Oceanography

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The forces at work are enormous and the stakes huge, said Oregon State University scientists in an article published February 10 in the journalScience. But inadequate ocean monitoring and lack of agreement on how to assess microbial diversity has made it difficult to reach a consensus on what the future may hold, they said.

"We're just beginning to understand microbial diversity in the oceans and what that may mean to the environment," said Stephen Giovannoni, an OSU professor of microbiology. "However, a large portion of the carbon emitted from human activities ends up in the oceans, which with both their mass of water and biological processes act as a huge buffer against climate change. These are extremely important issues."

The interest is growing, scientists say, because nearly half of the world's photosynthesis is contributed by microbial plankton, and the process of marine carbon production and consumption is much faster than on land. A turnover of terrestrial plant biomass takes 15 years, they say, while marine turnover takes just six days.

As the ocean surface warms, evidence shows that it will become more "stratified," or confined to layers that mix less than they did in the past. This should reduce overall ocean productivity, Giovannoni said, but so little is known about the effect on ocean microbes that the implication for carbon sequestration and global warming is less clear.

Some OSU research on routine seasonal changes of microbes in the Sargasso Sea of the Atlantic Ocean suggests that different and specialized microbial communities can become more dominant when water warms.

As warmer oceans become a more long-term and global phenomenon, researchers need to know more about these microbes, and whether their behavior will amplify or reduce atmospheric carbon and the greenhouse effect.

It could be either, Giovannoni said.

"Some warming of surface waters may reduce carbon sequestration, which could cause a feedback loop to increase global warming," Giovannoni said.

"Other forces, what we call the microbial carbon pump, could cause carbon to sink into the deep ocean and be segregated from the atmosphere for thousands of years," he said. "We know both of these processes exist, but which one will become dominant is unpredictable, because we know so little about ocean microbes."

It was only two decades ago that OSU scientists discovered SAR11, an ocean microbe and the smallest free-living cell known, but one that's now understood to dominate life in the oceans, thrives where most other cells would die and plays a huge role in carbon cycling on Earth.

Microbial action also surprised scientists just recently, Giovannoni noted, when specific microbe populations surged following the Gulf Coast oil spill and cleaned up much of the oil faster than many thought possible. And some plans to "fertilize" the ocean and sequester atmospheric carbon through marine phytoplankton growth have been put on hold, he said, because it just isn't certain what would happen.

To reduce that uncertainty, Giovannoni advocates more aggressive development and implementation of marine microbial monitoring technology around the world, to add to what scientists can already learn from study of satellite images. And the field is so new, he said, that many researchers are not even comparing the same types of data or standardizing the tools they use to assess microbial diversity -- a problem that needs to be addressed.

Dramatic advances in DNA sequencing in recent years, Giovannoni said, should also help researchers unravel the ocean microbe mystery.

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Journal Reference:

Stephen J. Giovannoni, Kevin L. Vergin. Seasonality in Ocean Microbial Communities. Science, 2012; 335 (6069): 671-676 DOI: 10.1126/science.1198078

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Seafloor Geography

2012-01-29T13:03:00.000-05:00

Good Afternoon Gentlemen,

You'll notice the new link in the "Class Related Files & Links" portion of this Oceanography Blog.

The link is to "Seafloor Geography Files." Clicking on that link will take you to that folder in my "Google Docs." Please note the following:

1. Download and save the PDF files. This contains the lists of seafloor geographic/bathymetric features that we'll be learning this trimester. Feel free to print it.

2. You must have the latest version of Google Earth installed on your computer. If you don't have it, please do that. Make sure you have all of stuff saved.

3. Download the five KMZ files. Each of these files contains placemarks that I made for each of the features on the aforementioned list. The placemarks are sorted by ocean basin, by symbol, and by color. When you download each of them, they should display in Google Earth. Make sure you save each file on your computer before closing Google Earth. This will allow you to avoid continually downloading them.

Good luck, and let me know how it goes. These are my first KMZ files.

Sargasso Sea

2012-01-27T18:12:00.000-05:00

NOAA just featured the Sargasso Sea in a short article. There is in the article an awesome animation showing currents that surround the Sargasso, including Gulf Stream Rings. They also mention sargassum, an amazing holopelagic algae.

A timely article indeed since we just completed Chap. 7 on ocean currents.

Click here to read and see more from NOAA: Sargasso Sea Article - NOAA

Newly Discovered Hydrothermal Vents

2012-01-18T21:27:00.000-05:00

World's Most Extreme Deep-Sea Vents Revealed: Deeper Than Any Seen Before, and Teeming With New Creatures

ScienceDaily (Jan. 10, 2012) — Scientists have revealed details of the world's most extreme deep-sea volcanic vents, 5 kilometres down in a rift in the Caribbean seafloor.

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The undersea hot springs, which lie 0.8 kilometres deeper than any seen before, may be hotter than 450°C and are shooting a jet of mineral-laden water more than a kilometre into the ocean above.

Despite these extreme conditions, the vents are teeming with thousands of a new species of shrimp that has a light-sensing organ on its back. And having found yet more 'black smoker' vents on an undersea mountain nearby, the researchers suggest that deep-sea vents may be more widespread around the world than anyone thought.

Reporting in the scientific journalNature Communications this week, a team led by marine geochemist Dr Doug Connelly at the National Oceanography Centre in Southampton and marine biologist Dr Jon Copley of the University of Southampton has revealed details of the world's deepest known 'black smoker' vents, so-called for the smoky-looking hot fluids that gush from them.

During an expedition in April 2010 aboard the Royal Research Ship James Cook, the scientists used the National Oceanography Centre's robot submarine called Autosub6000 and a deep-diving vehicle, HyBIS, manufactured by the British firm, Hydro-Lek to locate and study the vents at a depth of five kilometres in the Cayman Trough, an undersea trench south of the Cayman Islands.

The vents, which the team named the Beebe Vent Field after the first scientist to venture into the deep ocean, are gushing hot fluids that are unusually rich in copper, and shooting a jet of mineral-laden water four times higher into the ocean above than other deep-sea vents. Although the scientists were not able to measure the temperature of the vents directly, these two features indicate that the world's deepest known vents may be hotter than 450 ºC, according to the researchers. "These vents may be one of the few places on the planet where we can study reactions between rocks and 'supercritical' fluids at extreme temperatures and pressures," says Connelly.

The team found a new species of pale shrimp congregating in hordes (up to 2,000 shrimp per m2) around the six-metre tall mineral spires of the vents. Lacking normal eyes, the shrimp instead have a light-sensing organ on their backs, which may help them to navigate in the faint glow of deep-sea vents. The researchers have named the shrimp Rimicaris hybisae, after the deep-sea vehicle that they used to collect them.

The Cayman shrimp is related to a species called Rimicaris exoculata, found at other deep-sea vents 4,000 kilometres away on the Mid-Atlantic Ridge. Elsewhere at the Beebe Vent Field, the team saw hundreds of white-tentacled anemones lining cracks where warm water seeps from the sea bed. "Studying the creatures at these vents, and comparing them with species at other vents around the world; will help us to understand how animals disperse and evolve in the deep ocean," says Copley.

The researchers also found black smoker vents on the upper slopes of an undersea mountain called Mount Dent. Mount Dent rises nearly three kilometres above the seafloor of the Cayman Trough, but its peak is still more than three kilometres beneath the waves. The mountain formed when a vast slab of rock was twisted up out of the ocean floor by the forces that pull the plates of Earth's crust apart.

"Finding black smoker vents on Mount Dent was a complete surprise," says Connelly. "Hot and acidic vents have never been seen in an area like this before, and usually we don't even look for vents in places like this." Because undersea mountains like Mount Dent may be quite common in the oceans, the discovery suggests that deep-sea vents might be more widespread around the world than previously thought.

The vents on Mount Dent, which the team has named the Von Damm Vent Field to commemorate the life of geochemist Karen Von Damm, are also thronged with the new species of shrimp, along with snake-like fish, and previously unseen species of snail and a flea-like crustacean called an amphipod. "One of the big mysteries of deep-sea vents is how animals are able to disperse from vent field to vent field, crossing the apparently large distances between them," says Copley. "But maybe there are more 'stepping stones' like these out there than we realised."

The UK expedition that revealed the vents followed a US expedition in November 2009, which detected the plumes of water from deep-sea vents in the Cayman Trough. A second US expedition is currently using a deep-diving remotely operated vehicle to investigate the vents further and the UK team also plans to return to the Cayman Trough in 2013 withIsis, the National Oceanography Centre's deep-diving remotely operated vehicle, which can work at depths of up to six kilometres.

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The above story is reprinted from materials provided byNational Oceanography Centre, Southampton (UK).
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Journal Reference:

Douglas P. Connelly, Jonathan T. Copley, Bramley J. Murton, Kate Stansfield, Paul A. Tyler, Christopher R. German, Cindy L. Van Dover, Diva Amon, Maaten Furlong, Nancy Grindlay, Nicholas Hayman, Veit Hühnerbach, Maria Judge, Tim Le Bas, Stephen McPhail, Alexandra Meier, Ko-ichi Nakamura, Verity Nye, Miles Pebody, Rolf B. Pedersen, Sophie Plouviez, Carla Sands, Roger C. Searle, Peter Stevenson, Sarah Taws, Sally Wilcox. Hydrothermal vent fields and chemosynthetic biota on the world's deepest seafloor spreading centre. Nature Communications, 2012; 3: 620 DOI: 10.1038/ncomms1636

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Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

Beebe Vent Field shrimp. (Credit: Image courtesy of National Oceanography Centre, Southampton (UK))

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US Volcano Monitoring

2012-01-15T12:57:00.000-05:00

Here's an excellent article on the history of volcano monitoring in the US. A timely article, indeed, given our discussions on plate tectonics, volcanoes, and the geological setting of the world ocean.

Here's the link: USGS 100th Anniversary of Volcano Monitoring

The USGS has some excellent links attached so that you can further explore their website.

Check out this other excellent volcano site too: Volcano World Home

New Shrimp at Hydrothermal Vents

2012-01-12T21:38:00.002-05:00

Pictures: Deepest Ocean Vents Swarm With Heat-Vision Shrimp?

Heat-Seeing Shrimp?

Image courtesy University of Southampton/NOC

Far beneath the Caribbean Sea (map), at the world's deepest volcanic ocean vents, robotic vehicles have helped find a new species of shrimp (pictured) that may have Superman-style heat vision.

Though the vent field and a sister site nearby were found in spring 2010, details and pictures of new species at the site were released just yesterday.

Located near the Cayman Islands, the hot seafloor vents are nearly 3.1 miles (5 kilometers) deep—about 2,900 feet (880 meters) deeper than the previous record holder.

About 12.4 miles (20 kilometers) away, the expedition also found a second mineral-rich vent field close to a section of seafloor where tectonic plates are separating.

There, unexpectedly, a chunk of mantle is poking through Earth's crust. (The planet's hot, semifluid mantle rock layer is typically contained miles below the planet's thin, hard outer crust.)

Though the mantle area is only half as deep as the deepest vent field, both sites are inhabited by hordes of new species, including sea anemones, fish, and swarms of 1-inch-long (2.5-centimeter-long) shrimp (above) with purple organs that may detect infrared light beaming from the vents.

"We were absolutely stunned to find these vent sites," said marine geochemistDoug Connelly of the U.K.'s National Oceanography Centre and a member of the expedition.

Vents like this "may be far more common than we think they are," he said. "We just may not be looking in all of the right places."

The discoveries follow closely behind another deep-sea expedition just north of Antarctica by the same team. That investigation found warm bastions of life—including new yeti crab species and a ghostly octopus—on the usually near-freezing ocean bottom. (See pictures: "'Lost World' of Odd Species Found Off Antarctica.")

Details of Earth's deepest volcanic vents are described today in the journalNature Communications.

—Dave Mosher

Microenvironments & Hydrothermal Vents

2012-01-04T22:38:00.000-05:00

Prior to their discover in the mid-1970s, scientists thought every organisms on earth depended on the sun for its existence. The communities of organisms around hydrothermal vents don't depend upon the sun, but rather the heat and sulfur expelled into the ocean at those sites.

Some new discoveries were recently made in neighborhood of Antarctica. Read on to find out more.

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'Lost World' Discovered Around Antarctic Vents

ScienceDaily (Jan. 3, 2012) — Communities of species previously unknown to science have been discovered on the seafloor near Antarctica, clustered in the hot, dark environment surrounding hydrothermal vents.

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The discoveries, made by teams led by the University of Oxford, University of Southampton, the National Oceanography Centre, and British Antarctic Survey, include new species of yeti crab, starfish, barnacles, and sea anemones, and even an octopus probably new to science.

For the first time researchers, using a Remotely Operated Vehicle (ROV), have been able to explore the East Scotia Ridge deep beneath the Southern Ocean where hydrothermal vents, including 'black smokers' reaching temperatures of up to 382 degrees Celsius, create a unique environment lacking sunlight but rich in certain chemicals.

The team report their findings in this week's PLoS Biology.

'Hydrothermal vents are home to animals found nowhere else on the planet that get their energy not from the Sun but from breaking down chemicals, such as hydrogen sulphide,' said Professor Alex Rogers of Oxford University's Department of Zoology, who led the research. 'The first survey of these particular vents, in the Southern Ocean near Antarctica, has revealed a hot, dark, 'lost world' in which whole communities of previously unknown marine organisms thrive.'

Highlights from the ROV dives include images showing huge colonies of the new species of yeti crab, thought to dominate the Antarctic vent ecosystem, clustered around vent chimneys. Elsewhere the ROV spotted numbers of an undescribed predatory seastar with seven arms crawling across fields of stalked barnacles and found an unidentified pale octopus nearly 2,400 metres down on the seafloor.

'What we didn't find is almost as surprising as what we did,' said Professor Rogers. 'Many animals such as tubeworms, vent mussels, vent crabs, and vent shrimps, found in hydrothermal vents in the Pacific, Atlantic, and Indian Oceans, simply weren't there.'

The team believe that the differences between the groups of animals found around the Antarctic vents and those found around vents elsewhere suggest that the Southern Ocean may act as a barrier to some vent animals. The unique species of the East Scotia Ridge also suggest that, globally, vent ecosystems may be much more diverse, and their interactions more complex, than previously thought.

In April Professor Rogers was part of an international panel of marine scientists who gathered at Somerville College, Oxford to consider the latest research on the world's oceans. A preliminary report from the panel in June warned that the world's oceans are at risk of entering a phase of extinction of marine species unprecedented in human history.

'These findings are yet more evidence of the precious diversity to be found throughout the world's oceans,' said Professor Rogers. 'Everywhere we look, whether it is in the sunlit coral reefs of tropical waters or these Antarctic vents shrouded in eternal darkness, we find unique ecosystems that we need to understand and protect.'

ROV dives were conducted with the help of the crews of RRSJames Cook and RRS James Clark Ross. The discoveries were made as part of a consortium project with partners from the University of Oxford, University of Southampton, University of Bristol, Newcastle University, British Antarctic Survey, National Oceanography Centre, and Woods Hole Oceanographic Institution supported by the UK's Natural Environment Research Council (NERC) and the US National Science Foundation (NSF).

A report of the research, entitled 'The discovery of new deep-sea hydrothermal vent communities in the Southern Ocean and implications for biogeography', is published this week in PLoS Biology.

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The above story is reprinted from materials provided byUniversity of Oxford.
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Journal Reference:

Alex D. Rogers, Paul A. Tyler, Douglas P. Connelly, Jon T. Copley, Rachael James, Robert D. Larter, Katrin Linse, Rachel A. Mills, Alfredo Naveira Garabato, Richard D. Pancost, David A. Pearce, Nicholas V. C. Polunin, Christopher R. German, Timothy Shank, Philipp H. Boersch-Supan, Belinda J. Alker, Alfred Aquilina, Sarah A. Bennett, Andrew Clarke, Robert J. J. Dinley, Alastair G. C. Graham, Darryl R. H. Green, Jeffrey A. Hawkes, Laura Hepburn, Ana Hilario, Veerle A. I. Huvenne, Leigh Marsh, Eva Ramirez-Llodra, William D. K. Reid, Christopher N. Roterman, Christopher J. Sweeting, Sven Thatje, Katrin Zwirglmaier. The Discovery of New Deep-Sea Hydrothermal Vent Communities in the Southern Ocean and Implications for Biogeography. PLoS Biology, 2012; 10 (1): e1001234 DOI:10.1371/journal.pbio.1001234

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Where Have All of the Oysters Gone?

2011-12-20T13:12:00.002-05:00

Just where Have All of the Oysters Gone? An excellent question indeed. Check out the NOAA "Habitat of the Month" article on oyster reefs to find out more. Once a dominant species in Chesapeake Bay and all of Long Island's coastal waters, their numbers now are a fraction of what they once were.

Click the link and read on to learn more. NOAA Habitat of the Month Article

More Radiation Leaks in Japan

2011-12-14T20:46:00.000-05:00

The contamination issues from the Fukushima nuclear complex in Japan continue.

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Scientists Assess Radioactivity in the Ocean from Japan Nuclear Power Facility

ScienceDaily (Dec. 9, 2011) — With current news of additional radioactive leaks from the Fukushima nuclear power plants, the impact on the ocean of releases of radioactivity from the plants remains unclear.

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But a new study by U.S. and Japanese researchers analyzes the levels of radioactivity discharged in the first four months after the accident.

It draws some basic conclusions about the history of contaminant releases to the ocean.

The study was conducted by Woods Hole Oceanographic Institution chemist Ken Buesseler and two colleagues based in Japan, Michio Aoyama of the Meteorological Research Institute and Masao Fukasawa of the Japan Agency for Marine-Earth Science and Technology.

They report that discharges from the Fukushima Dai-Ichi nuclear power plants peaked one month after the March 11 earthquake and tsunami that precipitated the nuclear accident, and continued through at least July.

Their study finds that the levels of radioactivity, while high, are not a direct threat to humans or marine life, but cautions that the effect of accumulated radionuclides in marine sediments is poorly known.

The release of radioactivity from Fukushima--both as atmospheric fallout and direct discharges to the ocean--represents the largest accidental release of radiation to the ocean in history.

Concentrations of cesium-137, a radioactive isotope with a 30-year half-life, at the plants' discharge points to the ocean peaked at more than 50 million times normal/previous levels.

Concentrations 18 miles offshore were higher than those measured in the ocean after the Chernobyl accident 25 years ago.

This is largely related to the fact, says Buesseler, that the Fukushima nuclear power plants are located along the coast, whereas Chernobyl was several hundred miles from the nearest salt water basins, the Baltic and Black Seas.

However, due to ocean mixing processes, the levels are rapidly diluted off the northwest coast of Japan.

The study used data on the concentrations of cesium-137, cesium-134 and iodine-131 as a basis to compare the levels of radionuclides released into the ocean with known levels in the sea surrounding Japan prior to the accident.

The resulting paper, Impacts of the Fukushima Nuclear Power Plants on Marine Radioactivity, is published in the current issue of the journal Environmental Science & Technology.

Buesseler was awarded a rapid-response grant from the National Science Foundation's (NSF) Division of Ocean Sciences to establish baseline concentrations of radionuclides in the Atlantic and Pacific Oceans.

"Understanding and management of the long-term geochemical fate and ecological consequences of radiochemical contamination of the sea is dependent on our knowledge of the initial conditions," says Don Rice, director of NSF's Chemical Oceanography Program. "Acquiring that knowledge depends on our ability to deploy experts to the scene with minimal delay."

The investigators compiled and analyzed data on concentrations of cesium and iodine in ocean water near the plants' discharge points.

The data were made public by TEPCO, the electric utility that owns the plants, and the Japanese Ministry of Culture, Sports, Science and Technology.

The team found that releases to the ocean peaked in April, a fact they attribute to "the complicated pattern of discharge of seawater and freshwater used to cool the reactors and spent fuel rods, interactions with groundwater, and intentional and unintentional releases of mixed radioactive material from the reactor facility."

The scientists also found that the releases decreased in May by a factor of 1,000, "a consequence of ocean mixing and a primary radionuclide source that had dramatically abated," they report.

While concentrations of some radionuclides continued to decrease, by July they were still 10,000 times higher than levels measured in 2010 off the coast of Japan.

This indicates that the plants "remain a significant source of contamination to the coastal waters off Japan," the researchers report.

"There is currently no data that allow us to distinguish between several possible sources of continued releases," says Buesseler.

"These most likely include some combination of direct releases from the reactors, or storage tanks or indirect releases from groundwater beneath the reactors or coastal sediments, both of which are likely contaminated from the period of maximum releases."

Buesseler says that at levels indicated by these data, the releases are not likely to be a direct threat to humans or marine biota in the surrounding ocean waters.

There could be an issue, however, if the source remains high and radiation accumulates in marine sediments.

"We don't know how this might affect benthic marine life, and with a half-life of 30 years, any cesium-137 accumulating in sediments or groundwater could be a concern for decades to come," he says.

While international collaborations for comprehensive field measurements to determine the full range of radioactive isotopes released are underway, says Buesseler, it will take some time before results are available to fully evaluate the impacts of this accident on the ocean.

The Gordon and Betty Moore Foundation also funded the research.

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Ken Buesseler, Michio Aoyama, Masao Fukasawa.Impacts of the Fukushima Nuclear Power Plants on Marine Radioactivity. Environmental Science & Technology, 2011; 45 (23): 9931 DOI: 10.1021/es202816c

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A new study analyzes levels of radioactivity released to the ocean in the Japan accident. (Credit: Ken Buesseler, WHOI)

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Merging Tsunamis

2011-12-06T17:30:00.000-05:00

I've been intrigued by tsunamis since I was a kid. Having researched the Japanese tsunami of 2011 and the Indonesian event of 2004 have been eye openers. Here's an interesting article regarding the Japanese event earlier this year.

Double Tsunami' Doubled Japan Destruction

ScienceDaily (Dec. 5, 2011) — Researchers have discovered that the destructive tsunami generated by the March 2011 Tōhoku-Oki earthquake was a long-hypothesized "merging tsunami" that doubled in intensity over rugged ocean ridges, amplifying its destructive power before reaching shore.

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Satellites captured not just one wave front that day, but at least two, which merged to form a single double-high wave far out at sea -- one capable of traveling long distances without losing its power. Ocean ridges and undersea mountain chains pushed the waves together, but only along certain directions from the tsunami's origin.

The discovery helps explain how tsunamis can cross ocean basins to cause massive destruction at some locations while leaving others unscathed, and raises hope that scientists may be able to improve tsunami forecasts.

At a news conference Dec. 5 at the American Geophysical Union meeting in San Francisco, Y. Tony Song, a research scientist at NASA's Jet Propulsion Laboratory (JPL); and C.K. Shum, professor and Distinguished University Scholar in the Division of Geodetic Science, School of Earth Sciences at Ohio State University, discussed the satellite data and simulations that enabled them to piece the story together.

"It was a one-in-ten-million chance that we were able to observe this double wave with satellites," said Song, the study's principal investigator. "Researchers have suspected for decades that such 'merging tsunamis' might have been responsible for the 1960 Chilean tsunami that killed many in Japan and Hawaii, but nobody had definitively observed a merging tsunami until now."

"It was like looking for a ghost," he continued. "A NASA/French Space Agency satellite altimeter happened to be in the right place at the right time to capture the double wave and verify its existence."

Shum agreed. "We were very lucky, not only in the timing of the satellite, but also to have access to such detailed GPS-observed ground motion data from Japan to initiate Tony's tsunami model, and to validate the model results using the satellite data. Now we can use what we learned to make better forecasts of tsunami danger in specific coastal regions anywhere in the world, depending on the location and the mechanism of an undersea quake."

The NASA/Centre National d'Etudes Spaciales Jason-1 satellite passed over the tsunami on March 11, as did two other satellites: the NASA/European Jason-2 and the European Space Agency's EnviSAT. All three carry a radar altimeter, which measures sea level changes to an accuracy of a few centimeters.

Each satellite crossed the tsunami at a different location. Jason-2 and EnviSAT measured wave heights of 20 cm (8 inches) and 30 cm (12 inches), respectively. But as Jason-1 passed over the undersea Mid-Pacific Mountains to the east, it captured a wave front measuring 70 cm (28 inches).

The researchers conjectured ridges and undersea mountain chains on the ocean floor deflected parts of the initial tsunami wave away from each other to form independent jets shooting off in different directions, each with its own wave front.

The sea floor topography nudges tsunami waves in varying directions and can make a tsunami's destruction appear random. For that reason, hazard maps that try to predict where tsunamis will strike rely on sub-sea topography. Previously, these maps only considered topography near a particular shoreline. This study suggests scientists may be able to create maps that take into account all undersea topography, even sub-sea ridges and mountains far from shore.

Song and his team were able to verify the satellite data through model simulations based on independent data, including the GPS data from Japan and buoy data from the National Oceanic and Atmospheric Administration's Deep-ocean Assessment and Reporting of Tsunamis program.

"Tools based on this research could help officials forecast the potential for tsunami jets to merge," said Song. "This, in turn, could lead to more accurate coastal tsunami hazard maps to protect communities and critical infrastructure."

Song and Shum's collaborators include Ichiro Fukumori, an oceanographer and supervisor in JPL's Ocean Circulation Group; and Yuchan Yi, a research scientist in the Division of Geodetic Science, School of Earth Sciences at Ohio State.

This research was supported by NASA.

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A 3D ocean model created by Y. Tony Song of NASA’s Jet Propulsion Laboratory and colleagues replicates the March 11, 2011 tsunami. The red line shows the path of the Jason-1 satellite, which crossed the wave front at the site of a double-high wave. (Credit: Image courtesy of NASA)

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Gateway to the Arctic

2011-11-22T22:14:00.000-05:00

The Arctic and Antarctic Regions are under intense scrutiny right now as the areas of the earth most susceptible to climate change. Despite many protestations to the contrary, many scientists simply cannot comprehend what changes are actually happening with regards to the earth's climate.

Watch the following video from UC Scripps Institute.

Also go to the link on this blog to the WHOI "Into the Dark and Ice Mission." Watch that video too. The two videos will give quite an interesting picture to this "gateway to the Arctic."

Fish vs. Sargassum

2011-11-18T20:39:00.000-05:00

It is truly amazing how organisms have evolved to fill every tiny niche that you can imagine. Sargassum is a member of phaeophyceae (phaeophyta). UC Berkeley has an excellent introduction to the phaeophytes at this link: UC Berkeley

Explorers during the Age of Exploration dreaded getting becalmed in the subtropical Atlantic Ocean and surrounded by vast areas of Sargassum.

Here's a great little video from National Geographic on the Sargassum fish.

Waterfront Property Anyone?

2011-11-13T21:48:00.002-05:00

Some upcoming investigations into a particular worrisome Antarctic glacier.

International Team to Drill Beneath Massive Antarctic Ice Shelf

ScienceDaily (Nov. 9, 2011) — An international team of researchers funded by NASA and the National Science Foundation (NSF) will travel next month to one of Antarctica's most active, remote and harsh spots to determine how changes in the waters circulating under an active ice sheet are causing a glacier to accelerate and drain into the sea.

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The science expedition will be the most extensive ever deployed to Pine Island Glacier. It is the area of the ice-covered continent that concerns scientists most because of its potential to cause a rapid rise in sea level. Satellite measurements have shown this area is losing ice and surrounding glaciers are thinning, raising the possibility the ice could flow rapidly out to sea.

The multidisciplinary group of 13 scientists, led by Robert Bindschadler, emeritus glaciologist of NASA's Goddard Space Flight Center in Greenbelt, Md., will depart from the McMurdo Station in Antarctica in mid-December and spend six weeks on the ice shelf. During their stay, they will use a combination of traditional tools and sophisticated new oceanographic instruments to measure the shape of the cavity underneath the ice shelf and determine how streams of warm ocean water enter it, move toward the very bottom of the glacier and melt its underbelly.

"The project aims to determine the underlying causes behind why Pine Island Glacier has begun to flow more rapidly and discharge more ice into the ocean," said Scott Borg, director of NSF's Division of Antarctic Sciences, the group that coordinates all U.S. research in Antarctica. "This could have a significant impact on global sea-level rise over the coming century."

Scientists have determined the interaction of winds, water and ice is driving ice loss from the floating glacier. Gusts of increasingly stronger westerly winds push cold surface waters away from the continent, allowing warmer waters that normally hover at depths below the continental shelf to rise. The upwelling warm waters spill over the border of the shelf and move along the sea floor, back to where the glacier rises from the bedrock and floats, causing it to melt.

The warm salty waters and fresh glacier melt water combine to make a lighter mixture that rises along the underside of the ice shelf and moves back to the open ocean, melting more ice on its way. How much more ice melts is what the team wants to find out, so it can improve projections of how the glacier will melt and contribute to sea-level rise.

In January 2008, Bindschadler was the first person to set foot on this isolated corner of Antarctica as part of initial reconnaissance for the expedition. Scientists had doubted it was even possible to reach the crevasse-ridden ice shelf. Bindschadler used satellite imagery to identify an area where helicopters could land safely to transport scientists and instrumentation to and from the ice shelf.

"The Pine Island Glacier ice shelf continues to be the place where the action is taking place in Antarctica," Bindschadler said. "It only can be understood by making direct measurements, which is hard to do. We're doing this hard science because it has to be done. The question of how and why it is melting is even more urgent than it was when we first proposed the project over five years ago."

The team will use a hot water drill to make a hole through the ice shelf. After the drill hits the ocean, the scientists will send a camera down into the cavity to observe the underbelly of the ice shelf and analyze the seabed lying approximately 1,640 feet (500 meters) below the ice. Next the team will lower an instrument package provided by oceanographer Tim Stanton of the Naval Postgraduate School in Monterrey, Calif., into the hole. The primary instrument, called a profiler, will move up and down a cable attached to the seabed, measuring temperature, salinity and currents from approximately 10 feet (3 meters) below the ice to just above the seabed.

A second hole will support a similar instrument array fixed to a pole stuck to the underside of the ice shelf. This instrument will measure how ice and water exchange heat. The team also will insert a string of 16 temperature sensors in the lowermost ice to freeze inside and become part of the ice shelf. The sensors will measure how fast heat is transmitted upward through the ice when hot flushes of water enter the ocean cavity.

Sridhar Anandakrishnan, a geophysicist with Pennsylvania State University in University Park, Pa., will study the shape of the ocean cavity and the properties of the bedrock under the Pine Island Glacier ice shelf through a technique called reflective seismology, which involves generating waves of energy by detonating small explosions and banging the ice with instruments resembling sledgehammers. Measurements will be taken in about three dozen spots using helicopters to move from one place to another.

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The above story is reprinted from materials provided byNASA/Goddard Space Flight Center.
Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

Coral Reef Recovery

2011-11-12T20:57:00.000-05:00

While many reefs are stressed nowadays, some reefs seem able to return to a healthy state. Upon further investigation, scientists have figured out that the recovery is due to parrotfish and surgeon fish. Both species are voracious herbivores. Check out this article from Science Daily.com.

'Fishy Lawnmowers' Help Save Pacific Corals

ScienceDaily (Nov. 10, 2011) — Can fish save coral reefs from dying? UC Santa Barbara researchers have found one case where fish have helped coral reefs to recover from cyclones and predators.

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Coral reefs worldwide are increasingly disturbed by environmental events that are causing their decline, yet some coral reefs recover. UCSB researchers have discovered that the health of coral reefs in the South Pacific island of Moorea, in French Polynesia, may be due to protection by parrotfish and surgeonfish that eat algae, along with the protection of reefs that shelter juvenile fish.

The findings are published in a recent issue of the journal PLoS ONE. The UCSB research team is part of the Moorea Coral Reef Long-Term Ecological Research (MCR LTER) project, funded by the National Science Foundation.

In many cases, especially in the case of severely damaged reefs in the Caribbean, coral reefs that suffer large losses of live coral often become overgrown with algae and never return to a state where the reefs are again largely covered by live coral. In contrast, the reefs surrounding Moorea experienced large losses of live coral in the past -- most recently in the early 1980's -- and have returned each time to a system dominated by healthy, live corals.

"We wanted to know why Moorea's reefs seem to act differently than other reefs," said Tom Adam, first author, research associate with MCR LTER, and postdoctoral fellow at UCSB's Marine Science Institute. "Specifically, we wanted to know what ecological factors might be responsible for the dramatic patterns of recovery observed in Moorea."

The research team was surprised by its findings. The biomass of herbivores on the reef -- fish and other animals that eat plants like algae -- increased dramatically following the loss of live coral. "What was surprising to us was that the numbers of these species also increased dramatically," said Andrew Brooks, co-author, deputy program director of MCR LTER, and associate project scientist with MSI. "We were not simply seeing a case of bigger, fatter fishes -- we were seeing many more parrotfishes and surgeonfishes, all of whom happened to be bigger and fatter. We wanted to know where these new fishes were coming from."

The researchers also found that not all of the coral reefs around Moorea were affected equally by an outbreak of predatory crown-of-thorns sea stars or by cyclones. The crown-of-thorns sea stars did eat virtually all of the live coral on the barrier reef -- the reef that separates the shallow lagoons from the deeper ocean. However, neither the sea stars nor the cyclones had much impact on the corals growing on the fringing reef -- the reef that grows against the island.

"We discovered that these fringing reefs act as a nursery ground for baby fishes, most notably herbivorous fishes," said Brooks. "With more food available in the form of algae, the survivorship of these baby parrotfishes and surgeonfishes increased, providing more individuals to help control the algae on the fore reef. In effect, the large numbers of parrotfishes and surgeonfishes are acting like thousands of fishy lawnmowers, keeping the algae cropped down to levels low enough that there is still space for new baby corals to settle onto the reef and begin to grow."

A major reason the reefs in the Caribbean do not recover after serious disturbances is because these reefs lack healthy populations of parrotfishes and surgeonfishes, due to the effects of overfishing, explained Adam. "Without these species to help crop the algae down, these reefs quickly become overgrown with algae, a situation that makes it very hard for corals to re-establish themselves," he said.

Managers have tried to reverse the trend of overfishing through the creation of Marine Protected Areas (MPAs), where fishing is severely restricted or prohibited. "Our results suggest that this strategy may not be enough to reverse the trend of coral reefs becoming algal reefs," said Brooks. "Our new and very novel results suggest that it also is vital to protect the fringing reefs that serve as nursery grounds. Without these nursery grounds, populations of parrotfishes and surgeonfishes can't respond to increasing amounts of algae on the reefs by outputting more baby herbivores."

In short, the research team found that by using MPAs, managers can help protect adult fish, producing bigger, fatter fish. "But if you don't protect the nursery habitat -- the babies produced by these bigger fish, or by fish in other, nearby areas -- you can't increase the overall numbers of the important algae-eating fish on the reef," said Brooks.

According to the scientists, it appears that Moorea's reefs may recover. "One final bit of good news is that we are seeing tens of thousands of baby corals, some less than a half-inch in diameter, on the fore reefs surrounding Moorea," said Brooks.

MCR researchers will follow the coral reef recovery process over the next decade or more, in search of additional information that can aid managers of the world's coral reefs.

Additional co-authors are Russell J. Schmitt and Sally J. Holbrook of UCSB's Marine Science Institute and the Department of Ecology, Evolution, and Marine Biology; Peter J. Edmunds and Robert C. Carpenter of California State University, Northridge; and Giacomo Bernardi, of UC Santa Cruz.

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The above story is reprinted from materials provided byUniversity of California - Santa Barbara.
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Thomas C. Adam, Russell J. Schmitt, Sally J. Holbrook, Andrew J. Brooks, Peter J. Edmunds, Robert C. Carpenter, Giacomo Bernardi. Herbivory, Connectivity, and Ecosystem Resilience: Response of a Coral Reef to a Large-Scale Perturbation. PLoS ONE, 2011; 6 (8): e23717 DOI: 10.1371/journal.pone.0023717

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Crown-of-thorns sea star feeding on a coral. (Credit: Gerick Bergsma)

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Coastal Blue Carbon

2011-11-08T21:26:00.000-05:00

If you're not sure what exactly coastal blue carbon is, read on at the link below. When I read the article, I realized that I was already familiar with the concept, just not the term.

NOAA article on coastal blue carbon

Hmmmm....Just how did that non-native species actually arrive?

2011-11-07T20:38:00.000-05:00

Invasive species are certainly nothing new. If anything, they've actually become more of a nuisance in our ever-more-global world.

Here's a fascinating article about invasive species being carried by ballast water in international freighters.

Coasts' Best Protection from Bioinvaders Falling Short: Not Enough Ships Able to Flush out Invasive Species Before They Reach Port

ScienceDaily (Nov. 6, 2011) — Invasive species have hitchhiked to the U.S. on cargo ships for centuries, but the method U.S. regulators most rely on to keep them out is not equally effective across coasts. Ecologists from the Smithsonian Environmental Research Center have found that ports on the East Coast and the Gulf of Mexico are significantly less protected than ports on the West Coast.

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Invaders are frequently introduced across oceans and along coastlines through the ballast water in ship hulls, water that often includes plankton and larval stages of marine and estuarine species. Large vessels need this water for balance as they load and unload cargo. However, by dumping ballast water in their ports of entry, they accidentally bring in new species that can alter or damage the local ecosystem. In 2004 policymakers thought they had found a solution: have cargo vessels exchange their ballast water in the open ocean, at least 200 nautical miles from land. This method, called "open-ocean exchange," flushes out or kills potential invaders by exchanging coastal water for water from the deep ocean.

But some ships do not use the practice and many more cannot without veering drastically off course. In perhaps the most comprehensive study to date, Whitman Miller and a team of scientists from SERC looked at all international ships entering the contiguous U.S. over three years. Published in the journalBioScience, the study analyzed approximately 105,000 vessel reports from January 2005 to December 2007. While most ships opted not to discharge their ballast water at all, a substantial number continued to dump unexchanged or improperly exchanged water into their ports of entry.

Not all coasts are affected equally. The Gulf of Mexico and the East Coast received much larger fractions of unexchanged ballast water than the West Coast. Roughly 5 percent of the ballast water discharged on the West Coast had not undergone open-ocean exchange. By contrast 21 percent of the discharged water in the Gulf and 23 percent on the East Coast went unexchanged.

Much of the problem comes down to simple geography. Depending on a ship's transit route, it may not have the time or space to conduct open-ocean exchange. A mere 24 percent of the ballast water discharged by ships journeying to U.S. ports along coastal routes, from Central or South America, for example, underwent open-ocean exchange. In contrast 91 percent of ballast water discharge by transoceanic shipping was exchanged in the open ocean, where ships have more opportunities to manage their water properly. Because so many of their incoming ships do not pass through the open ocean, ports in the Gulf and East Coast receive more potentially harmful water.

The vast discrepancies point to the need for another solution, ecologists say. If ships could treat their ballast water on board without having to journey to the open ocean, every coast would be safer.

"The Gulf of Mexico coast receives more overseas ballast water discharge than the East or West coasts, and most of this water is either unexchanged or exchanged inside coastal waters," said Miller. "Given the geographic constraints of shipping, and the complexity of the invasion process, it is clear that we need to move to onboard ballast water treatment technologies that will allow ships to operate anywhere in the world without fear of releasing harmful invasive species."

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