similar underwater volcanoes and people haven't paid much attention to the threat." The researchers have already received reports of more erratic boulders from islands around the Pacific. Future study could indicate how frequently these monster waves occur and which areas are at risk for future tsunamis.

The 460,000 years old skull of a woolly rhino, reconstructed from 53 fragments, is the oldest example of the mighty, ice age beasts ever found in Europe. The extinct mammals reached a length of three and a half metres in adulthood and, unlike their modern relatives, were covered in shaggy hair. The research team says that the find from Germany fills a gap in our understanding of how these animals evolved. "This is the oldest woolly rhinoceros found in Europe," said Ralf-Dietrich Kahlke, Senckenberg Research Institute, Weimar, Germany. "It gives us a precise date for the first appearance of cold-climate animals spreading throughout Asia and Europe during the ice ages," he added.Gamma-ray burst was brightest ever

Astronomers from around the world have combined data from ground and space based telescopes to paint a detailed portrait of a stellar explosion that was briefly brighter than the galaxy that contained it, visible to the naked eye despite originating halfway across the universe. The gamma-ray burst, was the result of a massive star's explosion 7.5 billion years ago that sent a pencil-beam of intense light on a direct collision course for Earth. It is the only known gamma-ray burst to have had a visible component bright enough to see with the naked eye. "This was the brightest optical and infrared event that mankind has ever recorded," said Joshua Bloom, Assistant Professor, Astronomy, University of California, Berkeley.

Great floods beneath the Antarctic ice sheet can now be linked directly to the speed at which that ice moves towards the ocean, scientists say. Leigh Stearns and colleagues have been able to show how the giant Byrd Glacier in east Antarctica sped up just as two lakes under the ice overflowed. The flood water acts as a lubricant, easing the ice over the bedrock. The observation is described as critical because of how it informs our understanding of future sea levels. The more ice the polar regions dump in the ocean, the higher the waters will rise. The work of Dr Stearns and colleagues, reported in Nature Geoscience, indicates that Antarctica's under-ice plumbing system must now be an important consideration in ice dynamics.Fish catches being used as animal feed

An alarming new study in the Annual Review of Environment and Resources contends that fully one-third of the world's marine fish catches are ground up and fed to farm-raised fish, pigs, and poultry. The researchers involved say that this squandering of forage fish (anchovies, sardines, menhaden, and other small to medium sized fish) is rapidly worsening the already serious over fishing crisis in our oceans. The study notes that forage fish account for a staggering 37 percent (31.5 million tonnes) of all fish taken from the world's oceans each year, and 90 percent of that catch is processed into fishmeal and fish oil.