August 9, 2006, 10:12 PM CT

Arctic Coring Expedition Yield New Clues

For the second time in as a number of months, the IODP Arctic Coring Expedition (ACEX) is making news with new analysis of ocean-floor sediments. In the Aug. 10 issue of Nature, an article authored by several of the expedition researchers summarizes their findings: more evidence that the Arctic was extremely warm, uncommonly wet, and ice-free up to the time the last massive amounts of greenhouse gases were released into the Earth's atmosphere - a period calculated to have occurred 55 million years ago, and known as the Paleocene/Eocene thermal maximum, or PETM.

Scientists have long recognized that a massive release of greenhouse gases, probably carbon dioxide or methane, occurred during the PETM. Surface temperatures also rose in a number of places by as much as 15 degrees Fahrenheit in the (relative) geological instant of about 100,000 years.

Arctic sediment samples were largely unavailable until 2004, when ACEX researchers recovered the first deep-ocean sediment samples from beneath the ice-laden waters near the North Pole. ACEX, only the second scientific expedition to be conducted by the Integrated Ocean Drilling Program (established in late 2003), recovered 339 meters of subseafloor sediment samples.

"Building a picture of ancient climatic events is a lot like putting together a jigsaw puzzle, and what ACEX allowed us to do was fill in a blank section of the PETM picture," said Gerald Dickens, a Rice University geochemist and co-author, who conducted the initial, shipboard chemical analyses of all the ACEX core samples.........

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August 9, 2006, 10:03 PM CT

West Coast Crustacean Found In Atlantic Waters

MIT scientists have confirmed the first sighting of a Dungeness crab in the Atlantic Ocean. The male, whose species is common on North America's West Coast, was caught off Thatcher Island, Massachusetts, on July 19 by Lou Williams, captain of the fishing vessel Orin C.

The origin of the crab is not known. One possibility is that it may have been purchased from a live seafood market and released. The size of the crab (18 cm) and its gender suggest it most likely arrived as an adult exotic species. Also known as invasive species or bioinvaders, exotic species are of concern because they can establish themselves in a new ecosystem, where they can proliferate and push out native species.

The crab was caught while Williams was gillnetting for groundfish at 45 fathoms. Suspecting the crab to be a Dungeness, he took it to Brandy Wilbur, aquaculture specialist for MIT Sea Grant, and Eric Sabo, educator at the Gloucester Maritime Heritage Center, for verification.

After distributing photographs of the crab to several scientists, the scientists received confirmation of the species, Cancer magister, from several experts: Julie Barber, Massachusetts Division of Marine Fisheries; Thomas C. Shirley, Texas A&M University at Corpus Christi; David Tapley, Salem State College; and Richard Strathmann and Eugene Kozloff, the University of Washington's Friday Harbor Laboratories.........

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August 7, 2006, 10:06 PM CT

Coral Microbial Ecology

Most people are familiar with tropical coral reefs, located in warm, shallow waters. However, corals also exist hundreds and even thousands of meters below the ocean's surface where it is cold and completely dark. In the last few decades, researchers have discovered and photographed incredible gardens of deep-sea corals off the coasts of North America, Great Britain, Europe, Scandinavia, Australia, and New Zealand. These corals survive without algal symbionts (because there is no light for photosynthesis) and may take a long time to grow.

Thus the potential role of coral-associated microbes is even more interesting. It is possible that the microbes are helping to feed these corals, similar to the chemosynthetic bacterial symbionts that feed hydrothermal-vent worms. The microbial communities of these coldadapted corals are also likely to contain novel organisms, which will not only increase our understanding of microbial diversity but could also be a source of new enzymes or pharmaceuticals.........

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August 7, 2006, 10:00 PM CT

Storing Man-made Carbon Dioxide

Deep-sea sediments could provide a virtually unlimited and permanent reservoir for carbon dioxide, the gas that has been a primary driver of global climate change in recent decades, as per a team of researchers that includes a professor from MIT.

The scientists estimate that seafloor sediments within U.S. territory are vast enough to store the nation's carbon dioxide (CO2) emissions for thousands of years to come.

"The exciting thing about this paper is that we show that CO2 injected beneath the seafloor is sequestered permanently," said Charles Harvey, an associate professor in MIT's Department of Civil and Environmental Engineering. Harvey is a co-author of a paper on the work that appears in this week's issue of the Proceedings of the National Academy of Sciences.

"CO2 injected underground on land is buoyant, and hence has the potential to escape back to the surface," Harvey said. "This is not the case under the deep ocean. Because the ocean floor is so cold, liquid CO2 stored beneath the floor is denser than water and will not rise to surface. Furthermore, the top of the injected CO2 plume will form a hydrate, an ice-like solid that plugs up the pore spaces, 'self-sealing' the injected CO2 plume into the deep sea sediments."

The leader of the work, Daniel P. Schrag, said, "Supplying the energy demanded by world economic growth without affecting the Earth's climate is one of the most pressing technical and economic challenges of our time." Schrag is a professor of earth and planetary sciences at Harvard University.........

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August 7, 2006, 9:55 PM CT

Kayaks Adapted To Test Marine Robotics

MIT scientists are working toward the day when a team of robots could be put into action like a team of Navy SEALs -- doing such dangerous work as searching for survivors after devastating hurricanes or sweeping harbors for mines.

Working in labs that resemble machine shops, these engineers are taking small steps toward the holy grail of robotics -- cooperative autonomy -- making machines work together seamlessly to complete tasks with a minimum of human direction.

The tool they're using is the simple kayak.

The scientists are taking off-the-shelf, $500 plastic kayaks and fitting them with onboard computers, radio control, propulsion, steering, communications and more to create Surface Crafts for Oceanographic and Undersea Testing (SCOUTs).

Much of the technology being tested is ultimately intended for use in underwater robots, or autonomous underwater vehicles (AUVs), but testing software on AUVs can easily become a multimullion-dollar experiment.

"I want to have master's students and Ph.D. students that can come in, test algorithms and develop them on a shoestring budget," said Associate Professor John J. Leonard of mechanical engineering. Leonard, together with MIT research engineer Joseph Curcio of mechanical engineering and an intern, Andrew Patrikalakis, unveiled SCOUT last fall in a paper for the IEEE Oceans Conference.........

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August 6, 2006, 10:53 PM CT

It's Making Them Even Cuter

As the heat wave rolls on, I turn to the local TV news website to find out if there are power outages, whether the subways are running, all that stuff.

But more than anything else, I really want to know one thing: how is the heat affecting cute baby animals?........

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August 6, 2006, 9:54 PM CT

Three-clawed Crab

A "mutant" crab with three pincers has been picked up off the Cornish coast.

Fisherman Jeff Brown caught the 20cm (7.8in) edible crab three miles off Portreath and realising its rarity, handed it into a Newquay aquarium.

The crab, christened Claudette by the Blue Reef aquarium staff, will be quarantined for several days before going on show.

Manager David Waines said additional fully formed pincers on crabs were "incredibly rare".........

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August 4, 2006, 6:59 AM CT

Focus On Synthetic Biology

Five MIT scientists are among the pioneers behind a new research center in synthetic biology, a precocious field whose primary long-term goal is to make it easier to design and build useful organisms.

Current work includes refining pieces of DNA into standard biological parts that scientists could then mix and match to produce novel biological systems -- such as bacteria that synthesize rare cancer drugs -- and also fostering the responsible development and application of next-generation biological technologies.

The Synthetic Biology Engineering Research Center (SynBERC) is funded by a five-year, $17 million grant from the National Science Foundation.

In addition to MIT, participating universities are the University of California at Berkeley; Harvard University; University of California at San Francisco; and Prairie View A&M University. Matching funds from industry and these universities bring the total five-year commitment to $20 million, with NSF offering the possibility of a five-year extension of the grant. The center is managed via the California Institute for Quantitative Biomedical Research and directed by Professor Jay Keasling of UC Berkeley. The work of the center will be distributed, with major nodes in Cambridge and in San Francisco.

"SynBERC is the first time we've had long-term support to improve the technical foundations that underlie the engineering of biology," said Andrew D. Endy, an assistant professor in MIT's Division of Biological Engineering and a co-investigator in the new center.........

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August 4, 2006, 0:17 AM CT

Searching For A Woodpecker

Unlike its more famous cartoon cousin Woody the Woodpecker, the ivory-billed woodpecker is believed to be extinct, or so most experts have believed for over half a century.

But last month researchers from NASA and the University of Maryland, College Park, Md., launched a project to identify possible areas where the woodpecker might be living. Finding these habitat areas will guide future searches for the bird and help determine if it is really extinct or has survived an elusive existence.

The question of whether the species still exists started when a kayaker reported spotting the woodpecker along Arkansas' Cache River in 2004. That sighting spawned an intensive search for the species by wildlife conservationists, bird watchers, field biologists and others.

In June a research aircraft flew over delta regions of the lower Mississippi River to track possible areas of habitat suitable for the ivory-billed woodpecker, one of the largest and most regal members of the woodpecker family. The project is supported by the U.S. Fish and Wildlife Service and the U.S. Geological Survey.

Researchers from NASA's Goddard Space Flight Center, Greenbelt, Md., and the University of Maryland used NASA's Laser Vegetation Imaging Sensor (LVIS) onboard the aircraft. The instrument uses lasers that send pulses of energy to the Earth's surface. Photons of light from the lasers bounce off leaves, branches and the ground and reflect back to the instrument. By analyzing these returned signals, researchers receive a direct measurement of the height of the forest's leaf covered tree tops, the ground level below and everything in between.........

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August 1, 2006, 7:13 AM CT

Species unique to tidal marshes face extinction

Tidal marshes occur in mid to high latitudes, along coasts that are protected within estuaries or behind barrier islands. They are most common in North America and China. Some tidal marsh species are protected from high salinity by relatively impermeable skin, and others have kidneys that can concentrate salts from large volumes of water or specialized glands that exude salt. Many are gray or black in color, which is believed to be an advantage because it matches the dark color of the soils often found in tidal marshes. Why endemic tidal marsh species seem to be largely restricted to North America--which has 24 of the worldwide total of 25--is not clear. Although it could reflect differing taxonomic practices in different countries, it may be related to the history of glaciation or of agriculture.
Endemic tidal marsh species are vulnerable to coastal development and to sea level rise, both of which are rapidly reducing the area of tidal marshes. They are also threatened by toxic wastes and invasive species. Greenberg and his coauthors argue for an expanded research program to try to understand how species will respond to these threats.

BioScience publishes commentary and peer-reviewed articles covering a wide range of biological fields, with a focus on Organisms from Molecules to the Environment. The journal has been published since 1964 by the American Institute of Biological Sciences, an umbrella organization for professional scientific societies and organizations that are involved with biology. It represents some 200 member societies and organizations with a combined membership of about 250,000.........

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