June 12, 2002
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Contents of this News Tip:
Galápagos
Iguana Deaths Reveal Surprising Damage From Low-Level
Oil Spills
The ecological effects of low-level oil spills may
be more serious than previously thought, according
to a study documenting the widespread death of marine
iguanas on a Galápagos island.
In research funded by the National Science Foundation
(NSF), Princeton University biologist Martin Wikelski
and colleagues reported that more than half the marine
iguanas on the Galápagos island of Santa Fe
died with a year after a grounded tanker dumped nearly
800,000 gallons of oil into nearby waters.
The consequences of the spill had been thought to be
relatively mild, because strong currents dispersed
the oil. In the immediate aftermath, it seemed that
the lives of all but a few marine animals were spared.
However, the researchers' findings suggest that many
iguanas died because oil killed off a beneficial microorganism
that lives in the animals' guts and helps them digest
their diet of seaweed. Iguana populations on other
Galápagos islands that were not affected by
the spill did not suffer declines during the same
period.
"Our results illustrate the severe effects that low-level
environmental contamination can have on wild animal
populations," Wikelski and colleagues wrote, adding
that the findings are a warning against complacency
over apparently "low-impact" contamination.
Wikelski's research confirmed a dire prediction he
had made based on results of his earlier work with
the iguanas. In an ongoing study, Wikelski and colleagues
have shown that iguanas that died because of famine
had increased blood levels of the stress hormone corticosterone
in the weeks before death.
By coincidence, the researchers had tested the corticosterone
levels in the iguanas just three days before the tanker
Jessica ran aground on San Cristóbal Island
Jan. 17, 2001. They returned after the accident and
found that the levels had increased dramatically,
leading Wikelski to predict that many iguanas would
die.
"In this context, corticosterone levels are a reliable
indicator of the induction of life-threatening stress,"
he said. This simple blood test could be valuable
to biologists who need to estimate the severity of
environmental disasters well before the animals start
to die, Wikelski said. [Cheryl Dybas]
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"Rosebud"
Replaces "Rose Garden" on Galápagos Seafloor
Scientists believe that the "Rose Garden" in the Galápagos
Islands - one of the first hydrothermal vent communities
discovered - may have been "paved over" by a recent
volcanic eruption. However, scientists on a recent
expedition to the site also discovered a thriving
new community of very young tubeworms, clams, and
mussels nearby which they have dubbed "Rosebud."
The 12-day expedition to the Galápagos Rift,
funded by NSF, the National Oceanic and Atmospheric
Administration's Ocean Exploration Program, and the
Woods Hole Oceanographic Institution, explored the
same sites where hydrothermal vents were first discovered
25 years ago.
First seen by researchers in 1979, the Rose Garden
site was found to have red-tipped tubeworms peeking
out of six-foot-tall white tubes that swayed in shimmering
warm vent fluids. Scientists had revisited the site,
an icon for deep-sea biologists, in the 1980s and
1990s and observed how mussels and clams had begun
to overrun the tubeworm population. The researchers
had hoped the recent expedition, which began on May
24, would extend this longest-running investigation
of how vent communities evolve over time.
But the expedition found no signs of Rose Garden. Instead,
scientists found a field of fresh lava and a new community
of very young clams, mussels and tubeworms as small
as one inch tall.
"The new Rosebud site could be very young - less than
a year old," said Tim Shank, a biologist at Woods
Hole. "We may have lost Rose Garden, but we have found
Rosebud. It is a brand new site, perhaps very near
its inception, whose evolution we can chronicle in
the future."
Scientists also discovered a new, shallower hydrothermal
vent located some 200 miles (322 km) west of the historic
Galápagos Rift vent site. The seafloor community
is brimming with large clams and mussels up to 10
inches (25 cm) across. [Cheryl Dybas]
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Scientists
Find Evidence of Cataclysmic Volcanic Event on Oahu
During a recent Ocean Drilling Program (ODP) expedition
known as Leg 200, researchers found new evidence for
a cataclysmic volcanic event two million years ago
on the Hawaiian Islands. The volcanic discovery was
an unexpected bonus for mission scientists who set
out last December to drill a hole in the sea floor
to house a deep-sea geophysical, geochemical and microbiological
observatory. NSF is the principal funding source for
ODP.
"Hotspot" volcanoes, such as the Hawaiian and Canary
Islands, are so steep that large segments often collapse
to the ocean floor in huge landslides. Two million
years ago, the Nuuanu landslide removed half of the
island of Oahu. While drilling Nuuanu deposits in
the Pacific Ocean 300km northeast of Oahu, ODP scientists
encountered two layers that were originally deposited
at temperatures exceeding 200 C (392 F).
"Our results indicate that this event was not merely
a landslide, but a hot explosion. The same process
could happen again to the Big Island," said Leg 200
co-chief scientist Ralph Stephen of the Woods Hole
Oceanographic Institution. Stephen led the expedition
along with co-chief scientist Junzo Kasahara of the
Earthquake Research Institute, University of Tokyo.
According to Stephen, the large landslide was associated
with an explosive event more than ten times larger
than the 1980 Mount Saint Helens eruption in Washington
State.
Under normal conditions, the magma under a volcano
is held in place by the weight of the overlying rock.
When a large landslide removes the rock, the hot magma
explodes into the surrounding air and sea. Drilling
on Leg 200 gave the first evidence that the Nuuanu
landslide could have been associated with such a violent
and hot event. [Cheryl Dybas]
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Federal Support
for Science and Engineering Increasing, Report Concludes
According to a recent NSF report, federal support for
academic science and engineering increased by 10 percent
between 1999 and 2000. Four-fifths of the increase
came from the Department of Health and Human Services,
which accounted for three-fifths of the $19.9 billion
total.
The data is contained in the report Federal Science
and Engineering Support to Universities, Colleges
and Nonprofit Institutions: Fiscal Year 2000.
Produced by NSF's Division of Science Resources Statistics,
the report also detailed information on federal support
in colleges and universities across the country.
Of the 100 universities and colleges receiving the
most federal funds, Johns Hopkins University, which
received $933 million in federal support, continues
to top the list. Four of the top 10 universities were
in California: the University of California at Los
Angeles was third; Stanford, fourth; the University
of California at San Diego, seventh; and the University
of California, San Francisco, tenth. Other universities
in the top ten were the University of Washington,
second; the University of Michigan, fifth; the University
of Pennsylvania, sixth; Harvard University, eighth;
and the University of Colorado, ninth.
Support for research and development projects accounts
for about 85 percent of the science and engineering
total. Universities also receive federal support for
fellowships, traineeships, training grants, facilities
and other activities. [Bill Harms]
For more information, see: http://www.nsf.gov/sbe/srs/nsf02319/start.htm.
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