| USGS Science Picks - August 4, 2009 August Highlights:
Leads (top news in natural science) Expedition to Map the Arctic Seafloor
American and Canadian scientists are setting sail on August 7 to map the
Arctic seafloor and gather data to help define the outer limits of the
continental shelf. The expedition will take place using two
icebreakers—U.S. Coast Guard Cutter Healy and Canadian Coast
Guard Ship Louis S. St-Laurent. The USGS will be working with
others on Healy to collect data primarily on seafloor depths and
morphology. The USGS will also be onboard the Canadian icebreaker to
coordinate with the Canadian Geological Survey, Natural Resources Canada.
Each country may exercise sovereign rights over their extended continental
shelf’s natural resources of the seabed and subsoil. The extended
continental shelf is beyond 200 nautical miles from shore, and its outer
limits can be defined according to criteria set forth in the United
Nations Convention on the Law of the Sea. The U.S. effort is coordinated
by the U.S. Extended Continental
Shelf Task Force. For more information, contact Jessica Robertson at
jrobertson@usgs.gov or (703)
648-6624.
Large Trees Declining in Yosemite
Large trees declined in Yosemite National Park during the 20th
century, and warmer climate conditions may have played a role. The number
of large-diameter trees in the park declined 24 percent between the 1930s
and 1990s. USGS and University of Washington scientists compared the
earliest records of large-diameter-tree densities (from 1932–1936) to the
most recent records (from 1988–1999). Since warmer conditions increase the
length of the summer dry season and decrease the snowpack that provides
much of the water for the growing season, climate change is a likely
contributor to these tree declines and should be taken into consideration.
Scientists also found a shift to fire-intolerant trees in some forests
that had not experienced fires for nearly a century, meaning that more
frequent and severe wildfires are possible in these areas. This research
was published in
Forest Ecology and Management (PDF). For more information,
contact Jessica Robertson at
jrobertson@usgs.gov or (703) 648-6624.
Climate a Hot Topic at Ecological Society of America Conference
USGS presentations will focus on climate change at the 2009 Ecological
Society of America Annual Meeting in Albuquerque, N.M., from August 2–7.
Media are invited to attend these discussions, which include habitat
modeling for a new climate, the effect of varying climates on tree
species, the regional implications of climate change, and ecosystem
responses to experimental warming and precipitation changes. Other USGS
presentations will range from new technologies to study the structures of
coastal ecosystems, recovery of coastal wetland vegetation after Hurricane
Katrina, and the effects of road development on watersheds. For more
information on USGS presentations at the ESA conference, contact Marisa
Lubeck at mlubeck@usgs.gov or (303)
202-4765. Brief descriptions of some USGS presentations can be found
online at the
USGS Newsroom and you can access conference information
online.
USGS Helping Astronauts Explore Space
Did you know that USGS scientists played an important role in the Apollo
11 moon landing 40 years ago? USGS astrogeologists trained Apollo
astronauts in collecting lunar samples and understanding the geology of
landing sites. In fact, the location where Apollo 11 Commander Neil
Armstrong uttered, “One small step for man, one giant leap for mankind,”
was selected based in part on USGS expertise. The landing site had easy
access to a variety of landforms, rock, and soil types to make data
collection efficient and safe. USGS scientists also helped with the
recently launched Lunar Reconnaissance Orbiter and provided critical
datasets for “Moon in Google Earth,” which allows users to explore the
moon in high detail. The USGS Astrogeology Research Branch (currently the
Astrogeology Science Center) was established in 1963 in Flagstaff, Ariz.,
and continues to provide critical support for NASA's lunar and planetary
missions. For more information, visit The
USGS Newsroom
or contact Jim Skinner at
jskinner@usgs.gov or at (703) 556-7043.
Feeds (science updates and happenings) Protecting Deltas: Visualizing Climate and Development Impacts
Sea-level rise, flooding and increased storm intensity are claiming lives,
destroying economies and clouding the future of residents along deltas and
great rivers. To help protect against these hazards, the USGS launched the
Delta Research and Global Observation Network (DRAGON) Partnership. This
is a global community of scientists who share data and develop computer
tools to forecast consequences of climate change and development projects.
Decision makers can use these data to make informed resource-management
decisions. The USGS also formed a partnership with the U.S. State
Department to develop a visualization system for the Mekong River Basin in
Southeast Asia. The system, called “Forecast Mekong,” will help identify
climate change impacts and other challenges to sustainable development in
the Mekong Basin. For more information, visit the
Delta Research and Global Observation
Network Web site or contact Gregory Smith at
smithg@usgs.gov or (337) 266-8501.
The Battle: Fish, Estrogen and Survival
Fish lesions, fish deaths and intersex fish (male fish with immature
female egg cells) are concerns in the Potomac and Shenandoah rivers, and
scientists have discovered a possible cause. New research shows that the
presence of estrogen and mimicking compounds may make fish more
susceptible to diseases, as exposure to estrogen reduces production of
immune-related proteins in fish. USGS scientists injected largemouth bass
with estrogen, and found that the fish had lowered levels of hepcidin, an
important iron-regulating hormone. Hepcidin in mammals, fish and frogs is
also suspected to act as antimicrobial peptides, which are the first line
of defense against disease-causing bacteria and some fungi and viruses.
For more information, visit the
Environmental Toxicology Fish Web site or contact Laura Robertson at
lrobertson@usgs.gov or (304)
724-4579.
Are Invasive Fish on a Crash Diet?
Bighead and silver carps are large invasive fishes, and their populations
have been rapidly increasing and disrupting the ecology of Midwestern
rivers over the past decade. Over the last 5 years, bighead and silver
carp have been getting skinnier, indicating that they are using up food
resources and may be competing with native fishes for food. The fish are
worst off in the Missouri River, where this spring the average fish was
skinnier than 99 percent of the fish between 2002 and 2005. It is possible
that the emaciated Missouri River populations could experience a die-off
or not be able to reproduce this year. If that happens, the Missouri River
could experience a short-term benefit because of competition with native
fishes and the fact that silver carp often jump and severely injure
boaters. For more information, visit the
Columbia
Environmental Research Center Web site or contact Duane Chapman at
dchapman@usgs.gov or (573)
876-1866.
Endangered Frog Takes a Leap Forward
Scientists have rediscovered a population of endangered mountain
yellow-legged frogs in San Bernardino National Forest’s San Jacinto
Wilderness. This is the first time in nearly 50 years that the frog has
been seen in the wilderness. The number of frogs in the area has not yet
been determined, but USGS scientists estimate there are only about 122
adult mountain yellow-legged frogs total from the other eight known
populations. This rediscovery by USGS and San Diego Natural History Museum
scientists, along with conservation efforts by multiple partners, renews
hope of survival for this endangered frog. For more information, visit the
USGS Newsroom.
You can also contact Adam Backlin at
abacklin@usgs.gov or (714) 508-4702, or Robert Fisher at
rfisher@usgs.gov or (619) 225-6422.
Guzzlers Satisfy Summer Thirst of Desert Bighorn Sheep
Decreases of natural water sources, which are critical to wildlife such as
desert bighorn sheep, have been documented in the Southwest. This area
will likely face increasing aridity due to global climate change and
continued water consumption from nearby cities. Animals in the region may
have to increase their use of artificial water sources during summer, and
an understanding of their habitat use is needed to develop effective water
management strategies. Scientists from the USGS and the University of
Nevada, Las Vegas, modeled potential historical and present-day summer
habitat of female bighorn sheep in Joshua Tree National Park, Calif. They
found that 47.7 percent of the sheep’s present-day summer habitat would be
lost without artificial water sources such as guzzlers and small, man-made
dams. Loss of this summer habitat could lead to smaller and more
fragmented sheep populations in the local area, with the potential
inability to persist across the region. The study was published in the
Journal of Arid Environments (PDF). For more information,
contact Kathleen Longshore at
longshore@usgs.gov or (702) 564-4505.
Story Seeds (points to ponder or investigate) Honey Mesquite: A Migrant Songbird's Cue to Good Eats
Do you ever wonder how birds find food as they migrate long distances from
season to season? Migrant songbirds, for example, travel from the United
States and Canada and head south to Central and South America for the
winter. To learn more about how migrating birds find food along the way,
USGS scientists and cooperators studied the behavior of 28 species of
neotropical migrant songbirds along the lower Colorado River from
2001–2004. Scientists found that songbirds flying over Cibola National
Wildlife Refuge, Ariz., relied on the flowering of honey mesquite (a
small-to-medium tree that produces seed pods) to detect the presence of
insects that they prey upon. Additionally, scientists found that more
flowers meant more insects. Understanding feeding behaviors, such as where
and why migrant birds stop to eat, will help land managers to better
protect key habitats used by these tiny travelers. For
more information, see the
USGS Fact Sheet 2009-3038 or contact Charles van Riper III at
charles_van_riper@usgs.gov
or (520) 626-7027.
Hair of the Grizzly Bear
To help in the recovery of threatened grizzly bears, USGS scientists have
been collecting and conducting DNA analysis of bear hair at rub sites
(bears naturally rub against trees and posts) since 2003. Data will help
identify their population size, distribution and genetic health. The USGS
began a new research project this summer to evaluate the effectiveness of
this hair collection approach in monitoring population trends, ultimately
helping to develop efficient forest management strategies. This project is
taking place in the Northern Continental Divide Ecosystem of northwestern
Montana. Collecting hair at rub sites could potentially provide a
low-impact, efficient and less expensive way to track population changes
over time, while retaining the scientific rigor necessary to assess
grizzly bear recovery status. For further information, visit the
Northern Rocky Mountain Science Center Web site or contact Katherine
Kendall at kkendall@usgs.gov or
(406) 888-7994.
Horn-ucopia of Coast Horned Lizards
As they work to help develop conservation strategies for declining coast
horned lizards, scientists have identified three species of the coast
horned lizard. The identified lizard species diverged from southern Baja
California in Mexico to northern California state. Coast horned lizard
populations have declined due to lost lowland habitat from agriculture and
urbanization, as well as the introduction of Argentine ants, which have
displaced the more nutritious native ants. Scientists also found enough
genetic and ecological differences to suggest that the one species of
coast horned lizard found in California—Phrynosoma blainvillii—has
at least three distinct populations and each one requires unique
management and protection strategies. The research, conducted by the USGS
and the University of California, Berkeley, was published in the
Proceedings of the National Academy of Sciences and can be viewed
online. For more information, contact Robert Fisher at
rfisher@usgs.gov or (619) 225-6422.
Digging for Minerals and Resources Online
What kind of bedrock underlies our family farm? Has gold ever been mined
in my state? What are the reported element concentrations in the nearby
stream waters? These are just a few of the questions that can be answered
by using the USGS Mineral Resources Online Spatial Data Web site. The USGS
provides free public access to earth science information across the entire
nation, and this tool allows you to create relatively simple interactive
maps and download information in various formats for home computers. One
of the Web site's most valuable applications is for resource analysis —
the synthesis of information about known localities of mineral deposits
and commodities in order to determine the likelihood of undiscovered or
undeveloped resources in a given area. Check out the
Mineral Resources On-Line Spatial Data
Web site. For more information, contact Peter Schweitzer at
pschweitzer@usgs.gov or (703)
648-6533.
Of Farmers and Frogs: Good News for Mississippi Conservation!
Frogs, toads and other species are benefiting from farmers’ voluntary
efforts to restore and protect wetlands in the Lower Mississippi Valley.
These areas were previously used for agriculture activities, and farmers
are taking action as part of the U.S. Department of Agriculture’s Wetlands
Reserve Program. USGS scientists sampled frogs and toads in program sites
as well as nearby agricultural sites, and compared results to evaluate the
program’s benefits. Researchers found that similar frog and toad species
inhabited both types of lands overall, but that a greater number of each
species inhabited program sites relative to agricultural sites. Wetlands
Reserve Program sites were also home to substantially more highly aquatic
species, such as northern cricket frogs, bronze frogs, and American
bullfrogs. Amphibians are excellent indicators of wetland conditions as
their skin is sensitive to environmental contaminants and they have a life
history tied to water. For more information, contact Hardin Waddle at
hwaddle@usgs.gov or (337) 266-8671.
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