Photo by Tom Kleindinst, Woods Hole Oceanographic Institution
Ferry takes on a new task as research vessel NANTUCKET
SOUND—A ferry that provides transportation from Woods Hole to Martha’s
Vineyard has added another role as a research vessel. Woods Hole
Oceanographic Institution biologist Scott Gallager and colleagues
installed a package of sensors on the ferry Katama (right) in
May 2006 to measure water temperature and clarity, and oxygen,
salinity, and chlorophyll levels, and to photograph plankton as the
ferry crisscrosses the western side of Nantucket Sound year-round,
several times daily.
With the interest and cooperation of the
Steamship Authority, which operates the ferry service between Cape Cod
and the islands of Martha’s Vineyard and Nantucket, the WHOI team will
install another instrument package on the ferry Eagle, which
runs between Hyannis and Nantucket on the eastern side of Nantucket
Sound. Their objective of the project, supported by Woods Hole Sea
Grant, is to develop a portrait of changing water conditions and
plankton communities in the sound. The sensor package can fit in a
suitcase and is placed in a cavity in the ship’s hull.
“Hitchhiking
science on a ferry provides a terrific opportunity for us to better
understand water quality and ocean life change over time,” Gallager
said.
Real-time data from his sensors travel over a wireless
connection to shore where Gallager and WHOI colleagues Steve Lerner,
Emily Miller, and Andy Maffei make them available to scientists and the
public on the project Web site.
Photo by L. Anderson
On the trail of microbes that cause seafood poisoning ST.
THOMAS, U.S VIRGIN ISLANDS—Ciguatera fish poisoning—which can cause
gastrointestinal, neurological, and cardiovascular problems for
humans—is the world’s most common form of illness from fresh seafood.
Despite its pervasive impacts on human health and seafood economies,
the tropical organisms that cause it have scarcely been studied.
In
April 2006, marine biologists Don Anderson of WHOI and Deana Erdner of
the University of Texas (a former MIT/WHOI Joint Program Student
with Anderson) began fieldwork with chemist Robert Dickey of the U.S.
Food and Drug Administration to study Gambierdiscus toxicus,
the dinoflagellate algae that produces the chemical precursors that are
transformed into ciguatoxins in the tissues of edible reef fish.
Funded
by the WHOI Ocean Life Institute’s Tropical Research Initiative, the
team collected hundreds of samples for a project that will analyze the
distribution, population genetics, and toxicity of Gambierdiscus around St. Thomas and St. John in the U.S. Virgin Islands. See Ciguatera Fish Poisoning.
Did humans kill off ancient wild horses? WOODS
HOLE—Between 10,000 and 20,000 years ago, many large mammals became
extinct in North America and around the world. The cause of these
extinctions has been hotly debated, with climate change and overhunting
by humans as the leading contenders.
In Alaska, the most recent
fossil remains of mammoths postdate the arrival of humans across the
Bering ice/land bridge into North America around 13,000 years ago, but
the most recent remains of wild horses predate human arrival. That
supported contentions that while human overhunting could have
contributed to the extinction of mammoths, it could not have been a
factor in the wild horse’s extinction.
But in the May 9, 2006, issue of the Proceedings of the National Academy of Sciences,
Andy Solow, senior scientist and director of the Marine Policy Center
at Woods Hole Oceanographic Institution, and co-authors David Roberts
and Karen Robbirt from the Royal Botanic Gardens at Kew, England,
showed that uncertainties in the dating of horse fossils are so large
that the coexistence of horses and humans cannot be ruled out.
Photo by Chad Hammerschmidt, Woods Hole Oceanographic Institution
Sunlight neutralizestoxic mercury in lakes ALASKA—Sunlight
triggers chemical reactions that help transport toxic mercury from the
atmosphere into rivers, lakes, and the ocean. But a new study also
showed for the first time that sunlight decomposes as much as 80
percent of the methylated mercury in Arctic lakes before it gets into
fish that humans eat.
The return of the sun after dark Arctic
winters oxidizes mercury in the atmosphere into a more reactive form
that attaches to rain, snow, or dust and falls into water bodies.
However, in their studies of four Alaskan lakes, marine biogeochemists
Chad Hammerschmidt of Woods Hole Oceanographic Institution and William
Fitzgerald of the University of Connecticut found that sunlight also
catalyzes the breakdown of methylmercury, the poisonous form that
accumulates in fish flesh.
The scientists noted that global
warming could increase precipitation and the decomposition of soil and
rocks, sending more mercury, as well as organic debris, into lakes and
oceans. The debris would make lakes cloudier, blocking the penetration
of sunlight and its potential poison-removing effects.
Photo at left by Simon Thorrold. Photo above by Chris Linder, Woods Hole Oceanographic Institution
Grouper dynamics GLOVER’S
REEF, BELIZE—Nassau groupers are large, delicious, and easy to catch
when they aggregate by the thousands to spawn on coral reefs in the
Caribbean. To protect the species from overfishing, conservationists
have proposed setting aside marine preserves, but they don’t know which
areas are most critical because they don’t know enough about how the
fish travel through the oceans from larval stages to adulthood.
In
January 2006, WHOI scientists launched a novel collaborative study,
funded by the Oak Foundation, on Glover’s Reef in Belize. To track fish
from their birthplaces, biologist Simon Thorrold “tags” fish embryos
with a nontoxic chemical marker that can be detected in the fish’s ear
bones throughout their lives.
He is working with biologist
Jesús Pineda and physical oceanographer Glen Gawarkiewicz, who uses a
free-swimming robotic vehicle, REMUS, to obtain detailed measurements
of currents that may sweep fish larvae on and off reefs. See the Fish Ecology Lab at WHOI and REMUS.
Photo courtesy of Joan Bernhard, Woods Hole Oceanographic Institution
She samples cell shells on the seafloor WESTERN NORTH ATLANTIC—WHOI geobiologist Joan Bernhard was chief scientist aboard R/V Oceanus
on a May 2006 cruise near the Bahamas to sample sediment from the sea
bottom and collect from it living, single-celled organisms called
foraminifera, or “forams,” for short. Most forams make shells whose
chemical composition is thought to reflect the characteristics of the
seawater surrounding them.
Bernhard
and WHOI geochemist Dan McCorkle (at left, processing samples in the
onboard refrigerated laboratory), and University of South Carolina
(USC) postdoctoral scientist Chris Hintz brought the samples back to
WHOI and USC, where they will culture the foraminifera in labs under
controlled conditions. Through these efforts, they seek more detailed
knowledge of how environmental conditions, such as water temperature
and acidity, control the chemistry of foram shells.
The
information will improve scientists’ ability to use long-preserved
foram shells in oceanic sediments to reconstruct past environmental
conditions, enabling better understanding of how and why conditions
have changed. See more on Bernhard’s research.
Photo by Patrick Rowe, Woods Hole Oceanographic Institution
Buoy riders GULF
STREAM—Service calls to buoys in the middle of the Gulf Stream are
anything but routine. Soon after this buoy was deployed in November
2005 in the Gulf Stream, it was damaged, researchers suspect, by a
collision with another ship. (Note the bent beam at the buoy’s top
right.)
WHOI scientists tried to make repairs when the WHOI research ship Atlantis was in the vicinity in January 2006, but seas were too rough. But in April, another WHOI research ship, Oceanus,
was scheduled to conduct research in the area. It dropped off WHOI
engineer Frank Bahr (left) and research specialist Jeff Lord of the
WHOI Physical Oceanography Department, who spent several hours bobbing
in the ocean, replacing damaged meteorological sensors on the buoy.
The
buoy is part of a major study, funded by the National Science
Foundation, to make long-term atmospheric and oceanographic
measurements in the Gulf Stream, whose warm waters give up their heat
to the atmosphere in winter and then become cooler and denser and sink.
This critical but little-studied process brings carbon dioxide,
nutrients, and heat from the ocean surface to the depths and has
significant impacts on climate and marine life. See The Hunt for 18° Water.
Photo by Chris Linder, Woods Hole Oceanographic Institution
A cryological journey ICELAND—MIT/WHOI
graduate students and faculty explored a bubbling, sulfur-encrusted hot
spring in June 2006 on a field trip to Iceland. The trip capped WHOI’s
Geodynamics Program, an annual semester of weekly seminars, given by
scientists invited from many research institutions, on cutting-edge
research on a particular earth sciences field. This year’s program
focused on all things cryological: ice sheets, glaciers, sea ice, and
subglacial life.
The Geodynamics Program
was started by WHOI scientists Henry Dick, Jack Whitehead, and Hans
Schouten in the early 1980s with funding from the Keck Foundation to
promote interdisciplinary research. Past year’s programs have explored
the frontiers of research about the early Earth, fluid flow within the
Earth, and catastrophic events, such as earthquakes, volcanic
eruptions, landslides, and hurricanes. Program sponsors now include the
WHOI Academic Programs Office and the Deep Ocean Exploration Institute.
WHOI Around the World See WHOI Around the World for an interactive map that highlights WHOI research expeditions on land and at sea since 2004.
