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Introduced, nonnative brook trout (Salvelinus fontinalis) were removed from a mountain lake in Mount Rainier National Park, Washington, to examine the capacity of native Ambystoma gracile (Northwestern Salamander) in the lake to respond to the intentional removal of fish. Temporal trends (Δ̄N) were calculated for A. gracile larvae/neotene and...

Concerns over greenhouse‐gas forcing and global temperatures have initiated research into understanding climate forcing and associated Earth‐system responses. A significant component is the Earth's cryosphere, as glacier‐related, feedback mechanisms govern atmospheric, hydrospheric and lithospheric response. Predicting the human and natural dimensions of climate‐induced environmental change requires global, regional and local...

The Woodrow Wilson Bridge on I-495 over the Potomac River in Prince Georges County, Maryland is being replaced. Physical local scour model studies for the proposed piers for the new bridge were performed in order to help establish design scour depths. Tests were conducted in two different flumes, one in...

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The restoration of rivers in watersheds with historic mining districts has become a topic of interest during the last decade. Rivers restoration in these areas is difficult because the mines and mills can be scattered over a wide area and often small. Many have also been abandoned. This paper presents...

In 1950 when Cherry Creek dam, which is located in Denver. Colorado, was completed, the design flood was 5,126 m3/s. Two recent probable maximum flood (PMF) estimates for the dam range from 14,840 to 18,750 m 3/s demonstrate the uncertainty in estimating extreme flooding in eastern Colorado. PMF difference is...

Beginning ca. A.D. 1400, Polynesian farmers established permanent settlements along the arid southern flank of Haleakala Volcano, Maui, Hawaiian Islands; peak population density (43-57 persons per km2) was achieved by A.D. 1700-1800, and it was followed by the devastating effects of European contact. This settlement, based on dryland agriculture with...

In July 1999, the U.S. Geological Survey installed an acoustic Doppler velocity meter in the Colorado River, near the city of Matagorda in southeast Texas. The meter is part of an integrated system used by the U.S. Army Corps of Engineers to control barge traffic that passes through a lock...

Recent advancements in acoustic science have improved the measurement of real-time flow conditions in complex open-channel flow systems with dynamic channel geometry, velocity distribution and direction, and other gradually varying hydraulic characteristics. In the lower Pascagoula River Basin, a drainage area of about 9,500 square miles in Mississippi, riverine and...

Understanding the flow paths in the vicinity of water well intakes is critical in the design of effective wellhead protection strategies for heterogeneous carbonate aquifers. High-resolution flow logs can be combined with geophysical logs and borehole-wall-image logs (acoustic televiewer) to identify the porous beds, solution openings, and fractures serving as...

The suppressive effects of trapping adult sea lampreys, Petromyzon marinus Linnaeus, and releasing sterile males (SMRT) or females (SFRT) into a closed system were expressed in deterministic models. Suppression was modeled as a function of the proportion of the population removed by trapping, the number of sterile animals released, the...

Analogous to ‘seed banks,’ ‘egg banks’ are important for seasonal succession and maintenance of invertebrate species diversity throughout wet and dry cycles in the prairie pothole region. Further, recruitment of invertebrates from relic egg banks in the sediments and dispersal of eggs into wetlands is believed to be important for...

Approximately 250,000 acres of backcountry in Rocky Mountain National Park (RMNP or the Park) may be designated as wilderness use areas in the coming years. Currently, over 3 million people visit RMNP each year; many drive through the park on Trail Ridge Road, camp in designated campgrounds, or hike in...

We investigated variation of fish assemblages in response to environmental factors using Long Term Resource Monitoring Program data. Data were collected from 1993 to 2000 from five physical habitats in the unimpounded upper Mississippi River. We captured 89 species composing 18 families. Of these, 26% were fluvial specialists, 25% were...

Artificial propagation of aquatic organisms is increasing globally and currently accounts for approximately 32% of total world fishery production (Vannuccini, 2004). Between 1970 and 2000, aquaculture production of salmonids has grown from less than 200,000 metric tons per year to over 1.5 million metric tons (Tacon, 2003). In 1995, the...

We appreciate the comment by Jackson et al. (1), which underscores two points made in our recent paper (2): (i) that desert subsoil nitrate (NO–3) inventories are spatially highly variable, and thereby warrant substantial measurement efforts to reduce uncertainty in global extrapolations, and (ii) that Chihuahuan Desert subsoil NO–3 inventories...

We compared detection rates of passive and playback breeding bird survey techniques on elusive marsh birds - Pied-billed Grebe (Podilymbus podiceps), American Bittern (Botaurus lentiginosus), Least Bittern (Ixobrychus exilis), Virginia Rail (Rallus limicola), and Sora (Porzana carolina) - during a two-year study at Lacreek National Wildlife Refuge, in southwestern South...

Primary succession of plant communities directed toward a climax is not a typical occurrence in wetlands because these ecological systems are inherently dependent on hydrology, and temporal hydrologic variability often causes reversals or setbacks in succession. Wetlands of the Great Lakes provide good examples for demonstrating the implications of hydrology...

We studied relationships among sediment variables (carbon content, C:N, hardness, oxygen penetration, silt-clay fraction), hydrologic variables (dissolved oxygen, salinity, temperature, transparency, water depth), sizes and biomass of common invertebrate classes, and densities of 15 common waterbird species in ponds of impounded freshwater, oligohaline, mesohaline, and unimpounded mesohaline marshes during winters...

In the Prairie Pothole Region (PPR) of North Dakota, USA, American mink (Mustela vison) are a major predator of ducklings. Mink populations plummet during severe droughts, but some mink survive where permanent fresh water is available. In 1992–1993, we evaluated whether development of a permanent water body, the 125-km...

Scanning electron microscopy (SEM) was used to investigate grain texture and pore structure development within various compositions of pure sI and sII gas hydrates synthesized in the laboratory, as well as in natural samples retrieved from marine (Gulf of Mexico) and permafrost (NW Canada) settings. Several samples of methane hydrate...

Spring snowmelt is the most important contribution of many rivers in western North America. If climate changes, this contribution may change. A shift in the timing of springtime snowmelt towards earlier in the year already is observed during 1948-2000 in many western rivers. Streamflow timing changes for the 1995-2099 period...

The 92 ha Cottonwood Lake Study Area is located in south-central North Dakota along the eastern edge of a glacial stagnation moraine known as the Missouri Coteau. The study area has been the focus of biologic and hydrologic research since the U.S. Fish and Wildlife Service purchased the site in...

Stress transfer from the great 1964 Prince William Sound earthquake is modeled on the Denali fault, including the Denali-Totschunda fault segments that ruptured in 2002, and on other regional fault systems where M 7.5 and larger earthquakes have occurred since 1900. The results indicate that analysis of Coulomb stress transfer...

The Land Cover Trends project studies the rates, causes, and consequences of contemporary (1973-2000) change in land use and land cover in the United States on an ecoregional basis. The Edwards Plateau ecoregion is the focus of this report. Landsat imagery from five dates during a nearly 30-year period are...