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Introduction
Want to join U.S. and Canadian scientists as they map the Arctic seafloor and gather data to help define the outer limits of the continental shelf? Discover how in this edition of USGS Science Picks. You can also find out about large trees declining in Yosemite and join USGS scientists at the Ecological Society of America Conference. In addition, discover USGS science related to Apollo and the moon, as well as fish, frogs, sheep, songbirds, grizzly bears, lizards and more! If you would like to receive Science Picks via e-mail, would like to change the recipient or no longer want to receive it, please e-mail jrobertson@xxxxxxxx.
August Highlights:
- Expedition to Map the Arctic Seafloor
- Large Trees Declining in Yosemite
- Climate a Hot Topic at Ecological Society of America Conference
- USGS Helping Astronauts Explore Space
- Protecting Deltas: Visualizing Climate and Development Impacts
- The Battle: Fish, Estrogen and Survival
- Are Invasive Fish on a Crash Diet?
- Endangered Frog Takes a Leap Forward
- Guzzlers Satisfy Summer Thirst of Desert Bighorn Sheep
- Honey Mesquite: A Migrant Songbird's Cue to Good Eats
- Hair of the Grizzly Bear
- Horn-ucopia of Coast Horned Lizards
- Digging for Minerals and Resources Online
- Of Farmers and Frogs: Good News for Mississippi Conservation!
Leads
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@xxxxxxxx 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@xxxxxxxx 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@xxxxxxxx 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@xxxxxxxx or at (703) 556-7043.
Feeds
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@xxxxxxxx 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@xxxxxxxx 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@xxxxxxxx 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@xxxxxxxx or (714) 508-4702, or Robert Fisher at rfisher@xxxxxxxx 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@xxxxxxxx or (702) 564-4505.
Story Seeds
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@xxxxxxxx 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@xxxxxxxx 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@xxxxxxxx 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@xxxxxxxx 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@xxxxxxxx or (337) 266-8671.
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